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Upon healing, burn wounds often leave hypertrophic scars (HTSs) marked by excess collagen deposition, dermal and epidermal thickening, hypervascularity, and an increased density of fibroblasts. The Galectins, a family of lectins with a conserved carbohydrate recognition domain, function intracellularly and extracellularly to mediate a multitude of biological processes including inflammatory responses, angiogenesis, cell migration and differentiation, and cell‐ECM adhesion. Galectin‐1 (Gal‐1) has been associated with several fibrotic diseases and can induce keratinocyte and fibroblast proliferation, migration, and differentiation into fibroproliferative myofibroblasts. In this study, Gal‐1 expression was assessed in human and porcine HTS. In a microarray, galectins 1, 4, and 12 were upregulated in pig HTS compared to normal skin (fold change = +3.58, +6.11, and +3.03, FDR <0.01). Confirmatory qRT‐PCR demonstrated significant upregulation of Galectin‐1 (LGALS1) transcription in HTS in both human and porcine tissues (fold change = +7.78 and +7.90, P <.05). In pig HTS, this upregulation was maintained throughout scar development and remodeling. Immunofluorescent staining of Gal‐1 in human and porcine HTS showed significantly increased fluorescence (202.5 ± 58.2 vs 35.2 ± 21.0, P <.05 and 276.1 ± 12.7 vs 69.7 ± 25.9, P <.01) compared to normal skin and co‐localization with smooth muscle actin‐expressing myofibroblasts. A strong positive correlation (R =.948) was observed between LGALS1 and Collagen type 1 alpha 1 mRNA expression. Gal‐1 is overexpressed in HTS at the mRNA and protein levels and may have a role in the development of scar phenotypes due to fibroblast over‐proliferation, collagen secretion, and dermal thickening. The role of galectins shows promise for future study and may lead to the development of a pharmacotherapy for treatment of HTS. [ABSTRACT FROM AUTHOR]

Deep partial thickness burns are clinically prevalent and difficult to diagnose. In order to develop methods to assess burn depth and therapies to treat deep partial thickness burns, reliable, accurate animal models are needed. The variety of animal models in the literature and the lack of precise details reported for the experimental procedures make comparison of research between investigators challenging and ultimately affect translation to patients. They sought to compare deep partial thickness porcine burn models from five well-established laboratories. In doing so, they uncovered a lack of consistency in approaches to the evaluation of burn injury depth that was present within and among various models. They then used an iterative process to develop a scoring rubric with an educational component to facilitate burn injury depth evaluation that improved reliability of the scoring. Using the developed rubric to re-score the five burn models, they found that all models created a deep partial thickness injury and that agreement about specific characteristics identified on histological staining was improved. Finally, they present consensus statements on the evaluation and interpretation of the microanatomy of deep partial thickness burns in pigs. [ABSTRACT FROM AUTHOR]

Burn injuries frequently result in hypertrophic scars (HTSs), specifically when excision and grafting are delayed due to limited resources or patient complications. In patient populations with dark baseline pigmentation, one symptom of HTS that often occurs is dyspigmentation. The mechanism behind dyspigmentation has not been explored, and, as such, prevention and treatment strategies for this morbidity are lacking. The mechanism by which cells make pigment is controlled at the apex of the pathway by pro-opiomelanocortin (POMC), which is cleaved to its products alpha-melanocyte-stimulating hormone (α-MSH) and adrenocorticotropin hormone (ACTH). α-MSH and ACTH secreted by keratinocytes bind to melanocortin 1 receptor (MC1R), expressed on melanocytes, to initiate melanogenesis. POMC protein expression is upregulated in hyperpigmented scar compared to hypopigmented scar by an unknown mechanism in a Duroc pig model of HTS. POMC RNA levels, as well as the POMC gene promoter methylation status were investigated as a possible mechanism. DNA was isolated from biopsies obtained from distinct areas of hyper- or hypopigmented scar and normal skin. DNA was bisulfite-converted, and amplified using two sets of primers to observe methylation patterns in two different CpG islands near the POMC promoter. Amplicons were then sequenced and methylation patterns were evaluated. POMC gene expression was significantly downregulated in hypopigmented scar compared to normal skin, consistent with previously reported protein expression levels. There were significant changes in methylation of the POMC promoter; however, none that would account for the development of hyper- or hypopigmentation. Future work will focus on other areas of POMC transcriptional regulation. [ABSTRACT FROM AUTHOR]

Background: Hidradenitis suppurativa is a chronic inflammatory skin disease, with significant morbidity secondary to its recurrent painful and exudative lesions. Given limited research on the cytoarchitecture of hidradenitis suppurativa, this study describes the microscopic structure and cell surface markers present in hidradenitis suppurativa tissue to better understand the disease and identify potential therapeutic targets. Methods: Skin biopsies of hidradenitis suppurativa lesions from patients who underwent surgical excision (n = 11) were compared with grossly normal-appearing perilesional skin (n = 5) and normal skin biopsies from unaffected individuals (n = 4). Histopathology and epidermal thickness were assessed using hematoxylin and eosin and picrosirius red staining, and CD3, a T-cell marker, and CD31 (PECAM), a vascular endothelial cell marker, were assayed using immunofluorescence. Data were analyzed and compared using analysis of variance and Student’s t test. Results: Histological examination showed that hidradenitis suppurativa samples had a significantly thicker epidermal layer than normal skin (335.23 ± 165.01 μm vs 57.24 ± 18.43 μm, P = .005), extending into and engulfing the dermis. The hidradenitis suppurativa dermis had extensive cellular infiltration and aggregation as well as disorganized collagen. Immunofluorescence analysis revealed that, at the dermal level, hidradenitis suppurativa lesions had a significantly greater quantity of CD3+ (324.29 ± 139.28 vs 14.93 ±16.32, P < .0001) and CD31+ (322.15 ± 155.46 vs 2.84 ± 5.56, P < .0001) cells/mm2 compared with normal skin samples. Conclusions: Hidradenitis suppurativa lesions have thicker epidermal layers, more dermal cellular infiltrate, and disorganized collagen fibers compared with normal skin. Furthermore, hidradenitis suppurativa dermis has a greater quantity of CD3+ and CD31+ cells than normal skin. [ABSTRACT FROM AUTHOR]

