A clinical evaluation of Biobrane(®) and Suprathel(®) in acute burns and reconstructive surgery

Current Approaches to Wound Repair in Burns: How far Have we Come From Cover to Close? A Narrative Review

Burn injuries are a significant global health concern, with more than 11 million people requiring medical intervention each year and approximately 180,000 deaths annually. Despite progress in health and social care, burn injuries continue to result in socioeconomic burdens for victims and their families. The management of severe burn injuries involves preventing and treating burn shock and promoting skin repair through a two-step procedure of covering and closing the wound. Currently, split-thickness/full-thickness skin autografts are the gold standard for permanent skin substitution. However, deep burns treated with split-thickness skin autografts may contract, leading to functional and appearance issues. Conversely, defects treated with full-thickness skin autografts often result in more satisfactory function and appearance. The development of tissue-engineered dermal templates has further expanded the scope of wound repair, providing scar reductive and regenerative properties that have extended their use to reconstructive surgical interventions. Although their interactions with the wound microenvironment are not fully understood, these templates have shown potential in local infection control. This narrative review discusses the current state of wound repair in burn injuries, focusing on the progress made from wound cover to wound closure and local infection control. Advancements in technology and therapies hold promise for improving the outcomes for burn injury patients. Understanding the underlying mechanisms of wound repair and tissue regeneration may provide new insights for developing more effective treatments in the future.

Multicellular bioprinted skin facilitates human-like skin architecture in vivo

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.

Outcomes of the Use of Hyaluronic Acid-Based Wound Dressings for the Treatment of Partial-Thickness Facial Burns

The purpose of this study was to assess clinical, functional and cosmetic outcomes of the use of hyaluronic acid-based wound dressings for partial-thickness facial burns. Patients with partial-thickness facial burns hospitalized at the Burn Center between April 2014 and April 2017 were evaluated. Data pertaining to demographic characteristics, etiology, and degree of burn and percentage of burn to TBSA were collected. Pain, infection rates, reapplication rates, length of hospital stay, duration of healing, and presence of scar formation were analyzed. Median percentage of burn to TBSA was 15% (interquartile range [IQR]: 9-20). Fifteen patients had only facial burns, while 39 patients had burns on other parts of the body in addition to the face. Nine patients had deep partial-thickness burns, while 45 had superficial partial-thickness burns. Median length of hospital stay was 7 days (IQR: 3-15) for the entire study population and 4 days (IQR: 2-7.5) for patients who had only facial burns. Median healing time was 9 days (IQR: 7-12). Fifty-one (94%) patients had a Vancouver Scar Scale score of zero at 6 months. Use of hyaluronic acid-based wound dressings for facial burns is an effective and safe option.

Skin Tissue Engineering Advances in Burns: A Brief Introduction to the Past, the Present, and the Future Potential

Burn injuries are a severe form of skin damage with a significant risk of scarring and systemic sequelae. Approximately 11 million individuals worldwide suffer burn injuries annually, with 180,000 people dying due to their injuries. Wound healing is considered the main determinant for the survival of severe burns and remains a challenge. The surgical treatment of burn wounds entails debridement of necrotic tissue, and the wound is covered with autologous skin substitutes taken from healthy donor areas. Autologous skin transplantation is still considered to be the gold standard for wound repair. However, autologous skin grafts are not always possible, especially in cases with extensive burns and limited donor sites. Allografts from human cadaver skin and xenografts from pig skin may be used in these situations to cover the wounds temporarily. Alternatively, dermal analogs are used until permanent coverage with autologous skin grafts or artificial skins can be achieved, requiring staged procedures to prolong the healing times with the associated risks of local and systemic infection. Over the last few decades, the wound healing process through tissue-engineered skin substitutes has significantly enhanced as the advances in intensive care ensuring early survival have led to the need to repair large skin defects. The focus has shifted from survival to the quality of survival, necessitating accelerated wound repair. This special volume of JBCR is dedicated to the discoveries, developments, and applications leading the reader into the past, present, and future perspectives of skin tissue engineering in burn injuries.

Advances in Skin Tissue Engineering and Regenerative Medicine

There are an estimated 500,000 patients treated with full-thickness wounds in the United States every year. Fire-related burn injuries are among the most common and devastating types of wounds that require advanced clinical treatment. Autologous split-thickness skin grafting is the clinical gold standard for the treatment of large burn wounds. However, skin grafting has several limitations, particularly in large burn wounds, where there may be a limited area of non-wounded skin to use for grafting. Non-cellular dermal substitutes have been developed but have their own challenges; they are expensive to produce, may require immunosuppression depending on design and allogenic cell inclusion. There is a need for more advanced treatments for devastating burns and wounds. This manuscript provides a brief overview of some recent advances in wound care, including the use of advanced biomaterials, cell-based therapies for wound healing, biological skin substitutes, biological scaffolds, spray on skin and skin bioprinting. Finally, we provide insight into the future of wound care and technological areas that need to be addressed to support the development and incorporation of these technologies.

