Search

Refractory wounds present a complex and serious clinical dilemma in plastic and reconstructive surgery. However, there are currently no standard guidelines for the treatment of refractory wounds. Artificial dermis (AD) has achieved some satisfactory results, but also has some limitations. Autologous platelet-rich plasma (PRP), as a cell-therapy material, was a valuable and safe treatment dressing for chronic non-healing wounds. This study aimed to evaluate the efficacies of artificial dermis (AD) with and without autologous platelet-rich plasma (PRP) in patients with refractory wounds. Sixteen patients with refractory wounds were randomly allocated to autologous PRP therapy combined with artificial dermis (PRP + AD [N = 8]) or an artificial dermis program only (AD [N = 8]). We compared the efficacies of the two methods in terms of times to wound healing, infection control, and AD vascularization, as well as hospitalization days and eventual clinical outcomes.13 patients achieved complete healing, including seven (87.5%) in the PRP + AD group and six (75.0%) in the AD group (P > .05). The times to wound healing, infection control, and AD vascularization, and hospitalization time after transfer were significantly shorter in the PRP + AD group compared with the AD group (P < .05). In conclusion, the combination of AD and PRP promoted refractory wound healing and shortened waiting times compared with simple dermal grafts., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objective: To investigate the clinical effect of human acellular dermal matrix (HADM) combined with split-thickness skin graft in repairing lacunar soft tissue defects of the lateral heel after calcaneal fracture., Methods: From June 2018 to October 2020, providers repaired 11 cases of lacunar soft tissue defects at the lateral part of the heel using HADM combined with split-thickness skin graft. After thorough debridement, the HADM was trimmed and filled into the lacunar defect area. Once the wound was covered, a split-thickness skin graft and negative-pressure wound therapy were applied. Providers evaluated the appearance, scar, ductility of the skin graft site, appearance of the donor site, healing time, and any reoperation at follow-up., Results: Of the 11 cases, 8 patients achieved successful wound healing by primary intention. Three patients showed partial necrosis in the edge of the skin graft, but the wound healed after standard wound care. Evaluation at 6 and 12 months after surgery showed that all patients had wound healing and mild local scarring; there was no obvious pigmentation or scar formation in the donor skin area. The average healing time was 37.5 days (range, 24-43 days)., Conclusions: The HADM combined with split-thickness skin graft is a simple and effective reconstruction method for lacunar soft tissue defect of the lateral heel after calcaneal fracture. In this small sample, the combination demonstrated few infections, minor scar formation, few donor site complications, and relatively short hospital stays., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Tissue-engineered skin is an effective material for treating large skin defects in a clinical setting. However, its use is limited owing to vascular complications. Human adipose tissue-derived microvascular fragments (HaMVFs) are vascularized units that form vascular networks by rapid reassembly. In this study, we designed a vascularized bionic skin tissue using a three-dimensional (3D) bioprinter of HaMVFs and human fibroblasts encapsulated in a hybrid hydrogel composed of GelMA, HAMA, and fibrinogen. Tissues incorporating HaMVFs showed good in vitro vascularization and mechanical properties after UV crosslinking and thrombin exposure. Thus, the tissue could be sutured appropriately to the wound. In vivo, the vascularized 3D bioprinted skin promoted epidermal regeneration, collagen maturation in the dermal tissue, and vascularization of the skin tissue to accelerate wound healing. Overall, vascularized 3D bioprinted skin with HaMVFs is an effective material for treating skin defects and may be clinically applicable to reduce the necrosis rate of skin grafts., (© 2023 Wiley Periodicals LLC.)

Purpose: This study aimed to investigate the biomechanical properties, cell migration, and revascularization of the acellular dermal matrix Epiflex. As a decellularized, freeze-dried human skin graft, Epiflex has broad applications in medical fields, particularly in implantology and dentistry. Understanding its biomechanical characteristics is crucial for its clinical adoption as a novel soft tissue graft option., Methods: Epiflex (n = 3) was evaluated in comparison to palatal tissue from body donors (n = 3). Key metrics, such as elongation and tear resistance, were quantified. Both graft types underwent histological analysis and scanning electron microscopy. Additionally, the healing properties of Epiflex were assessed using a Chorioallantoic Membrane (CAM) Assay., Results: Biomechanically, Epiflex (mean = 116.01 N) demonstrated the ability to withstand greater forces (p = 0.013) than human palatal tissue (mean = 12.58 N). When comparing the elongation, no significant difference was measured (ASG mean = 9.93 mm, EF mean = 9.7 mm). Histologically, Epiflex exhibited a loosely connected network of collagen fibers with a dense upper layer. The CAM Assay indicated efficient revascularization., Conclusion: Epiflex appears to be a viable option for soft tissue augmentation, particularly appealing to patient groups who avoid all or specific animal-derived products due to ethical or religious reasons., (© 2024. The Author(s).)

Wound healing can be influenced by genes that control the circadian cycle, including Per2 and BMAL1, which coordinate the functions of several organs, including the skin. The aim of the study was to evaluate the role of PER2 during experimental skin wound healing. Two groups (control and Per2-KO), consisting of 14 male mice each, were anesthetized by inhalation, and two 6 mm wounds were created on their dorsal skin using a punch biopsy. A silicone ring was sutured around the wound perimeter to restrict contraction. The wound healing process was clinically measured daily (closure index) until complete wound repair. On Day 6, histomorphometric analysis was performed using the length and thickness of the epithelial migration tongue, in addition to counting vessels underlying the lesion by immunofluorescence assay and maturation of collagen fibers through picrosirius staining. Bromodeoxyuridine (BrdU) incorporation and quantification were performed using the subcutaneous injection technique 2 h before euthanasia and through immunohistochemical analysis of the proliferative index. In addition, the qualitative analysis of myofibroblasts and periostin distribution in connective tissue was performed by immunofluorescence. Statistically significant differences were observed in the healing time between the experimental groups (means: 15.5 days for control mice and 13.5 days for Per2-KO; p = 0.001). The accelerated healing observed in the Per2-KO group (p < 0.05) was accompanied by statistical differences in wound diameter and length of the migrating epithelial tongue (p = 0.01) compared to the control group. Regarding BrdU immunoreactivity, higher expression was observed in the intact epithelium of Per2-KO animals (p = 0.01), and this difference compared to control was also present, to a lesser extent, at the wound site (p = 0.03). Immunofluorescence in the connective tissue underlying the wound showed a higher angiogenic potential in the Per2-KO group in the intact tissue area and the wound region (p < 0.01), where increased expression of myofibroblasts was also observed. Qualitative analysis revealed the distribution of periostin protein and collagen fibers in the connective tissue underlying the wound, with greater organization and maturation during the analyzed period. Our research showed that the absence of the Per2 gene positively impacts the healing time of the skin in vivo. This acceleration depends on the increase of epithelial proliferative and angiogenic capacity of cells carrying the Per2 deletion., (© 2024 The Authors. Journal of Cellular Biochemistry published by Wiley Periodicals LLC.)

Chronic, nonhealing wounds remain a clinical challenge and a significant burden for the healthcare system. Skin-resident and infiltrating T cells that recognize pathogens, microbiota, or self-antigens participate in wound healing. A precise balance between proinflammatory T cells and regulatory T cells is required for the stages of wound repair to proceed efficiently. When diseases such as diabetes disrupt the skin microenvironment, T cell activation and function are altered, and wound repair is hindered. Recent studies have used cutting-edge technology to further define the cellular makeup of the skin prior to and during tissue repair. In this review, we discuss key advances that highlight mechanisms used by T cell subsets to populate the epidermis and dermis, maintain skin homeostasis, and regulate wound repair. Advances in our understanding of how skin cells communicate in the skin pave the way for therapeutics that modulate regulatory versus effector functions to improve nonhealing wound treatment., (Copyright © 2023 by The American Association of Immunologists, Inc.)

Bioprinting is a promising alternative method to generate skin substitutes because it can replicate the structural organization of the skin into biomimetic layers in vitro. In this study, six primary human skin cell types were used to bioprint a trilayer skin construct consisting of epidermis, dermis, and hypodermis. Transplantation of the bioprinted skin with human cells onto full-thickness wounds of nu/nu mice promoted rapid vascularization and formation of epidermal rete ridges analogous to the native human epidermis, with a normal-looking extracellular matrix. Cell-specific staining confirmed the integration of the implanted cells into the regenerated skin. Using a similar approach, a 5 centimeter-by-5 centimeter bioprinted autologous porcine skin graft was transplanted onto full-thickness wounds in a porcine excisional wound model. The bioprinted skin graft improved epithelialization, reduced skin contraction, and supported normal collagen organization with reduced fibrosis. Differential gene expression demonstrated pro-remodeling protease activity in wounds transplanted with bioprinted autologous skin grafts. These results demonstrate that bioprinted skin can support skin regeneration to allow for nonfibrotic wound healing and suggest that the skin bioprinting technology may be applicable for human clinical use.

