Dates
Location
8:00 am - 8:15 am
Sashwati Roy, PhD; Timothy W. King, MD, PhD; Praveen R. Arany, DDS, PhD
8:15 am - 9:15 am
George Brooks, MD
Details
9:15 am - 9:30 am
9:30 am - 11:00 am
Anders Carlsson, PhD; Kai Leung, MD; Elof Eriksson, MD, FACS
Details
11:00 am - 11:15 am
11:15 am - 12:45 pm
Anie Philip, PhD; Marjana Tomic-Canic, PhD
Details
12:45 pm - 2:00 pm
Vickie Driver, DPM; Mitchell Sanders, PhD; Gary Robinson, PhD
Details
2:00 pm - 3:30 pm
Praveen R. Arany, DDS, PhD; Sashwati Roy, PhD; Akhilesh Gaharwar, PhD
Details
3:30 pm - 3:45 pm
3:45 pm - 5:15 pm
Gayle M. Gordillo, MD; Geoffrey C. Gurtner, MD; Michael S. Conte, MD, FACS; Peter Rubin, MD; James Wrobel, MD; Robert S. Kirsner, MD
Details
6:30 pm - 9:30 pm
7:30 am - 9:00 am
9:00 am - 9:15 am
9:15 am - 9:30 am
9:30 am - 10:30 am
Geoffrey Gurtner, MD, FACS; William Marston, MD
10:30 am - 10:45 am
10:45 am - 11:45 am
Chandan K. Sen, PhD; Michael Murphy, MD
Details
11:45 am - 12:00 pm
12:00 pm - 1:30 pm
1:30 pm - 1:45 pm
1:45 pm - 4:00 pm
Sashwati Roy, PhD; Geoffrey C. Gurtner, MD; Phil Stevens, PhD
Details
4:00 pm - 4:15 pm
4:15 pm - 5:15 pm
Oral abstract presentations will feature the highest scoring abstracts submitted to the WHS.
Mitchell Sanders, PhD; John McQuilling, PhD
Heather Powell, PhD; Latha Satish, PhD
Swathi Balaji, PhD; Joshua Tam, PhD
Randolph Stone, PhD; Shanmugasundaram Natesan, PhD
5:30 pm - 8:30 pm
WHS Exhibit Booth #532
7:30 am - 9:00 am
9:00 am - 9:15 am
9:15 am - 10:15 am
Steven Percival, PhD; Lindsay Kalan, PhD; Diane Newman, PhD
Details
10:15 am - 10:30 am
10:30 am - 11:30 am
David J. Margolis, MD; Robert S. Kirsner, MD
Details
11:30 am - 11:45 am
11:45 am - 2:15 pm
12:15 pm - 2:00 pm
Luisa Ann DiPietro, DDS, PhD; Irena Pastar, PhD
Details
11:45 am - 2:15 pm
12:15 pm - 2:00 pm
Luisa Ann DiPietro, DDS, PhD; Irena Pastar, PhD
Details
2:00 pm - 2:15 pm
2:15 pm - 3:15 pm
Oral presentations will feature the highest scoring abstracts submitted to the WHS
Details
Mithun Sinha, PhD; Norifumi Urao, PhD
Robert D. Galiano, MD; Rodney Chan, MD
Allen Holloway, MD; Veronica Haywood, PT
Kara L. Spiller, PhD; Jessica Eager, PhD
3:15 pm - 3:30 pm
3:30 pm - 4:30 pm
Eric Brey, PhD; Heather Powell, MD; Ardeshir Bayat, MB, BS, PhD
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4:30 pm - 4:45 pm
4:45 pm - 5:40 pm
Swathi Balaji, PhD
Details
5:40 pm - 5:45 pm
5:45 pm - 6:45 pm
6:45 pm - 7:15 pm
Timothy W. King, MD, PhD; Praveen R. Arany, DDS, PhD
Details
7:15 pm - 8:45 pm
7:30 am - 9:00 am
9:00 am - 9:15 am
9:15 am - 10:15 am
Traci A. Wilgus, PhD; Kenneth W. Liechty, MD
Details
10:15 am - 10:30 am
10:30 am - 11:30 am
Oral presentations will feature the highest scoring abstracts submitted to the WHS.
Details
Daria A. Narmoneva, PhD; Subhadip Ghatak, PhD
Harvey N. Himel, MD, MPH; Nandini Ghosh, PhD
Rummana Aslam, PhD; Luris C. De Calero MD
Anie Philip, PhD; Yasser Almadani, PhD
11:30 am
11:45 am - 2:15 pm
Anita Roberts
Casey Bartow-McKenney
Distinguished Service
Lisa Gould
Junior Faculty
Ivan Jozic
Travel Award
Nandini Ghosh
Travel Award
AMITAVA Das
Travel Award
Jayson Jay
Travel Award
Clark Bonham
Travel Award
Ayan Biswas
Travel Award
Sara Ud-Din
Travel Award
Artem Trotsyuk
Travel Award
Syrine Arif
WHS Translational Regenerative Science
Irena Pastar
WHS Translational Regenerative Science
Britta A. Kuehlmann
Young Inestigator
Kanhaiya Sign
Young Inestigator
Ji Won Son
Young Inestigator
Melissa McCarthy
Young Inestigator
Karamjeet Kaur
Young Inestigator
Yasser Almadani
Young Inestigator
Georgios Theocharidis
Young Inestigator
Christopher Turner
Young Inestigator
Hima Vangapandu
SAWC Research Scholar
Traci Wilgus
SAWC Research Scholar
JongWon Rhie
Industrial Research Poster
AMITAVA DAS
Industrial Research Poster
Katie Mowry
Industrial Research Poster
Latrisha Petersen
Industrial Research Poster
Katie Mowry
Industrial Research Poster
Angana Kharge
Industrial Research Poster
Sandeep Dhall
Industrial Research Poster
AMITAVA DAS
Industrial Research Poster
Angana Kharge
Industrial Research Poster
Paul Bonvallet
Industrial Research Poster
Yong Mao
M1.01.
BACKGROUND Chronically open wounds are a common complication for diabetic patients. These ulcers (DFUs) are notoriously difficult to treat for a variety of reasons, but the major challenge stems from the mystery as to why some wounds respond to treatment and others do not. The goal of our study is to create a diagnostic assay that will determine the likelihood a DFU wound will close by 12 weeks in response to the standard of care. METHODS We used Nanostring™ for gene expression analysis of 227 wound healing and macrophage phenotype related genes in debrided tissue from the first visit to the clinic of 23 patients. The top 10 most highly expressed genes were used to train a neural network algorithm to classify healing outcome at 12 weeks as fully closed, remained open, or required amputation. 10-fold cross validation was performed to determine the best number of hidden units. The dataset was then divided into training and testing cohorts using a 60/40 split. RESULTS After training, the algorithm correctly classified the outcome for 7 of the 10 patients, resulting in 80% specificity and 60% sensitivity when the outcomes are binarized by combining the remained open and required amputation groups. CONCLUSIONS These results, while preliminary, suggest that gene expression analysis of debrided tissue from the first visit can be used as a method of predicting healing outcome for DFUs. Because this method relies solely on the first visit, it has the potential to guide patients and clinicians toward treatment options better suited to the wound environment and more likely to facilitate healing.
M1.02.
BACKGROUND Plasma-based products have been utilized in a variety of tissue engineering applications, including soft tissue repair and burn wound healing. Plasma contains soluble fibrinogen, which can be converted into an insoluble fibrin-based gel in the presence of thrombin. Plasma gels can serve as three-dimensional templates to deliver therapeutic cells or as growth factor-laden supplements for tissue regeneration in vivo. Unfortunately, plasma-based materials are often soft and easily deformed, thus limiting their usefulness in harsh clinical settings. Therefore, simpler methods to create sturdier plasma/fibrin-based materials are needed. To this end, we hypothesized that mixing alginate and plasma together will create a plasma-alginate composite (PAC) material with improved mechanical and biological properties. METHODS Plasma and alginate were mixed together to create PAC gels with unique formulations. The stiffness and degradation kinetics of the PAC gels were assessed using rheology and a tissue plasminogen activator (tPA)-based degradation assay, respectively. Stem cells were cultured in the PAC gels for 8 days to assess in vitro cell viability and phenotype. An alginate-free plasma gel was used as a control throughout. RESULTS Our results demonstrated that PAC gels with specific compositions of alginate and plasma were 10-times stiffer than the plasma-only gels. Interestingly, tPA-mediated gel lysis rates were independent of alginate concentration. The stiffer PAC gels enabled stem cell proliferation and maintained cell stemness over 8 days in vitro. The presence of alginate within the PAC gel also helped maintain the gel shape and size in culture. CONCLUSIONS In sum, we envision this PAC gel system will extend the use of plasma-based therapies for tissue engineering and wound healing applications. The improved mechanical properties of the PAC gel system will be useful in demanding clinical settings, such as austere trauma environments or mass casualty scenarios.
M1.03.
Introduction: We are interested in improving wound healing therapies through the understanding of potential cellular and molecular mechanisms, especially those influenced by the Notch signaling cascade. We have previously shown that inhibiting Notch inhibits wound healing. Based upon our previous work, our hypothesis is that topical application of the Notch ligand, JAG1, to ex vivo excisional wounds of mice increases wound healing rates as compared to untreated wounds. We also wanted to determine if age and gender influence the wound healing rates. Methods: Skin biopsies 6-mm in diameter with another wound of 3-mm in the center were cultured ex vivo from 10-12 week-old (young) and at least one-year-old (aged) mice. We included both male and female mice from control and skin specific (K14) knockouts of Notch1 and Notch2. Topical application of JAG1 (1 μg/ml, 7 nM), vehicle (PBS), PBS+DAPT (gamma secretase/Notch signaling inhibitor) or JAG1+DAPT were applied every two days. Photomicrographs were taken and histological analysis performed. The tissue growth was calculated as the difference of the area at each timepoint minus the area at time=0. Significance was defined as p<0.05 using two-way ANOVA. Results: Significant tissue growth was seen in the biopsies from control mice, young and aged, males and females; compared to K14-Notch1 or K14-Notch2 knockouts. Treatment with DAPT inhibited the growth in mice where JAG1 had an effect. Conclusions: Notch activation by JAG1 increases the rate of tissue growth of cutaneous wounds in an ex vivo murine wound-healing model, regardless age/gender, but not in Notch1 or Notch2 knockouts, indicating that Notch signaling is crucial in wound healing. Further study of Notch in wound healing should be conducted which may then lead to better therapeutics.
M1.04.
Background: Painful, motion-limiting hypertrophic scars (HTS) form subsequent to protracted wound healing in patients with severe full-thickness burns and pose difficult treatment challenges. Newer evidence points to mast cells as important regulators of intricate signaling cascades during the initiation and progression of post-burn scars. Previous investigations have demonstrated increased mast cell densities in burn wounds and during the formation of HTS. Mast cell proteases contribute directly to myofibroblast differentiation and excessive proliferation in burn wounds. Methods: Cromolyn sodium (CS) is an FDA-approved mast cell stabilizer known to inhibit degranulation and has been successfully used to relieve detrimental symptoms associated with mast cell activation. Here, we directly applied a 4% topical emulsification of CS to the post-burn HTS of red Duroc pigs (n=6). 3D images and scar biopsies were obtained monthly. Results: Toluidine blue stained scar tissue showed that CS significantly reduced mast cell density (p<0.05) over time. Histologically, epidermal thickness was also significantly reduced in CS-treated wounds. 3D analysis demonstrated that CS reduced scar height and volume while scar perimeter increased (p<0.05), flattening the scar over time compared to vehicle treatment alone or autologous split-thickness skin grafts. Additionally, immunohistochemical analysis showed that CS treatment significantly minimized dermal fibroblast expression of the protease-activated receptor-2 (PAR2, p<0.05) further indicating that fibrotic phenotype may be driven by mast cell tryptase activation of PAR2. Conclusion: Together, this evidence suggests that localized mast cell stabilization may be an effective approach to reduce pathologic scarring following a severe burn.
M1.05.
BACKGROUND: Most diabetes-related lower limb amputations can be attributed to the infection of foot ulcers. To reduce the risk of infection and subsequent amputation, not only medical care but also patients’ self-management is necessary during treatment periods. Therefore, it is important that nurses encourage patients to improve their self-management abilities. Using peers to lead health programs helps build a high level of rapport among individuals with similar age and life experiences. The present study aimed to examine the effects of a peer-led self-management program for patients with diabetic foot ulcers. METHODS: Participants included 60 patients with diabetic foot ulcers (30 in the experimental group and 30 in the control group). In the experimental group, the designed intervention was implemented by a peer leader, while the control group received “usual care,” which included some education materials. Outcome variables, including self-efficacy, quality of life (QoL), and wound state (Wagner grade and size) were measured at the baseline and again four weeks later. ANOVA/ANCOVA were used for data analysis. RESULTS: The peer-led group reported higher improvements in self-efficacy and QoL following the program as compared to the control group (F=4.36, p=0.04; F=4.94, p=0.03, respectively). Changes in wound state (Wagner grade and size) did not differ significantly between the two groups (F=0.10, p=0.76; F=0.05, p=0.83, respectively); however, an increasing trend was observed in the experimental group. CONCLUSIONS: The peer-led self-management program was effective in increasing self-efficacy and QoL in patients with diabetic foot ulcers.
M1.06.
BACKGROUND Immune cells are involved in all aspects of the wound healing repair process including the initial haemostasis phase and their function in driving scar formation. It is thought that various immune cells including macrophages and T-cells, play a role in aberrant wound healing and the fibrotic process seen in scar formation in adult skin. Their link to abnormal healing has led to increased attention in the context of cutaneous repair. High numbers of immune cells have been found in hypertophic and keloid scars compared to normotrophic scars. Nevertheless, there is a paucity of evidence of their role and activity over time in acute cutaneous wound healing and normal skin scarring in humans. METHODS We utilised 5mm skin-biopsies taken from the upper arms of 62 healthy volunteers performed at multiple time points; at initial day 0 and at weekly intervals thereafter (weeks (W) 1,2,3,4,5,6,8). Detailed immunohistochemistry (IHC) was undertaken to evaluate the time course of immune cell recruitment in this human wound healing model. RESULTS Double staining for M2 macrophages using CD68/CD206 demonstrated a 127% increase in cell count from day 0 (uninjured intact skin) to week 5 (110, 250 respectively; p=0.02), with a subsequent 50% reduction to values closer to baseline by week 8 (125). We performed analysis on CD8 T cells and demonstrated a 82% increase in number from uninjured intact skin (64) to week 5 (117; p=0.03) where this plateaued thereafter to week 8 (109). The number of intraepidermal langerin+ Langerhans cells increased from uninjured intact skin (18) to week 4 (54) and reduced slightly by week 8 (42). CONCLUSIONS These findings could lead to further studies on mechanisms of immune cell localisation and may aid the discovery of novel therapeutic agents aimed at reducing immune cell numbers in pathological skin conditions.
M1.07.
We assessed roles of Smad7 in skin inflammation and wound healing using genetic and pharmacological approaches. In K5.TGFβ1/K5.Smad7 bigenic (double transgenic) mice, Smad7 transgene expression reversed TGFβ1 transgene-induced inflammation, fibrosis and subsequent epidermal hyperplasia, and molecularly abolished TGFβ and NF-κB activation. Next, we produced recombinant human Smad7 protein with a Tat-tag (Tat-Smad7) that rapidly permeates cells. Tat-Smad7 subcutaneous injection attenuated infiltrated F4/80+ and CD11b+ leukocytes and αSMA+ fibroblasts prior to attenuating epidermal hyperplasia in K5.TGFβ1 skin. Further, topically applied Tat-Smad7 on wounds of K5.TGFβ1 skin accelerated wound closure with improved re-epithelialization and reductions in inflammation and fibrotic response. A short treatment with Tat-Smad7 was also sufficient to reduce TGFβ and NF-κB signaling in K5.TGFβ1 skin and wounds. Relevant to clinic, we found that human diabetic wounds had elevated TGFβ and NF-κB signaling compared to normal skin. To assess the oncogenic risk of a potential Smad7-based therapy, we exposed K5.Smad7 skin to chemical carcinogenesis and found reductions in myeloid leukocyte infiltration in tumors but not accelerated carcinogenesis compared to wildtype littermates. Our study suggests the feasibility of using exogenous Smad7 below an oncogenic level to alleviate skin inflammation and wound healing defects associated with excessive activation of TGFβ and NF-κB.
M1.08.