Background: The study of photobiomodulation in wound healing is encumbered by limited wound study models. The aim of this study was to investigate the efficacy of a 3-dimensional dermal tissue culture model as a cost-saving alternative to conventional photobiomodulation study techniques. Methods: Nine dermal analogue tissue cultures were treated for 2 days with sham or 660-nm wavelength of light at either 1.5 or 3 mW/cm2 of energy. Tissue cytokine mRNA production was assessed by real-time reverse transcription-polymerase chain reaction, and tissue and supernatant protein were evaluated by immunofluorescence, enzyme-linked immunosorbent assay, and Western blot. Results: Photobiomodulation with 660-nm wavelength light induced transcription of IL-1β and IL-6 mRNA and decreased that of IL-8. Tissue protein content of IL-6 and IL-8 was unchanged, whereas supernatant protein content of IL-8 was significantly increased (P=.023) by 1.5mW/cm2 treatment. To describe the localization of cytokines between tissue and supernatant, the relative diffusion of each was calculated and found to be 15-fold higher for IL-6 than for IL-8 despite an overall higher concentration of IL-8 in the tissue. Conclusion: In this study, photobiomodulation elicited mRNA and protein changes quantifiable in both the tissue and supernatant. In addition, the use of this advanced culture model allowed for histological assessment and the comparison of “local” versus “circulatory” responses between the tissue and supernatant, respectively. [ABSTRACT FROM AUTHOR]

Background: A functional coagulation assay was used to investigate the extrinsic pathway of coagulation on citrated whole blood samples from healthy adult male Sprague Dawley rats using the mini cup and pin system. Methods: Reference values for coagulation parameters from forty-three animals were calculated using data obtained from the ROTEM® delta hemostasis analyzer with the EXTEM test. Results: The following ranges, presented as the 2.5-97.5 percentiles, were established: CT [18-77], CFT [20-80], α [73-86], MCF [53-70], and ML [1-22], along with others. Conclusions: These reference ranges can be used in future studies in rats to identify clinically significant coagulopathies. [ABSTRACT FROM AUTHOR]

A study of polarized light transport in scattering media exhibiting directional anisotropy or linear birefringence is presented in this paper. Novel theoretical and experimental methodologies for the quantification of birefringent alignment based on out-of-plane polarized light transport are presented here. A polarized Monte Carlo model and a polarimetric imaging system were devised to predict and measure the impact of birefringence on an impinging linearly polarized light beam. Ex-vivo experiments conducted on bovine tendon, a biological sample consisting of highly packed type I collagen fibers with birefringent property, showed good agreement with the analytical results. [ABSTRACT FROM AUTHOR]

Compression therapy has long been a standard treatment for hypertrophic scar prevention. However, due to the lack of objective, quantitative assessments, and measurements of scar severity, as well as the lack of a self-operated, controllable, and precise pressure delivery technique, limited concrete evidence exists, demonstrating compression therapy's efficacy. We have designed and built an automatic pressure delivery system to apply and maintain constant pressure on scar tissue in an animal model. A force sensor positioned on a compression plate reads the imposed force in real-time and sends the information to a feedback system controlling two position actuators. The actuators move accordingly to maintain a preset value of pressure onto the skin. The system was used in an in vivo model of compression therapy on hypertrophic scars. It was shown that the system was capable of delivering a constant pressure of 30 mmHg on scar wounds for a period of two weeks, and that phenotypic changes were seen in the wounds. [ABSTRACT FROM AUTHOR]

Burn wound healing can be significantly delayed by infection leading to increased morbidity and hypertrophic scarring. An optimal antimicrobial agent would have the ability to kill bacteria without negatively affecting the host skin cells that are required for healing. Currently available products provide antimicrobial coverage, but may also cause reductions in cell proliferation and migration. Cold atmospheric plasma is a partially ionized gas that can be produced under atmospheric pressure at room temperature. In this study a novel handheld Aceso Plasma Generator was used to produce and test Aceso Cold Plasma (ACP) in vitro and in vivo. ACP showed a potent ability to eliminate bacterial load in vitro for a number of different species. Deep partial-thickness and full-thickness wounds that were treated with ACP after burning, after excision, after autografting, and at days 5, 7, and 9 did not show any negative effects on their wound healing trajectories. On par with in vitro analysis, bioburden was decreased in treated wounds vs. control. In addition, metrics of hypertrophic scar such as dyschromia, elasticity, trans-epidermal water loss (TEWL), and epidermal and dermal thickness were the same between the two treatment groups.It is likely that ACP can be used to mitigate the risk of bacterial infection during the phase of acute burn injury while patients await surgery for definitive closure. It may also be useful in treating wounds with delayed re-epithelialization that are at risk for infection and hypertrophic scarring. A handheld cold plasma device will be useful in treating all manner of wounds and surgical sites in order to decrease bacterial burden in an efficient and highly effective manner without compromising wound healing. • ACP showed a potent ability to eliminate bacterial load in vitro for a number of different species. • ACP was compatible with deep partial thickness burn wound healing. • ACP was compatible with full thickness burn wound healing after skin grafting. [ABSTRACT FROM AUTHOR]