The current standard of care for the coverage of large wounds often involves split thickness skin grafts (STSGs) which have numerous limitations. One promising technique that has gained traction is fractional autologous skin grafting using full-thickness skin columns (FTSC). Harvesting occurs orthogonally by taking numerous individual skin columns containing the epidermis down through the dermis and transferring them to the wound bed. The purpose of this porcine study was to investigate the efficacy of implanting FTSCs directly into deep partial-thickness burn wounds, as well as examining donor site healing at the maximal harvest density. It was hypothesised that by utilising FTSCs, the rate of healing in deep partial thickness burns can be improved without incurring the donor morbidity seen in other methods of skin grafting. Deep partial-thickness burns were created on the dorsum of female red duroc swine, debrided 3 days later and FTSCs were implanted at varying expansion ratios directly into the burn wounds. At day 14, 1:50 expansion ratio showed significantly faster re-epithelialisation compared to the debrided burn control and 1:200. Donor sites (at 7%-10% harvest density) were 100% re-epithelialised by day 7. Additionally, the maximal harvest density was determined to be 28% in an ex vivo model, which then five donor sites were harvested at 28% density on a red duroc swine and compared to five STSG donor sites. At maximal harvest density, FTSC donor sites were significantly less hypopigmented compared to STSGs, but no significant differences were observed in re-epithelialisation, contraction, blood flow or dermal thickness. In conclusion, implantation directly into deep partial-thickness burns is a viable option for the application of FTSCs, favouring lower expansion ratios like 1:50 or lower. Little difference in donor site morbidity was observed between FTSC at a maximal harvest density of 28% and STSGs, exceeding the optimal harvest density., (© 2023 The Authors. Wound Repair and Regeneration published by Wiley Periodicals LLC on behalf of The Wound Healing Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.)

The substitute materials of autologous tissue graft for periodontal soft tissue augmentation surgery develop rapidly. The use of substitute material can avoid the second operation area, shorten the operation time, reduce the postoperative reaction and pain, and is not limited by the quantity, suitable for a wide range of cases. In this paper, the characteristics, histological study, clinical application and therapeutic effect of acellular dermal matrix as a substitute material for autologous tissue transplantation were introduced to provide reference for clinical work.

Trauma, burns, and diabetes result in nonhealing wounds that can cause bone or tendon exposure, a significant health threat. The use of an artificial regeneration template combined with skin grafting as an alternative method to highly invasive flap surgery has been shown to be an effective way to cover full-thickness skin defects with bone or tendon exposure for both functional and aesthetic recovery. However, artificial regeneration templates, such as Pelnac, are overwhelmingly expensive, limiting their clinical use. Here, we demonstrate for the first time that polyurethane film combined with absorbable gelatine sponge, affordable materials widely used for haemostasis, are effective for dermal reconstruction in wounds with bone or tendon exposure. The absorbable gelatine sponge combined with polyurethane film was applied to eight patients, all resulting in adequate granulation that fully covered the exposed bone or tendon. The outcome of absorbable gelatine sponge combined with polyurethane film application indicates that this approach is a potential novel and cost-effective dermal reconstruction strategy for the treatment of severe wounds with bone or tendon exposure., (© 2022 The Authors. International Wound Journal published by Medicalhelplines.com Inc (3M) and John Wiley & Sons Ltd.)

Acellular skin as a scaffold has a good potential to regenerate or repair damaged tissues. Growth factors such as Plasma Rich in Growth Factor (PRGF) as a rich source of active proteins can accelerate tissue regeneration. In this study, an acellular scaffold derived from fish skin with growth factors was used to repair full-thickness skin defects in a rat model. Cellular results demonstrated that epithelial cells adhere well to acellular scaffolds. The results of animal studies showed that the groups treated with acellular scaffold and growth factor have a high ability to close and heal wounds on the 28th day after surgery. Histological and staining results showed that in the treated groups with scaffold and growth factor, an epidermal layer was formed with some skin appendages similar to normal skin. Overall, such scaffolds with biological agents can cause an acceptable synergistic effect on skin regeneration and wound healing., (© 2022 The Authors. International Wound Journal published by Medicalhelplines.com Inc (3M) and John Wiley & Sons Ltd.)

Introduction: The ocular surface may be damaged by several ocular conditions such as chemical trauma, infection, neoplasia or autoimmune disease causing a loss of tissue and function leading to a painful loss of vision. Tissue regeneration is needed to re-establish homeostasis of the ocular surface and to preserve vision. Present replacement strategies have limitations ranging from availability of the same type of tissue to long-term stability. NHSBT currently produces decellularised dermis (DCD) for clinical allografting; comprising a "thin" (up to 1.0 mm) and a thick (>1.2 mm) DCD, used to treat non-healing leg ulcers or in rotator cuff repair. Even the thin DCD, however, is too thick for ophthalmic purposes. The objective of this study was to develop a new ultra-thin DCD for ocular allografting., Materials and Methods: Skin was retrieved, with consent for non-clinical use, from the back, front and back of the thighs of 3 different deceased donors, within 48 hours post-mortem. The tissue was cut into 5x5 cm squares and decellularised over 5 days as follows: decontamination with antimicrobials, de-epidermalisation (1M NaCl), hypotonic washes, detergent washes (with 0.01% SDS) and nuclease incubation. The DCD obtained was examined for integrity, handleability, residual remaining DNA and potential ultra-structural changes (by histology, DAPI and hematoxylin and eosin staining)., Results: We obtained an intact ultra-thin DCD using the same standard GMP protocol, regularly used to decellularise skin for clinical use. Tissue handleability was comparable to amniotic membrane, as evaluated by the ophthalmic surgeons as well as tissue bank assistants. The mean thickness of the tissue was 0.25 mm (±0.11) at the end of processing (total N=18 samples from 3 donors). Histology confirmed successful removal of epithelial cells and integrity of the extracellular matrix., Conclusion: We have successfully validated standard operating procedures for the production of ultra-thin DCD, in the attempt to obtain a valid alternative to amnion for the reconstruction of specific ocular regions (fornix, eye lids), where increased strength may be required. The thickness measurements at the end of processing suggest ultra-thin DCD obtained could represent a promising scaffold for regeneration of conjunctival tissue., (© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Current cellular hydrogel-based skin grafts composed of human dermal fibroblasts and a hydrogel scaffold tend to minimize contraction of full-thickness skin wounds and support skin regeneration. However, there has been no comparison between the sources of the dermal fibroblast used. Products using human adult or neonatal foreskin dermal fibroblasts are often expanded in vitro and used after multiple passages without a clear understanding of the effects of this initial production step on the quality and reproducibility of the cellular behavior. Based on the known effects of 2D tissue culture expansion on cellular proliferation and gene expression, we hypothesized that differences in donor age and time in culture may influence cellular properties and contractile behavior in a fibroblast-populated collagen matrix. Using porcine skin as a model based on its similarity to human skin in structure and wound healing properties, we isolated porcine dermal fibroblasts of three different donor ages for use in a 2D proliferation assay and in a 3D cell-populated collagen matrix contractility assay. In 2D cell culture, doubling time remained relatively consistent between all age groups from passage 1 to 6. In the contractility assays, fetal and neonatal groups contracted faster and generated more contractile force than the adult group at passage 1 in vitro . However, after five passages in culture, there was no difference in contractility between ages. These results show how cellular responses in a hydrogel scaffold differ based on donor age and time in culture in vitro , and suggest that consistency in the cellular component of bioengineered skin products could be beneficial in the biomanufacturing of consistent, reliable skin grafts and graft in vivo models. Future research and therapies using bioengineered skin grafts should consider how results may vary based on donor age and time in culture before seeding. Impact statement Little is known about the impact of donor cell age and time in culture on the contraction of cellular, hydrogel-based skin grafts. These results show how cellular phenotypes of porcine fibroblasts differ based on donor age and time in culture. This information is beneficial when addressing important inconsistencies in biomanufacturing of bioengineered skin grafts and in vitro models. These findings are relevant to research and therapies using bioengineered skin graft models and the results can be used to increase reproducibility and consistency during the production of bioengineered skin constructs. The information from this study can be extrapolated to future in vivo studies using human dermal fibroblasts in an in vivo model to help determine the best donor age and time in culture for optimal wound healing outcomes or more reproducible in vitro testing constructs.

Wound healing entails a fine balance between re-epithelialization and inflammation 1 , -during re-epithelialization and inflammation following injury in vivo. We show that loss of Piezo leads to faster wound closure due to increased wound edge intercalation and exacerbated myosin cable heterogeneity. Moreover, we show that loss of Piezo leads to impaired inflammation due to lower epidermal calcium levels and, subsequently, insufficient damage-induced ROS production. Despite initially appearing beneficial, loss of Piezo is severely detrimental to the long-term effectiveness of repair. In fact, wounds inflicted on Piezo knockout embryos become a permanent point of weakness within the epithelium, leading to impaired barrier function and reduced ability of wounded embryos to survive. In summary, our study uncovers a role for Piezo in regulating epithelial cell dynamics and immune cell responsiveness during damage repair in vivo. We propose a model whereby Piezo acts as molecular brake during wound healing, slowing down closure to ensure activation of sustained inflammation and re-establishment of a fully functional epithelial barrier.2 so that the risk of infection is minimized, tissue architecture is restored without scarring, and the epithelium regains its ability to withstand mechanical forces. How the two events are orchestrated in vivo remains poorly understood, largely due to the experimental challenges of simultaneously addressing mechanical and molecular aspects of the damage response. Here, exploiting Drosophila's genetic tractability and live imaging potential, we uncover a dual role for Piezo-a mechanosensitive channel involved in calcium influx 3 -during re-epithelialization and inflammation following injury in vivo. We show that loss of Piezo leads to faster wound closure due to increased wound edge intercalation and exacerbated myosin cable heterogeneity. Moreover, we show that loss of Piezo leads to impaired inflammation due to lower epidermal calcium levels and, subsequently, insufficient damage-induced ROS production. Despite initially appearing beneficial, loss of Piezo is severely detrimental to the long-term effectiveness of repair. In fact, wounds inflicted on Piezo knockout embryos become a permanent point of weakness within the epithelium, leading to impaired barrier function and reduced ability of wounded embryos to survive. In summary, our study uncovers a role for Piezo in regulating epithelial cell dynamics and immune cell responsiveness during damage repair in vivo. We propose a model whereby Piezo acts as molecular brake during wound healing, slowing down closure to ensure activation of sustained inflammation and re-establishment of a fully functional epithelial barrier., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