In vitro evaluation of a synthetic (Biobrane®) and a biopolymer (Epicite) wound dressing with primary human juvenile and adult fibroblasts after different colonization strategies

BACKGROUND

The three-dimensional [3D] wound dressings Biobrane® and Epicite are used in the wound management. Fibroblasts are important for successful deep wound healing. The direct effect of Biobrane® and Epicite on human fibroblasts, particularly of juvenile individuals, remains unclear. Therefore, this study compared the survival and growth characteristics of juvenile and adult dermal fibroblasts on Biobrane® and Epicite using different culture models.

METHOD

Murine (L929), primary juvenile and adult human fibroblasts were seeded on both materials using two dimensional (2D, slide culture) or 3D culture at the medium-air interface and dynamical rotatory culture. Cell adherence, viability, morphology, actin cytoskeleton architecture and DNA content were monitored. Scanning electron microscopy (SEM) analyses could be only performed from Biobrane®. Permeability of both materials were tested.

RESULTS

The majority of all tested fibroblasts species survived on both dressings with no significant differences between 1 and 14 days. Juvenile and adult fibroblasts exerted typical fibroblast morphology with spindle-shaped cell bodies on the materials. SEM visualized morphological differences between murine and human fibroblasts on Biobrane®. Juvenile and adult fibroblasts colonized Biobrane® in rotatory culture after 7 days the most. The Biobrane® rotatory culture of L929 and juvenile fibroblasts showed after 7 days the significantly highest DNA amount. No major gender differences could be observed. Biobrane® had a higher permeability than Epicite.

CONCLUSION

Both wound dressing can be colonized by fibroblasts suggesting their high cytocompatibility. Fibroblast survival and morphology on Biobrane® and Epicite depended on the culture system and the fibroblast source.

Recent Progress in Development of Dressings Used for Diabetic Wounds with Special Emphasis on Scaffolds

Diabetic wound (DW) is a secondary application of uncontrolled diabetes and affects about 42.2% of diabetics. If the disease is left untreated/uncontrolled, then it may further lead to amputation of organs. In recent years, huge research has been done in the area of wound dressing to have a better maintenance of DW. These include gauze, films, foams or, hydrocolloid-based dressings as well as polysaccharide- and polymer-based dressings. In recent years, scaffolds have played major role as biomaterial for wound dressing due to its tissue regeneration properties as well as fluid absorption capacity. These are three-dimensional polymeric structures formed from polymers that help in tissue rejuvenation. These offer a large surface area to volume ratio to allow cell adhesion and exudate absorbing capacity and antibacterial properties. They also offer a better retention as well as sustained release of drugs that are directly impregnated to the scaffolds or the ones that are loaded in nanocarriers that are impregnated onto scaffolds. The present review comprehensively describes the pathogenesis of DW, various dressings that are used so far for DW, the limitation of currently used wound dressings, role of scaffolds in topical delivery of drugs, materials used for scaffold fabrication, and application of various polymer-based scaffolds for treating DW.

Use of a biosynthetic wound dressing to treat burns: a systematic review

OBJECTIVE

Accelerating the process of wound healing, reducing infection risks, and decreasing pain and discomfort in the burn area are important goals of burn treatment. To achieve these goals, the use of biosynthetic wound dressings has increased in recent years. Suprathel (PolyMedics Innovations, Germany) is a biosynthetic wound dressing used to treat both partial-thickness burns and split-thickness skin graft (STSG) donor sites, full-thickness wounds, large-scale abrasions, and scar revisions.

METHOD

This study is a systematic review of empirical evidence reported on the application of the biosynthetic wound dressing in burns up to 2017. Keywords such as 'Suprathel', 'effectiveness', 'safety', and 'cost' were searched in PubMed, Cochrane, Scopus and Embase databases.

RESULTS

A total of 14 publications were identified, based on the inclusion and exclusion criteria. The findings reported in the literature reviewed were classified in terms of safety, effectiveness and cost-effectiveness of use of the biosynthetic wound dressing. Regarding safety and effectiveness, the dressing was found to yield desirable results, particularly for partial thickness burns and STSG donor sites. As of 2017 no health economics assessments have been carried out.

CONCLUSION

Despite the desirable advantages of the biosynthetic wound dressing with respect to its effectiveness, safety and ease of use, its major limitation was found to be its cost. However, in the absence of comprehensive studies on the quantification of all factors, there is scant scientific evidence for making reliable conclusions from this systematic review.

Amnion and collagen-based blended hydrogel improves burn healing efficacy on a rat skin wound model in the presence of wound dressing biomembrane

BACKGROUND

A burn wound is one of the most frequent and devastating injuries for patients which requires extensive care. Early treatment of burn wounds improves healing significantly.

OBJECTIVE

This study was designed to investigate the efficacy of amnion and collagen-based hydrogels on cutaneous burn wound healing in rats with covering membrane.

