Steven Boyce, PhD
Department of Surgery, University of Cincinnati, and, Shriners Hospitals for Children, Cincinnati, Ohio, USA
Skin wounds from burns vary widely in area, depth, and etiology. The majority of burns in the USA are treated in outpatient facilities, and typically do not require grafting to obtain rapid closure with minimal scar. Burns requiring hospital admission may also require grafting with autologous, split-thickness skin grafts, subject to availability. After wounds are closed, management of scar in the grafted wounds and donor sites contributes importantly to functional and cosmetic outcomes. Two adaptations to conventional management of burn wounds include negative pressure wound therapy to facilitate wound closure, and laser treatment of hypertrophic scars to improve color and pliability.
In addition to the traditional approaches to burn wound care, a variety of alternative materials has been developed during the past three decades. With origins in polymer chemistry and cell biology, most of these alternatives are considered ‘engineered tissue substitutes’ for repair of dermal and/or epidermal compartments of the skin. These alternatives respond to the need for greater availability of skin substitutes for earlier wound closure, or definitive closure of extensive, full-thickness wounds. Dermal substitutes include biologic or synthetic polymers for recruitment of autologous fibro-vascular tissue, while epidermal substitutes consist of epidermal keratinocytes either distributed as sprays, or expanded in culture to form partially-stratified cell sheets. Autologous dermal-epidermal skin substitutes have been reported to simultaneously replace the fibro-vascular and epithelial components of the skin. Collectively, these materials have provided important advancements for wound closure, but result in scar that lacks epidermal appendages (hair, glands), complete sensory nerve, and/or native anatomy of dermal matrix.
Continuing research into engineered skin substitutes has demonstrated examples of hair, sebaceous glands, sweat glands, stimulation of innervation, and promotion of vascular development. These studies have regulated the cellular pathways of developmental biology to regenerate partial or complete anatomy and physiology of the skin by pre-natal mechanisms. Stem cells (e.g., pre-natal, induced Pluripotent Stem Cells) that express specific genetic programs can restore the structures and functions found in healthy, uninjured skin, and promise to provide full recovery of cutaneous properties without scar. These distinctions of regenerative medicine suggest that it may deliver both greater availability and elimination of scar in future management of burn wounds.