In oral surgery, tissue loss may occur in some cases, resulting in bone exposure and subsequent wound infection and possible scar formation during secondary healing. In this study, Terudermis ® Artificial Dermis (AD-T), a dermal defect graft made from processed bovine dermis collagen and gelatin sponge (GS) were used as dressings on 100-mm 2 wounds with exposed bone on the heads of rats. For the control group, the wound was left exposed. The wound-healing efficacy of the treatment was compared macroscopically and histologically among the three groups at 1, 2, and 4 weeks after surgery. Complete wound healing was achieved faster in the AD-T group than in the GS group, and osteoblasts appeared on the bone surface, indicating accelerated bone remodeling. Furthermore, in the AD-T group, there was an increased production of newly formed blood vessels, fibroblasts and osteoblasts positive for anti-cortactin antibodies, which are believed to contribute to wound healing. Our findings suggest that AD-T is better than GS as a wound dressing material.

Significance: Hypertrophic scars (HTS) are a fibroproliferative disorder that occur following deep dermal injury and affect up to 72% of burn patients. These scars result in discomfort, impaired mobility, disruption of normal function and cosmesis, and significant psychological distress. Currently, there are no satisfactory methods to treat or prevent HTS, as the cellular and molecular mechanisms are complex and incompletely understood. This review summarizes the biology of proteins in the dermal extracellular matrix (ECM), which are involved in wound healing and hypertrophic scarring. Recent Advances: New basic research continues toward understanding the diversity of cellular and molecular mechanisms of normal wound healing and hypertrophic scarring. Broadening the understanding of these mechanisms creates insight into novel methods for preventing and treating HTS. Critical Issues: Although there is an abundance of research conducted on collagen in the ECM and its relationship to HTS, there is a significant gap in understanding the role of proteoglycans and their specific isoforms in dermal fibrosis. Future Directions: Exploring the biological roles of ECM proteins and their unique isoforms in HTS, mature scars, and normal skin will further the understanding of abnormal wound healing and create a more robust understanding of what constitutes dermal fibrosis. Research into the biological roles of ECM protein isoforms and their regulation during wound healing warrants a more extensive investigation to identify their distinct biological functions in cellular processes and outcomes.

Introduction: Chronic, non-healing wounds are a growing concern in healthcare delivery. Tissue oxygenation is recognised as critical to successful wound healing. However, the quality and quantity of the information extracted by hyperspectral imaging depend on the optical tissue model. This article aims to develop a simplified and computationally efficient approach comparable in quality with the two-layer model., Methods: We have considered the epidermal layer as a 'thin-film' within the dermal layer. By considering the mismatched boundary and developing a four-flux model for light transport within the tissue, we have obtained a quasi two-layer model with a closed-form solution similar to the single-layer model., Results: We have compared the developed model with the two-layer model (reference) and the single-layer model for the broad range of physiologically relevant parameters. The thickness of the epithelium: 50, 80, and 120 μm. Melanin concentration: 1, 2, 4, 8, 16, and 32%. Blood concentration: 0.2%, 1%, and 7%. Oxygen saturation: 60%, 80%, and 99%. Our initial results show that the accuracy of the proposed quasi two-layer model significantly (by a factor of 10) outperforms the single-layer model and is in close agreement with the two-layer model., Conclusions: The proposed quasi two-layer model significantly (by the factor of 10) outperforms the single-layer model and is closely aligned with the two-layer model., (© 2022. Springer Nature Switzerland AG.)

Keratinocyte migration is vital in the re-epithelialisation of the skin during wound healing. Multiple factors conspire to impair closure of chronic wounds such as diabetic foot ulcers, venous leg ulcers and pressure wounds. Despite deep mechanistic understanding of microRNA (miRNA) biogenesis and function, the translational potential of these small genetic molecules has not been exploited to promote wound repair. In this review, I focus on miRNAs whose importance for wound healing stems from their impact on epidermal keratinocyte behaviour. These include miR-21-5p, miR-31-5p, miR-132-3p, miR-19b, miR-20a, miR-184, miR-129-5p and miR-335-5p which regulate diverse aspect of keratinocyte biology such as migration, proliferation, differentiation, inflammation and wound closure. A combinatorial approach where two or more miRNA mimics targeting distinct but complementary wound healing processes is proposed as this may enhance wound repair more effectively than any single miRNA mimic alone., (© 2021 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals LLC.)

Torealize intelligent and personalized medicine, it is a huge challenge to develop a hydrogel dressing that can be used as a sensor to monitor human health in real-time while promoting wound healing. Herein, an injectable, self-healing, and conductive chitosan-based (CPT) hydrogel with pH responsiveness and intrinsic antibacterial properties was fabricated via a Schiff base linkage and a hydrogen bond. Due to the introduction of Schiff base bonds, the injectable CPT hydrogel exhibits various excellent properties, such as pH responsiveness to sol-gel transition, self-healing properties, and broad-spectrum antibacterial properties even without additional antibacterial agents. In vitro experiments verify the excellent biocompatibility of the as-prepared hydrogel. An in vivo experiment in a mouse full-thickness skin-wound model was performed to confirm the outstanding effect on wound healing. Meanwhile, as epidermal sensors, the conductive hydrogel that perceives various human activities in real-time could provide the real-time analysis of the patient's healthcare information. Based on these excellent properties, the CPT hydrogel, as a biological dressing with a sensing function, lays a solid foundation for the further realization of personalized medicine.

Objective: To explore the effects of orienting three-dimensional porous network (type A) and honeycomb briquette-shaped vertically penetrating three-dimensional porous network (type B) on the vascularization rate of artificial dermis. Methods: The experimental research method was used. The artificial dermis was composed of a double layer of silicone layer and scaffold layer. Based on the difference of scaffold layer, they were divided into type A and type B artificial dermis (type A dermis and type B dermis, for short) containing type A and type B structure, respectively. The type A and type B structures were prepared by gradient freeze-drying technique and physical pore-making technique, respectively. The micro-morphology of two kinds of dermis scaffold was observed by scanning electron microscopy. The porosity of two kinds of dermis scaffold was measured by the Pyrex method. According to the method of national medical industry standard, the hydroxyproline content in degradation liquids and their residues in two kind of dermis were determined after degradation at 4, 8, 13, and 24 h, reflecting the degradation rates of two kinds of dermis. According to the random number table, L929 cells were divided into type A dermis group, type B dermis group, negative control group, and positive control group. The positive control group was added with minimum essential medium (MEM) containing 5% dimethyl sulfoxide, The negative control group was added with high-density polyethylene extract, and the other two groups were added with the corresponding extract. At 24 hours after culture, the growth rate of L929 cells was detected by methyl thiazolyl tetrazolium, and the cytotoxicity was graded. L929 cells and human umbilical vein endothelial cells (HUVECs) were inoculated into pore plates with two kinds of dermis preinstalled. On 1, 4, 7, and 14 d after inoculating, the adhesion and growth of L929 cells on the surfaces of the two kinds of scaffolds were detected by immunofluorescence method. On 7 d after inoculating, the migration of the above two kinds of cells into the two kinds of dermal scaffolds was detected by immunofluorescence and hematoxylin-eosin (HE) staining. Three full-thickness skin defect wounds of 5.0 cm×5.0 cm were created on both sides of the back of three 6-month-old healthy male Ba-Ma mini pigs. According to the random number table, six columns of wounds were divided into type A dermis two-step method group, type B dermis two-step method group, and type B dermis one-step method group. The wounds in type A dermis two-step method group and type B dermis two-step method group were transplanted with type A or type B dermis respectively before, and with autologous split-thickness skin grafting later. The wounds in type B dermis one-step method group were transplanted in a synchronous procedure including type B dermis (without silicone layer) and autologous skin grafting simultaneously. The bleeding, exudation, and infection of the wounds on the back in type A dermis two-step method group and type B dermis two-step method group on the 7th day after the second transplantation and in type B dermis one-step method group on the 14th day after the first transplantation were generally observed. The area of autologous skin graft was measured by the transparent film grid method, and the survival rate of autologous skin was calculated. On 4, 7, and 14 d after the first transplantation, the inflammatory cells, fibroblasts (Fbs), and capillary infiltration into the scaffolds of the three groups were detected by HE staining. On 7, 14 d after the first transplantation, the vascularization of the scaffolds was further observed by immunohistochemistry. On 28, 90 d after the first operation, the degradation of the scaffolds of type A dermis and type B dermis was observed by HE staining. Data were statistically analyzed with one-way analysis of variance, independent sample t test, and Bonferroni correction. Results: A large number of round and oval micropores were evenly distributed on the surface of type A scaffold, and the cylindrical hole walls could be observed arranging in a parallel direction in the longitudinal section. The honeycomb briquette-shaped penetrating macropores on the surface of type B scaffold were arranged in an orderly matrix. The pore walls of the honeycomb briquette-shaped penetrating macropores were connected by micropores to form a network structure. The porosity of type A dermis was (93.21±0.72)%, which was similar to (95.88±1.00)% of type B dermis ( t =4.653, P >0.05). The degradation rates of type A dermis at 4, 8, 13, and 24 h were similar to those of type B dermis at the corresponding time point ( t =0.232, 0.856, 0.258, 7.716, P> 0.05). At 24 h after culture, the proliferation rates of L929 cells in the type A dermis group, type B dermis group, and negative control group were significantly higher than those of the positive control group ( t =2 393.46, 2 538.27, 1 077.77, P <0.01). The cytotoxicity rating of cells in positive control group was grade 4, while that of the other three groups was grade zero. On 1, 4, 7, and 14 d after inoculation, both L929 cells and HUVECs proliferated in a time-dependent manner in two kinds of dermal scaffolds. The adhesion growth and proliferation rate of the two kinds of cells on the surface of type B dermis was higher than that of type A dermis. On 7 d after inoculation, both L929 cells and HUVECs covered the surface of type B dermis and migrated into one side of the silicone layer. However, the above two kinds of cells migrated slowly into type A dermis, and only a few cells were found on one side of the silicone layer. There was no bleeding, exudation, or infection in the wounds repaired by type A and type B dermis. The survival rate of autologous skin grafting of 6 wounds in each group was 100%. On 4, 7, and 14 d after the first operation, inflammatory cells, Fbs, and capillaries gradually infiltrated into the scaffold layer, and the cell infiltration rate from high to low was type B dermis one-step method group, type B dermis two-step method group, and type A dermis two-step method group. The scaffold in wound in the type B dermis one-step method group gradually collapsed on 28 d after the first operation, and completely degraded in 3 months after the first operation. The scaffold degradation rate of type A dermis two-step method group was similar to that mentioned above. Conclusions: The honeycomb briquette-shaped vertically penetrating three-dimensional porous network structure of type B scaffold can accelerate its vascularization process, which is beneficial to autogenous split-thickness skin in one-step procedure to repair full-thickness skin defects wound in Ba-Ma mini pigs. Compared with the "two-step method" of staged transplantation of type A scaffold and autologous split-thickness skin, and one-step transplantation has equal efficacy and can provide a better choice for wound treatment.