METHODS

We prepared a novel cell free hydrogel comprising human amnion, rabbit collagen, carboxymethyl cellulose sodium salt, citric acid, methyl paraben, propyl paraben, glycerin and triethanol amine. The wound covering membrane was developed from rabbit collagen and prawn shell chitosan. Beside swelling ratio, water absorption, equilibrium water content, gel fraction and spreadability analysis, in vitro cytotoxicity and biocompatibility tests were performed for the formulated hydrogels. Following the skin irritation study, second-degree burns were created on the dorsal region of the rats and the gels were applied with/without covering membrane to study the wound contraction and re-epithelialization period.

RESULTS

The formulated hydrogels were observed non-cytotoxic and compatible with human blood cells. No erythema and edema were found in skin irritation assay confirming the safety and applicability. Hydrogel consisting in a combination of amnion and collagen demonstrated significantly rapid wound healing, driven by complete re-epithelialization (16.75 ± 0.96 days) and closure by wound contraction (72 ± 3.27%, P < 0.0000009) when wound dressing membrane was used, whereas this gel alone healed about 62.5 ± 4.43% (P < 0.00001) and required 18.75 ± 0.50 days to complete re-epithelialization. Additionally, the gel with covering membrane treated group had maximum average body weight, food and water intake.

CONCLUSION

The amnion and collagen-based blended gel offers alternative possibilities to treat skin wounds when covered with film, which could overcome the limitations associated with modern therapeutic products such as high costs, long manufacturing times, complexities, storing, and presence of living biomaterials.

Outcomes of the glove-gauze regimen for managing burn injuries of the hand

We studied the efficacy of the glove-gauze regimen in treating superficial, partial-thickness and small full-thickness hand burns. Outcome measures included healing time, need for surgical intervention, need for formal physical therapy, restoration of range of motion, return to function and incidence of infection. All patients (n = 123) successfully completed the regimen with an average healing time of 3.7 weeks. None required surgical debridement and seven (6%) required formal physical therapy. One hundred and eighteen patients (96%) regained full range of motion and 122 (99%) returned to their previous level of work. We believe that the glove-gauze regimen provides a simplified and effective means of managing hand burns. We conclude from our patients that the glove-gauze regimen is an effective treatment that can ensure uneventful healing of superficial, partial-thickness and small full-thickness burns. A majority of our patients healed with full range of motion and function without formal physical therapy.Level of evidence: IV.

A bio-degradable synthetic membrane to treat superficial and deep second degree burn wounds in adults and children - 4 year experience

INTRODUCTION

A new bio-degradable synthetic membrane was recently introduced to treat second degree burns in adults and pediatric patients.

OBJECTIVE

To assess complications and outcomes using this absorbable synthetic membrane to treat second degree burns.

METHODS

229 burn patients, 138 pediatric, with superficial and deep second -degree wounds, treated with the absorbable synthetic membrane (Suprathel®, Polymedics, Denkendorf, Germany) were included in this study. Patients were treated under anesthesia or moderate sedation. The wound bed was prepared by using either rough debridement or dermabrasion excision. After hemostasis, the membrane was applied to the wound with an outer layer dressing of fatty gauze, bridal veil, absorptive gauze and an ACE® wrap. The outer dressing was removed every one to four days, depending on exudate, in order to closely follow the wound through the translucent membrane and fatty gauze layers. After complete epithelialization, the dressing separated and could be removed. The study focused on the need for subsequent grafting, healing time, patient pain level, hypertrophic scarring and rate of infection.

RESULTS

All wounds in this study that were treated with Suprathel® healed without grafting. The average TBSA (Total Body Surface Area) was 8.9% (1%-60%). Average time to healing was 13.7 days for ≥ 90% epithelialization with 11.9 days for pediatric patients versus 14.7 days for adults. Throughout the treatment period, the average pain level was 1.9 on a 10-point scale. 27 patients developed hypertrophic scarring in some areas (11.7%). Average Length of stay (LOS) was 6.9 days. The rate of infection was 3.8% (8/229). Failure or progression to full thickness in part of the wounds was 5.2% (12/229).

CONCLUSION

In treating second degree burn wounds, this membrane provides a simple, effective solution alternative with good outcomes and less pain than conventional and previously studied treatment options in the same institution. Fewer dressing changes and easier overall management of the wounds contribute to its favorable profile.

Bioprinted Skin Recapitulates Normal Collagen Remodeling in Full-Thickness Wounds

