Xenoderm dressing in the treatment of second degree burns

Glycosaminoglycans Modulate the Angiogenic Ability of Type I Collagen-Based Scaffolds by Acting on Vascular Network Remodeling and Maturation

Type I collagen, prevalent in the extracellular matrix, is biocompatible and crucial for tissue engineering and wound healing, including angiogenesis and vascular maturation/stabilization as required processes of newly formed tissue constructs or regeneration. Sometimes, improper vascularization causes unexpected outcomes. Vascularization failure may be caused by extracellular matrix collagen and non-collagen components heterogeneously. This study compares the angiogenic potential of collagen type I-based scaffolds and collagen type I/glycosaminoglycans scaffolds by using the chick embryo chorioallantoic membrane (CAM) model and IKOSA digital image analysis. Two clinically used biomaterials, Xenoderm (containing type I collagen derived from decellularized porcine extracellular matrix) and a dual-layer collagen sponge (DLC, with a biphasic composition of type I collagen combined with glycosaminoglycans) were tested for their ability to induce new vascular network formation. The AI-based IKOSA app enhanced the research by calculating from stereomicroscopic images angiogenic parameters such as total vascular area, branching sites, vessel length, and vascular thickness. The study confirmed that Xenoderm caused a fast angiogenic response and substantial vascular growth, but was unable to mature the vascular network. DLC scaffold, in turn, produced a slower angiogenic response, but a more steady and organic vascular maturation and stabilization. This research can improve collagen-based knowledge by better assessing angiogenesis processes. DLC may be preferable to Xenoderm or other materials for functional neovascularization, according to the findings.

Consensus on the treatment of second-degree burn wounds (2024 edition)

Second-degree burns are the most common type of burn in clinical practice and hard to manage. Their treatment requires not only a consideration of the different outcomes that may arise from the dressing changes or surgical therapies themselves but also an evaluation of factors such as the burn site, patient age and burn area. Meanwhile, special attention should be given to the fact that there is no unified standard or specification for the diagnosis, classification, surgical procedure, and infection diagnosis and grading of second-degree burn wounds. This not only poses great challenges to the formulation of clinical treatment plans but also significantly affects the consistency of clinical studies. Moreover, currently, there are relatively few guidelines or expert consensus for the management of second-degree burn wounds, and no comprehensive and systematic guidelines or specifications for the treatment of second-degree burns have been formed. Therefore, we developed the Consensus on the Treatment of Second-Degree Burn Wounds (2024 edition), based on evidence-based medicine and expert opinion. This consensus provides specific recommendations on prehospital first aid, nonsurgical treatment, surgical treatment and infection treatment for second-degree burns. The current consensus generated a total of 58 recommendations, aiming to form a standardized clinical treatment plan.

Clinical Impact of Cryopreservation on Split Thickness Skin Grafts in the Porcine Model

Vital, genetically engineered, porcine xenografts represent a promising alternative to human cadaveric allografts (HCA) in the treatment of severe burns. However, their clinical value would be significantly enhanced if preservation and long-term storage-without the loss of cellular viability-were feasible. The objective of this study was to examine the direct impact of cryopreservation and the length of storage on critical in vivo and in vitro parameters, necessary for a successful, potentially equivalent substitute to HCA. In this study, vital, porcine skin grafts, continuously cryopreserved for more than 7 years were compared side-by-side to otherwise identically prepared skin grafts stored for only 15 minutes. Two major histocompatibility complex (MHC)-controlled donor-recipient pairs received surgically created deep-partial wounds and subsequent grafting with split-thickness porcine skin grafts, differentiated only by the duration of storage. Clinical and histological outcomes, as well as quantification of cellular viability via a series of 3-4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide (MTT) assays, were assessed. No statistically significant differences were observed between skin grafts cryopreserved for 15 minutes vs 7 years. Parametric distinctions between xenografts stored for short- vs long-term durations could not be ascertained across independent clinical, histological, or in vitro evaluative methods. The results of this study validate the ability to reliably preserve, store, and retain the essential metabolic activity of porcine tissues after cryopreservation. Plentiful, safe, and readily accessible inventories of vital xenografts represent an advantageous solution to numerous limitations associated with HCA, in the treatment of severe burns.