Diabetic foot ulcer (DFU) is a diabetes complication which greatly impacts the patient's quality of life, often leading to amputation of the affected limb unless there is a timely and adequate management of the patient. DFUs have a high economic impact for the national health system. Data have indeed shown that DFUs are a major cause of hospitalization for patients with diabetes. Based on that, DFUs represent a very important challenge for the national health system. Especially in developed countries diabetic patients are increasing at a very high rate and as expected, also the incidence of DFUs is increasing due to longevity of diabetic patients in the western population. Herein, the surgical approach focused on the targeted use of the acellular dermal matrix has been integrated with biochemical and morphological/histological analyses to obtain evidence-based information on the mechanisms underlying tissue regeneration. In this research report, the clinical results indicated decreased postoperative wound infection levels and a short healing time, with a sound regeneration of tissues. Here we demonstrate that the key biomarkers of wound healing process are activated at gene expression level and also synthesis of collagen I, collagen III and elastin is prompted and modulated within the 28-day period of observation. These analyses were run on five patients treated with Integra ® sheet and five treated with the injectable matrix Integra ® Flowable, for cavitary lesions. In fact, clinical evaluation of improved healing was, for the first time, supported by biochemical and histological analyses. For these reasons, the present work opens a new scenario in DFUs treatment and follow-up, laying the foundation for a tailored protocol towards complete healing in severe pathological conditions.

Wound coverage by split-thickness skin graft (SSG) and epidermal graft (EG) shortens healing time, with comparable outcomes. However, the healing mechanism of EG is not as well understood as SSG. The difference in the healing mechanisms of EG and SSG was investigated using gap junctional proteins, proliferative marker, and cytokeratin markers. Paired punch biopsies were taken from the wound edge and wound bed from patients undergoing EG and SSG at weeks 0 and 1 to investigate wound edge keratinocyte migratory activities (connexins 43, 30, and 26), wound bed activation (Ki67), and the presence of graft integration to the wound bed (cytokeratins 14 and 6). Twenty-four paired biopsies were taken at weeks 0 and 1 (EG, n = 12; SSG, n = 12). Wound edge biopsies demonstrated down-regulation of connexins 43 (P = .023) and 30 (P = .027) after EG, indicating accelerated healing from the wound edge. At week 1, increased expression of Ki67 (P < .05) was seen after EG, indicating activation of cells within the wound bed. Keratinocytes expressing cytokeratins 6 and 14 were observed on all wounds treated with SSG but were absent at week 1 after EG, indicating the absence of graft integration following EG. Despite EG and SSG both being autologous skin grafts, they demonstrate different mechanisms of wound healing. EG accelerates wound healing from the wound edges and activates the wound bed despite not integrating into the wound bed at week 1 post-grafting as opposed to SSG, hence demonstrating properties comparable with a bioactive dressing instead of a skin substitute., (© 2021 The Authors. International Wound Journal published by Medicalhelplines.com Inc (3M) and John Wiley & Sons Ltd.)

This article discusses the effects of ageing on the skin, particularly the main structural and functional changes that occur in the epidermis and dermis that make the skin more vulnerable to damage. Specific alterations that occur with ageing include slower epidermal turnover, flattening of the epidermal-dermal junction, loss of moisture and hydration as well as reduced immunity placing the skin at increased risk of damage. The discussion will also examine common periwound complications associated with ageing including; maceration, excoriation, dry skin, hyperkeratosis, callus, contact dermatitis and eczema. Strategies to manage these problems and interventions to reduce the risk of these complications include moisturising the skin to make it more resilient, debriding keratinised and callus tissue in the periwound area, appropriate choice of dressings to manage excessive exudate, careful removal of dressings as well as treating inflammatory conditions of the periwound skin.

Objective: The extracellular matrix (ECM) is one of the most important elements in wound healing. Absence or dysfunction of the ECM may impair wound healing. The application of acellular dermal matrix (ADM) as a substitute for ECM has been suggested. This study investigated the clinical application and wound healing effects of a paste-type ADM in patients presenting with hard-to-heal wounds due to various causes., Method: Patients with a hard-to-heal wound for >1 month, from September 2017 to February 2019, were included in this study. After debridement, the paste-type ADM was applied, at zero (baseline), two and four weeks. After application of the paste-type ADM, a conventional dressing was applied using polyurethane foam. Wound size, the formation of granulation tissue, re-epithelialisation, complete healing and adverse events were recorded at zero (baseline), one, two, four, eight and 12 weeks after the initial treatment., Results: A total of 18 patients took part (eight male, 10 female, mean age of 56±16.16 years). The mean wound area decreased from 17.42±10.04cm 2 to 12.73±7.60cm 2 by week one (p<0.05), to 10.16±7.00 by week two (p<0.0005), to 5.56±5.25 by week four (p<0.0001), to 2.77±5.15 by week eight (p<0.0001) and to 2.07±4.78 by week 12 (p<0.0001). The number of patients with >75% re-epithelialisation increased from two (11.1%) at two weeks to five (27.8%) at four weeks, to 11 (61.1%) at eight weeks and to 13 (72.2%) at 12 weeks. The number of patients showing complete wound healing was two (11.1%) at four weeks, nine (50.0%) at eight weeks and 12 (66.7%) at 12 weeks. No adverse events were reported during treatment., Conclusion: The paste-type ADM used in this study is a viable option for facilitating wound healing; it can shorten hospitalisation, and promote a faster recovery and return to normal life activities.

Acellular matrix is a type of promising biomaterial for wound healing promotion. Although acellular bovine and porcine tissues have proven effective, religious restrictions and risks of disease transmission remain barriers to their clinical use. Acellular fish skin (AFS), given its similarity to human skin structure and without the aforementioned disadvantages, is thus seen as an attractive alternative. This study aims to fabricate AFS from the skin of black carp ( Mylopharyngodon piceus ), evaluate its physical and mechanical properties and assess its impact on wound healing. The results showed that AFS has a highly porous structure, along with high levels of hydrophilicity, water-absorption property and permeability. Furthermore, physical characterization showed the high tensile strength of AFS in dry and wet states, and high stitch tear resistance, indicating great potential in clinical applications. Cell Counting Kit-8 was used to test the viability of L929 cells when culturing in the extracts of AFS. Compared with the control group, there is no significant difference in optical density value when culturing in the extracts of AFS at days 1, 3 and 7 (* p > 0.05). In vivo wound healing evaluation then highlighted its promotion of angiogenesis and collagen synthesis, its function in anti-inflammation and acceleration in wound healing. Therefore, this study suggests that AFS has potential as a promising alternative to mammal-derived or traditional wound dressing., (© 2021 IOP Publishing Ltd.)