Over 1 million burn injuries are treated annually in the United States, and current tissue engineered skin fails to meet the need for full-thickness replacement. Bioprinting technology has allowed fabrication of full-thickness skin and has demonstrated the ability to close full-thickness wounds. However, analysis of collagen remodeling in wounds treated with bioprinted skin has not been reported. The purpose of this study is to demonstrate the utility of bioprinted skin for epidermal barrier formation and normal collagen remodeling in full-thickness wounds. Human keratinocytes, melanocytes, fibroblasts, dermal microvascular endothelial cells, follicle dermal papilla cells, and adipocytes were suspended in fibrinogen bioink and bioprinted to form a tri-layer skin structure. Bioprinted skin was implanted onto 2.5 × 2.5 cm full-thickness excisional wounds on athymic mice, compared with wounds treated with hydrogel only or untreated wounds. Total wound closure, epithelialization, and contraction were quantified, and skin samples were harvested at 21 days for histology. Picrosirius red staining was used to quantify collagen fiber orientation, length, and width. Immunohistochemical (IHC) staining was performed to confirm epidermal barrier formation, dermal maturation, vascularity, and human cell integration. All bioprinted skin treated wounds closed by day 21, compared with open control wounds. Wound closure in bioprinted skin treated wounds was primarily due to epithelialization. In contrast, control hydrogel and untreated groups had sparse wound coverage and incomplete closure driven primarily by contraction. Picrosirius red staining confirmed a normal basket weave collagen organization in bioprinted skin-treated wounds compared with parallel collagen fibers in hydrogel only and untreated wounds. IHC staining at day 21 demonstrated the presence of human cells in the regenerated dermis, the formation of a stratified epidermis, dermal maturation, and blood vessel formation in bioprinted skin, none of which was present in control hydrogel treated wounds. Bioprinted skin accelerated full-thickness wound closure by promoting epidermal barrier formation, without increasing contraction. This healing process is associated with human cells from the bioprinted skin laying down a healthy, basket-weave collagen network. The remodeled skin is phenotypically similar to human skin and composed of a composite of graft and infiltrating host cells. Impact statement We have demonstrated the ability of bioprinted skin to enhance closure of full-thickness wounds through epithelialization and normal collagen remodeling. To our knowledge, this article is the first to quantify collagen remodeling by bioprinted skin in full-thickness wounds. Our methods and results can be used to guide further investigation of collagen remodeling by tissue engineered skin products to improve ongoing and future bioprinting skin studies. Ultimately, our skin bioprinting technology could translate into a new treatment for full-thickness wounds in human patients with the ability to recapitulate normal collagen remodeling in full-thickness wounds.

Feasibility of Pure Silk for the Treatment of Large Superficial Burn Wounds Covering Over 10% of the Total Body Surface

Large, superficial burn wounds require many painful dressing changes and, thus, dressings that can stay on the wound and peel off during re-epithelization such as Biobrane® and Suprathel® are preferred, but they are costly. Natural silk has shown good outcomes with respect to wound healing, scarring, and patient satisfaction. This study aimed to evaluate the efficacy of natural silk compared with that of initially used dressings for the treatment of superficial burn wounds greater than 10% of the TBSA. Patients with superficial burns covering &gt;10% of the TBSA were treated with pure silk for the first time (treatment group). Complications during wound healing with respect to the need for further surgery and scarring were compared with those of patients with similar burns of more than 10% TBSA and treated with nylon mesh and collagen instead of silk (treatment group). The treatment and control group comprised 25 and 13 patients, respectively. In total, 88% of patients in the treatment group did not require further treatment, while two patients with chemical burns needed further surgeries. Moreover, patients reported high satisfaction with respect to scarring and aesthetic outcome. Meanwhile, 85% of patients in the control group healed without further surgery and showed higher median hypopigmentation and hyperpigmentation after 12 months. Silk is an effective wound dressing for the treatment of large superficial burn wounds. It avoids painful dressing changes and yields satisfactory aesthetic outcomes. However, especially in large burns, careful initial wound depth assessment is crucial to prevent infection and reoperations.

Amnion membrane hydrogel and amnion membrane powder accelerate wound healing in a full thickness porcine skin wound model

There is a need for effective wound treatments that retain the bioactivity of a cellular treatment, but without the high costs and complexities associated with manufacturing, storing, and applying living biological products. Previously, we developed an amnion membrane‐derived hydrogel and evaluated its wound healing properties using a mouse wound model. In this study, we used a full thickness porcine skin wound model to evaluate the wound‐healing efficacy of the amnion hydrogel and a less‐processed amnion product comprising a lyophilized amnion membrane powder. These products were compared with commercially available amnion and nonamnion wound healing products. We found that the amnion hydrogel and amnion powder treatments demonstrated significant and rapid wound healing, driven primarily by new epithelialization versus closure by contraction. Histological analysis demonstrated that these treatments promote the formation of a mature epidermis and dermis with similar composition to healthy skin. The positive skin regenerative outcomes using amnion hydrogel and amnion powder treatments in a large animal model further demonstrate their potential translational value for human wound treatments.

Characterization of burn wound healing gel prepared from human amniotic membrane and Aloe vera extract

Background

Skin burn wound is a notable medical burden worldwide. Rapid and effective treatment of burnt skin is vital to fasten wound closure and healing properly. Amniotic graft and Aloe vera are widely used as wound managing biomaterials. Sophisticated processing, high cost, availability, and the requirement of medics for transplantation limit the application of amnion grafts. We aim to prepare a novel gel from amnion combined with the Aloe vera extract for burn wound healing which overcome the limitations of graft.

Methods

Two percent human amniotic membrane (AM), Aloe vera (AV) and AM+AV gels were prepared. In vitro cytotoxicity, biocompatibility, cell attachment, proliferation, wound healing scratch assays were performed in presence of the distinct gels. After skin irritation study, second-degree burns were induced on dorsal region of Wistar rats; and gels were applied to observe the healing potential in vivo. Besides, macroscopical measurement of wound contraction and re-epithelialization; gel treated skin was histologically investigated by Hematoxylin and eosin (H&E) staining. Finally, quantitative assessment of angiogenesis, inflammation, and epithelialization was done.

