A new model for preclinical testing of dermal substitutes for human skin reconstruction

BACKGROUND: Currently, acellular dermal substitutes used for skin reconstruction are usually covered with split-thickness skin grafts. The goal of this study was to develop an animal model in which such dermal substitutes can be tested under standardized conditions using a bioengineered dermo-epidermal skin graft for coverage. METHODS: Bioengineered grafts consisting of collagen type I hydrogels with incorporated human fibroblasts and human keratinocytes seeded on these gels were produced. Two different dermal substitutes, namely Matriderm(®), and an acellular collagen type I hydrogel, were applied onto full-thickness skin wounds created on the back of immuno-incompetent rats. As control, no dermal substitute was used. As coverage for the dermal substitutes either the bioengineered grafts were used, or, as controls, human split-thickness skin or neonatal rat epidermis were used. Grafts were excised 21 days post-transplantation. Histology and immunofluorescence was performed to investigate survival, epidermis formation, and vascularization of the grafts. RESULTS: The bioengineered grafts survived on all tested dermal substitutes. Epidermis formation and vascularization were comparable to the controls. CONCLUSION: We could successfully use human bioengineered grafts to test different dermal substitutes. This novel model can be used to investigate newly designed dermal substitutes in detail and in a standardized way

International clinical recommendations on scar management.

Many techniques for management of hypertrophic scars and keloids have been proven through extensive use, but few have been supported by prospective studies with adequate control groups. Several new therapies showed good results in small-scale trials, but these have not been repeated in larger trials with long-term follow-up. This article reports a qualitative overview of the available clinical literature by an international panel of experts using standard methods of appraisal. The article provides evidence-based recommendations on prevention and treatment of abnormal scarring and, where studies are insufficient, consensus on best practice. The recommendations focus on the management of hypertrophic scars and keloids, and are internationally applicable in a range of clinical situations. These recommendations support a move to a more evidence-based approach in scar management. This approach highlights a primary role for silicone gel sheeting and intralesional corticosteroids in the management of a wide variety of abnormal scars. The authors concluded that these are the only treatments for which sufficient evidence exists to make evidence-based recommendations. A number of other therapies that are in common use have achieved acceptance by the authors as standard practice. However, it is highly desirable that many standard practices and new emerging therapies undergo large-scale studies with long-term follow-up before being recommended conclusively as alternative therapies for scar management