BACKGROUND – This study examined knowledge, attitudes, beliefs, and behaviors about antibiotic use by adults who had a wound within the past year. METHODS – The parent study was descriptive, cross-sectional that enrolled adults (N=505) across community-based (library, senior center, community recreation center, art center) and outpatient and hospital clinic sites; 26 of the participants reported a wound within the past year and are the focus of this report. Participants with wounds were 57.7% women, African American (42.3%) or Caucasian (30.8%) and had some college education (65.4%). Participants responded to an antibiotic knowledge, attitudes, beliefs, and behavior questionnaire. Hierarchical agglomerative cluster analysis of variables was used to find clusters of items on the attitude, beliefs, and behavior questions. Descriptive statistics and Spearman’s rho correlation were also examined. RESULTS – The mean antibiotic knowledge score was 69%. Higher antibiotic knowledge was significantly related to higher education (rs=.71, p < .001) and higher rating of health (rs=.43, p=.028). There were 2 attitude and beliefs clusters: most participants (>85%) recognized the need for medical supervision of antibiotic use (cluster 1); belief about the need for antibiotics to prevent illness or treat wounds varied from 27% to 62% (cluster 2). There were 4 behavior clusters: almost all filled and took the antibiotic if prescribed (96%, cluster 1); disagreed with unapproved methods of obtaining antibiotics (>71%, cluster 2); and used prescribed antibiotics correctly (>87%, cluster 3). Participants heard about antibiotic resistance through TV or radio (36%) or internet (40%), cluster 4. CONCLUSION – Knowledge about antibiotics was low, while attitudes were positive. These findings identify the need for non-commercial information on the role of antibiotics in wound care.
P.IRD1.
Background: Collagen based dressings are widely used in wound care. However understanding of their mechanism of action is scanty. Previous studies using a modified collagen gel (MCG) dressing demonstrated robust vascularization of ischemic wounds and improved healing outcomes. Wound macrophages play a critical role in enabling wound angiogenesis and timely healing. Methods: In this work, we sought to investigate the direct action of MCG dressing on wound macrophage phenotype and function using a established murine PVA sponge model. Results: MCG increased macrophage recruitment to the wound site and attenuated pro-inflammatory (mϕinf) macrophage polarization (p˂0.05; n=3). Decreased mϕinf polarization was associated with increased production of anti-inflammatory cytokine IL-10 and proangiogenic VEGF (p˂0.05; n=6) indicative of a direct action of MCG in supporting resolution of inflammation and improving angiogenesis in wounds. Impaired clearance of apoptotic cell bioburden at wound-site enables chronic inflammation. Previous studies in our laboratory reported that engulfment of apoptotic cells by macrophages (efferocytosis) drives polarization of macrophages to reparative phenotype via a miR-21-PDCD4-IL-10 pathway. Elevated efferocytosis index (p˂0.05; n=4) was noted in macrophages from MCG treated wounds. Such favorable outcome resulted in a significant induction (p˂0.05; n=4) of miR-21 expression. Interestingly, MCG-mediated induction of IL-10 was blunted under conditions of miR-21 knockdown (p˂0.05; n=4) by miR-21-zip pointing towards miR-21 as a causative factor. Pharmacological inhibition of JNK in macrophages resulted in attenuated IL-10 (p˂0.05; n=4) production by MCG, implicating miR-21-JNK pathway in MCG-mediated IL-10 release by wound macrophages. Conclusion: This work presents direct evidence demonstrating that a collagen based wound care dressing may influence wound macrophage function and therefore modify wound inflammation outcomes.
P.IRD2.
Angiogenesis is critical for successful wound healing; low oxygen levels and decreased perfusion in chronic wounds increase risk of impaired healing and infection. While a variety of approaches have been used to promote healing through acute oxygenation of wound beds with hyperbaric oxygen or negative pressure therapy, promotion of endogenous vasculature by releasing proangiogenic growth factors to the wound environment remains a promising alternative. Placental membranes have been shown to promote wound repair responses in vitro through a variety of mechanisms including promotion of angiogenesis. In the current study, we have evaluated pro-angiogenic responses in endothelial cells. To identify the signaling-pathways through which dACM-derived factors induce these responses, we performed a global analysis of both serine/threonine and tyrosine kinase activity using a high-throughput commercial platform (PamGene). Human microvascular endothelial cells (HMVECs) were treated for 30 minutes with either assay media or dACM conditioned media (CM). CM was obtained by incubating dACM grafts in basal media for 3-5 days at 4°C at a ratio of 1 cm2 dACM to 1 mL media. Cell lysate was run on the “kinomics” platform to directly detect phosphorylation of ~290 peptide probes by active kinases in each sample. dACM-derived factors were found to drive gross changes in kinase activity, with ERK1, ERK2, TEX14, and PDK1 most significantly upregulated in dACM-treated cells. Pathways functionally enriched in kinases activated by dACM include MAPK signaling, FC-epsilon receptor signaling, and toll-like receptor (TLR) 5 signaling pathway. The activation of VEGFR-2 by pro-angiogenic VEGF-A has been shown to preferentially signal through the PLCj-PKC-MAPK pathway. While generally associated with pathogen recognition and innate immunity, TLR4 signaling has been implicated in angiogenesis through an inflammatory pathway. This work provides an unbiased identification of pathways important for induction of angiogenesis by dACM in vitro.
P.IRD3.
Wound healing research has primarily focused on chronic or surgical wounds. There is a need for greater understanding of the minor wound and changes that occur with the biophysical and biological environments during its healing cycle. These environmental changes may impact the likelihood of infection, time of healing, tensile strength of healed wounds, scarring, and overall skin health. This clinical study was conducted to better understand biophysical and metabolite changes of the minor wound using novel methods in wound research. This single center, 15-day, clinical trial enrolled 35 healthy subjects. Each subject had 5 tape-stripped minor wounds created on their backs; each wound was randomized to coverage with one of 5 different marketed adhesive bandages or was left uncovered. On average, wounds covered with Band-Aid® Brand Adhesive Bandages resulted in significantly less water loss and faster recovery of redness (oxyhemoglobin level) in the wound as compared to uncovered wounds. This correlated very well with the metabolomics analysis which revealed that covered wounds had decreased metabolites associated with oxidative stress, lipid inflammation, cellular dehydration and collagen turnover. These improved biophysical and metabolite outcomes resulted in most Band-Aid® Brand Adhesive Bandage-covered wounds trending towards faster wound closure than uncovered wounds. In summary, this study identified key differences in wound healing of covered vs. uncovered minor wounds including cellular metabolites and environmental factors such as pH, water loss and oxyhemoglobin levels. These findings provide new insight into our understanding of the minor wound and highlight key features that could be targeted to provide a more optimal healing environment.
P.IRD4.
Angiogenesis is an essential part of wound healing, and placental membranes have been shown to have angiogenic properties both in vitro and in vivo. The purpose of this study was to evaluate the angiogenic properties of a commercially available dehydrated Amnion/Chorion membrane (dACM) º in vivo. Gelatin sponges soaked with conditioned media (CM) from dACM were implanted subcutaneously into Sprague Dawley rats and retrieved at 7 and 14 days and evaluated via histology and gene expression. CM was obtained by incubating dACM grafts in basal media for 5 days at 4°C at a ratio of 1 cm2 dACM to 1 mL media. The protocol for this study was reviewed and approved by the Bridge PTS IACUC (protocol 17-02). Control groups consisted of sponges soaked with basal media. At 7- and 14-days, implants were retrieved with half placed in 10% neutral buffered formalin for histological evaluation, and half placed in RNAzol for PCR evaluation for angiogenesis related targets. Fixed samples were then embedded and sections were then stained with CD31 and αSMA with hematoxylin counterstaining. By 7 days there were significant increases in several pro-angiogenic genes in the dACM CM group including FN1, EFNA1, TGFB3, VEGFC, TYMP, THBS1, and SERPINE1. ANGPT2, an antagonist of angiopoietin 1, was significantly downregulated at 7 days. At 7 days SMA quantification showed small increases in staining within the dACM implant compared to negative controls, but no differences in αSMA staining on the outside of the implant. By 14 days, αSMA staining outside the implant was increased in dACM CM groups compared to controls. These results demonstrate that dACM contains a number of growth factors and cytokines that promote a pro-angiogenic response in vivo.
P.IRD5.
Background: Soft tissue defects treated with dermal substitutes often require a two-stage procedure to achieve epidermal closure. The purpose of the first stage is to achieve an appropriate dermal bed which can support a thin autologous split thickness skin graft (STSG) applied in a second stage, typically 2-3 weeks after the initial stage. A single-stage procedure, in contrast, will save the patient a second operative procedure, minimize hospital stay and thereby reduce overall cost of care. However, single-stage procedures could result in graft loss due to lack of contact between the graft and wound bed leading to insufficient nutrient support, and therefore additional procedures are required to achieve epidermal closure. We hypothesize that creation of micro channels in the dermal substitute may facilitate rapid cellular migration and formation of well vascularized granulation tissue to support graft viability. Methods: We investigate the effect of introducing channels into a collagen-chondroitin-6-sulfate (C6S) matrix on STSG take and compare findings to a collagen—C6S matrix without channels. In a pilot study, 4x4cm full-thickness wounds were created on the dorsum of a Yorkshire pig. A pattern of channels was mapped with a 2mm biopsy punch. STSG was applied to the wounds directly over the matrix with and without channels. Dressing changes were performed at 3 to 4 day intervals up to sacrifice at Day 14. Results: In non-fenestrated group, the autograft became necrotic and sloughed by Day 11. In contrast, the autograft was well integrated in the channel group. At 14 days, histology showed that granulation tissue formed within the channels to provide sufficient blood supply and nutrients to the overlying STSG, thereby enhancing graft survival. Conclusion: In this pilot single stage study, channels in the collagen–chondroitin-6-sulfate matrix based matrix increased autograft take. This feature is expected to prevent the added morbidity associated with prolonged multi-staged reconstructions.
P.IRD6.
BACKGROUND Fibrosis, the thickening and scarring of an injured connective tissue due to excessive extracellular matrix (ECM) deposition, leads to loss of organ function. Multiple cells types including platelets, neutrophils, mast cells and macrophages, fibrocytes, fibroblasts and myofibroblasts contribute to scar formation via secretion of inflammatory factors that lead to an increase in oxidative stress and abnormal ECM deposition. Aging is a known factor associated with reduction in tissue regeneration and predisposition to fibrosis.
METHODS In this study we investigated the anti-fibrotic activity of an injectable cellular placental formulation (ICPF) using a bleomycin-induced dermal fibrosis model in 22 months old C57Bl/6 mice. The ICPF consisted of a mixture of placental amnion/chorion and umbilical cord tissue derived extracellular matrix and cells. Two groups of mice (n=6) received either 100μL of ICPF (treatment) or PBS (control) injection in the middle of a 1×1 cm2 area drawn on the upper dorsa of each mouse. Then, a total of 10 doses of bleomycin (100μl of 0.5mg/mL each time) were subcutaneously administered every other day for 21days at 5 points within the 1×1 cm2 area: the first four injections were administered into four different corners of the square followed by the fifth injection given in the middle of the square. After the completion of bleomycin injections skin samples were collected for histological analysis and RNA tissue extraction for PCR.
RESULTS Histological analysis showed no dermal fibrosis in the ICPF-treated animals, however epidermal hyperplasia and myofiber degeneration were evident in the control group. PCR array for 84 genes involved in regulation of inflammation and wound healing confirmed pathological changes in the control group.
CONCLUSIONS Results of this study demonstrate ICPF’s potential to prevent fibrosis, which may have a therapeutic value for patients at higher risk for fibrosis due to aging, genetic predisposition, or exposure to radiation.
P.IRD7.
Background: Thermal injury of the face results in ectropion (epithelial-ocular junction), eversion of the lip (epithelial-oral junction), skin contracture, and excessive scar formation. The resultant facial disfiguration along with features such as oral incompetence burdens the subject socially, emotionally, and psychologically. The goal of this work was to test the healing outcomes of a glycerin-based wound dressing Elasto-Gel on a preclinical porcine model of maxillofacial burn trauma. Methods: Fourth degree burn wounds involving 50% of the face were made on female domestic Yorkshire pigs using a gauged, electrically powered burner which continually measures the temperature of the instrument and increases the power to the heated stylus to maintain the desired temperature. Wounds were treated with placebo dressing (Acticoat) or Elasto-Gel once a week for 84 days. The burn affected 50% of the face and caused injury to the mandibular bone. Progression of burn wound healing was followed using noninvasive imaging such as (1) laser speckle microperfusion imaging, (2) harmonic ultrasound Doppler imaging, and (3) computed tomography with angiography for 3D reconstruction of face and vasculature. Results: The application of heat resulted in a fourth degree burn with bone involvement showing severe deficits including ectropion, eversion of the oral mucosa, overt contracture and excessive scarring. Affected pigs suffered from drooling during eating. Contracture and scarring were dramatically evident at d84 post burn. Elasto-Gel significantly accelerated the rate of wound closure during the acute phase (p<0.05; n=3). The later phase of healing was characterized by increased regression of blood vessels upon Elasto-Gel treatment (p<0.05; n=3). Interestingly Elasto-Gel treated wounds showed significantly less scar area at all time-points (d21, d42, d63 and d84; p<0.05; n=3). Conclusion: This work constitutes maiden report on a porcine model of severe facial burn contracture. Application of Elasto-Gel dressing minimized scar outcomes.
P.IRD8.
Keratin is a fibrous structural protein that provides mechanical stability to cells of the epithelium. These proteins can be used in wound healing applications in the form of scaffolds, hydrogels, and wound dressings. Here, we evaluated the in vitro and in vivo biological response to different presentations of keratin within a bioengineered collagen matrix. Keratin was extracted from end-cut human hair through a proprietary oxidative process. Two different configurations of keratin-collagen matrices were fabricated: keratin hydrogel was superficially layered on one side of a collagen sponge, lyophilized, and sterilized (bilayer keratin-collagen matrix); keratin powder was directly incorporated into solubilized collagen, lyophilized, crosslinked, and sterilized (Keratin-collagen matrix). In in vitro cell culture, adult fibroblasts were seeded on matrices and cultured up to 14 days. Samples were analyzed for DNA, collagen type I (ELISA) and imaged using confocal microscope. In vivo, partial-thickness wounds (2.5cm square) were created on the dorsum of Yorkshire pigs. Wounds were treated with the bilayer keratin-collagen matrix, the keratin-collagen matrix or the collagen matrix. Dressing changes were performed at 3 or 4-day intervals up to sacrifice at Day 7 or 21. In vitro cell culture studies demonstrated that the keratin-based matrices supported fibroblast growth, collagen type I deposition and migration of dermal fibroblasts. There were no adverse effects. The keratin prototypes demonstrated complete matrix take. Histologically, at Day 7 keratin-collagen matrix demonstrated enhanced epithelial burrowing suggesting the incorporation of keratin into collagen resulted in greater keratinocyte activity. Further, there was less contraction in both keratin prototypes compared to collagen-only matrices suggesting greater mechanical stability. In conclusion, two different configurations of keratin-collagen scaffolds were successfully fabricated. Pilot results demonstrate enhanced keratinocyte activity in the keratin-collagen matrix in early stages of wound healing. Future studies evaluating the impact of keratin on long term healing are warranted.
P.IRD9.
The growing demand for cell and tissue-based products, such as placental allografts rich in growth factors, cytokines, and extracellular matrix, stems from their ability to accelerate the wound healing process, especially in chronic wounds. However, processing of these placental tissues may damage the inherent factors contained in these membranes. The aim of this study is to assess the bioactivity of a novel, dehydrated amniotic membrane allograft (DAMA) composed of an amnion layer. DAMA was homogenized and assessed for concentrations of growth factors and cytokines. Cell attachment, proliferation, and Type I collagen expression was assessed over a 7 day period with neonatal fibroblasts seeded in the presence of DAMA membranes. A Boyden chamber migration assay, utilizing a porous membrane with cells seeded on one side, was used to assess chemotactic migration of human mesenchymal stem cells (hMSCs). To determine whether DAMA can reduce the expression of pro-inflammatory cytokines, an inflammation assay was performed with lipopolysaccharide activated peripheral blood mononuclear cells (PBMCs). DAMA membranes contain viable growth factors and cytokines such as bFGF, EGF, PDGF, IL-4, IL-6, TIMP-1, and TIMP-2. Cell and matrix staining show that neonatal fibroblasts not only survive, but are proliferating and expressing Type I collagen in the presence of DAMA. Additionally, DAMA promotes significantly higher hMSC migration than controls (n=4, p<0.05). Finally, supernatants of PBMCs in the presence of DAMA demonstrates reduced expression of pro-inflammatory cytokines (>90%) for IL-6, IL-8, IL-1β, and TNF-α as compared to those without DAMA. The culmination of this work suggests that DAMA may improve the chronic wound milieu by providing essential cytokines, and growth factors to create an appropriate environment for wound healing.
P.IRD10.