Results

The gels were tested to be non-cytotoxic to nauplii and compatible with human blood and skin cells. Media containing 500 μg/mL AM+AV gel were observed to promote HaCaT and HFF1 cells attachment and proliferation. In vitro scratch assay demonstrated that AM+AV significantly accelerated wound closure through migration of HaCaT cells. No erythema and edema were observed in skin irritation experiments confirming the applicability of the gels. AV and AM+AV groups showed significantly accelerated wound closure through re-epithelialization and wound contraction with P < 0.01. Macroscopically, AM and AM+AV treated wound recovery rates were 87 and 90% respectively with P < 0.05. Histology analysis revealed significant epitheliazation and angiogenesis in AM+AV treated rats compared to control (P < 0.05). AM+AV treated wounds had thicker regenerated epidermis, increased number of blood vessels, and greater number of proliferating keratinocytes within the epidermis.

Conclusion

We demonstrated that a gel consisting of a combination of amnion and Aloe vera extract has high efficacy as a burn wound healing product. Amniotic membrane combined with the carrier Aloe vera in gel format is easy to produce and to apply.

Advancements in Regenerative Strategies Through the Continuum of Burn Care

Burns are caused by several mechanisms including flame, scald, chemical, electrical, and ionizing and non-ionizing radiation. Approximately half a million burn cases are registered annually, of which 40 thousand patients are hospitalized and receive definitive treatment. Burn care is very resource intensive as the treatment regimens and length of hospitalization are substantial. Burn wounds are classified based on depth as superficial (first degree), partial-thickness (second degree), or full-thickness (third degree), which determines the treatment necessary for successful healing. The goal of burn wound care is to fully restore the barrier function of the tissue as quickly as possible while minimizing infection, scarring, and contracture. The aim of this review is to highlight how tissue engineering and regenerative medicine strategies are being used to address the unique challenges of burn wound healing and define the current gaps in care for both partial- and full-thickness burn injuries. This review will present the current standard of care (SOC) and provide information on various treatment options that have been tested pre-clinically or are currently in clinical trials. Due to the complexity of burn wound healing compared to other skin injuries, burn specific treatment regimens must be developed. Recently, tissue engineering and regenerative medicine strategies have been developed to improve skin regeneration that can restore normal skin physiology and limit adverse outcomes, such as infection, delayed re-epithelialization, and scarring. Our emphasis will be centered on how current clinical and pre-clinical research of pharmacological agents, biomaterials, and cellular-based therapies can be applied throughout the continuum of burn care by targeting the stages of wound healing: hemostasis, inflammation, cell proliferation, and matrix remodeling.

A Prospective, Randomized, Controlled Trial Comparing the Outpatient Treatment of Pediatric and Adult Partial-Thickness Burns with Suprathel or Mepilex Ag

Modern treatment of partial-thickness burns follows the paradigm of less frequent dressing changes to allow for undisturbed reepithelialization of the burn wound. We compared Mepilex Ag (M), a silver-impregnated foam dressing, and Suprathel (S), a DL-lactid acid polymer, in the outpatient treatment of partial-thickness burns in pediatric and adult patients. Patients were enrolled in a randomized, controlled, prospective clinical trial. We monitored time to reepithelialization, wound pain, discomfort during dressing changes, and treatment cost. Objective scar characteristics (elasticity, transepidermal water loss, hydration, and pigmentation) and subjective assessments (Patient and Observer Scar Assessment Scale) were measured at 1 month post burn. Data are presented as mean ± SEM, and significance was accepted at P < 0.05. Sixty-two patients (S n = 32; M n = 30) were enrolled; age, sex, and burn size were comparable between the groups. Time to reepithelialization was not different between the groups (12 days; P = 0.75). Pain ratings were significantly reduced during the first 5 days after burn in the Suprathel group in all patients (P = 0.03) and a pediatric subgroup (P < 0.001). Viscolelasticity of burned skin was elevated compared with unburned skin in the Mepilex Ag group at 1 month post burn. Patients treated with Suprathel reported better overall scar quality (S: 2; M: 4.5; P < 0.001). The cost of treatment per square centimeter for Mepilex Ag was considerably lower than that of Suprathel. Both dressings are feasible and efficacious for the outpatient treatment of minor and selected moderate partial-thickness burns. Reduced pain, especially in a pediatric patient population, may be advantageous, despite increased treatment cost.