Natural products such as honey, rosemary and chamomile oils have many health benefits particularly skin regeneration. These products were previously examined individually as enhancer of skin wound healing. The purpose of this study was to evaluate the clinical and histopathological features associated with using a mixture of rosemary and chamomile oils with honey, as a composite, in healing of equine-skin wounds experimentally and clinically. For experimental and clinical evaluation 15 donkeys and 122 clinical cases were used, respectively. For the experimental part, animals were divided into five equal groups. In each animal one skin wound was created bilaterally on the back region. All left-side wounds were treated with saline. Right-side wounds were treated with one of the following treatments, gentamycin, zinc, Kruuse Manuka, Revan and the composite ointments. Each wound treated once daily until one of the wounds healed completely. wounds were evaluated grossly and histopathologically. In clinical cases, wounds were dressed with the composite once daily and monitored until healing. Experimentally induced wounds treated with the composite were healed firstly, while all other wounds were still opened. Histologically, the skin of the composite treated wounds regenerated completely and efficiently. While the skin of the other wounds, showing incomplete regeneration of epidermis and dermis. Under field condition, the composite accelerates healing of different forms of equine wounds. The tested composite induce efficient and rapid skin regeneration., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Wound healing is a complex and critical process, which includes three stages: inflammation, proliferation, and remodeling. The epidermal cells are precisely regulated in this process. On one hand, keratinocytes around the wound edge migrate and proliferate to form a new basement membrane to cover the wound. On the other hand, the epidermal stem cells are activated with the proliferation and differentiation being enhanced, and the terminal differentiation and apoptosis being inhibited; and together with keratinocytes, epidermal stem cells promote the process of re-epithelialization under the regulation of various factors. In the epidermis, there is a group of resident T cell subsets, dendritic epidermal lymphocytes (DETCs) that play a key role in protecting the function of epidermal tissue. DETCs are activated after recognizing unknown antigens, the activated DETCs secret cytokines such as insulin-like growth factor Ⅰ, keratinocyte growth factor-1/2, granulocyte-macrophage colony stimulating factor, interferon-γ, and transforming growth factor-β, which promote epidermal homeostasis and re-epithelialization by regulating the dynamic balance among keratinocytes migration, proliferation, and apoptosis, and the differentiation of epidermal stem cells around the wound edge. This article discusses the biological characteristics of DETCs and their roles in the maintenance of epidermal homeostasis and wound healing.

Objective: The presence of sub-epidermal moisture (SEM) over a bony prominence is indicative of incipient pressure ulcer (pressure injury/decubitus/bedsore) (PU). Early identification of patients at increased risk of PU can prompt interventions that reduce the incidence and severity of hospital (or community)-acquired PUs (HAPUs). This study evaluated the clinical utility of a SEM Scanner device in HAPU management., Method: The study used a pragmatic 'real-world' approach. HAPU data before and during SEM Scanner use were obtained through routine audit. Patients had regular visual and daily SEM Scanner skin assessments over the sacrum and heels. Nursing care otherwise followed standard of care according to the established protocols of individual participating sites. HAPU incidence rates were determined and feedback gathered from health professionals on how the device influenced HAPU-related clinical decision-making., Results: There were 15 participating sites: 13 acute care, one palliative care and one community care setting. The sample size was 1478 patients. All sites reported a substantial reduction in mean HAPU incidence: 87.2% in acute care settings; 46.7% in the palliative care setting and 26.7% in the community care setting. A 100% incidence reduction was reported in 10 (66.7%) sites. In the palliative care setting, SEM Scanner results changed HAPU-related clinical decision-making for 40% of patients scanned. The community care site demonstrated a 82% change in clinical decision-making., Conclusion: In this study, SEM analysis fitted seamlessly into routine skin assessment and enabled early identification of increased risk of tissue damage, with clinically important reductions in the incidence of HAPU across all participating sites.

Thermal injuries are caused by exposure to a variety of sources, and split thickness skin grafts are the gold standard treatment for severe burns; however, they may be impossible when there is no donor skin available. Large total body surface area burns leave patients with limited donor site availability and create a need for treatments capable of achieving early and complete coverage that can also retain normal skin function. In this preclinical trial, two cellular and tissue based products (CTPs) are evaluated on twenty-four 5 × 5 deep partial thickness (DPT) burn wounds. Using appropriate pain control methods, DPT burn wounds were created on six anesthetized Yorkshire pigs. Wounds were excised one day post-burn and the bleeding wound beds were subsequently treated with omega-3-rich acellular fish skin graft (FSG) or fetal bovine dermis (FBD). FSG was reapplied after 7 days and wounds healed via secondary intentions. Digital images, non-invasive measurements, and punch biopsies were acquired during rechecks performed on days 7, 14, 21, 28, 45, and 60. Multiple qualitative measurements were also employed, including re-epithelialization, contraction rates, hydration, laser speckle, and trans-epidermal water loss (TEWL). Each treatment produced granulated tissue (GT) that would be receptive to skin grafts, if desired; however, the FSG induced GT 7 days earlier. FSG treatment resulted in faster re-epithelialization and reduced wound size at day 14 compared to FBD (50.2% vs. 23.5% and 93.1% vs. 106.7%, p < 0.005, respectively). No differences in TEWL measurements were observed. The FSG integrated into the wound bed quicker as evidenced by lower hydration values at day 21 (309.7 vs. 2500.4 µS, p < 0.05) and higher blood flow at day 14 (4.9 vs. 3.1 fold change increase over normal skin, p < 0.005). Here we show that FSG integrated faster without increased contraction, resulting in quicker wound closure without skin graft application which suggests FSG improved burn wound healing over FBD.

The skin is a critical barrier that protects against damage and infection. Within the epidermis and dermis reside γδ T cells that play a variety of key roles in wound healing and tissue homeostasis. Skin-resident γδ T cells require T cell receptor (TCR) ligation, costimulation, and cytokine reception to mediate keratinocyte activity and inflammatory responses at the wound site for proper wound repair. While both epidermal and dermal γδ T cells regulate inflammatory responses in wound healing, the timing and factors produced are distinct. In the absence of growth factors, cytokines, and chemokines produced by γδ T cells, wound repair is negatively impacted. This disruption in γδ T cell function is apparent in metabolic diseases such as obesity and type 2 diabetes. This review provides the current state of knowledge on skin γδ T cell activation, regulation, and function in skin homeostasis and repair in mice and humans. As we uncover more about the complex roles played by γδ T cells in wound healing, novel targets can be discovered for future clinical therapies.

A complex skin structure (such as a nipple) can be successfully decellularized under conditions that prevent extracellular matrix crosslinking or undue matrix degradation [1]. This treatment removes cellular antigens, thus mitigating immunorejection concerns and enabling allogeneic transplantation for nipple reconstruction after mastectomy. Non-human primate studies have shown that host-mediated re-vascularization and re-epithelization of the decellularized nipples occurs within six weeks and nipple projection is maintained over the same timeframe [1]. The mechanisms by which a decellularized graft located on the surface of the body heals are incompletely understood, but are likely to follow a similar path to decellularized allografts that are implanted within the body, with some modifications. The following is a description of probable temporal events leading to healing under this circumstance., Competing Interests: Declaration of competing interest Both Drs. Johnson and Klein are Consultants to Bioaesthestics, Inc., which funded this work., (Copyright © 2020 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Impaired skin regeneration in chronic wounds like in diabetes corresponds to high oxidative stress, poor angiogenesis and insufficient collagen hyperplasia. Therefore, a multifaceted strategy for treatment is required to address critical issues associated with chronic wound healing. Fascinating application of nanomaterials in chronic wounds is still limited; hence, in the present work bioactive solubilized decellularized dermal matrix (sADM) was employed to form a hydrogel with chitosan (CTS) at physiological pH/temperature and modified with reactive oxygen species (ROS) scavenging carbon nanodots (ND). A detailed in vitro investigation found that the ND modified bioactive hydrogel (CsADMND) is suitable for human amniotic membrane derived stem cell (hAMSC) delivery. Also, CsADMND was observed to possess a good ROS scavenging property, hemocompatibility and pro-angiogenic potential as demonstrated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), haemolysis and chick chorioallantoic membrane (CAM) assay, respectively. The hybrid hydrogel promoted migration of cells in vitro in scratch assay owing to its antioxidant potential and the presence of bioactive moieties. Further, its efficacy in healing full thickness (FT) chronic wounds was evaluated in a streptozotocin (STZ) induced diabetic model. The CsADMND hydrogel after association with hAMSCs led to stimulation of early angiogenesis, superior collagen deposition, rapid wound closure, complete reepithelialisation, and formation of distinct organized dermal epidermal junctions (DEJ) post 21 days of healing. These results suggest that the hAMSC laden CsADMND hydrogel may serve as a promising therapeutic strategy for the management of chronic wounds.