BACKGROUND Human amniotic membrane (AM) has intrinsic anti-inflammation, anti-fibrosis and antimicrobial prosperities. The cryopreserved amniotic membrane that retain all native tissue components including viable cells shows clinical benefit in treating chronic wounds. However, cryopreservation requires ultra-low temperature storage and distribution, which limits the use of cryopreserved products. To overcome this limitation, a lyopreservation method has been developed to preserve the viable tissue for ambient storage. This study is to determine if the viable lyopreserved AM (VLAM) retains the viable and functional cells. METHODS Live-dead staining and imaging such as scanning electron microscopy (SEM) and confocal microscopy were used to detect the viable cells in AM and the native structures of AM. Osteogenic differentiation of VLAM was used to verify the presence of living multipotent cells in VLAM. Moreover, the anti-fibrotic activity of VLAM was studied using gene expression profiling (RNA array and quantitative PCR) and scratch wound migration assays. RESULTS SEM analysis showed that the native tissue structure is preserved in VLAM. Using live/dead staining, we showed that the viable cells were present and persisted for up to 21 days in the culture medium in fresh AM and VLAM but not in a devitalized lyopreserved AM (DLAM). The functionality of cells in VLAM was measured by their differentiation potential and anti-fibrotic activity. With osteogenic induction, cells in VLAM, but not in DLAM, deposited calcium within the membrane in an induction-dependent and time-dependent manner. The migration of human lung fibrotic fibroblasts was reduced in the presence of VLAM but not DLAM. RNA array and qPCR analyses of fibrotic lung fibroblasts indicated that the presence of VLAM reduced expression of pro-fibrotic genes such as type I collagen, alpha smooth muscle actin and increased expression of anti-fibrotic growth factors and cytokine such as hepatocyte growth factor, TGF-β3 and IL-1β. CONCLUSIONS The results from this study demonstrate that endogenous cells in VLAM remained viable and functional.
P.AW01.
BACKGROUND: While better resuscitation systems have reduced the incidence of open abdomen (OA) in major burn patients, there are still a few who require damage control laparotomy and OA for intestinal ischemia. In the context of severe metabolic derangement this poses a unique management challenge with high morbidity and mortality.
METHODS: We present 2 OA burn patients managed with the ABRA Dynamic Tissue System (DTS) in combination with a Porcine Urinary Bladder Matrix (PUBM) xenograft. Data was collected on the mechanism of injury, patient presentation, surgical management of the burns as well as the open abdomen, and patient outcomes via retrospective chart review.
RESULTS: One patient was a 54-year-old male sustaining 37% TBSA after propane gas explosion. He developed Ogilvie’s syndrome with cecal ischemia and perforation, requiring a resection with ileostomy and mucous fistula. After laparotomy he had a myofascial gap of 19 cm and visceral extrusion of 6 cm. We achieved primary myofascial closure after 21 days of ABRA installation. The second patient was a 68-year-old male with 42% TBSA following a natural gas explosion, requiring decompressive laparotomy for compartment syndrome. He had a myofascial gap of 21 cm with visceral extrusion of 8 cm and was primarily closed 12 days following ABRA installation.
CONCLUSION: We present the first reported experience of successful primary closure of the open abdomen in burn patients using a novel technique. Working around the burns to install the device, the management of fluid loss and fluid shift issues exacerbated by the burns, addressing multiple organ dysfunction/failure issues presented particularly unique challenges.
P.AW02.
P.AW03.
BACKGROUND The anterolateral thigh flap is one of the most useful flap in reconstruction, because of its reliability, large skin flap territory, and versatility1 In addition to this, the relatively small number of side effects is a common reason for this flap. The primary repair is usually done in donor site closure, but it takes a lot of tension and causes several donor site morbidity such as pain. We tried Acellular dermal matrix graft as a way to overcome this.METHODAmong the patients using the Anterolateral thigh free flap, 20 cases of donor fascia sutured with artificial dermis, and 21 cases of primary fascia suture were used for total 41 flaps. The postoperative ambulation recovery time, pain score, drainage removal, and wound problems of the donor site were investigated. RESULTS Of the 41 cases, there were no serious complications in the donor site including infection. Of 20 cases using the acellular dermal matrix, there was seroma and partial necrosis of skin and artificial dermis in each case. In one case, acellular dermal matrix was removed. However, the group using artificial dermis walked 4.9 days earlier than the control group and had a visual analogue scale at 5 days postoperatively of 1.8 points lower. ConclusionOur study suggested that, if we use it selectively, acellular dermal matrix may play an effective role in the donor site closure in anterolateral thigh flap. LEGEND
| complication | Primary closure (n=21) | ADM graft (n=20) | p value |
| Wound infection | 0 | 0 | |
| Wound dehiscence | 0 | 2 (10%) | 0.409 |
| Seroma | 0 | 2 (10%) | 0.409 |
| Herniation | 0 | 0 |
| Primary closure (n=21) | ADM graft (n=20) | p value | |
| Age | 59.43 | 57.60 | 0.674 |
| Skin defect width | 5.86 | 7.18 | 0.009* |
| Fascia defect width | 5.17 | 5.25 | 0.515 |
| Hospital admission date | 33.90 | 29.75 | 0.388 |
| ICU admission date | 4.14 | 2.50 | 0.134 |
| Drain removal date | 7.24 | 6.85 | 0.735 |
| Foley cath removal date | 11.67 | 9.25 | 0.177 |
| Postoperative gait date | 16.52 | 11.65 | 0.038* |
| Visual analogue scale | 4.52 | 2.70 | 0.010* |
P.AW04.
BACKGROUND
Clinically, lower eyelid skin defect is caused by skin tumor, trauma, and lower blepharoplasty. Since the lower eyelid is located in the mid-face area and is a very important position for cosmetics, special consideration for the subsequent scarring as well as functional reconstruction is needed. We report the results of cosmetic and functional results with single or combined use of midface lift and skin graft depending on the location and size of the defect.
METHIDS
From 2010 to 2016, 84 patients with lower eyelid skin defect were included. The causes were as follows: skin malignant tumors in lower eyelid (37 cases), lower eyelid plasty (32 cases), benign tumors (6 cases), and trauma (11cases). In 63 patients, only supraperiosteal lift (39) or full subperiosteal lift (20) were performed.
RESULTS
When the defects were mainly in the middle and outer part of the lower eyelid, reconstruction was performed using a midface lift technique. A superficial cheek lift was performed when the defect site was less than 1.5 cm, and a full subperiosteal midface lift was performed when the defect site was 1.5 cm~2 cm or more. In this way, reducing the necessity and area of skin graft and place the scar in the subcilliary area. Thus, we obtained satisfactory results in cosmetics.
CONCLUSION When the defects were mainly in the middle and outer part of the lower eyelid, reconstruction was performed using a midface lift technique. A superficial cheek lift was performed when the defect site was less than 1.5 cm, and a full subperiosteal midface lift was performed when the defect site was 1.5 cm~2 cm or more. In this way, reducing the necessity and area of skin graft and place the scar in the subcilliary area. Thus, we obtained satisfactory results in cosmetics.
LEGENDFig.1., Fig.2.
P.AW05.
BACKGROUND: Wounds affect 5.7 million people at an annual cost of US$20 billion only in the US. For the population, wound pain is a crucial problem in patients with both acute and chronic wounds. To improve patients’ quality of life and promote wound healing, appropriate and effective wound pain management is important to implement. However, it is still challenging to assess wound pain in elderly patients, especially those who are cognitively impaired, because several subjective pain assessment tools do not fully capture the subjective experience of pain in these populations. Previous studies reported that biochemical analysis of wound exudates and wound tissues can be used for objective wound pain assessment. However, there is still no validated wound pain biomarker. To identify wound pain biomarker candidates, we aimed to explore the transcriptomic profile of a surgical wound from rats. METHODS: A 1 cm surgical incision was made on the left hind paws of rats and the mechanical and thermal withdrawal thresholds were recorded before, 1 and 6 hours, and 1, 3, 6, and 12 days after wounding using von Frey and Hargreaves tests, respectively. Wound samples were collected at the same timepoints and next generation RNA sequencing analysis was conducted. RESULTS/CONCLUSIONS: This abstract will present the transcriptomic profile of the surgical incision rat model and corresponding gene expression changes associated with mechanical and thermal hyperalgesia. These initial findings have the potential to identify biomarkers of wound pain.
P.AW06.
BACKGROUND -Pigs are one of the most heavily utilized models for the development and testing of novel drugs and dressings in the field of wound healing. As a contract laboratory specializing in wound care, we have a large body of historical data on wound healing rates in Yorkshire pigs within a specific range of age and size. The purpose of this analysis was to compare the data from over 300 control wounds from multiple wound healing studies performed over a roughly 6-year period. METHODS -Data from these studies was collated and overall trends were delineated.RESULTS-The analysis shows that, in this model, a very reproducible time-frame for healing can be observed: with the granulation phase occurring from Days 0-4, the reepithelialization phase occurring from Days 4-14, and the remodeling phase occurring from Days 14-21. Extrapolated rates of change for these different periods are also reported. CONCLUSIONS- This data could be useful in future studies for the verification of normative wound behavior and as a baseline for comparison with novel wound healing agents or dressings designed to accelerate or decelerate wound healing.
P.AW07.
Introduction: Neuropathy and denervation are known to be associated with impaired wound healing in animal models and clinical populations. We sought to evaluate the association between epidermal nerve fiber characteristics and wound healing outcomes after head and neck surgery. Methods: A prospective cohort study was performed at a tertiary care hospital. Patients undergoing head and neck surgery for benign and malignant disease were recruited and enrolled. Full thickness cutaneous specimens were obtained at surgery and evaluated with immunohistochemical staining via confocal microscopy with quantification of epidermal nerve fibers. Cutaneous evaluation included antibody driven staining for protein gene product 9.5 (pan-neuronal staining), substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal peptide (VIP), and nerve growth factor beta. Other utilized tissue antigens included endothelial marker – CD31, basement membrane marker – type IV collagen, and mast cell marker – tryptase. Patient characteristics and clinical outcomes were recorded. Results: 17 patients were enrolled with complete data collection. In this small sample size, while none of our analyses reached statistical significance, lower epidermal nerve fiber counts were associated with increased overall post-operative complications (p = 0.09), other complications (p = 0.11), and need for long term wound care after surgery (p = 0.21). Conclusions: Cutaneous nerve fibers are postulated to play an important role in acute wound healing. We quantitatively and qualitatively evaluate epidermal nerve fibers via confocal microscopy in the setting of acute wound healing after head and neck surgery; we find associations between lower nerve fiber counts and poorer wound healing outcomes in this small clinical cohort.
P.ANG01.
Background: Efficient wound healing process require a tight interplay between factors governing epithelial to mesenchymal transition (EMT) and wound vascularization. Zinc finger E-box binding homeobox 1 (ZEB1), primarily studied in the context of tumor biology, is a potent EMT-activator. ZEB1 is a transcriptional repressor of epithelial genes like E-cadherin, loss of which cause EMT. Additionally, ZEB1 stimulates angiogenesis via induction of VEGF-A and acting as an endothelial cell survival factor.Methods: Quantitative Stable Isotope Labeling by Amino acids in Cell culture (SILAC) analysis was used to elucidate the ripple effect of ZEB1 overexpression on epithelial cell proteome. Role of ZEB1 in dermal wounds in vivo was assessed using Zeb1 heterozygous Zeb1+/- mice as homozygous Zeb1-/- mice are not viable. Additionally, diabetic wounds were also studied to test ZEB1 and its potential role in compromised healing. Chromatin immunoprecipitation (ChIP) assay and Immunoprecipitation-Mass Spectrometry were done to investigate the differential binding activity of ZEB1 to its target molecules under normoglycemic and hyperglycemic conditions. Results: Cutaneous wounding resulted in loss of epithelial marker E-cadherin with concomitant gain of ZEB1 (n=3,p<0.05). SILAC analyses revealed that the dominant proteins downregulated post ZEB1 overexpression belong to adherens junction pathways. Zeb-1+/- mice exhibited compromised wound closure due to defective EMT and angiogenic response (n=3,p<0.05). Under hyperglycemic conditions, as noted in 12 week old db/db mice, ZEB1 was induced by two orders of magnitude in the skin(n =3,p<0.05). Furthermore, under such conditions ZEB1 lost its ability to bind E-cadherin (n= 3,p<0.05). Keratinocyte E-cadherin, thus upregulated, resisted EMT required for wound healing. Extraordinarily high ZEB1, under diabetic conditions, compromised wound angiogenesis by diminishing VEGF-A mediated signaling. Diabetic wound healing was improved in ZEB+/- mice recognizing ZEB1 as a novel therapeutic target.Conclusion: This work recognizes ZEB1 as a critical determinant of normal and diabetic wound angiogenesis and closure.
P.ANG02.
Background: We have previously demonstrated the specific induction of CD34+/pro-collagen I+ fibrocytes for angiogenesis by basic fibroblast growth factor (bFGF) treatment in rat skin wounds. In this process, bFGF treatment markedly induced formation of capillary-like structures composed of CD34+/pro-collagen I+ fibrocytes in vivo. However, the in vitro evidence of fibrocyte induction for angiogenesis remains unclear. Methods and Results: To clarify the specific induction of this type of fibrocytes in vitro, we conducted collagen gel 3 dimensional culture incubated with bFGF-treated granulation tissue cells and found CD34+/procollagen+ double positive cells and capillary-like structures composed of the double positive cells in the gel. Significantly increased numbers of this type of fibrocyte were found in the collagen gel compared with the collagen gel cultured with non-treated granulation tissue cells after 7 days for treatment. We also found the capillary-like structures composed of CD34+/procollagen+ fibrocytes in the gel. Conclusion: This study demonstrated the capability of bFGF to induce angiogenic properties of fibrocytes in vitro, which provides new insight into mechanisms of angiogenesis resulting from fibrocyte expression during granulation tissue formation for healing.
P.BIO01.
Background Polydioxanone has been widely used in the medical field since about 30 years ago. In the 2000s, PDS foil began to be applied to rhinoplasty and septoplasty. However, in Asia PDS plates are not widely used due to lack of awareness and high prices. The author changed the process of the product from rolling extrusion method to flat die forging and lowered the price of the product. Also, we compare the biocompatibility of PDS plates (Ethicon Inc, Johnson & Johnson) and Newly developed materials in vivo and in vitro.
Methods In the in vivo experiments, the melting point and decomposition rate of DSC and TGA were evaluated and initial tensile strength was measured. In the in vivo experiments, implants of 1cm x1cm x0.15mm in size were inserted into the mice subcutaneously, and they were were harvested en bloc after 2, 5, 10, 15, and 25 weeks with hematoxylin-eosin and Masson’s trichrome to evaluate inflammation, extracellular matrix deposition, vascularization, and degradability.
Results There was no significant difference between PDS plates and Newly developed material in thermal analysis , tensilie strength test. Both products were completely degraded and were not observed in tissue slides in 25weeks. Histologic analysis showed similar results in inflammation, extracellular matrix deposition and vascularization.
ConclusionIn vivo and vitro experiments showed no significant difference in biocompatibility and degradability between newly developed material and PDS PLATE. The results of this study suggest that the use of absorbable graft materials may be more versatile in rhinoplasty and septoplasty.LEGENDFig. 1.
Fig. 2. Fig. 3. Fig. 4.
P.BIO02.
P.BIO03.
Background: The need for hemostatic antimicrobial dressings has increased in recent years due to issues in prolonged field care arising from combat trauma in remote areas. We have recently demonstrated that minimally processed “griege” (unbleached) cotton fibers demonstrate enhanced clotting relative to highly processed USP type 7 bleached cotton gauze. This effect is due to the material surface polarity and swell ratio of the fibers that retain complex organic polymers and molecular components present in and near the cotton fiber cuticle. We hypothesized that a textile could be constructed conserving the hemostasis-accelerating properties of minimally processed cotton, while exerting antimicrobial activity. Methods: Spun bond nonwovens of varying surface polarity were designed and prepared based on ratios of greige cotton/ bleached cotton/polypropylene fibers. Thromboelastographic analysis was performed on fabric samples in citrated blood to evaluate the rate and strength of fibrin and clot formation. Lee White clotting times were obtained to assess the materials clotting activity in platelet fresh blood. Electrokinetic analysis of samples was performed to analyze for material surface polarity i.e. plateau potential, and fiber swell ratio. Assessment of antimicrobial activity was performed with an AATCC 100 assay. Fibroblast growth assessments were also performed. Results: Hemostatic properties varied with composition ratios, fiber density, and process hydrostatic pressures and speeds. A correlation of increased percent greige cotton and decreased clotting time demonstrates that greige cotton may be utilized in hemostatic dressings. Antimicrobial activity was observed against gram negative and positive bacteria. No fibroblast cytotoxicity was detected. Conclusion: Hydroentanglement is an efficient and effective process for imparting structural integrity to cotton based textiles, while conserving enhanced hemostatic function and conferring antimicrobial activity. This study demonstrates that an affordable and effective hemostatic gauze can be constructed from commonly available materials using high throughput manufacturing methods.
P.BIO04.