Stem cells, niches and scaffolds: Applications to burns and wound care

The importance of skin to survival, and the devastating physical and psychological consequences of scarring following reparative healing of extensive or difficult to heal human wounds, cannot be disputed. We discuss the significant challenges faced by patients and healthcare providers alike in treating these wounds. New state of the art technologies have provided remarkable insights into the role of skin stem and progenitor cells and their niches in maintaining skin homeostasis and in reparative wound healing. Based on this knowledge, we examine different approaches to repair extensive burn injury and chronic wounds, including full and split thickness skin grafts, temporising matrices and scaffolds, and composite cultured skin products. Notable developments include next generation skin substitutes to replace split thickness skin autografts and next generation gene editing coupled with cell therapies to treat genodermatoses. Further refinements are predicted with the advent of bioprinting technologies, and newly defined biomaterials and autologous cell sources that can be engineered to more accurately replicate human skin architecture, function and cosmesis. These advances will undoubtedly improve quality of life for patients with extensive burns and difficult to heal wounds.

Solubilized Amnion Membrane Hyaluronic Acid Hydrogel Accelerates Full-Thickness Wound Healing

The early and effective treatment of wounds is vital to ensure proper wound closure and healing with appropriate functional and cosmetic outcomes. The use of human amnion membranes for wound care has been shown to be safe and effective. However, the difficulty in handling and placing thin sheets of membrane, and the high costs associated with the use of living cellularized tissue has limited the clinical application of amniotic membrane wound healing products. Here, we describe a novel amnion membrane-derived product, processed to result in a cell-free solution, while maintaining high concentrations of cell-derived cytokines and growth factors. The solubilized amnion membrane (SAM) combined with the carrier hyaluronic acid (HA) hydrogel (HA-SAM) is easy to produce, store, and apply to wounds. We demonstrated the efficacy of HA-SAM as a wound treatment using a full-thickness murine wound model. HA-SAM significantly accelerated wound closure through re-epithelialization and prevented wound contraction. HA-SAM-treated wounds had thicker regenerated skin, increased total number of blood vessels, and greater numbers of proliferating keratinocytes within the epidermis. Overall, this study confirms the efficacy of the amnion membrane as a wound treatment/dressing, and overcomes many of the limitations associated with using fresh, cryopreserved, or dehydrated tissue by providing a hydrogel delivery system for SAM. Stem Cells Translational Medicine 2017;6:2020-2032.

In view of standardization Part 2: Management of challenges in the initial treatment of burn patients in Burn Centers in Germany, Austria and Switzerland

INTRODUCTION

Initial therapy of severe burns in specialized burn trauma centers is a challenging task faced by the treating multi-professional and interdisciplinary team. A lack of consistent operating procedures and varying structural conditions was recently demonstrated in preliminary data of our group. These results raised the question on how specific treatment measures in acute burn care are met in the absence of standardized guidelines.

MATERIAL AND METHODS

A specific questionnaire containing 57 multiple-choice questions was sent to all 22 major burn centers in Germany, Austria and Switzerland. The survey included standards of airway management and ventilation, fluid management and circulation, body temperature monitoring and management, topical burn wound treatment and a microbiological surveillance. Additionally, the distribution of standardized course systems was covered.

RESULTS

17 out of 22 questionnaires (77%) were returned completed. Regarding volume resuscitation, results showed a similar approach in estimating initial fluid while discrepancies persisted in the use of colloidal fluid and human albumin. Elective tracheostomy and the need for bronchoscopy with suspected inhalation injury were the most controversial issues revealed by the survey. Topical treatment of burned body surface also followed different principles regarding the use of synthetic epidermal skin substitutes or enzymatic wound debridement. Less discrepancy was found in basic diagnostic measures, body temperature management, estimation of the extent of burns and microbiological surveillance.

CONCLUSION

While many burn-related issues are clearly not questionable and managed in a similar way in most participating facilities, we were able to show that the most contentious issues in burn trauma management involve initial volume resuscitation, management of inhalation trauma and topical burn wound treatment. Further research is required to address these topics and evaluate a potential superiority of a regime in order to increase the level of evidence.

Usability and effectiveness of Suprathel® in partial thickness burns in children

Purpose

Evaluation of usability and effectiveness of Suprathel^® in the treatment of partial thickness burns in children.

Methods

A prospective, observational study to evaluate adherence of Suprathel^® to the wound bed, reepithelialization time, grafting, wound colonization and infection, pain, dressing changes, length of hospital stay (LOS) and scar formation.

Results

Twenty-one children (median age 2.4 years, range 5 months–14 years) with a median total body surface area (TBSA) of 4 % (range 1–18) were included. Median LOS was 10 days (range 3–20). Median outer layer dressing changes was 3 (range 1–14). Suprathel^® was only adherent in wounds debrided with Versajet^®. Median reepithelialization time was 13 days (range 7–29). Three patients needed a split skin graft. There were 7 (33 %) patients with wound colonization before application of Suprathel^®. This increased to 12 (57 %) patients during treatment. One patient developed a wound infection. Median visual analog scale (VAS) scores for background and procedural pain in patients >7 years were 3.2 (range 2–5) and 3.5 (range 2–5), respectively. In younger patients, median background and procedural COMFORT-B scores were 13.8 (range 10–23) and 14.8 (range 13–23, p = 0.03), respectively. Patient and Observer Scar Assessment Scale (POSAS) scores were favorable after 3 and 6 months post burn.