Objective: To explore the mechanism of dendritic epidermal T lymphocytes (DETCs) in promoting healing of full-thickness skin defect wound on mice by regulating the proliferation and differentiation of epidermal stem cells (ESCs) in mice. Methods: (1) Ten 8-week-old wild type (WT) male C57BL/6 mice (the same sex and kind below) were sacrificed to collect the skin of back for extracting DETCs to culture. Five WT and five 8-week-old T cell receptor (TCR) δ(-)/(-) mice were selected and enrolled in WT control group and TCR δ(-)/(-) control group, respectively. A full-thickness skin defect wound with diameter of 6 mm was made on both sides of spinal line on the back of mice without any treatment after injury. Another fifteen 8-week-old TCR δ(-)/(-) mice were selected and divided into phosphate buffer solution (PBS), DETC, and insulin-like growth factor-Ⅰ(IGF-Ⅰ) groups according to the random number table (the same grouping method below), with 5 mice in each group, and the same full-thickness skin defect wound was made on each mouse. Immediately after injury, mice in PBS, DETC, and IGF-Ⅰ groups were injected subcutaneously around each wound with 10 μL sterile PBS , DETCs (cell concentration of 1×10(6)/mL), and 5 mg/mL recombinant mice IGF-Ⅰ, respectively. The percentage of the residual wound area was calculated on post injury day (PID) 2, 4, 6, and 8. (2) Three 8-week-old WT mice were enrolled in WT control group and nine 8-week-old TCR δ(-)/(-) mice were divided into TCR δ(-)/(-) control group, PBS group, and DETC group, with 3 mice in each group. The full-thickness skin defect wound was made as in experiment (1) . On PID 3, the protein expression of IGF-Ⅰ in the epidermis tissue of wound margin was detected by chemiluminescence imaging analyzer. (3) Three 8-week-old WT mice were enrolled in WT control group and six 8-week-old TCR δ(-)/(-) mice were divided into PBS and DETC groups, with 3 mice in each group, and the full-thickness skin defect wound was made as in experiment (1). On PID3, DETCs were extracted from the wound margin epidermis tissue to detect the percentage of DETCs expressing IGF-Ⅰ by flow cytometer. (4) The mice were taken as in experiment (2) and divided into WT control, PBS, DETC, and IGF-Ⅰ groups. A straight full-thickness skin defect incision with length of 3 cm was made in the direction of one inner ear. Mice in WT control group didn't have any other treatment after injury, and immediately after injury, mice in PBS, DETC, and IGF-Ⅰ groups were injected subcutaneously around each wound with 10 μL sterile PBS, DETCs (cell concentration of 1×10(6)/mL), and 5 mg/mL recombinant mice IGF-Ⅰ, respectively. On PID 12, epidermis tissue of wound margin was collected, and immunofluorescence staining was performed to observe the number of keratin 15 positive cells. (5) The same mice were collected, grouped, and treated as in experiment (4). On PID12, the epidermis tissue of wound margin was collected and immunofluorescence staining was performed to observe the number of keratin 10 positive cells. (6) Twenty 3-day-old WT mice (the same below) were sacrificed to collect the whole skin, which was used to extract ESCs, with 5 mice detecting one index. The ESCs were divided into DETC co-culture group and control group, which were added with 1 mL DETCs (cell concentration of 1.25×10(6)/mL) and DETC medium, respectively. The percentage of 5-ethynyl-2'-deoxyuridine (EdU) positive cell on culture day (CD) 3, the percentages of CD49f(+) CD71(-) and keratin 14 positive cells on CD 5, and the percentage of keratin 10 positive cell on CD 10 in 2 groups were detected by flow cytometer. (7) Twenty mice were taken to extract ESCs, with 5 mice detecting one index. The ESCs were divided into control group and IGF-Ⅰ group, which were added with 1 mL sterile PBS and 10 ng/mL recombinant mice IGF-Ⅰ, respectively. The percentages of EdU positive cell, CD49f(+) CD71(-) cell, keratin10 positive cell, and keratin 14 positive cell were detected as in experiment (6). The sample in each group of experiments (6) and (7) was three. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and t test. Results: (1) On PID 4, 6, and 8, the percentage of residual wound area in TCR δ(-)/(-) control group was significantly higher than that in WT control group ( t =2.78, 3.39, 3.66, P <0.05 or P <0.01). The percentage of residual wound area in DETC group and IGF-Ⅰgroup on PID 4, 6, and 8 was apparently lower than that in PBS group ( t =2.61, 3.21, 3.88, 2.84, 2.91, 2.49, P <0.05 or P <0.01). (2) On PID 3, the protein expression of IGF-Ⅰ in the epidermis tissue of wound margin of mice in TCR δ(-)/(-) control group was significantly lower than that in WT control group ( t =17.34, P <0.01). The protein expression of IGF-Ⅰ in the epidermis tissue of wound margin of mice in DETC group was significantly higher than that in PBS group ( t =11.71, P <0.01). (3) On PID 3, the percentage of DETCs expressing IGF-Ⅰ in the epidermis tissue of wound margin of mice in PBS group was significantly lower than that in WT control group and DETC group ( t =24.95, 27.23, P <0.01). (4) On PID 12, the number of keratin 15 positive cells in the epidermis tissue of wound margin of mice in PBS group was significantly lower than that in WT control group, DETC group, and IGF-Ⅰ group ( t =17.97, 11.95, 7.63, P <0.01). (5) The number of keratin 10 positive cells in the epidermis tissue of wound margin of mice in PBS group was significantly higher than that in WT control group, DETC group, and IGF-Ⅰ group ( t =11.59, 9.51, 3.48, P <0.05 or P <0.01). (6) The percentages of EdU positive cells on CD 3, CD49f(+) CD71(-) cells on CD 5, and keratin 14 positive cells on CD 5 in DETC co-culture group were respectively (43.5±0.6)%, (66.5±0.5)%, (69.3±1.7)%, apparently higher than (32.3±1.3)%, (56.4±0.3)%, (54.9±1.3)% in control group ( t =7.97, 17.10, 6.66, P <0.01). The percentage of keratin 10 positive cells on CD 10 in DETC co-culture group was (55.7±0.7)%, significantly lower than (67.1±1.2)% in control group ( t =8.34, P <0.01). (7) The percentages of EdU positive cells on CD 3, CD49f(+) CD71(-) cells on CD 5, and keratin 14 positive cells on CD 5 in IGF-Ⅰ group were respectively (42.1±0.9)%, (81.1±1.3)%, (66.8±1.0)%, apparently higher than (32.4±0.7)%, (74.9±0.7)%, (52.0±1.9)% in control group ( t =8.39, 4.24, 7.25, P <0.05 or P <0.01). The percentage of keratin 10 positive cells on CD 10 in IGF-Ⅰ group was (53.5±1.1)% , significantly lower than (58.2±0.3)% in control group ( t =3.99, P <0.05). Conclusions: DETCs can promote the proliferation and anti-apoptotic potential of ESCs and inhibit their differentiation into end-stage by secreting IGF-Ⅰ, thus promoting wound healing of full-thickness skin defects in mice.

The mechanism underlying the effect of bioelectric field on wound healing in vivo has not been previously investigated. Here, we aimed to investigate the effects of an applied electric field (EF) on epidermal cell migration during wound healing. Using a Bama miniature pig wound model, we applied a power-up device (negative electrode in the wound centre and positive electrode around the wound) with pulsed electrical power, to apply a continuous, stable, and tolerable EF to the wound and provide directional signals for keratinocyte migration towards the wound centre. An EF of 100 mV/mm applied in the same direction as the bioelectric field accelerated wound healing. The keratinocytes exhibited regular and similar shapes, uniform arrangement, and an organised migration pattern. In contrast, 100 mV/mm applied countercurrent to the bioelectric field, delayed wound healing and hindered the keratinocyte migration towards the wound centre. Further, the cells were disorganised, misshapen, irregular, and disoriented. Via the application of a directional stable EF, this study morphologically identified the relationships among wound EF, keratinocyte migration, and wound healing and established theoretical and empirical foundations for the clinical application of bioelectric fields., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Dermal fibroblasts exhibit considerable heterogeneity during homeostasis and in response to injury. Defining lineage origins of reparative fibroblasts and regulatory programs that drive fibrosis or, conversely, promote regeneration will be essential for improving healing outcomes. Using complementary fate-mapping approaches, we show that hair follicle mesenchymal progenitors make limited contributions to wound repair. In contrast, extrafollicular progenitors marked by the quiescence-associated factor Hic1 generated the bulk of reparative fibroblasts and exhibited functional divergence, mediating regeneration in the center of the wound neodermis and scar formation in the periphery. Single-cell RNA-seq revealed unique transcriptional, regulatory, and epithelial-mesenchymal crosstalk signatures that enabled mesenchymal competence for regeneration. Integration with scATAC-seq highlighted changes in chromatin accessibility within regeneration-associated loci. Finally, pharmacological modulation of RUNX1 and retinoic acid signaling or genetic deletion of Hic1 within wound-activated fibroblasts was sufficient to modulate healing outcomes, suggesting that reparative fibroblasts have latent but modifiable regenerative capacity., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Nonhealing wounds can be a major clinical problem. Impaired wound healing is often related to massive tissue injury, concomitant wound healing deficiencies (chronic wounds), burn injury, or congenital conditions. We propose a novel biological dressing as an alternative surgical approach. The dressing is a form of an allogenic human skin graft equivalent with further use of allogeneic stem cells classified as an advanced therapy medicinal product. This new allogenic acellular human skin graft has been specifically developed to address the clinical indications for dressing wound lesions and promoting tissue repair in specific rare genetic diseases., Methods: This case report illustrates the use of an acellular human skin allograft seeded with multipotent stem cells in the treatment of tissue injuries (burns), congenital conditions, and chronic wounds. Donor-tissue processing yields an acellular dermal matrix with integral collagen bundling and organization, as well as an intact basement membrane complex., Results: Preclinical observations show prolonged viability of acellular human skin grafts with multipotent stem cells. This was confirmed with histological and electron-microscopic evaluation of biopsies, which demonstrated host-cell infiltration and neovascularization of the biological dressing. Moreover, the dressings were characterized by low immunogenicity, as confirmed by histology exam and T-cell proliferation assays in vitro., Conclusion: Our data confirmed the safety and efficacy of the evaluated acellular human skin grafts, which may be used in patients with rare diseases, such as epidermolysis bullosa, burn injuries, and chronic wounds., (Copyright © 2020. Published by Elsevier Inc.)