BACKGROUND: Ideal acellular dermal matrices (ADM) for breast reconstruction exhibit porosity for rapid biointegration and high elasticity for desired clinical outcomes. In a novel in vivo model of irradiated breast reconstruction, we demonstrate excellent biointegration of Artia®, a porcine product chemically prepared to mimic the elasticity of human ADM, with the natural porosity to encourage cellular ingrowth. METHODS: Utilizing the murine dorsal skinfold model, Artia® was implanted, n=8 (35Gy radiation) to the skin, and n=8 (0Gy radiation). Real-time photoacoustic microscopy (PAM) evaluations of vascular integration and oxygen saturation within the ADM were made over 14 days. At 21 days, vascular ingrowth (CD31), fibroblast scar tissue formation (smooth muscle actin, vimentin) and macrophage function (M2:M1 ratio) were evaluated. RESULTS: SEM demonstrates organized collagen fibrils with natural fenestrating pores to allow cellular ingrowth. Repeated PAM imaging demonstrated vascular ingrowth increasing over 14 days, with a commensurate increase in oxygen saturation within the ADM. By day 21, robust CD31 staining was seen with low SMA and vimentin fibrosis expression. M2 macrophages were over-represented in the macrophage population consistent with a remodeling physiology. CONCLUSIONS: Artia® demonstrates excellent incorporation, with increased oxygen saturation content by 14 days, consistent with other collagen substrates. CD31 and SMA histological values demonstrate appropriately high vascularity and modest fibrosis while SEM documents the porosity ideal for biointegration. Artia® performance in this model also demonstrates consistent performance in an irradiated skin envelope. Taken together with its enhanced elasticity and handling advantages, this porcine ADM product is well poised to be clinically applicable to breast reconstruction.
P.BIO05.
Background:Human amniotic membrane (AM) has been widely applied in the management of burns, dermatological defects and ocular surface reconstruction [1-5]. Data from use of cryopreserved AM and fluid allograft containing live cells, proteins, cytokines and growth factors healed in patients with foot and ankle wounds suggesting that, in addition to structural matrix and growth factors, retaining AM cell viability is an important indicator of healing efficacy [6-10]. The use of cryopreserved amniotic tissue presents a few challenges, namely the availability of cryo-storage at the site and added process of rinsing the cryopreservation solution from the tissue prior to use. The lyophilized AM appears as a shelf stable paper-like sheet. It can be rehydrated using a saline rinse or the fluid from the patient’s own wound. Methods:We evaluated a lyopreserved viable AM samples for cell viability and compared to the cryopreserved viable AM. For this study, 3 individual samples of cryopreserved and lyopreserved AM derived from 3 different donors were assessed for cell viability. Each section was stained with SYTO 24 green fluorescent dye staining viable cells and Ethidium Homodimer-1 red fluorescent dye staining dead cells. Stained samples were analyzed using fluorescent microscopy. Imaging was performed for 10 microscopic fields for each section at 5x and 10x magnification for viable and non-viable cells. Images of viable and non-viable cells were overlapped and blindly assessed using a semiquantitative scale: non-viable, <50% viable, ~50% viable, or >50% viable. Results:Both preservation techniques resulted in AM tissues that had an average viability of greater than 50% with no statistically significant difference in viability between the cryopreserved and lyopreserved samples. Conclusion:AM tissue allograft that is stable and can be stored in the office without freezing and thawing the product simplifies documentation of storage and makes the product more accessible and easier to apply. These data suggest that a lyopreserved viable AM would produce equivalent clinical outcomes as it was reported for the cryopreserved viable AM product.
P.BIO06.
Background: Traditional in vitro skin equivalents lack tension, or have irregular tension based on the requirement to begin culture submerged followed by emerged culture. We developed a dermal equivalent composed of fibroblasts and collagen embedded within a plastic ring to allow isometric tension to develop. We asked whether the tension was sufficient to allow fibroblasts to proliferate during the emerged culture period, and how the epidermis was affected by this culture condition. Methods: Dermal equivalents were cultured for 4 to 7 days to allow tension generation, followed by keratinocyte plating and subsequently emerged culture for up to 21 days. Optical coherence tomography (OCT) was used to monitor the development of the epidermis during the emerged culture conditions. Skin equivalents were pulsed with ethynyl deoxyuridine to determine proliferation at day 7 and 14. Tissues were then histologically prepared and stained to determine proliferation and differentiation. Fibroblasts in the dermis entered the S phase of the cell cycle more often in tissues under tension, more so on day 7 than day 14. Results: The epidermal tissue was able to stratify and differentiate under both tension-maintaining and low-tension environments. OCT results agreed well with the histologically-prepared specimens. Conclusions: This model will be a useful in vitro model to study skin processes that require tension and fibroblast proliferation. OCT will allow the ability to monitor tissue progression while in culture, thereby reducing the need to sacrifice tissues for histology prior to end-stage assays or xenografting.
P.BIO07.
Background – Coconut oil is popularly publicized as beneficial for skin health, due to the antimicrobial and anti-inflammatory properties conferred by the presence of flavonoids and antioxidants. However, direct effects of virgin coconut oil (VCO) on regulation of gene expression, and extracellular matrix production, during wound healing in vitro have not been fully characterized. Methods – To assess the effects of VCO on wound healing in vitro, we utilize the fibroblast scratch wound assay. Further, hydrophobicity of complete VCO suggests that localized delivery methods may potentially improve wound healing effects in vivo by extending the exposure period. Thus, we investigate regulated delivery of VCO spatiotemporally in vitro using Bombyx mori silk hydrogels. Results – Here, we show that VCO promotes rate of fibroblast migration by 35% in a scratch wound assay, significantly improving wound closure above vehicle-only controls. Conclusion – This system will facilitate the assessment of extracellular matrix production and organization, and sustained delivery of promigratory VCO, to promote further understanding of the effects of this naturally-derived compound on skin wound healing.
P.BIO08.
Objective: Developing a software that runs on portable devices to reconstruct wounds and analyze the healing process by measuring 3D surface shapes and volumes of wounds. Introduction: Continuous precise monitoring of the wound healing progress will help clinicians to assess the efficacy of treatment procedure and identifying early signs of stasis which saves time and money. Therefore, in this study, a novel computational framework and software tool will be developed to reconstruct 3D surface shapes of wounds, from which wound analysis will be conducted to measure surface areas and volumes over time. To make access to the hardware easier and less expensive in clinics, the algorithms and software will be developed on common smart phones especially the newly released iPhoneX equipped with 3D scanning and reconstruction capabilities. Materials and methods: iPhoneX will be used as an end-user device to collect raw images of wounds. Algorithms will be first developed to detect regions of wounds from 2D images and areas are to be calculated as an important indicator for wound healing process. The SDK libraries provided by Apple Inc. will be utilized to reconstruct 3D shapes as well as the corresponding texture (or RGB color) of wounds. Computational approaches will be implemented to extract wound boundaries and to quantify the wounds in 3D. Compared to the 2D image-based method, the 3D approach would provide higher accuracy and reliability on analysis of wound healing. Results: We expect to show results on wound extraction and quantification in 2D images. Meanwhile, preliminary results will be demonstrated on 3D reconstruction of wounds from multiple images of wounds. Conclusion: 3D reconstruction of wounds provides more accurate analysis of wound healing, as compared to 2D image-based approaches. Software running portable devices such as iPhoneX would provide much easier access to hardware without purchasing additional 3D scanning devices
P.BW01.
Background: Mass casualty caused by radiation requires fast assessment of patients’ health and sorting for optimal use of resources. Identifying level of exposure and hence the most suitable care is very challenging. We evaluated the impact of different radiation doses on mice using mRNA integrity in different specimens in search for changes marking outcome. Methods: Groups of mice (6-3 mice/group) received 0.5, 1, 5, 10, 20 Greys of radiation with or without a 20% burn injury. Animals were euthanized at 2hours, 12 hours, 1day, 2days, 3 days, 6days, 7 days, or 14 days post exposure. mRNA was isolated from blood and other tissue biopsies. The quality of mRNA was evaluated using bioanalyzer and RIN value were tallied. Results: Analysis of the integrity of mRNA showed that blood samples registered the best radiation dose-dependent damage. The damage either progressed by time and was not salvageable and associated with high mortality rates, or recovered after durations varied with the intensity of exposure. Combination with burns increased mortality significantly. Conclusions: These results provide a simple and accurate technique to guide health providers for best patients care administration under strenuous conditions of radiation mass causality.
P.BW02.
The use of enzymatic detachment for keratinocyte sheets (KS) negatively affects their quality which prevents their translation to clinical practice for treating burn wounds. We hypothesized that non-enzymatic detachment will preserve extracellular matrix of KS and result in better burn wound healing. To test the efficacy of KC sheets, six full thickness skin burns were induced in sheep dorsum under anesthesia and analgesia. After 24 hrs, burned skin was excised and wounds were grafted with ovine cadaver skin. Autologous keratinocytes were isolated the same day of cadaver skin grafting mimicking clinical situations. The efficacy of KS, cultured on conventional and temperature-responsive dishes, on burn wound healing was compared. Cells cultured in temperature-responsive dishes were detached by temperature reduction to 20°C (T sheets) without using enzyme. While the keratinocytes cultured in conventional dishes were detached by enzyme (Dispase) (D sheets). After 3 weeks, when cadaver skin was rejected, wounds were covered with either T or D sheets. Additionally, wounds without any cover/treatment were served as a control. After KS treatment, wounds were monitored for additional 14 days and samples were collected postmortem for various assays. Keratinocyte sheet thickness was significantly higher in T sheets compared to D sheets before grafting. Wound re-epithelialization rate was significantly higher at days 7 and 14 in wounds grafted with T sheets compared to D sheets. Wounds treated with T sheets had less hemorrhage, ulceration and neutrophil infiltration. Epidermis thickness was comparable in wounds treated with both types of sheets, while the dermal-epidermal junction was well defined in wounds covered with T sheets at 14th day as evidenced by continuous and better-defined lamina densa and higher number of hemi-desmosomes. Novel non-enzymatic method for KS detachment provides better sheet quality and accelerates healing of grafted burn wounds.
P.BW03.
Background: Burn wound healing can be enhanced by daily mechanical debridement and topical antimicrobials to remove potential slough and prevent infection. However, if biofilms form they are recalcitrant to antimicrobials and can impact wound healing by impairing granulation tissue formation and re-epithelialization. The incidence of biofilm formation in human burn wounds is understudied and predicting burn wounds more susceptible to biofilm is challenging. Here we describe the development of a biofilm model of human burn wounds to study infection dynamics and response to treatments.
Methods:Human skin discarded after elective surgical procedures was burned ex-vivo using a metal soldering device and placed into tissue culture medium. After 24 hrs each burn wound was inoculated with 1×10^5 colony forming units (CFU) of GFP labelled Pseudomonas aeruginosa PAK. P. aeruginosa colonized and expanded within the tissue in a reproducible and time-dependent manner (n=8) and was assessed by quantitative culture after 24 and 48 hrs post-inoculation. Biofilm formation was determined visually by live-imaging with confocal microscopy.
Results: After 24 hrs individual cells in a patchy monolayer were found to preferentially attach to specific topographic features of the burn tissue. By 48 hrs post-infection sessile bacterial cells within highly ordered and three-dimensional structures up to 17 uM thick were observed. Multiple structures were observed across the surface of the burn wound and within the interstitial space where motile planktonic cells were found.
Conclusions: Together these data suggest that biofilm formation occurs non-uniformly in burn tissue in a manner that may be related to the degree of necrotic tissue. Future studies will focus on the evaluation of clinically-used wound treatments to determine their capacity for eradication of biofilm in burns.
P.BW04.
Background: Bacterial infection accounts for 75% of fatalities in patients with a burn greater than 40% of their total body surface area (TBSA). This study investigated the systemic host response to Pseudomonas aeruginosa biofilm infection within deep partial-thickness (DPTB) and full-thickness burn (FTB) wounds using a scald rat burn model. Methods: DPTB or FTB wounds (~10% TBSA) were created in anesthetized male Sprague-Dawley rats using a modified Walker-Mason scald model (n=120). Immediately post-burn, the wound was inoculated with a clinical strain (strain 1244) of P. aeruginosa at 1×103 or 1×104 cells/wound). At 1, 3, 7, and 11 days post-burning, animals were euthanized and blood was collected for complete blood count, serum, and plasma analysis. Results: P. aeruginosa developed robust infections within both burn scenarios, having ~1×108 CFU/g of burn tissue within 7 days. Burns alone showed increases in neutrophils, monocytes, and basophils overtime, which were further elevated by the infection (particularly in FTB-104). These results were supported by cytokine profiling and may have also been influenced by both danger and pathogenic associated molecular patterns. Conclusions: A dynamically complex response was seen in both DPTB and FTB wounds with and without P. aeruginosa infection. These studies may provide insights to improve treatment methods for burn care. Disclaimer: The opinions or assertions contained herein are the private views of the author and not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense.
P.BW05.
Background: Plasminogen is a proenzyme that plays a role in fibrin clot degradation, extracellular matrix remodeling, and regulation of inflammation following cutaneous injury, such as a burn. It has been proposed that plasminogen may be useful as a drug to improve wound healing and prevent burn conversion. Before introducing exogenous plasminogen for this purpose, it is important to first investigate its ability to localize to the site of injury. Methods: Sprague-Dawley rats received deep partial thickness comb burns and were treated with plasma-derived human plasminogen via subcutaneous (SC) or intravenous (IV) injection. Saline injection was used in control animals. Animals were treated at hours 4, 12, 24, 36, and 48 post injury. At each timepoint, blood and biopsies from burned and unburned interspace skin were collected. Four days post injury, animals were necropsied and tissues preserved. Tissue and plasma were assayed for human and rat plasminogen using ELISA. Results: Human plasminogen was quantified in the rat plasma, burned tissue, and interspace tissue of SC and IV treated groups. Burned and interspace tissue from the SC treatment group had more human plasminogen than the IV treated group at hour 24 (n=3, p < 0.005). No difference in rat plasminogen localization to burned tissue was observed (n=3, p ≥ 0.35). There was an increase in rat plasminogen localization to interspace tissue at day four in IV treated group compared to sham (n=3, p < 0.02). The amount of rat plasminogen present in the liver was unchanged (n=3, p ≥ 0.82). Conclusions: Xenogenic plasminogen can successfully localize in a host to burn-injured and healthy tissue. Both the SC and IV routes of administration are effective at delivering xenogenic plasminogen to the injury site without negatively impacting host endogenous plasminogen production.
P.BW06.
BACKGROUND
Two-dimensional (2D) cell culture and animal -models show only limited comparability to the in vivo situation of burn wounds. Therefore, a human burn wound model, which is based on a reconstructed human epidermis (RHE), was developed.
METHODS
Burn injuries were introduced to RHE (based on an open source protocol developed by Pumay et al.; and refined by Groeber et al.). via contact with an 83°C heated metal rod and examined for up to 14 days subsequently. The properties of models were characterized by viability testing, electrical impedance measurement, measurement of secreted factors in the supernatant, glucose consumption and histological examination.
RESULTS
Burnt areas in wound models showed significantly lower viability in MTT tests, compared to surrounding tissue at the wound edges. Furthermore, burning led to significant differences concerning secretion of LDH, glucose consumption and barrier integrity over the course of 14 days in three different donors. Histological examination showed excessive damage of basal and suprabasal cells in the burn area, and ingrowing cells from the wound edges. Treatment of injuries with commercially available products showed promising results regarding wound healing, which were comparable to the in vivo situation. Moreover, in comparison to a non-thermal wound model significant differences between the different wound models were found, comparable to those of the in vivo situation.
CONCLUSIONS
Burned RHE models represent a reproducible in vitro test model for burn wounds and their treatment. The models showed symptoms of injury and healing comparable to clinical observation in histological examination, as well as in molecular and physical measurements. They therefore hold the potential to replace, or at least reduce, animal based test procedures.
P.BW07.
Burn depth is a significant determinant of the time required for healing, and a major factor influencing long-term appearance and functional outcome. Making accurate predictions for time to healing and regenerative potential in indeterminate depth burns (IDB), a subset of deep partial thickness burns, is a challenge to burn surgeons. The management of IDB is becoming more sophisticated with the development of new excision tools and an increasing number of available tissue-engineered products. Despite the availability of newer and non-invasive imaging technologies for burn depth determination, visual assessment by a surgeon remains the standard of care. Often, in IDB cases, autologous grafting instead of a skin substitute is chosen as the method for wound closure, due to a concern for wound-healing outcomes. A better understanding of the wound-healing potential for IDBs may help surgeons develop methods to identify wounds that would benefit from a skin substitute rather than an autograft. Clinical data from pre- and post-operative images along with patient outcomes from a randomized clinical study provide context to aid in our understanding of wound healing as a function of wound depth. Here, we present an analysis from a randomized clinical trial to assess the relationship between wound depth and outcome, following treatment with a viable engineered skin tissue.
P.BW08.