Porcine Xenograft and Epidermal Fully Synthetic Skin Substitutes in the Treatment of Partial-Thickness Burns: A Literature Review

Background and Objectives: Porcine xenografts have been used successfully in partial thickness burn treatment for many years. Their disappearance from the market led to the search for effective and efficient alternatives. In this article, we examine the synthetic epidermal skin substitute Suprathel^® as a substitute in the treatment of partial thickness burns. Materials and Methods: A systematic review following the PRISMA guidelines has been performed. Sixteen Suprathel^® and 12 porcine xenograft studies could be included. Advantages and disadvantages between the treatments and the studies’ primary endpoints have been investigated qualitatively and quantitatively. Results: Although Suprathel had a nearly six times larger TBSA in their studies (p < 0.001), it showed a significantly lower necessity for skin grafts (p < 0.001), and we found a significantly lower infection rate (p < 0.001) than in Porcine Xenografts. Nonetheless, no significant differences in the healing time (p = 0.67) and the number of dressing changes until complete wound healing (p = 0.139) could be found. Both products reduced pain to various degrees with the impression of a better performance of Suprathel^® on a qualitative level. Porcine xenograft was not recommended for donor sites or coverage of sheet-transplanted keratinocytes, while Suprathel^® was used successfully in both indications. Conclusion: The investigated parameters indicate that Suprathel^® to be an effective replacement for porcine xenografts with even lower subsequent treatment rates. Suprathel^® appears to be usable in an extended range of indications compared to porcine xenograft. Data heterogeneity limited conclusions from the results.

Vital, Porcine, Gal-Knockout Skin Transplants Provide Efficacious Temporary Closure of Full-Thickness Wounds: Good Laboratory Practice-Compliant Studies in Nonhuman Primates

Vital, genetically engineered porcine skin transplants have long been regarded as a promising treatment option for severe burn wounds. The objective of this two-part, preclinical study was to evaluate the ability of vital, split-thickness skin xenotransplants derived from designated pathogen-free, alpha 1,3 galactosyltransferase knockout miniature swine to provide temporary wound closure of full-thickness wound defects intended to model severe and extensive, deep partial- and full-thickness burn wounds. In part 1 of the study, four full-thickness wound defects were introduced in four cynomolgus macaques recipients and, then engrafted with two xenografts and two allografts to achieve temporary wound closure. On POD-15, autografts were used to achieve definitive wound closure and were observed until POD-22. In part 2 of the study, four additional subjects each received two full-thickness wound defects, followed by two xenografts to achieve temporary wound closure, and were observed postoperatively for 30 days without further intervention. All grafts were assessed for signs of adherence to the wound bed, vascularity, and signs of immune rejection via gross clinical and histological methods. Xenograft and allograft comparators were equivalent in part 1, and later autografts were otherwise indistinguishable. In part 2, all xenotransplants demonstrated adherence, vascularity, and survival until POD-30. These were unexpected results that exceed previously published findings in similar models. Furthermore, the ensuing GLP-study report directly supported regulatory clearance, permitting a phase I clinical trial. This solution holds great promise as an alternative to human cadaver allograft, the current standard of care for the treatment of severe burns.

Overview of Silk Fibroin Use in Wound Dressings

Recently, biomimetic wound dressings were introduced as potential replacements for treating skin injuries. Although there are some clinically available skin replacements, the range of wound types and locations necessitates a broader range of options for the clinic. Natural polymeric-based dressings are of central interest in this area due to their outstanding biocompatibility, biodegradability, low toxicity, and non-allergenic nature. Among them, silk fibroin (SF) has exceptional characteristics as a wound dressing. SF-based dressings can also be used as carriers for delivering drugs, growth factors, and bioactive agents to the wound area, while providing appropriate support for complete healing. In this review, we describe recent advances in the development of SF-based wound dressings for skin regeneration.