Pelnac Gplus Ⓡ , Integra Ⓡ , and Terudermis Ⓡ are approved artificial dermis products in Japan. Previously, we proved that Pelnac Gplus Ⓡ was able to sustain basic fibroblast growth factor (bFGF) and accelerated wound healing by releasing impregnated bFGF. In this study, we impregnated Pelnac Gplus Ⓡ , Integra Ⓡ , and Terudermis Ⓡ with bFGF and compared the binding activity and wound-healing process. We applied bFGF to each material and compared the bFGF concentrations in the surrounding area after 24-h incubation. For the in vivo study, dermal substitutes were impregnated with bFGF and implanted into full-thickness wounds of BKS.Cg-+Leprdb/+Leprdb/Jcl mice. Wounds were evaluated at days 7, 14, and 21 after implantation. The in vitro study showed that bFGF is strongly bound to Integra Ⓡ , followed by Pelnac Gplus Ⓡ and Terudermis Ⓡ . The in vivo study showed that fibroblasts and capillaries had infiltrated into the Pelnac Gplus Ⓡ but not the Integra Ⓡ or Terudermis Ⓡ . Furthermore, long epithelium and wide granulation tissue were formed in the Pelnac Gplus Ⓡ with bFGF group. The Terudermis Ⓡ with bFGF group had more capillaries than other groups, but only at the base of the wound. The combination of Pelnac Gplus Ⓡ with bFGF may be a novel approach for treating full-thickness skin defects or chronic skin ulcers., Competing Interests: Conflict of interest This research was supported partially by the research promotion grant of Kansai Medical University and partially funded by grants for research received from Gunze Ltd. The funder had no role in study design, data collection, and analysis, decision to publish, or preparation of the manuscript., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Background and objectives : Skin grafting is a method usually used in reconstructive surgery to accelerate skin regeneration. This method results frequently in unexpected scar formations. We previously showed that cutaneous wound-healing in normal mice is accelerated by a micrograft (MG) technique. Presently, clinical trials have been performed utilizing this technology; however, the driving mechanisms behind the beneficial effects of this approach remain unclear. In the present study, we focused on five major tissue reactions in wound-healing, namely, regeneration, migration, granulation, neovascularization and contraction. Methods: Morphometrical analysis was performed using tissue samples from the dorsal wounds of mice. Granulation tissue formation, neovascularization and epithelial healing were examined. Results: The wound area correlated well with granulation sizes and neovascularization densities in the granulation tissue. Vascular distribution analysis in the granulation tissue indicated that neovessels extended and reached the subepidermal area in the MG group but was only halfway developed in the control group. Moreover, epithelialization with regeneration and migration was augmented by MG. Myofibroblast is a known machinery for wound contraction that uses α-smooth muscle actin filaments. Their distribution in the granulation tissue was primarily found beneath the regenerated epithelium and was significantly progressed in the MG group. Conclusions: These findings indicated that MG accelerated a series of wound-healing reactions and could be useful for treating intractable wounds in clinical situations.

Tissue fibrosis is the deposition of excessive extracellular matrix and can occur as part of the body's natural wound healing process upon injury, or as a consequence of diseases such as systemic sclerosis. Skin fibrosis contributes to significant morbidity due to the prevalence of injuries resulting from trauma and burn. Fibroblasts, the principal cells of the dermis, synthesize extracellular matrix to maintain the skin during homeostasis and also play a pivotal role in all stages of wound healing. Although it was previously believed that fibroblasts are homogeneous and mostly quiescent cells, it has become increasingly recognized that numerous fibroblast subtypes with unique functions and morphologies exist. This Review provides an overview of fibroblast heterogeneity in the mammalian dermis. We explain how fibroblast identity relates to their developmental origin, anatomical site and precise location within the skin tissue architecture in both human and mouse dermis. We discuss current evidence for the varied functionality of fibroblasts within the dermis and the relationships between fibroblast subtypes, and explain the current understanding of how fibroblast subpopulations may be controlled through transcriptional regulatory networks and paracrine communications. We consider how fibroblast heterogeneity can influence wound healing and fibrosis, and how insight into fibroblast heterogeneity could lead to novel therapeutic developments and targets for skin fibrosis. Finally, we contemplate how future studies should be shaped to implement knowledge of fibroblast heterogeneity into clinical practice in order to lessen the burden of skin fibrosis., Competing Interests: Competing interestsThe authors declare no competing or financial interests., (© 2020. Published by The Company of Biologists Ltd.)

Reactive Skin Decontamination Lotion (RSDL ® ) is an FDA-approved skin decontamination kit carried by service members for removal and neutralisation of vesicants and nerve agents. The RSDL kit, comprised of a lotion-impregnated sponge, was shown to be the superior medical decontamination device for chemical warfare agent (CWA) exposure on intact skin. In the event of a chemical exposure situation (i.e. terrorism, battlefield) physical injuries are probable, and preservation of life will outweigh the risk associated with application of RSDL to compromised skin. The purpose of this study was to quantify the rate and quality of wound healing in epidermal skin wounds treated with RSDL in a porcine model. Degree of wound healing was assessed using bioengineering methods to include ballistometry, colorimetry, evaporimetry, and high-frequency ultrasonography. Clinical observation, histopathology and immunohistochemistry were also utilised. All pigs received four bilateral superficial abdominal wounds via a pneumatic dermatome on their ventral abdomen, then were treated with the following dressings over a seven-day period: RSDL sponge, petroleum based Xeroform ® gauze, 3 M™ Tegaderm™ Film, and 3 M™ Tegaderm™ Foam. Two additional non-wounded sites on the flank were used as controls. Two groups of pigs were then evaluated for a 21- or 56-day time period, representing short- and long-term wound-healing progression. Our findings indicated RSDL had a negative impact on wound-healing progression at both 21 and 56 days post-injury. Wounds receiving RSDL demonstrated a decreased skin elasticity, significant transepidermal water loss, and altered skin colouration and thickness. In addition, the rate of wound healing was delayed, and return to a functional skin barrier was altered when compared to non-RSDL-treated wounds. In conclusion, wound management care and clinical therapeutic intervention plans should be established to account for a prolonged duration of healing in patients with RSDL-contaminated wounds.

Silk fibroin (SF), which offers the benefits of biosafety, biocompatibility, and mechanical strength, has potential for use as a good biomedical material, especially in the tissue engineering field. This study investigated the use of SF biomaterials as a wound dressing compared to commercially available collagen materials. After human fibroblasts (WI-38) were cultured on both films and sponges, their cell motilities and gene expressions related to wound repair and tissue reconstruction were evaluated. Compared to the collagen film (Col film), the SF film induced higher cell motility; higher expressions of genes were observed on the SF film. Extracellular matrix production-related genes were up-regulated in WI-38 fibroblasts cultured on the SF sponges. These results suggest that SF-based biomaterials can accelerate wound healing and tissue reconstruction. They can be useful biomaterials for functional wound dressings.

An inadequate response from macrophages, key orchestrators of the wound healing process, has been implicated in the pathophysiology of impaired healing in diabetes. This study explored the utility of nanoparticles presenting the α-gal (Galα1-3Galβ1-4GlcNAc-R) epitope to induce anti-Gal antibody-mediated local transient recruitment of macrophages to accelerate wound closure and healing in a diabetic murine model. α1,3galactosyltrasferase knockout mice were stimulated to produce anti-Gal antibodies and subsequently diabetes was induced by streptozotocin-induced β-cell destruction. Six mm full-thickness skin wounds were made and α-gal nanoparticles (AGN) were topically applied on postwounding days 0 and 1. Wounds were analysed histologically for macrophage invasion and markers of wound healing, including epithelialization, vascularization and granulation tissue deposition through postoperative day 12. We found that application of AGN transiently but significantly increased macrophage recruitment into the wounds of diabetic mice. Treated wounds demonstrated more rapid closure and enhanced wound healing as demonstrated by significantly accelerated rates of epithelialization, vascularization and granulation tissue deposition. Thus, topical treatment of full-thickness wounds in diabetic mice with α-gal nanoparticles induced a transient but significant increase in macrophage recruitment resulting in an accelerated rate of wound healing. Using α-gal nanoparticles as a topical wound healing adjunct is a simple, safe and effective means of augmenting dysregulated macrophage recruitment present in the diabetic state., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Platelets are a recognised potent source of transforming growth factor-β1 (TGFβ1), a cytokine known to promote wound healing and regeneration by stimulating dermal fibroblast proliferation and extracellular matrix deposition. Platelet lysate has been advocated as a novel personalised therapeutic to treat persistent wounds, although the precise platelet-derived growth factors responsible for these beneficial effects have not been fully elucidated. The aim of this study was to investigate the specific role of platelet-derived TGFβ1 in cutaneous wound healing. Using a transgenic mouse with a targeted deletion of TGFβ1 in megakaryocytes and platelets (TGFβ1 fl/fl .PF4-Cre), we show for the first time that platelet-derived TGFβ1 contributes to epidermal and dermal thickening and cellular turnover after excisional skin wounding. In vitro studies demonstrate that human dermal fibroblasts stimulated with platelet lysate containing high levels of platelet-derived TGFβ1 did not exhibit enhanced collagen deposition or proliferation, suggesting that platelet-derived TGFβ1 is not a key promoter of these wound healing processes. Interestingly, human keratinocytes displayed enhanced TGFβ1-driven proliferation in response to platelet lysate, reminiscent of our in vivo findings. In summary, our novel findings define and emphasise an important role of platelet-derived TGFβ1 in epidermal remodelling and regeneration processes during cutaneous wound healing., (© 2020 The Authors. Journal of Tissue Engineering and Regenerative Medicine published by John Wiley & Sons Ltd.)