BACKGROUND Polygonum cuspudatum is a traditional Chinese herb medicine, which had been widely used for treatment of burns and trauma. Polydatin(PD) is a monocrystalline isolated from Polygonum cuspudatum. Previous studies demonstrated that PD could resist oxidative stress, reduce cytokine and mediators of inflammation and regulate neutrophil chemotaxis in inflammatory reactions. METHODS 168 deep partial thickness burn wounds were made on the back of 84 SD rats . The rats were randomly divided into 6 groups: ① low concentration Polydatin gel(4μg/g), LPD; ② medial concentration Polydatin gel (20μg/g), MPD; ③ high concentration Polydatin gel(100μg/g), HPD; ④epithelial growth factor gel, EGF; ⑤ silver sulfadiazine, SD-Ag; ⑥blank gel control, BG. The mean time and rate of wound healing were analysed. The processes of wound healing were studied with gross pathological histological observation. The neutrophil count and expression of myeloperoxidase (MPO) were used to assess inflammatory cells infiltration. An immunohistochemistry study with CD31 was used to indicate angiogenesis. Microcirculation was detected at different time point. RESULTS The mean wound healing time of HPD group was 22.9±2.3days, which is the shortest one. The neutrophil count and expression of MPO in Polydatin groups were less than the other groups. Masson staining showed collagen synthesis in Polydatin groups were started early and remolded very well. CD31 expression indicated HPD, EGF and SD-Ag groups markedly stimulated angiogenesis. Hexamine silver staining showed better reestablishment of basement membrane in HPD group. The records indicated that the HPD improved the microcirculation in early time and ameliorate the angiogenesis after healing. CONCLUSIONS Compared with other groups, HPD group could promote wound healing both in time and in quality by means of alleviating swell, improving microcirculation ,decreasing inflammatory cell infiltration, increasing angiogenesis, regulating collage synthesis and reestablishment of basement membrane. Polydatin gel is a new medicine for treatment of burn wound.
P.CW01.
Background: In the United States, pressure injuries are believed to affect over 2.5 million people. Recent guidelines have recommended the consideration of polyurethane foam dressings on heels and the sacrum as part of a pressure injury prevention strategy. The following study assesses the reduction in tissue strain and stresses associated with the use of a new silicone foam dressing as well as its ability to manage moisture. Methods: Finite Element Analysis models (FEA) were developed and used to investigate the ability of 3M Tegaderm™ Silicone Foam (TSF) and Mepilex Border Sacrum (MBS) dressings to reduce tissue strains surrounding the sacral bone. The loading modeled on the dressings were either compression only (modeling a patient laying supine) or combined compression and shear (modeling a patient laying in a 45° Fowler position). Two commercially available silicone foam dressings were modeled as well as a no-dressing control. Fluid handling properties for TSF were assessed by applying dressings under compression to a glass cylinder. Ringer’s solution was dispensed at 1cc / hr to the dressing / cylinder interface and after 72 hours the surface area of the dressing saturated with fluid was measured. Results: FEA modeling showed that both the MBS and TSF dressings achieved reductions in tissue distortional stress and strain energy density relative to no dressing conditions. The use of either silicone foam dressing results in lower volume of tissue at higher stresses and deformation compared to no dressing. TSF dressing construction drew fluid away from the simulated patient interface and into the absorbent pad thereby minimizing the saturated surface area (26.2%) in contact with the skin. Conclusion: The results of the FEA modeling combined with the fluid handling properties of the TSF dressing demonstrate that TSF provides an option for pressure ulcer prevention programs.
P.CW02.
BACKGROUND After unlicensed filler injection, some patients may have problems with contour irregularity. Since forehead is exposed and the lesions are likely extensive, complete surgical removal may be difficult. In addition, pharmacological treatments such as steroids may have a temporary effect. We report satisfactory results after foreign body removal combined with the subcutaneous forehead lift.
METHODS
From January 2016 to December 2017, Seven patients with the previous history of unauthorized dermal filler injection were included in this study and age range was between 42 – 65 years (mean age was 53). The average follow-up period was 15 months. Operation methods are that first, forehead flap is dissected meticulously under subcutaneous plane through the pretrichial incision. After removal of the exposed foreign body as efficient as possible, the remaining skin was removed from the top to tighten the skin. Simultaneously, if there is the foreign body in the glabella area, because of restrictions on approaching glabella area, it is suctioned after tumescent solution injection through needle puncture located on both medial eyebrows.
RESULTS The procedure was successful in all patients. Any complications such as skin necrosis, infection, hematoma and wound dehiscence were not observed during the follow-up period. The functional and aesthetic outcome was all satisfactory in all patients.
CONCLUSIONS
The procedure was successful in all patients. Any complications such as skin necrosis, infection, hematoma and wound dehiscence were not observed during the follow-up period. The functional and aesthetic outcome was all satisfactory in all patients.
LEGENDFig.1Fig.2
P.CW03.
Background The reconstruction of soft tissue defects with a similar type of tissue and minimizing morbidities are important. Here we describe our surgical experience using customized reconstruction with keystone design flap variants created from tissue adjacent to surgical defects. Methods We retrospectively reviewed a data of 48 consecutive soft tissue reconstruction using keystone design flap variants between March 2017 and December 2017. Results Soft tissue reconstruction was performed and there was no major complication in the follow-up period. The dimensions of the wound defect ranged from 1 x 1 cm2 to 15 x 15 cm2 with a mean size of 4.7 x 3.5 cm2, while the dimensions of the customized keystone design flap ranged from 2 x 1 cm2 to 18 x 15 cm2 with a mean size of 6.9 x 4.4 cm2. Minor dehiscence in 3 cases (6%) and partial flap loss in 1 case (2%) were noticed. Two cases were healed spontaneously and other two cases were reconstructed with contralateral mini keystone design flap or split-thickness skin grafting. All patients were satisfied with the aesthetic outcomes. Conclusions Due to its simple design, reliability, versatility, minimal donor-site morbidity, and excellent cosmesis, our customized keystone design flaps could be reasonable surgical options in various clinical circumstances.
P.CW04.
Background: Current studies on Panax ginseng have demonstrated that it has various medicinal properties including angiogenesis, immuno-stimulation, anti-microbial functions, and anti-inflammatory actions, which can be helpful in chronic wound healing. However, a direct role for P. ginseng in chronic wound healing has not been demonstrated. The present study was designed to evaluate the effects of P. ginseng extract on diabetic fibroblasts in vitro. Methods: For the experimental group, human diabetic fibroblasts were cultured in the presence of Ginsenoside Rb1 (G-Rb1), the active component in P. ginseng (10 ng/mL). No-G-Rb1-treated diabetic fibroblasts were used as controls. Cell proliferation, collagen synthesis, growth factor (basic fibroblast growth factor, bFGF; vascular endothelial growth factor, VEGF; transforming growth factor-ß1, TGF-ß1) production, matrix metalloproteinase 1 (MMP-1) synthesis, and tissue inhibitor of metalloproteinases 1 (TIMP-1) synthesis were compared using enzyme-linked immunosorbent assay (ELISA) kits and immunofluorescence staining. Results: In the ELISA, the G-Rb1-treated group was superior to the control group in cell proliferation, collagen synthesis, VEGF level, TGF-ß1 level, and TIMP-1 production by 48%, 20%, 47%, 14%, and 85%, respectively (p < 0.05). In the immunofluorescence staining, the G-Rb1-treated group was also superior to the control group in cell proliferation, collagen synthesis, VEGF level, TGF-ß1 level, and TIMP-1 production by 34%, 46%, 80%, 72%, and 164%, respectively (p < 0.05). However, both ELISA and immunofluorescence staining revealed that differences in bFGF and MMP-1 levels between the two groups were not statistically significant. Conclusion: P. ginseng treatment may stimulate the wound healing activity of diabetic fibroblasts in vitro.
P.CW05.
The purpose of this study is to develop the skin-contact layer of a tri-layered wound dressing with optimal material and geometric properties needed to deliver gentamicin sulfate (GS) for the effective control of pathogenic Pseudomonas. Poly-l-lactide (PLA), poly-ε-caprolactone (PCL), and copolymer (PLC) were characterized using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Fiber monofilaments were fabricated using a lab-scale continuous twin screw melt-extruder and spinneret system (Alex James and Associates, Inc.; Greenville, SC). Tensile strength testing was performed to rate fiber properties conducive to knitting. A 34-multifilament PLA yarn was extruded with Stantex® spin finish and the elastic modulus significantly differed (p<0.08) from the monofilament. PLA yarn exhibited resistance to breakage needed for knitting and was chosen as the contact layer material. Contact layers were soaked in solutions between 1μg/ml and 10,000μg/ml of GS. Drug elution was determined by a modified dialysis membrane method, where contact layers were submerged in PBS with the release measured via fluorescent spectrometry using o-Pthaldialdehyde. Contact layers were placed into active cultures of P. putida. Antibacterial efficacy was determined by measuring the optical density over five days. Each soaking condition had a burst release after 5 hours. The elution profile for all conditions released antibiotic over the minimum inhibitory concentration (MIC) against P. putida. The antibacterial experiments showed that GS exhibited both cidal and static antibacterial effects by killing bacteria and further inhibiting growth, respectively. The control contact layer showed minor bacterial inhibition of growth indicating that spin finish might have antibacterial properties. This study explores the ideal biomaterial’s resistance to breakage needed for knitting. The elution profile exhibited a burst release over short time intervals, where antibiotic effectiveness remains highest.
P.CW06.
Purpose: Allograft Adipose Matrices (AAMs) are a helpful non-surgical alternative to skin grafts that accelerate healing in chronic wounds. Particularly in diabetic foot ulcers, AAMs have a secondary effect of shock absorption and reduce wound formation, but the effect of AAMs has yet to be investigated in a wider variety of chronic wounds, such as diabetic and non-diabetic tunneling foot ulcers. In our clinic, we completed a case series of chronic wounds to assess the effectiveness of AAMs and the time course of healing with AAMs. Methods: The case series comprised of 5 patients, ranging in age from 57-78 yo, with 2 males and 3 females. Wounds ranged from 2-12 mos in chronicity, with an average of 6.2 mos. 3 patients had diabetic foot ulcers, 1 patient had a non-diabetic foot ulcer, and 1 patient had a post-surgical abdominal wound. Wound follow-up ranged from 1 wk – 14 wks, with an average of 5.2 wks. AAM was reapplied with each follow-up as needed, as determined by the principal investigator. Results: Wound size ranged from 8 mm x 5 mm to 10 mm x 10 mm, with an average of 6.6 mm x 5.8 mm. 2 patients saw their wounds completely heal, at 7 and 14 wks. 1 patient’s wound was healing at their latest follow-up 2 wks after initial AAM application. The last two patients, with a post-surgical abdominal wound and non-diabetic foot ulcer, respectively received surgical correction at 1 and 3 wks follow-up. Conclusion: In our clinic, the application of AAMs saw marked improvement in some wounds but not others. AAM was successful in resolving several foot wounds in our clinic, and encourages further, more detailed research in how AAMs affect foot ulcers of a variety of etiologies as well as more types of chronic wounds.
P.CW07.
AimTo investigate immune responsiveness and growth factor release of an autologous leukocyte-and-platelet-rich fibrin patch (APFP) for treating chronic wounds. MethodsAPFPs were prepared from healthy donors as described in Lundquist, et al20131. In short, 18 ml blood was filled into a vacuumed device2and processed for 20 min in an automated 2-step program. The resulting 3-layered patch consist of fibrin, platelets and leukocytes. APFP were analyzed for immune cells by histopathology and flowcytometry. Cytokine and growth factor production was analyzed in culture supernatants after in vitro stimulation with: lipopolysaccharide (LPS), IL-4/IL-13 and Chronic Wound Fluid (CWF) and cytokine and growth factor production was assessed by ELISA. APFP culture supernatants were added (10%) to keratinocyte cell line (HaCaT) cultures for 18 hours and proliferation was assessed by MTT assay, and migration by scratch assay. A skin explant model (approval number: H-17041884) was used to evaluate APFP effect on epithelization. ResultsWe show that APFP contain intact monocytes, T cells and B cells. APFP responded with production of IL-1beta, IL-6, IL-10 and IL-1Ra to LPS and CWF in vitro stimulation (48 hours), respectively. In contrast, IL-4/13 stimulation resulted in exclusive IL-1Ra production. Furthermore, supernatants from APFP cultures induced proliferation and migration in HaCaT cells and skin explant wounds. Topical application of APFP biopsies on skin explant wounds showed migration of the advancing epithelial tongue. ConclusionsWe find that APFP can respond and adapt appropriately in the management of chronic wounds by delivering immune cells, cytokines and growth factors.
P.CW08.
It is well known that a balanced redox state in the wound tissue is critical for proper healing. Also critical is the skin microbiome: competition between commensal bacteria and invading biofilm-forming bacteria can increase inflammation and tissue damage. We show that oxidative stress (OS) levels affect wound closure, biofilm development and granulation tissue maturation in a dose-dependent manner. Higher OS levels lead to longer healing times and stronger biofilm development. Granulation tissue formation is delayed and the resulting scar tissue is not well developed. Although the microvessels present in the tissue have well developed basal lamina and the basal lamina under the epidermis seems to be complete, the levels of interstitial collagen are significantly reduced suggesting that the healing tissue is much weaker when the levels of OS are high. How the biological interactions between OS and bacteria in the wound determine wound healing outcomes, is not known. We hypothesize that the levels of OS are critical for establishing a microenvironment that affects the ability of bacteria to colonize the wound. To test this hypothesis, we cleaned the skin to greatly reduce the pre-existing microbiome, created wounds and then inoculated them with bacteria previously isolated from chronic wounds, in the presence or absence of high levels of OS. We inoculated with either an aggressive biofilm-forming bacteria, Pseudomonas aeruginosa, or a more mild biofilm-forming bacteria, Enterobacter cloacae. When inoculated with OS, P. aeruginosa formed biofilm and damaged wound tissue, leading to the development of chronic wounds. Inoculation with E. cloace with OS, however, resulted in little biofilm and less tissue damage. When inoculated with either bacteria without OS, the infection resolved and the wounds healed. These results indicate that high levels of OS are necessary for the bacteria to form biofilm in wounds and lead to chronicity.
P.CW09.
There is a critical need to heal diabetic chronic wounds. A major contributor to non-healing of diabetic ulcers is the presence of biofilm. However, current treatments cannot eradicate biofilm because the etiology of biofilm initiation and development is poorly understood. In the studies presented here we used next generation sequencing and our db/db-/- model of chronic wounds, which naturally develops biofilm when we raise the levels of oxidative stress in the wound right after wounding. We identified bacteria in the microbiome of these chronic wounds from wounding to 20d post-wounding when the wounds are fully chronic to determine how the composition of the microbiome evolves and how it differs from that found in non-chronic wound at comparable times. We then used this longitudinal repeated measures dataset from chronic or non-chronic wounds, to identify bacteria that have differing time trends in the two groups for the purpose of identifying probiotics. A statistical model is fit through Generalized Estimating Equations (GEE), and then a test is performed for interaction between group and time with generalized score statistics. This interaction test is done for each of the bacteria, and significant tests indicate that the trend of counts differs for the chronic and the non-chronic group over time. When the interaction test is significant, probiotics are identified as those bacteria that have increasing time trends in the non-chronic group and flat or decreasing time trends in the chronic group. Bacteria of interest as possible probiotics are for example Propionibacterium sp. The identification of probiotic bacteria that can be used for treatment of chronic wounds is novel and could potentially contribute to the development of novel approaches for the treatment of diabetic foot ulcers.
P.CW10.
P.EP01.
P.EP02.
P.FS01.
Fibrotic diseases like Dupuytren’s contracture (DC) involve scar formation and excess production of extracellular matrix components. The differentiation of fibroblasts into myofibroblasts plays a main role in DC as it generates contraction in areas without wound openings, leads to the deposition of scar tissue, and eventually flexes one or more fingers. Additionally the disease has a high recurrence rate. Previously we showed that glycated chitosan (GC), a polysaccharide used as an immunoadjuvant, inhibited myofibroblast differentiation in a DC fibroblast culture; our goal was to expand those results to include other DC cell lines and determine whether single-walled carbon nanotube-conjugated GC (SWNT-GC) would be similarly effective. The GC-incorporated and vehicle control (water) stress-relaxed collagen matrices, in vitro 3D models, were used to show the compaction (defined as anchored matrix height reduction) of DC fibroblasts. Matrix height was measured daily for 12 days using optical coherence tomography. Fibroblasts were unable to compact in GC- and SWNT-GC-collagen matrices to the same extent as vehicle control lattices. To determine the amount of tension generated, matrices were mechanically released from the substratum on day 12. Proliferative myofibroblasts were identified by the presence of alpha smooth muscle actin via immunofluorescent staining. Compared to control conditions there were fewer myofibroblasts in GC and SWNT-GC treatment but without significant decrease in the number of nonproliferative fibroblasts. This suggests that GC and SWNT-GC may be a possible treatment for the recurrent problem of fibrotic diseases by inhibiting fibroblast migration and myofibroblast phenotypes.
