Bioengineered skin substitutes
Skin autografts are commonly used to cover acute surgical wounds and chronic ulcers. However, harvesting skin grafts creates another wound that must heal, and suitable skin is unavailable in some cases such as extensive thermal burns. Sterilised cadaver allografts provide temporary wound dressings but eventually slough off. There has been intensive research and development in recent years to provide a satisfactory substitute for healthy skin. Replacement of dermal matrix and epidermis is required.
Cultured keratinocyte autografts can provide permanent coverage of large area from a skin biopsy. However, 3 weeks are needed for graft cultivation.
Keratinocyte allografts cultured from neonatal foreskins are available immediately. They can be cryopreserved and banked, but are not currently commercially available.
Applying a substitute dermal matrix has been shown to improve the likelihood that cultured epidermal cells (or an autologous split skin graft) will take. Several immunologically inert systems are now under investigation for management of refractory venous and diabetic ulcers.