Conclusions

Suprathel^® provides potential advantages regarding pain and scar formation, but extensive wound debridement is needed to achieve adequate adherence.

A systematic review of objective burn scar measurements

BACKGROUND

Problematic scarring remains a challenging aspect to address in the treatment of burns and can significantly affect the quality of life of the burn survivor. At present, there are few treatments available in the clinic to control adverse scarring, but experimental pharmacological anti-scarring strategies are now beginning to emerge. Their comparative success must be based on objective measurements of scarring, yet currently the clinical assessment of scars is not carried out systematically and is mostly based on subjective review of patients. However, several techniques and devices are being introduced that allow objective analysis of the burn scar. The aim of this article is to evaluate various objective measurement tools currently available and recommend a useful panel that is suitable for use in clinical trials of anti-scarring therapies.

METHODS

A systematic literature search was done using the Web of Science, PubMed and Cochrane databases. The identified devices were then classified and grouped according to the parameters they measured. The tools were then compared and assessed in terms of inter- and intra-rater reproducibility, ease of use and cost.

RESULTS

After duplicates were removed, 5062 articles were obtained in the search. After further screening, 157 articles which utilised objective burn scar measurement systems or tools were obtained. The scar measurement devices can be broadly classified into those measuring colour, metric variables, texture, biomechanical properties and pathophysiological disturbances.

CONCLUSIONS

Objective scar measurement tools allow the accurate and reproducible evaluation of scars, which is important for both clinical and scientific use. However, studies to evaluate their relative performance and merits of these tools are scarce, and there remain factors, such as itch and pain, which cannot be measured objectively. On reviewing the available evidence, a panel of devices for objective scar measurement is recommended consisting of the 3D cameras (Eykona/Lifeviz/Vectra H1) for surface area and volume, DSM II colorimeter for colour, Dermascan high-frequency ultrasound for scar thickness and Cutometer for skin elasticity and pliability.

Evaluation of commonly used temporary skin dressings and a newly developed collagen matrix for treatment of superficial wounds

OBJECTIVE

In the authors' experience, extended superficial-thickness wounds often were treated with the application of synthetic temporary wound dressings. There is a broad range of expensive products available in this market. The aim of this study was to compare commonly used temporary skin dressings with a newly developed collagen matrix.

METHODS

A total of 56 standardized superficial skin defects were generated on the back of 28 adult male Lewis rats using a skin dermatome. The wounds were treated with Biobrane (Smith & Nephew, St Petersburg, Florida) (n = 14), Suprathel (PolyMedics, Denkendorf, Germany) (n = 14), and newly developed Collagen Cell Carrier (Naturin Viscofan, Weinheim, Germany) (CCC; n = 14). Histological evaluation was performed at 3 months' postoperative in regard to quality of newly formed skin.

RESULTS

In regard to epidermal cell count and thickness of skin, Biobrane and Suprathel demonstrated comparable values, whereas CCC demonstrated higher epidermal cell count and thicker neoepidermis. The epidermal thickness of CCC was comparable to untreated, healthy skin.

CONCLUSIONS

The presented results reveal the potential of CCC in the treatment of superficial skin defects and encourages further evaluation of CCC in surgical applications and regenerative medicine.

Use of a copolymer dressing on superficial and partial-thickness burns in a paediatric population

OBJECTIVE

Despite extensive research into the treatment of partial-thickness burns, to date there has not been the emergence of a preeminent modality. This pilot study, the first such study to be performed in a burn unit in the US, was designed to evaluate the efficacy and outcomes of the application of copolymer dressing (Suprathel; PolyMedics Innovations Corporation, Stuttgart, Germany) for both superficial and deeper partial-thickness burns.

METHOD

The copolymer dressing was used as a primary wound dressing to treat superficial and deep partial-thickness burns (average 5% total body surface area) in paediatric patients. Burns were debrided within 24 hours, at bedside, in the burn unit or in the operating room. The copolymer dressing was then applied directly to the wound and covered with a non-adherent second layer and an absorptive outer dressing. After discharge, patients were seen every 5-7 days until healed. Parameters evaluated included average hospital length of stay, average number of intravenous doses of narcotics administered, pain score at first follow-up visit, average time to complete re epithelialisation, incidence of burn wound infection, and patient/parent satisfaction on a 4-point scale. We also evaluated our experience with the dressing. Data were evaluated retrospectively under an Investigational Review Board approved protocol.

RESULTS

Of the 17 patients assessed the average hospital length of stay was 1.4 days during which the average number of intravenous narcotic doses administered before copolymer dressing application was 1.5 and after was 0.1 doses. At the first follow-up visit, average pain score was 1.2 on a 10-point scale and the average time to re epithelialisation was 9.5 days. There was no incidence of burn wound infection. Patient/parent satisfaction was average of 3.66 on a 4-point scale. The staff had found that the self-adherence and elasticity of the dressing made it easy to apply and stay adherent, especially in areas of difficult contour. There were no readmissions for further debridement or skin grafting.