P.GRO01.
Background: Axolotl Biologix is a regenerative medicine company producing allograft products from the human amnion using the BioSym™ process. Axolotl Ambient™, a conditioned media rich in cytokines and growth factors is derived from human amniotic epithelial and amniotic mesenchymal stromal cells. Axolotl DualGraft™ is a dehydrated, acellular human amniotic membrane that promotes soft tissue repair by serving as a barrier and extracellular matrix scaffold and providing a source of growth factors. Both allografts were used with difficult-to-close or intractable wounds to assess their efficacy in facilitating wound closure and healing. Methods: Axolotl Ambient™ was injected into the wound margins and Axolotl DualGraft™ was placed within the exposed wound bed. Wounds were bandaged per standard of care and imaged regularly to monitor wound healing progression. ELISAs were used to measure growth factors promoting angiogenesis (FGF-b, ANG-2, and VEGF) and cellular proliferation and ECM growth (EGF and TGF-β). Biological activity of the allografts was measured by in vitro cell-based assays, including endothelial cell tube forming assays and cellular proliferation assays. Results: Compared to controls, assay data showed an increase in endothelial cell mesh networks with the allografts and an increase in cellular proliferation. Conclusions: Clinical application of the allografts in intractable wounds have yielded dramatic improvement in wound closure and reepithelialization. In vitro assays showed increased mesh networks and cellular number which correlated with clinical observations, suggesting Axolotl Ambient™ and Axolotl DualGraft™ facilitate closure and healing of intractable dermal wounds via increased angiogenesis and cellular proliferation. Longitudinal clinical studies are ongoing, concurrent with additional benchtop studies to further elucidate clinically observed wound healing.
P.GRO02.
P.IB01.
BACKGROUND – A growing body of evidence acknowledges the presence of microbial biofilms in human, chronic wounds. As such, the modified Robbins’ device remains an important tool in the study of biofilms, and is routinely used to assess the antimicrobial properties of novel agents on biofilms. Therefore, it is necessary to fully understand the natural lifespan of biofilms cultured using this testing system in order to differentiate between biofilm reduction caused by nutrient depletion vs exposure to anti-biofilm agents. METHODS – We assessed the longevity of three microbes (Escherichia coli, Staphylococcus aureus, and Candida albicans) in nonnutritive phosphate buffered saline (PBS) incubated in 6-port static testing devices. The biofilms were established in a modified Robbins’ device on PVC plastic sampling coupons. After 22 hours incubation at 37°C ± 3°C in half strength Tryptic Soy Broth (TSB; bacterial test systems) or half strength Yeast Dextrose Broth (YD/B; eukaryotic test system) circulating at 60 mL/hour, via a peristaltic pump, the sampling coupons were transferred from the modified Robbins’ device to a 6-port static sampling device filled with PBS. Coupons were then sampled to identify the concentration of viable microbes remaining on the coupon. RESULTS – At 7 days, log reductions in recoverable colony forming units were 5, 2, and 0.5 logs for E. coli, S. aureus, and C. albicans, respectively. CONCLUSIONS – These results show the importance of testing biofilm survival independent of test articles since there is a large range in biofilm longevity for different microbial species.
P.IB02.
Pseudomonas aeruginosa (gram-negative bacterium) is an opportunistic pathogen found in many infected-wounds, impairing their healing. We tested hypothesis that knocking out Pseudomonas genes that are overexpressed during wound infection can cripple pathogen’s ability to cause inflammation and impair healing. We assessed two pathways, Type 3 secretion system (T3SS) and alginate-biosynthesis. We generated single- and double-mutant strains of ExsA (T3SS activator), AlgD (GDP-mannose 6-dehydorogenase of alginate-biosynthesis) and their complementary strains (control strains), evaluated their pathogenicity in rabbit ear full-thickness excision-wound infection model. Strains were inoculated (106CFU) into wounds on post-wounding day-3. After 24hrs, at 5 and 9 days, wounds were harvested to measure viable, total bacterial counts, inflammation (cytokines), and wound healing (epithelial-gap). On day-9 post-infection (mature-biofilm in wild-type (PAO1)), viable counts of exsA‾/algD‾ double-mutant were 100-fold less than counts of single-mutants, wild-type, or double-mutant complement. Compared to wound beds infected with wild-type and control-strains, wound beds infected with mutant, exsA‾, algD‾, or exsA‾/algD‾, produced higher levels of TNF-α, IL1-β, and IL-6 at 24hrs and day-5. However, at day-9, wound beds infected with wild-type, mutant and control strains produced similarly low levels of TNF-α and IL1-β, while IL-6 was elevated in algD‾-infected wound beds. Only strains with both mutations knocked out were more susceptible to macrophage phagocytosis in vitro, were less viable in wound bed, and had less effect on impairment of wound healing. Thus, simultaneous targeting of a gene in T3SS and a gene in alginate-biosynthesis attenuated P. aeruginosa pathogenicity, supporting the possibility of dual-targeted anti-virulence strategy.
P.IB03.
Background: Per National Surgical Quality Improvement Program (NSQIP) reports, infection rates in contaminated and dirty wounds range from 10 to >27%. Infected or contaminated wound sites have historically been managed with incision and drainage with gauze packing or negative pressure therapy. Here, we review our experience with skin closure over vessel loops and assess the results of this technique in a variety of clinical situations, hypothesizing that microsurgical drainage improves or attenuates post-operative infectious complications. Methods: We retrospectively reviewed the data of all children with infected or contaminated wound sites operated on by a single surgeon with skin closure over vessel loops from 9/2016 to 9/2018. Demographics, indications for surgery, complications, and follow-up were assessed. Results: Over a two year period, 33 children underwent skin closure over vessel loops. The majority were female(82%), Hispanic(40%), and <5y(58%; mean 6.5y, range 4mo-16y). 33% were obese, defined as weight for age >95th percentile. Operations were classified as primary skin and soft tissue infection(SSTI; 81%), complex wound repair for trauma(12%), and enterostomy takedown(6%). 7(21%) of these patients previously presented to an outside hospital with failed intervention/management. Of the SSTIs, the extremities were the most common operative sites(30%); none were necrotizing or involved the joint. Post-operative length of stay averaged 1.5 days. 76% of patients returned to clinic for follow-up and/or vessel loop removal. At 30 days post-op, no patients in our cohort returned to the emergency room with recurrent infection or wound dehiscence. Conclusions: We report the technique of skin closure over vessel loops in contaminated wounds demonstrates no evidence of subsequent infection in standard follow-ups, an improvement over national infection rates. These results are indicative of specific advantages related to microsurgical drainage, including ease of wound maintenance and improved cosmesis, and that liberal use of vessel loops in these challenging wound classes will improve care for children.
P.IB04.
Background: Candida albicans (CA) are common opportunistic pathogen that causes skin infections, mucosal infection or systematic infections in immunocompromised or neutropenic patients. Recent report show that electric field based therapies are effective to manage biofilm infection. In this work we tested the effect of similar electric field on the growth of CA. CA used for this study was isolated from human mouth swab and is known to be resistant to most fungicides (ATCC 64124). Method: A United States Food and Drug Administration-cleared wireless electroceutical dressing (WED) was tested. WED relies on electrochemistry enabled by Ag/Zn printed on polyster fabric to generate weak electric field. The same fabric excluding the printed metal served as control. The final stock of yeast used for experiments was 8 x 108 cells/ml. CA was treated with WED or the above-mentioned control followed by culture in Yeast Extract Peptone Dextrose (YPD) agar employing pour plate technique. Log reduction was calculated using the formula Log Reduction = Log10(U0) – Log10(Tt ).Result: Under control conditions, following 24h of culture 70 x 106 colonies were observed (n=3, two independent experiments). However, exposure to WED resulted in complete abrogation of all colonies in each of the six plates (n=3, two independent experiments). Conclusion: This work provides first evidence that WED is effective in managing pathogenic yeast infection. Clinical studies testing WED in a clinical setting for the management of yeast infection are warranted.
P.NOV01.
Background: Patients and surgeons are often disappointed with the scar length after conventional staged excision. We developed an alternative approach to facilitate scar length reduction. This study aimed to report the efficacy of our staged excision method, which comprises hexagonal-pattern excision, wide undermining, and a purse-string suture. Methods: Sixty-five patients with 65 lesions were included in this study. Lesion length and width were recorded, and the scar area was calculated at every stage. We compared the final scar length with that obtained after the conventional staged excision method using a theoretical scar model. Patient satisfaction was also evaluated. Results: The mean longest axis length was 9.41 ± 3.83 cm preoperatively, 9.50 ± 3.92 cm after the first stage postoperatively, and 10.19 ± 3.98 cm after the final stage. The mean lesion width was 6.50 ± 3.48 cm preoperatively, 3.60 ± 1.77 cm after the first stage postoperatively, and 0.42 ± 0.31 cm after the final stage. The actual scar length was much shorter than what would have been possible using the conventional staged excision. The patient satisfaction score was 8.8 ± 1.1/10.0. Conclusion: Staged excision with a hexagonal-pattern excision, wide undermining, and purse-string closure may improve aesthetic results.
P.NOV02.
To clarify clinically challenging palpebral arteriovenous malformations (AVMs) and to propose a novel therapeutic modality, we developed a multi-disciplinary approach for the management of naturally progressing to wounding and severe disfigurement and worsening with ulcer. First, the central retinal artery was secured with embolization via the trans-ophthalmic arterial, a terminal branch of the internal carotid artery (ICA), and then the branches of the external carotid artery were embolized to cause a response in the AVM vasculature followed by sclerotherapy and surgery. The effects of this strategy on minimizing the risk of major complications were evaluated. Over a three-year follow-up of five cases of palpebral and peri-orbital AVMs in four females and one male aged 20 to 50 years with a mean age of 38 years, complete remission of the lesions was seen with no major complication, such as blindness, ptosis, or cerebral infarction, with functionally sound and esthetically acceptable results with no recurrence or worsening over three years. Planned treatment of palpebral and peri-orbital AVMs, which have been often left untreated because of their complex vasculature and a risk of total blindness due to occlusion of the central retinal artery. A wait-and-watch” approach is frequently taken. It is important to secure the periphery to the bifurcation of the central retinal artery of the ICA; then, embolization through the external carotid artery (ECA) results in complete remission of the lesion, followed by sclerotherapy and surgery which are successful both in terms of function and esthetics. Therefore, we conclude trans-ophthalmic arterial embolization first to secure the central retinal artery leads to safer and complete resolution of palpebral and peri-orbital AVMs; wounding or therapeutic complications such as skin necrosis may be seen, but this approach results in complete remission in three years with no major complications.
P.NOV03.
Diabetes is associated with impaired vasculature and altered tissue microenvironment that contribute to nonhealing diabetic ulcers. Although electric field (EF)-based therapies are promising, progress is impeded by poor understanding of the EF interactions with tissues. The goal is to develop a wireless electrotherapy for chronic wounds using a novel EF modality designed to activate vascular cells within the wound. The hypothesis is that the specific EF stimulation will enhance vascularization, reduce inflammation and improve wound healing in both acute and diabetic porcine models, vs. control (no-EF) treatment. 2×2 cm wounds (n=12-16) were created on the dorsum of STZ-diabetic and non-diabetic Yorkshire pigs, covered with Tegaderm™ and treated with wireless non-thermal EF (1hr/day, 3-5days/week, up to 4wks) or served as controls (6-8 wounds/group). EF distribution in the wound was determined using numerical in-situ simulation (ANSOFT/HFSS). Histological analyses demonstrated that EF stimulation results in a dramatic 80-100% increase in the blood vessel density vs. non-EF controls in non-diabetic (p<0.0005) and diabetic wounds (p<0.005), with EF-stimulated wounds (both diabetic and non-diabetic) achieving epidermal reestablishment similar to that of the unwounded skin, indicating regenerative healing and less scarring. There was a (non-significant) trend for higher VEGF expression in the EF group. EF treatment significantly enhanced wound reepithelization in non-diabetic (4.2cm2 vs. 3.3cm2, p<0.01, day5) and diabetic groups (2.5cm2 vs. 3.04cm2, p<0.01, day8) vs. no-EF controls, and improved repair tissue strength (5.02MPa vs. 4.04MPa, p<0.01, d15, non-diabetic group). In conclusion, the novel non-contact EF stimulation may be a promising strategy for restorative wound healing therapies to improve healing outcomes and decrease amputations in patients with non-healing ulcers.
P.NOV04.
BACKGROUND The impact of light on Wound healing has been documented extensively since Dr. Andre Mester first began his research work in 1965. In 1985 our research group at Harbor UCLA began investigating the use of red 632 nm and Infrared at 904 nm on collagen synthesis in vitro and in Vivo on hairless mouse and porcine models. These were some of the first publications indicating that light had the ability to influence healing rates. Since then many hundreds of articles have been published indicating that PBM is effective in various stages of wound healing.
METHODS An analysis of the current literature and review by clinical experts with direct clinical experience in wound healing will be used to present proposed wound management approaches using Photobiomodulation therapy.
RESULTS The wound healing process consists of three basic phases inflammation, proliferation and remodeling. Many clinical trials fail to take into consideration the optimal wavelengths and dose based on the stage of healing, wound infection, level of exudate and patient co-morbidities. In addition, good wound management involves wound debridement and the appropriate dressing choices for the stage of healing as well as identification of factors inhibiting wound healing. The type of wound and chronicity is also a determinant factor for consideration in the treatment approach. Post-surgical wounds (with or without infection or sepsis), pressure ulcers, arterial or venous insufficiency and diabetic ulcers are generally managed with specific clinical pathways. Deep tissue injury and contusions are an important part of wound healing which require a different treatment approach.
CONCLUSIONS Key elements involved in wound healing such as light transmission considerations, fluence and irradiance, pulsed vs CW modes and complimentary therapies will be discussed with presentations of proposed clinical pathways for treatment of various wound types.
P.REG01.
BACKGROUND-Volumetric muscle loss, caused by severe trauma or combat injury, results in extensive fibrosis and loss of muscle function due to destruction of the biomechanical and biochemical muscular microenvironment. As such, strategies that recapitulate native guidance and differentiation cues found in mature muscle tissue and enable repopulation of the site of defect with mature, functional muscle cells are highly desirable. METHODS-We overexpressed myoD, an early transcription factor that drives myogenic commitment and differentiation, in L6 rat myoblasts and characterized their differentiation in vitro. We then implanted decellularized muscle-derived matrices repopulated with myoD-overexpressing myoblasts or GFP-overexpressing myoblasts in rat latissimus dorsi defect models and assessed integration by gross appearance and expression of MHC by immunohistochemistry and Western blot analyses.RESULTS-We determined that MyoD-overexpressing myoblasts differentiated effectively in vitro. Decellularized rat muscle tissue-derived matrix populated with myoblasts integrated well into the latissimus dorsi in vivo. Matrices repopulated with myoD-overexpressing myoblasts demonstrated greater expression of MHC and increased formation of mature myofibrils at the defect site when implanted in vivo compared to matrices repopulated with GFP-overexpressing myoblasts. CONCLUSIONS-These data suggest that myoblast-repopulated allogeneic matrices may be useful in aiding functional muscle recovery. Our ongoing studies seek to determine the degree of functional muscle recovery yielded by this approach and by similar approaches, to investigate alternative matrix sources for optimal myogenic recovery, and to explore alternative cell sources that create the best conditions to promote healing in wounded muscle tissue.
P.ST01.
Adipose-derived stem cells (ASCs) have been studied for their ability to augment wound healing. To understand their role, we applied ASCs topically to the burn wounds in an ovine model of burn. Application of ASCs significantly increased expression of the vascular endothelial growth factor (VEGF) (p<0.05) and collagen-1 (p<0.01) proteins. Expression of monocyte chemo-attractant protein-1 (MCP-1) mRNA transcripts was significantly higher with ASC treatment compared to untreated (p<0.05). MCP-1 has been implicated in wound healing as well, therefore we set out to elucidate the role of MCP-1 in processes underlying wound healing, including angiogenesis and cell migration. ASCs (n=3) express significantly greater basal levels of MCP-1 compared to bone marrow-derived stem cells or fibroblasts (each p<0.05). To determine the effect of MCP-1 on angiogenesis, human umbilical vein endothelial cells (HUVECs) were treated with 100 ng/mL MCP-1 or 2% ASC-conditioned-media (CM). Expression of MCP-1, VEGF-165, and HIF-1α mRNA transcripts increased with both treatments (p<0.05), confirming that MCP-1 works in an autocrine fashion. Similarly, fibroblast migration increased significantly with either 2% ASC-CM or MCP-1 treatment (p<0.001). In conclusion, we found that ASCs constitutively produce abundant levels of MCP-1, which may be responsible for their therapeutic properties, and that this increase in MCP-1 expression may underlie increased angiogenesis and cell migration.
P.LB01.
P.LB02.
P.LB03.