Delivery systems of current biologicals for the treatment of chronic cutaneous wounds and severe burns

While wound therapy remains a clinical challenge in current medical practice, much effort has focused on developing biological therapeutic approaches. This paper presents a comprehensive review of delivery systems for current biologicals for the treatment of chronic wounds and severe burns. The biologicals discussed here include proteins such as growth factors and gene modifying molecules, which may be delivered to wounds free, encapsulated, or released from living systems (cells, skin grafts or skin equivalents) or biomaterials. Advances in biomaterial science and technologies have enabled the synthesis of delivery systems such as scaffolds, hydrogels and nanoparticles, designed to not only allow spatially and temporally controlled release of biologicals, but to also emulate the natural extracellular matrix microenvironment. These technologies represent an attractive field for regenerative wound therapy, by offering more personalised and effective treatments.

Burn injury: Challenges and advances in burn wound healing, infection, pain and scarring

Severe burn injuries are the most traumatic and physically debilitating injuries affecting nearly every organ system and leading to significant morbidity and mortality. Early burn wound excision and skin grafting are common clinical practices that have significantly improved the outcomes for severe burn injured patients by reducing mortality rate and days of hospital stay. However, slow wound healing, infection, pain, and hypertrophic scarring continue to remain a major challenge in burn research and management. In the present article, we review and discuss issues in the current treatment of burn injuries; the advances and novel strategies developed in the past decade that have improved burn management; and also, pioneer ideas and studies in burn research which aims to enhance burn wound care with a focus on burn wound infection, pain management, treatments for scarring and skin tissue engineering.

The Use of Dermal Skin Substitutes for the Treatment of the Burned Hand

The hand is commonly affected in burn injuries. Joints and extensor tendons are vulnerable given their superficial location. Durable coverage that permits relative frictionless tendon gliding and minimizes scar contracture is required to optimize functional outcomes. When soft tissue donor sites are limited, the use of dermal skin substitutes provides stable coverage with minimal scarring, good mobility, and acceptable appearance. A comprehensive review of dermal skin substitutes and their use with burn reconstruction of the hand is provided.

Even Better Than the Real Thing? Xenografting in Pediatric Patients with Scald Injury

This article reviews a single burn center experience with porcine xenografts to treat pediatric scald injuries, over a 10-year period. The authors compare xenografting to autografting, as well as wound care only, and provide outcome data on length of stay, incidence of health care-associated infections, and need for reconstructive surgery.

Comparison of the Application of Allogeneic Fibroblast and Autologous Mesh Grafting With the Conventional Method in the Treatment of Third-Degree Burns

Wound healing is a multipart process involving different cell types and growth factors. Third-degree burns are usually treated by early excision and skin grafting. Tissue engineering has been developed in this field in response to limitations associated with autografts. Allogeneic fibroblasts on meshed split thickness skin grafts (STSGs) are known to have useful properties in wound healing and can be used to construct a new model of living skin substitute. Fourteen patients were chosen from June 2009 until December 2010 as the sample for this study. After debridement and wound excision, meshed STSG was used to cover the entire wound. Alloskin (allofibroblasts cultured on a combination of silicone and glycosaminoglycan) was applied on one side and petroleum jelly-impregnated gauze (Iran Polymer and Petrochemical Institute) was applied on the other. The healing time, scar formation, and pigmentation score were assessed for the patients. All analyses were undertaken with SPSS 17 software. Alloskin demonstrated good properties compared to petroleum jelly-impregnated gauze. The average healing time and hypertrophic scar formation were significantly different between the two groups. In addition, the skin pigmentation score in the alloskin group was closer to normal. Alloskin grafting, including fibroblasts on meshed STSG, may be a useful method to reduce healing time and scar size and may require less autologous STSG in extensive burns where a high percentage of skin is burned and there is a lack of available donor sites.