Background: Various methods were introduced to overcome the autograft shortage in burn wound care, including cell transplantation and tissue engineering., Aims: To evaluate the healing effect of allogenic human Wharton's jelly stem cells (hWJSCs) seeded onto acellular dermal matrix (ADM) in rat burn injuries., Patients and Methods: Human Wharton's jelly stem cells provided from umbilical cord tissue were characterized before transplantation, and the growth kinetic was determined. Skin samples from cosmetic surgeries were used for preparation of ADM. Forty male Sprague Dawley rats were randomly divided into 4 equal groups. Third-degree burn was induced for all animals by exposing to hot water using a 2 cm ring for 10 seconds. Group 1 was burned rats that did not receive any treatment. After burn injury, the second group received silver sulfadiazine (SSD), the third group was treated just by using ADM, and the fourth group received 2 × 10 6 hWJSCs seeded onto ADM. The animals were euthanized for histologic evaluation after 7, 14, and 21 days., Results: Human Wharton's jelly stem cells were characterized to be spindle shape and positive for osteogenic and adipogenic induction and for mesenchymal markers but lacked hematopoietic markers. Population doubling time (PDT) was 40.1 hours with an increasing growth trend until day 6th. Macro- and microscopically, the healing was mild in ADM group and moderate in ADM + hWJSCs group after 21 days., Conclusion: Allogenic hWJSCs seeded onto ADM improved the healing process in burn wounds denoting to their therapeutic and anti-inflammatory effects in burn wounds that can be added to the literature., (© 2019 Wiley Periodicals, Inc.)

Objective: Activation of epidermal stem cells (EpSCs) from their quiescent niche is an integral component of wound reepithelialization and involves Wnt/β-catenin (β-Cat) signaling and remodeling of the actin cytoskeleton. The aim of this study was to investigate the effect of Flightless I (Flii), a cytoskeletal protein and inhibitor of wound healing, on EpSC activation during wound repair. Approach: Genetically modified Flii mice ( Flii knockdown: Flii +/- , wild type: WT, Flii overexpressing: Flii Tg/Tg ) received two incisional wounds along the lateral axis of the dorsal skin. Indicators of EpSC activation (epidermal growth factor receptor 1 [EGFR1], leucine-rich repeats and immunoglobulin-like domains-1 [Lrig1], K14), Wnt/β-Cat signaling (Lgr6, Flap2, β-Cat, and axis inhibition protein 2 [Axin2]), and cell proliferation (proliferating cell nuclear antigen [PCNA]) were assessed using immunohistochemistry. β-Cat stabilization was examined using western blotting with cell cycling and differentiation of isolated CD34 + ITGA6 high EpSCs examined using real time-quantitative polymerase chain reaction after treatment with wound-conditioned media. Results: Flii +/- led to increased numbers of activated EpSCs expressing PCNA, elevated EGFR1, and decreased Lrig1. EpSCs in Flii +/- hair follicle niches adjacent to the wounds also showed expression of Wnt-activation markers including increased β-Cat and Lgr6, and decreased Axin2. EpSCs (CD34 + ITGA6 high ) isolated from Flii +/- unwounded skin showed elevated expression of cell-cycling genes including ΔNp63, filaggrin ( Fila ) , involucrin ( Invo ) , cyclin D1 ( Ccnd1 ), and cell-division cycle protein-20 ( Cdc20 ); and elevated ΔNp63 and Invo after treatment with wound-conditioned media compared with WT and Flii Tg/Tg counterparts. Innovation: Flii was identified as an inhibitor of EpSC activation that may explain its negative effects on wound reepithelialization. Conclusion: Flii may inhibit EpSC activation by interrupting Wnt/β-Cat signaling. Strategies that reduce Flii may increase activation of EpSCs and promote reepithelialization of wounds., Competing Interests: The content of this study was exclusively contributed and written by the authors listed. No ghost writers were involved in the completion of this article., (Copyright © 2020 by Mary Ann Liebert, Inc., publishers.)

Our knowledge of transcriptional heterogeneities in epithelial stem and progenitor cell compartments is limited. Epidermal basal cells sustain cutaneous tissue maintenance and drive wound healing. Previous studies have probed basal cell heterogeneity in stem and progenitor potential, but a comprehensive dissection of basal cell dynamics during differentiation is lacking. Using single-cell RNA sequencing coupled with RNAScope and fluorescence lifetime imaging, we identify three non-proliferative and one proliferative basal cell state in homeostatic skin that differ in metabolic preference and become spatially partitioned during wound re-epithelialization. Pseudotemporal trajectory and RNA velocity analyses predict a quasi-linear differentiation hierarchy where basal cells progress from Col17a1 Hi /Trp63 Hi state to early-response state, proliferate at the juncture of these two states, or become growth arrested before differentiating into spinous cells. Wound healing induces plasticity manifested by dynamic basal-spinous interconversions at multiple basal transcriptional states. Our study provides a systematic view of epidermal cellular dynamics, supporting a revised "hierarchical-lineage" model of homeostasis., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

Acellular fish skin (ACS) has emerged as a dermal substitute used to promote wound healing with decreased scar formation and pain relief that may be due to polyunsaturated fatty acid (PUFA) content. However, the PUFA content of ACS is still unknown. The aim of this study was to compare the total fatty acids and lipid profiles of ACS to two bovine-based grafts and standard of care human cadaver skin (HCS). Furthermore, there was also the goal to assess the capability of ACS lipid content to enhance wound healing. The fatty acid analysis was performed with GC-FID, and an LC-MS untargeted method was developed in order to the analyse the lipid profiles of the grafts was. The enhancement of wound healing by the ACS extract was investigated in vitro on HaCat cells. Our results showed that ACS had the highest content of PUFA (27.0 ± 1.43% of their total fatty acids), followed by HCS (20.6 ± 3.9%). The two grafts of bovine origin presented insignificant PUFA amounts. The majority of the PUFAs found in ACS were omega-3, and in HCS, they were omega-6. The untargeted lipidomics analysis demonstrated that ACS grafts were characterized by phosphatidylcholine containing either 20:5 or 22:6 omega-3 PUFA. The ACS lipid extract increased the HaCat cells migration and enhanced wound closure 4 hr earlier versus control. Our study demonstrated that ACS has a lipid profile that is distinct from other wound healing grafts, that PUFAs are maintained in ACS post-processing as phosphatidylcholine, and that ACS lipid content influences wound healing properties., (© 2019 John Wiley & Sons, Ltd.)

Background: Acellular matrix (AM) therapy has shown promise in the treatment of diabetic foot ulcers (DFUs) in several studies. The clinical effects of AM therapy were not well established. Therefore, we conducted a meta-analysis of randomized clinical trials (RCTs) to examine the efficacy and safety of AM therapy for patients with DFUs., Methods: A literature search of 5 databases was performed to identify RCTs comparing AM therapy to standard therapy (ST) in patients with DFUs. The primary outcome was the complete healing rate and the secondary outcomes mainly included time to complete healing and adverse events., Results: Nine RCTs involving 897 patients were included. Compared with ST group, patients allocated to AM group had a higher complete healing rate both at 12 weeks (risk ratio (RR) = 1.73, 95% confidence interval (CI): 1.31 to 2.30) and 16 weeks (RR = 1.56, 95% CI: 1.28 to 1.91), a shorter time to complete healing (mean difference (MD) = -2.41; 95% CI: -3.49 to -1.32), and fewer adverse events (RR = 0.64, 95% CI: 0.44 to 0.93)., Conclusion: The present study suggests that AM therapy as an adjuvant treatment could further promote the healing of full-thickness, noninfected, and nonischemia DFUs. AM therapy also has a safety profile. More large well-designed randomized clinical trials with long follow-up duration are needed to further explore the efficacy and safety of AM therapy for DFUs., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this paper., (Copyright © 2020 Wentao Huang et al.)

The efficacy of decellularized products for healing of acute and chronic wounds mostly relies on physical and chemical properties, processing methods and host response. Human Amniotic Membrane (HAM) is considered as an effective and highly used wound dressing in clinic. According to the proposed decellularization protocols for developing of HAM, we have compared different protocols to introduce the most efficient methods, which can be used as a functional dermal matrix. In this study, different methods of HAM decellularization were used to achieve an optimal process. After achievement of appropriate decellularized method in vitro the amniotic membrane were examined in term of animal in vivo study and human clinical trial. The results of in vitro and in vivo assay indicate that the HAMs which were prepared with peracetic acid (2 M) had a significantly different in term of GAGs quantification, DNA isolation and quantification, histological assessment, collagen analysis, Cell-Tissue Interaction Study and cytotoxicity (P < 0/05). Tissue samples treated with peracetic acid (2 M) were more acceptable than that of samples prepared with other protocols in terms of preserving natural components and structure and removing of cell fragments. The peracetic acid-processed HAM was further functionally evaluated through in vivo assessments that can further lead to tissue reconstruction within the human host., (Copyright © 2019 Elsevier Inc. All rights reserved.)