Longitudinal transcriptome analyses of burn wounds in red Duroc vs. Yorkshire pig
Background:Hypertrophic scar (HTS) is characterized by firm, raised lesions, and is one of the adverse outcomes of deep-partial thickness (DPT) dermal burn injuries. HTS results in contractures causing negative-functional and aesthetic consequences while hindering full recovery and quality of life. HTS is associated with unique gene expression profiles, however, the dynamics of global gene expression during the course of hypertrophic scarring is not well characterized.
Method:RNA sequencing was used to determine the total transcriptome of superficial, deep-partial burn wounds and unburned tissue isolated on days 0, 3, 7, 15, 30 and 60 post-burn from red Duroc (prone to scarring) and Yorkshire pigs (less prone to scarring). Differentially-expressed genes (DEG) between burn types and time-points were analyzed to determine unique gene expression profiles. K-mean analyses were performed to cluster longitudinal gene expression profiles based on temporal trends.
Results:Shared DEGs between superficial and DPT burn wounds increased from 62 to 616 genes as the wound progressed from D0 to D3 and stabilized on D7 with 601 shared DEGS. K-mean clustering analyses of the burn types between Yorkshires and Durocs categorized 3,903 genes based on expression profiles and temporal trends.
Conclusion:We have detected DEGs between superficial and deep-partial genes temporally in Yorkshires and Durocs. These genes may serve as biomarkers for future therapeutic studies.
P.LB04.
Background: Elderly burn patients in long-term care suffer increased morbidity and mortality due to age-associated complications after burn injury. Patients are susceptible to slower healing and wound infection due to age-associated immune dysfunction, thinning skin and underlying diseases such as cardio-pulmonary dysfunction and diabetes. Pressurized pulse irrigation (PPI) is a form of hydromechanical debridement applied in operating rooms for surgical and traumatic wounds. Closed Pulse Irrigation (CPI*) utilizes a “closed” delivery system allowing point-of-care (POC) treatments in long-term care using an omnidirectional irrigation containment device. Daily CPI* treatment removes planktonic and biofilm bacteria, tissue necrosis and foreign bodies from wound surfaces thereby promoting rapid granulation/epithelialization. Purpose: We describe 4 elderly burn wound patients with 10 separate 2 ͦ /3 ͦ difficult non-healing burn wounds, who were successfully healed without complication after hydromechanical burn wound debridement. Methods: CPI* hydromechanical debridement was implemented by trained Nursing/Rehabilitation Interdisciplinary Wound Teams in long-term settings. All burn wounds were treated using a standardized CPI*- POC delivery system with 3 Liters of 0.9 % Normal Saline (85 ͦF) at 8 – 15 psi pressure. Daily dressings included Silver Sulfadiazine 1% or Hydrogel. Results: CPI* hydromechanical debridement was well tolerated and achieved complete secondary healing without complications, re-admission or surgical excision. Conclusions: The CPI* system provides a standardized, effective, low cost solution for treatment of non-healing elderly burn wounds. CPI* hydromechanical debridement is a burn wound innovation that appears to improve elderly burn wound long-term outcomes and should be further investigated.
P.LB05.
BACKGROUND VZV infection following flap surgery could indicate reinnervation.
However, the exact mechanism underlying reinnervation has not yet been fully elucidated.METHODS Our patient was a 58-year-old woman who underwent
surgery for cancer of her left breast (stage IIIA, T2N2M0) 8 years ago. We reconstructed a radiation ulcer of the back with double-opposing keystone flaps harvested from the adjacent soft tissue.RESULTS On postoperative day 4, vesicular lesions on the right flank and
back appeared, suggesting possible VZV infection.CONCLUSIONSThis report raises the possibility that the virus can spread through the environment when perfusion is performed in immunocompromised patients
P.LB06.
Background: To date, there has been no studies aimed at identifying the archaea residents of the human chronic wounds and contributions of archaeal residents of the human microbiome to the microbiome community function and the human health is largely unknown. As essential inhabitants of the human gut microbiome, the gut archaeome harbors keystone species attributed to critical metabolic processes for the microbiome. Methods: Using high-resolution whole-metagenomic sequencing of a diverse collection of human chronic wounds (venous leg ulcer, diabetic foot ulcer, pressure ulcer, and post-surgery dehisced wounds) and based on the available archaea sequence databases, 40% of the 45 human chronic wounds detected the presence of archaeal sequences, at varying abundance. The repertoire of the chronic wound archaeome exhibited similarities to the archaeal community profile associated with the more studied human gut microbiome, in particular during disease (e.g., Irritable bowel syndrome). Majority of the chronic wound archaeome belonged to Euryarchaeota followed by Crenarchaeota family. Dominant members were classified as methanogenic, acidophilic, and halophilic archaea. Conclusion: Our findings provide initial bases for further investigation of the human wound archaeome and discovery of potential functional roles (e.g., metabolic) of archaea in human wound healing processes and state of the chronic wound microbiome. DOD disclaimer. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense.
P.LB07.
The molecular basis for why diabetic foot ulcers (DFUs) are recalcitrant to healing has not been fully understood. A single drug, becaplermin, approved by the FDA for this ailment 20 years ago, is not standard of care. We elucidated that MMP-9 is the biochemical culprit in this recalcitrance and discovered a selective MMP-9 inhibitor referred to as (R)-ND-336, which speeds up healing in diabetic mice better than becaplermin. Treatment with becaplermin resulted in reduced MMP-9 activity. On the other hand, aclerastide, a peptide analog of angiotensin II that failed in phase 3 clinical trials for the treatment of DFUs, increased MMP-9 activity and is likely a contributor to its clinical failure. We validated the target MMP-9 in humans and found that the more severe and infected DFUs have 34-fold higher levels of MMP-9 than non-diabetic controls. The purpose of this study was to evaluate the efficacy of (R)-ND-336 in infected diabetic mice. Diabetic mice were inflicted with full-thickness wounds and infected with Staphylococcus epidermidis biofilm; delayed wound healing, increased inflammation, and upregulation of active MMP-9 in macrophages were observed compared to uninfected wounds. Upregulation of MMP-9 in infected diabetic mice paralleled the higher levels of active MMP-9 observed in the more severe and infected human DFUs. Topical treatment of infected diabetic mouse wounds with (R)-ND-336 was started on day 7 and was found to accelerate wound healing. (R)-ND-336 holds promise as a therapeutic agent for the treatment of DFUs.
P.LB08.
Abstract Keloids are abnormal scar giving a disfiguring appearance and extending beyond the original wound. Keloids have a multi-factorial pathogenesis where a number of factors interplay to form these lesions in individuals with higher genetic predisposition. The multi-factorial pathogenesis can be summarized as either an increased exposure to and /or expression of inflammatory mediators. Human Beta Defensins (HBD) are a group of innate immune peptides which although originally considered to be primarily anti-microbial in function have been identified to have diverse functions. In this study we investigate the expression of these immune peptides in Keloids. Methods.Keloid sample from different parts in 10 patients were analyzed for expression of HBD-1,2,3 at Protein level and mRNA levels. The expression at mRNA level was assessed using real tome duplex rt-PCR and protein expression was done using immunohistochemistry. The Expression was analyzed in relation to normal skin sample as control. Results None of the Keloid sample expressed HBD2 at mRNA and protein levels. While mean expressions of HBD-1 and 3 both at mRNA and protein levels were 3 and 5 times higher than the normal skin samples around the Keratinocytes. Conclusion-For the first time the study demonstrates the expression profile of HBD in Keloid. The absence of HBD-2 expression at both mRNA and protein levels suggest a possible role of these peptide in Keloid pathogenesis. The study also alludes to the possible diverse role of HBD peptides apart from being antimicrobial.
P.LB09.
BACKGROUND: Impaired wound-healing is a severe complication of diabetes, which affects about 9.3% of the US population. Some of the major environmental factors in the pathologically complex diabetic wounds are correlated with chronic inflammation, hypoxia, and elevated glucose levels. The molecular mechanisms by which these factors lead to poor wound healing, however, are not well understood. The current study evaluates the intracellular (hexosamine pathway) and extracellular (TLR pathway) mechanisms by which Has2 and its hyaluronan production participate in inflammation during cutaneous wound healing. METHODS: To understand the contribution of dermal Has2 function to wound healing, conditional Has2 knockout in the mouse dermis was achieved by crossing Hyaluronan synthase 2 (Has2/loxP) with fibroblast specific Dlk1-CreER. The ability of Has2 to serve as a regulator of inflammation were also tested using diabetic foot ulcer waste tissues and cultured human primary dermal fibroblasts that are non-diabetic and diabetic. RESULTS: Human diabetic foot ulcer characterized by dysregulated hyaluronan expression with increased immune cell infiltration and inflammatory activity. Diabetic fibroblasts in culture expressed higher baseline immune gene expression compared with non-diabetic cells. Both intracellular and extracellular hyaluronan were critical for regulation of inflammatory factors including IL6 and IL8 in primary human fibroblasts. Has2 loss in the dermal fibroblasts of transgenic mouse model resulted in impaired wound healing with increased inflammation and O-GlcNAcylation. CONCLUSIONS our studies suggest that Has2 driven hyaluronan production plays a critical role in both granulation tissue formation and inflammation.
P.LB10.
BACKGROUND: To evaluate the effect of using an autologous platelet and leucocyte patch on self-esteemed health status in people with hard-to-heal diabetic foot ulcers extending into tendon.METHODS: This is a health related quality of life sub-group analysis from a randomized controlled trial evaluating the effect of weekly applications of an autologous platelet and leucocyte patch (3C Patch). After a 4 week run-in-period those with a reduction in ulcer area of < 50% were randomized to either pre-specified good standard care alone or care supplemented by weekly application of the patch. The primary outcome showed a 1.58 (95% CI 1.06 – 2.35; p= 0.024) higher healing rate in the intervention group. Study participants reported their HRQoL using EQ-5D at baseline and after 12 and 20 weeks. In this analysis participants with ulcers extending into tendon were included.RESULTS: 18 people (10 intervention and 8 controls) were included. At the 20 week follow-up visit 40% of the participants in 3C Patch group improved at least one level in the dimension usual activities (p=0.046, Wilcoxon Rank-test) and 30% at least one level in mobility (n.s) compared to baseline. In the control group no improvements in any of the five HRQoL dimensions could be seen. CONCLUSIONS: The use of 3C Patch in people with hard to heal diabetic foot ulcers extending to tendon is associated with improved ability to cope with usual daily activities.
P.LB11.
Background. In chronic diabetic wounds, the normal response to hypoxia is impaired and many cellular processes involved in wound healing are hindered. The hypoxia regulator HIF-1α activates factors that promote cellular motility and proliferation, new vessel formation, and re-epithelialization. PHD2 negatively regulates HIF-1α activity under normoxia. HIF-1α also upregulates microRNA-210, which in turn regulates certain factors in ways that are antagonistic to wound repair. Methods. We identified a highly potent short synthetic hairpin RNA (sshRNA) that inhibits expression of PHD2 and an antisense oligonucleotide (antimiR) that inhibits miR-210. Both oligonucleotides were chemically modified for biostability. To assess activity and delivery in diabetic mice, PHD2-targeting sshRNAs and antimiR-210 were formulated using layer-by-layer (LbL) technology, in which RNAs are incorporated into a multilayer coating on a Tegaderm mesh. This coating gradually degrades under physiological conditions, releasing the RNAs. Formulated treatments were applied to full-thickness excisional wounds in db/db mice. Results. Transfection of our sshRNA silenced PHD2 transcripts, stabilized HIF-1α and, in combination with the antimiR-210, increased mobility of cultured keratinocytes. Wounds treated with a single application of PHD2 sshRNA or antimiR-210 closed 4 days faster than untreated wounds, and wounds treated with both oligonucleotides closed 4.75 days faster. Cellular uptake was confirmed using fluorescent sshRNA. Markers for neovascularization and cell proliferation (CD31 and Ki67) were increased in the wound area following treatment, and VEGF increased in sshRNA-treated wounds. Conclusions. Our results suggest that silencing of PHD2 and miR-210 either together or separately by localized delivery of sshRNAs and antimiRs is a promising approach for the treatment of chronic wounds.
P.LB12.
Cryoglobulins (CG) are aggregates of immunoglobulin that precipitate from serum at reduced temperatures. The major clinical manifestations of CG is inflammation of small vessels, which seen at myocardial infarction (MI). There are three types of CG. Type I CG are monoclonal IgM. Type II CGs, complexes between polyclonal IgG and monoclonal IgM anti-IgG. The IgM anti-IgG binds to IgG, Fab fragments and Fc fragments, thus forming immune complexes.Type III AGs have polyclonal IgG and polyclonal IgM in the cryoglobulin immune complexes. We studied the level of all 3 types of CGs during acute Q-MI, at days 1,3,5,7,12,14. 33 patients (19 male and 14 female from ICUnit), and 23 control group, age from 35 to 57. Spectrophotometer have been used to measure the level of CGS. We found – at day 1, acute Q-MI – high level of type III CGs (high level of IgG, and IgM), if level of IgM went up to the day 3, and then slowly decreased, IgG, dropped to the day 7 , and then went up again. Fibronectin, went up to day 3, dropped by day 7, and went up again (same with IgM pattern). We might conclude, during acute phase of MI, type III cryoglobulins with fibronectin is dominate up to day 3. CG types chances with clinical dynamics, showing importance of CG in pathogenesis of MI.
P.LB13.
BACKGROUND: Increasing number of studies reveals the importance of long non-coding RNAs (lncRNAs) in gene expression control underlying many physiological and pathological processes. However, their role in skin wound healing remains poorly understood. METHODS: We focused on a skin specific lncRNA LOC105372576, and studied its expression and function in human wounds. RESULTS: We found that LOC105372576 expression was increased during physiologic wound healing. In human non-healing wounds, however, its level was significantly lower compared to normal wounds under re-epithelization. LOC105372576 was characterized as a nuclear localized, RNAPII-transcribed and polyadenylated lncRNA. In keratinocytes, its expression was induced by TGF-β signaling. Knockdown of LOC105372576 and activation of its endogenous transcription respectively reduced and increased the motility of keratinocytes and re-epithelization of human ex vivo skin wounds. Therefore, LOC105372576 was termed as Wound and Keratinocyte Migration Associated lncRNA 1 (WAKMAR1). Further study revealed that WAKMAR1 regulated a network of protein-coding genes important for cell migration, most of which were under the control of transcription factor E2F1. Mechanistically, WAKMAR1 enhanced E2F1 expression by interfering with E2F1 promoter methylation through the sequestration of DNA methyltransferases. CONCLUSIONS: Collectively, we have identified a novel lncRNA important for keratinocyte migration which deficiency may be involved in the pathogenesis of chronic wounds.
P.LB14.
Strategies to address corneal surface defects are insufficient to successfully resolve damage caused by injury and/or disease. To address this issue, we have developed an ocular wound chamber (OWC) that allows for the continuous delivery of therapeutics. The aim of this study was to test human platelet lysate (hPL) as a therapeutic for corneal epithelial defects when used with the OWC. Corneal injuries were created in anesthetized hairless guinea pigs by demarcating the central cornea with a 4 mm punch biopsy followed by debridement of the cornea. An OWC was placed over injured eyes and animals randomly grouped followed by injection of 20% hPL, 100% hPL, or vehicle into the chamber. Eyes were assessed at 0, 24, 48, and 72h using intraocular pressure (IOP), optical coherence tomography (OCT), and fluorescein imaging. Whole globes were histologically processed and H&E stained. No significant differences in IOP were recorded as a result of corneal wounding, chamber placement, and/or therapeutic application. OCT images demonstrated increased corneal swelling at 48h (P=0.031) and 72h (P=0.006) in the vehicle group compared to 20% hPL. Fluorescein imaging showed increased wound closure in 20% hPL animals at 24h compared to 100% hPL (P=0.0004) and vehicle (P<0.0001). By 48h, 20% and 100% hPL animals exhibited increased corneal re-epithelialization (P<0.0001, P=0.0126) compared to vehicle. H&E staining revealed cellular infiltrate in the stroma of all groups. Results from this study demonstrate hPL delivery via the OWC improves corneal re-epithelialization compared to vehicle alone. This study supports the expanded usage of the OWC in combination with hPL to manage a variety of corneal surface injuries, diseases and/or periocular conditions.
P.LB15.
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P.LB18.