Genetically modified porcine split-thickness skin grafts as an alternative to allograft for provision of temporary wound coverage: preliminary characterization

Temporary coverage of severely burned patients with cadaver allograft skin represents an important component of burn care, but is limited by availability and cost. Porcine skin shares many physical properties with human skin, but is susceptible to hyperacute rejection due to preformed antibodies to α-1,3-galactose (Gal), a carbohydrate on all porcine cells. Our preliminary studies have suggested that skin grafts from α-1,3-galactosyltransferase knock out (GalT-KO) miniature swine might provide temporary wound coverage comparable to allografts, since GalT-KO swine lack this carbohydrate. To further evaluate this possibility, eight non-human primates received primary autologous, allogeneic, GalT-KO, and GalT+xenogeneic skin grafts. Additionally, secondary grafts were placed to assess whether sensitization would affect the rejection time course of identical-type grafts. We demonstrate that both GalT-KO xenografts and allografts provide temporary coverage of partial- and full-thickness wounds for up to 11 days. In contrast, GalT+xenografts displayed hyperacute rejection, with no signs of vascularization and rapid avulsion from wounds. Furthermore, secondary GalT-KO transplants failed to vascularize, demonstrating that primary graft rejection sensitizes the recipient. We conclude that GalT-KO xenografts may provide temporary coverage of wounds for a duration equivalent to allografts, and thus, could serve as a readily available alternative treatment of severe burns.

Porcine xenografts vs. (cryopreserved) allografts in the management of partial thickness burns: is there a clinical difference?

Porcine xenografts and cryopreserved allografts are used for the management of partial thickness burns and both biological materials have strong advocates with regard to clinical performance, the possibility of disease transfer from donor to recipient and other clinical aspects. A literature analysis was performed in an attempt to investigate whether true (statistically significant) differences exist on clinical performance and on other determinants for use. Comparing the results of this study with a similar, previously published study performed on possible differences amongst different types of allograft in the management of partial thickness burns, both allografts and porcine xenograft seem to perform equally well clinically with regard to healing related outcomes. In addition, the risk of disease transfer, in real life, was shown to be minimal. Consequently, clinical aspects being equal, other aspects such as price and availability should be used to decide which material to use for the management of partial thickness burns.

New biological temporary skin cover Xe-Derma(®) in the treatment of superficial scald burns in children

BACKGROUND

Xe-Derma® is a new dry sterile biological cover derived from acellular pig dermis. Hydrated Xe-Derma® displays bio-mechanical features similar to the normal skin. The aim of the present study was to compare the efficacy of Xe-Derma® with hydrocolloid dressing Askina THINSite® for treatment of superficial burns in children in a prospective study.

MATERIALS AND METHODS

In a prospective study, 86 patients (5 months to 7 years of age) with superficial scald burns on a surface area of 1-35% BSA were enrolled. In the course of the study, 43 patients were treated with Xe-Derma® and 43 patients with Askina THINSite®. We collected data including the percentage of BSA covered with biological or synthetic material, epithelization time, the number of complete conversions (deepening of 100% of covered area into deep dermal wound) under each cover, the number and extent of partial conversions (deepening of less then 100% of covered area into deep dermal wound), infectious complications, the number of reapplications of the temporary cover and the extent in square centimetres of dressing material needed for successful healing of 1% BSA.

RESULTS

No significant difference in the epithelization time, percentage of conversion from superficial to deep dermal burns and percentage of infectious complication was detected between the two groups. However, patients in the Xe-Derma® group were burned on a more extensive burn surface area (p ≤ 0.028). Xe-Derma® showed adherence to the wound and therefore there has been no need to be changed The number of reapplications and therefore also the number of square centimetres needed for successful healing of 1% BSA were statistically higher in the Askina THINSite® group (p < 0.01) due to increased secretion and accumulation of fluid underneath this hydrocoloid cover. The minimal frequency of changes of this biological cover material brings a significant benefit to pediatric patients.

CONCLUSION

Acellular pig dermis Xe-Derma® represents a reliable biological cover material. It is an advantageous alternative to synthetic temporary skin covers in the treatment of superficial scald burns in children.

The use of skin substitutes in hand burns

Several skin substitutes are available that can be used in the management of hand burns; some are intended as temporary covers to expedite healing of shallow burns and others are intended to be used in the surgical management of deep burns. An understanding of skin biology and the relative benefits of each product are needed to determine the optimal role of these products in hand burn management.