CONCLUSION

Our experience shows that patients may be discharged shortly after the application of the copolymer dressing, with manageable pain scores and ease of use as determined by the caretakers high satisfaction. This new, fully synthetic copolymer dressing is easy to apply, does not require any additional antimicrobial coverage and may be used to successfully manage deeper partial-thickness burns, donor sites or burns in areas of contour, where many other dressings might not be considered or be appropriate.

DECLARATION OF INTEREST

None declared.

Burns in children: standard and new treatments

Outcomes of patients with burns have improved substantially over the past two decades. Findings from a 2012 study in The Lancet showed that a burn size of more than 60% total body surface area burned (an increase from 40% a decade ago) is associated with risks and mortality. Similar data have been obtained in adults and elderly people who have been severely burned. We discuss recent and future developments in burn care to improve outcomes of children.

Biological therapies for the treatment of cutaneous wounds: phase III and launched therapies

INTRODUCTION

Normal wound healing mechanisms can be overwhelmed in the setting of complex acute and chronic tissue injury. Biological therapies are designed to augment and/or restore the body's natural wound healing abilities. There are a variety of available and emerging technologies utilizing this approach that have demonstrated the ability to augment wound healing.

AREAS COVERED

In this review, the clinical data on launched and emerging biological therapies for wound healing applications are summarized. The methodologies discussed include biological skin equivalents, growth factors/small molecules and stem cell-based therapies.

EXPERT OPINION

While many products possess convincing clinical data demonstrating their efficacy in comparison to standard treatment options, more robust, controlled studies are needed to determine the relative value among established and emerging biological therapies. Future bioengineering and stem cell-based approaches are of particular interest due to the simultaneous correction of multiple deficiencies present in the nonhealing wound.

Bioprinted amniotic fluid-derived stem cells accelerate healing of large skin wounds

Stem cells obtained from amniotic fluid show high proliferative capacity in culture and multilineage differentiation potential. Because of the lack of significant immunogenicity and the ability of the amniotic fluid-derived stem (AFS) cells to modulate the inflammatory response, we investigated whether they could augment wound healing in a mouse model of skin regeneration. We used bioprinting technology to treat full-thickness skin wounds in nu/nu mice. AFS cells and bone marrow-derived mesenchymal stem cells (MSCs) were resuspended in fibrin-collagen gel and "printed" over the wound site. At days 0, 7, and 14, AFS cell- and MSC-driven wound closure and re-epithelialization were significantly greater than closure and re-epithelialization in wounds treated by fibrin-collagen gel only. Histological examination showed increased microvessel density and capillary diameters in the AFS cell-treated wounds compared with the MSC-treated wounds, whereas the skin treated only with gel showed the lowest amount of microvessels. However, tracking of fluorescently labeled AFS cells and MSCs revealed that the cells remained transiently and did not permanently integrate in the tissue. These observations suggest that the increased wound closure rates and angiogenesis may be due to delivery of secreted trophic factors, rather than direct cell-cell interactions. Accordingly, we performed proteomic analysis, which showed that AFS cells secreted a number of growth factors at concentrations higher than those of MSCs. In parallel, we showed that AFS cell-conditioned media induced endothelial cell migration in vitro. Taken together, our results indicate that bioprinting AFS cells could be an effective treatment for large-scale wounds and burns.

Evaluation of hydrogels for bio-printing applications

In the United States alone, there are approximately 500,000 burn injuries that require medical treatment every year. Limitations of current treatments necessitate the development of new methods that can be applied quicker, result in faster wound regeneration, and yield skin that is cosmetically similar to undamaged skin. The development of new hydrogel biomaterials and bioprinting deposition technologies has provided a platform to address this need. Herein we evaluated characteristics of twelve hydrogels to determine their suitability for bioprinting applications. We chose hydrogels that are either commercially available, or are commonly used for research purposes. We evaluated specific hydrogel properties relevant to bioprinting applications, specifically; gelation time, swelling or contraction, stability, biocompatibility and printability. Further, we described regulatory, commercial and financial aspects of each of the hydrogels. While many of the hydrogels screened may exhibit characteristics suitable for other applications, UV-crosslinked Extracel, a hyaluronic acid-based hydrogel, had many of the desired properties for our bioprinting application. Taken together with commercial availability, shelf life, potential for regulatory approval and ease of use, these materials hold the potential to be further developed into fast and effective wound healing treatments.

Beware of the commercialization of human cells and tissues: situation in the European Union

With this analysis we would like to raise some issues that emerge as a result of recent evolutions in the burgeoning field of human cells, tissues, and cellular and tissue-based product (HCT/P) transplantation, and this in the light of the current EU regulatory framework. This paper is intended as an open letter addressed to the EU policy makers, who will be charged with the review and revision of the current legislation. We propose some urgent corrections or additions to cope with the rapid advances in biomedical science, an extensive commercialization of HCT/Ps, and the growing expectation of the general public regarding the ethical use of altruistically donated cells and tissues. Without a sound wake-up call, the diverging interests of this newly established ‘healthcare’ industry and the wellbeing of humanity will likely lead to totally unacceptable situations, like some of which we are reporting here.