Background: Biofilms exist in virtually all chronic wounds and impair wound healing, yet most commercially available antimicrobials are ineffective in managing these biofilms. A novel Antimicrobial Wound Cleanser (AWC)* and Gel (AWG)+ have been formulated with synergistic mechanisms intended to safely eliminate wound biofilms so that wound healing can progress. The aim of this study was to test the efficacy of the AWC and AWG in reducing or eliminating immature and mature biofilms. Method: Immature biofilm testing was performed on P. aeruginosa, S. aureus (MRSA), and C. albicans using a modification of the MBEC peg biofilm assay. Biofilms were grown on pegs within a 96 well plate, treated with AWC (10 minutes), AWG (24 hours), or commercial cleanser or gel controls, neutralized, and then placed back into growth media so that any remaining biofilms would regrow. Mature biofilm testing was performed using P. aeruginosa, S. aureus, and C. albicans grown on ex vivo pig dermal explants to evaluate the combination of AWC and AWG. Biofilms were treated for 10 minutes with AWC followed by one application of AWG, or commercial controls, and samples were taken for biofilm quantification every 24 hours for 72 hours. Results: In the immature biofilm model, little to no biofilm regrowth was observed after treatment with AWC or AWG, while in the mature biofilm model, the combination of AWC and AWG reduced all the biofilms by at least 6 logs by 72 hours. Conclusions: The results indicate that AWC and AWG are effective against immature and mature biofilms. *Sanara MedTech, Inc. BIAKŌSTM Antimicrobial Skin and Wound Cleanser, +Sanara MedTech, Inc. BIAKŌSTM Antimicrobial Wound Gel
P.LB19.
Background: Wound biofilms, which are ubiquitous in chronic wounds, can cause inflammation and delayed wound healing. A novel Antimicrobial Wound Gel* has been formulated with synergistic mechanisms intended to safely eliminate wound biofilms. This formulation disrupts biofilm extracellular polymeric substances (EPS) by removing metal cations, disassembling lipids, and aggregating the polymers that create the structure so that the antimicrobial can target and kill the microbes. This research validates the safety profile of this biofilm destructing gel. Method: Biocompatibility was demonstrated using Agar Diffusion Testing, Primary Skin Irritation Testing, Direct Buehler Sensitization, and Pyrogen Testing, which were performed according to ISO 10993. Additionally, a swine wound healing study was performed to determine the effects of AWG on the local tissue response and healing of deep partial thickness excisional wounds using histology at days 3 (n=8/group) and 6 (n=4/group). A semi-quantitative analysis of several inflammatory cell types and extent of tissue response was performed. AWG was compared to a commercial control+ and an untreated control. Results: All biocompatibility test results were passing. On the early assessment day (day 3) of the wound healing study, local tissue response to AWG was comparable to the untreated control, while the commercial product showed a delay in epithelialization. By day 6, both treatment groups showed wound healing comparable to the untreated control. Conclusions: The findings confirm that the presence of biofilm disruption and antimicrobial agents within AWG do not negatively impact the biocompatibility or the natural wound healing process. *Sanara MedTech, Inc. BIAKŌSTM Antimicrobial Wound Gel, +B.Braun Prontosan Wound Gel X
P.LB20.
Background: Surgical site infection (SSI) is a complication of surgery which delays healing, lowers quality of life and increases healthcare costs. SSI’s pose significant challenges to wound healing at home. Pressurized irrigation is standard operating room practice for contaminated, infected or traumatic surgical wounds to remove bacteria, necrosis and debris. This new “biophysical” approach offers bacterial biofilm management in a containment system allowing bedside hydromechanical removal of biofilm bacteria without operating room costs. Purpose: We describe a 70 yo female who developed a posterior neck SSI and surgical wound after lipoma excision. Daily Closed Pulse Irrigation* (CPI*) was used to successfully manage a non-healing posterior midline Methicillin-Resistant Staphylococcus Aureus (MRSA) wound in the home setting. Methods: 10 daily closed pressurized irrigation treatments with hydrogel dressings were performed at home to achieve complete healing. CPI* uses a mechanical irrigator (8-15 psi) without suction to deliver 3 L NS at 90⁰ F, in a safe, portable, bedside containment system. Results: Clinical results show that daily closed pressurized irrigation was perfomed to successfully treat a non-healing MRSA cervical SSI wound by providing more frequent and reliable non-invasive reduction of bacterial bioburden. This case demonstrates that daily closed pressurized irrigation can promote rapid healing by secondary intention at home and reduce cost. Conclusions: CPI* is a low-cost solution that improved outcomes and quality of life for patients at home. A self-contained delivery system allowed frequent safe, hydromechanical debridement with rapid granulation/epithelialization and should be further investigated.
P.LB21.
Background: Substance use disorders (SUDs) are on the rise in the United States. Injection drug use (IDU) causes chronic wounds due to vein, muscle, subcutaneous injection site infections, adverse skin reactions (i.e. cocaine-levamasole), talc injection or overdose pressure injury. Methicillin-resistant Staphylococcus aureus (MRSA) frequently produces severe cellulitis, abscesses, necrotizing fasciitis resulting in non-healing wounds. Opiate use disorder (OUD) patients are at risk of non-healing due to mu receptor inhibition of keratinocytes resulting in higher pain levels, longer length of stay, higher re-admission rates and higher healthcare costs. Pressurized pulsed irrigation (PPI) is standard practice for contaminated, infected or traumatic wounds, to remove wound bacteria biofilm, necrotic tissue and debris. Closed Pulse Irrigation* (CPI*) is a system that provides frequent PPI hydromechanical debridement without cross-contamination, anesthetics, bleeding and high surgical cost. Purpose: We describe two OUD patients with multiple non-healing extremity wounds who received CPI* hydromechanical debridement as a new “antibiofilm” strategy to control wound bacterial burden and promote healing. Methods: Closed pressurized irrigation uses a hydromechanical irrigator (8 – 15 psi) to deliver 3 L NS at 90⁰ F within a safe, omnidirectional containment system to serially debride OUD wounds patients during opiate detoxification admission. Hydrogel dressings were applied. Results: Clinical results demonstrate that daily PPI was used to successfully promote healing in OUD patients while admitted for detoxificaton. An average of 20 daily closed pressurized irrigation treatments achieved complete healing with an improved quality of life and safe transition to home. Conclusions: Effective management of SUDs wound patients is critical. SUDs wound patients receiving PPI showed significant early improvement leading to successful healing by secondary intention.
P.LB22.
BACKROUND
Despite increase in awareness of antibiotic stewardship there is still misuse of systemic antibiotics for wound care. At the core of the problem is lack of evidence-based education in wound medicine, wound infection and biofilms.
METHODS
We created an interdisciplinary wound care team including physician leadership, nursing leadership, physical therapists, occupational therapists, nutritionist, and director of quality and safety. The wound care team together with the hospital infection control committee implemented a multi-dimensional strategic plan for reducing the misuse of systemic antibiotics as part of treatment of wounds. Our hospital setting is acute inpatient rehabilitation hospital where approximately 12-20 percent of inpatients have wounds. Our daily census is 40 to 43 patients. Our strategy included ongoing series of wound lectures for all providers on basics of wound care, effective wound dressing techniques, wound bed preparation, wound infection, biofilms, and chronic wound inflammation. We implemented weekly interdisciplinary wound care teaching rounds which involves teaching of wound team members, bedside nurses, as well as the patient and patient caregiver. We designed and implemented hands on training in wound care including debridement techniques and application of effective compression. Wound team meets regularly to look at trends and troubleshoot and foresee challenges.
RESULTS
We have practically eliminated the use of systemic antibiotics for wound care by education on evidence-based guidelines for wound care
CONCLUSIONS
Providing evidence-based wound education to providers to help them differentiate signs of wound inflammation vs infection, understand wound microbe interaction, biofilms, and acquire skills to decrease wound bio burden, we can significantly reduce misuse of systemic antibiotics. This is a significant positive contribution to institutional antibiotic stewardship. This is a pilot trial in one out of four rehab hospitals in a network and we plan to implement this protocol across the network.
P.LB23.
BACKGROUND Chronic wounds frequently become colonized with biofilm-producing microbes resistant to treatment with antibiotics. These infected wounds are susceptible to excessive and prolonged inflammation and are not able to respond to normal epithelial migration and cellular proliferation stimuli. Antimicrobials, hydrogels, and enzymatic debridement ointments are often applied but can inhibit wound healing. The delivery of photobiomodulation to a chronic wound site is a promising alternative. In-vitro, as well as published animal and human studies indicates specific wavelengths of visible light have antimicrobial effects on gram positive and negative bacteria, fungi and multi-drug resistant organisms in conjunction with stimulating wound healing. METHODS A Phase 1 clinical study was undertaken to evaluate a Continuous Low-Irradiance Phototherapy (CLIP) system that emits blue (<430nm) light via a handheld powerpack attached to a single-use (28-day period) light-emitting patch, worn continuously. The study evaluates safety and efficacy of the CLIP system on 10 adult pts. presenting with venous leg ulcers or diabetic foot ulcers that failed to close >30% with standard of care (SOC) over a 2-week screening period. RESULTS Endpoints include monitoring adverse events; re-epithelialization based on percentage area reduction; bioburden; and inflammation as evaluated by digital imaging and wound swabs; and evaluation of pain at rest and during application-inspection of the light-emitting patch at clinic visits. CONCLUSION To date 7-patients have been accrued with no adverse events and reduced pain levels. Initial data indicates that the CLIP therapy has been able to reduce bioburden and inflammation and increase re-epithelialization. The potential of continuous, wearable, home-based photobiomodulation may provide a new and effective wound healing treatment option.
P.LB24.
Deep thickness skin wound remains a major challenge for reconstructive surgery. A novel approach of tissue engineering, based on an allogeneic adipose-derived 3D scaffold-free technology, was proposed.Adipose-derived stromal cells (ASCs) were isolated from human adipose tissue to constitute the 3D-graft (n=9). The ultrastructure was assessed by microtomography/SEM. The protein content was determined by proteomic/ELISA. The in vivo biocompatibility was assessed in nude and Wistar rats up to 4 weeks (n=20) as well as the safety in terms of tumorigenicity/toxicity/biodistribution (following GLP). The efficacy was then evaluated in a model of ischemic (vs. non-ischemic) wound in hyperglycemic Wistar rats (n=42).The 3D-graft is a translucid and malleable membrane to be easily handled and sutured in the wound bed. A mean of 175±86 cells/mm² was found to be embed in the extracellular matrix with a low level of mineralization (0.30±0.31%v/v). The expression of the biological pathways involved in early wound healing and the VEGF/SDF1a contents (181±12 and 663±27 ng/g, respectively) were over-expressed in the graft. The biocompatibility and the safety of the 3D-graft were confirmed at 4 and up to 24 weeks post-implantation, respectively. The 3D-graft was easily applied (by a simple bandage) on the ischemic/hyperglycemic wounds (on the leg) and promoted an earlier wound closure (27 vs. 34 days for sham, respectively) associated with dermis/epidermis reconstruction, transient aSMA positive staining and lymphocytes/macrophages recruitment after 10-15 days.In conclusion, the scaffold-free approach with allogenic 3D-graft (derived from ASCs) demonstrated the safety and efficacy in stringent model of hyperglycemic and ischemic deep-thickness wound.
P.LB25.
Background: The repai of skin is a well-orchestrated process. Although healing is a tightly regulated, abnormal tissue repair often lead to the unwanted formation of scars causing aesthetic and functional problems. Although scarring is a significant health problem and directly impact the human’s well-being, effective treatment options are lacking. There is a critical need for the identification of novel therapies to treat scars. Objective: To determine the clinical effects of topical administration of rapamycin gel as a strategy to mitigate scarring in vivo. Methods: Balb/c mice (n=24) were randomly assigned to control and experimental groups in which the formation of scars was induced using a mechanotransduction scar animal model. Topical rapamycin gel and vehicle were administered daily on the scars. Histological parameters of scar were analyzed along with biomarkers for mTOR pathway activation and drug delivery efficacy. Immunofluorescence stainings were performed with antibodies against p-S6 protein, alpha-smooth muscle actin, and Periostin, as well as the identification of collagen deposition using picrosirius staining. Results: Scar tissues displayed mTOR pathway activation along with increased vascularity and Periostin. Topical administration of rapamycin gel resulted in small scar formation as confirmed by the reduced distances between adipose tissues, muscles, and hair follicles. Rapamycin gel influenced blood vessels and Periostin deposition and preserved architecture of the stromal.
P.LB26.
Background: Calreticulin (CRT), an ER chaperone, has been shown to have extracellular functions via outside-in signaling. We show that both intracellular CRT and extracellular CRT are required for the synthesis and release of the extracellular matrix (ECM) proteins, collagen, fibronectin, and elastin. Using diabetic mice, topically applied CRT for 4 days post-wounding healed full thickness excisional wounds by tissue regeneration characterized by abundant neo-dermis, epidermal appendage neogenesis, and no scarring. By day 14 post-wounding upon epidermal closure, hair follicles evaginate from the epidermis into the dermis, which show pigmentation by day 21 post-wounding. In vitro, we have shown that induction of ECM proteins by CRT in fibroblasts [to fill in the wound defect] is via TGF-beta signaling. However, as TGF-beta critically induces scarring and CRT heals by tissue regeneration, we interrogated potential mechanisms that might be involved in CRT modulation of TGF-beta-induced fibrosis/scarring using human dermal fibroblasts. Results: Inhibiting protein translation with cycloheximide, we show that CRT induces a faster turn-over rate of ECM proteins than TGF-beta. On a molar basis, TGF-beta induces between 1.7-3.4 higher levels ECM proteins than CRT. Over time, the production of ECM proteins by CRT decreases earlier than by TGF-beta. The connection between TGF-β and Wnt pathways plays a role in fibrosis by inducing ECM proteins. As a mechanism involved in fibrosis, TGF-beta was shown to downregulate DKK-1, an inhibitor of Wnt signaling. In contrast, CRT increases DKK-1 as a potential mechanism for decreasing Wnt-related beta-catenin activation. Furthermore, at 3h, CRT induces miR29, known to block collagen and fibronectin transcription. Conclusion: Revealing mechanisms involved in CRT attenuation of TGF-beta induced scarring should implicate new therapeutic targets for tissue regeneration of chronic wounds.
P.LB27.
P.LB28.
Background: Various treatments such as surgical excision, steroid injection, pressure therapy, and radiation therapy (RT) are available for auricular keloid. In particular, surgical excision in the treatment of auricular keloid is important, because recurrence rates are low compared to other sites. Objectives: We aimed to evaluate the clinical outcome of intralesional excision followed by postoperative triamcinolone acetonide intralesional injection (TA ILI) in the management of auricular keloid.Methods: We conducted a surgery records and charts review of patients who underwent auricular keloid management with intralesional excision and TA ILI. We also analyzed the recurrence rate over a 2-year period and evaluated the patient satisfaction using 11-point questionnaire (0-10).Results: A total of 18 Korean patients (2 males and 16 females), mean age of 26.5 years, with total 20 lesions were evaluated (2 patients had bilateral lesions). Lobular type (n= 10, 50%) was the most common, followed by anterior/posterior button (n= 3, 15%), wrap-around (n= 3, 15%), dumbbell (n= 2, 10%), and sessile type (n= 2, 10%). Total recurrence rate was 5% (1 of 20) within 24 months follow-up period, and mean satisfaction score was 9.6 (more than moderately satisfied). No serious and persistent adverse events were reported during the follow-up period.Conclusion: We confirmed that TA ILI after intralesional excision can be effective for auricular keloid management. With an effective surgical procedure and minimal postoperative treatment, a low recurrence rate close to that of postoperative RT was obtained.Key words: Auricle, ear, keloid, intralesional excision, intralesional injection, triamcinolone acetonide
P.LB29.
BACKGROUND Inactivation of poly(ADP-ribose) polymerase 1 (PARP1) has been found to have protective effect in several fibrotic diseases; however, the role of PARP1 in keloid has not been studied yet. Herein, we evaluated the therapeutic efficacy of PARP1 inhibitor (rucaparib) for keloids. METHODS A total of eight patients with eight keloids were achieved. The protein expressions of PARP1 and smad3 in keloid tissue or normal human dermal tissue were evaluated with western blotting. Primary cultures from keloids or control normal skin were performed. The effect of PARP1 inhibitor was evaluated using MTT assay and migration assay. We further analyze the effect of PARP1 inhibitor on patient derived keloid xenograft murine model. RESULTS The protein expressions of PARP1 and smad3 were significantly higher in keloid tissue as compared to normal dermal tissue. Rucaparib (20 μM) significantly suppressed the proliferation of keloid fibroblasts. Moreover, the combination of rucaparib (20 μM) and triamcinolone (50 μM) showed additive suppressive effect on keloid fibroblasts as compared to rucaparib therapy alone. Migration assay showed rucaparib (10 μM) significantly suppressed the migration of keloid fibroblasts as compared to control. Fibrosis markers including matrix metallopeptidase (MMP)-1, 2, 3, 9 and α-smooth muscle actin (SMA), fibronectin, and connective tissue growth factor (CTGF) in keloid fibroblasts significantly decreased after rucaparib treatment (20 μM). In patient-derived keloid xenograft model, rucaparib significantly reduced the size of keloid tissue compared to control by 55 %. CONCLUSIONS Our data suggest PARP1 might be a novel therapeutic target for keloid disease. Rucaparib might be a promising therapeutic drug for the treatment of keloid disease.
