Tissue‐engineering approaches to enhance nerve regeneration during wound healing

Deep and extensive burns induce a partial or total destruction of cutaneous peripheral nerves, and a subsequent loss of tactile sensibility. Conventional treatments of deep wounds do not achieve a complete restoration of touch perception. Hence, innervation deficiency of skin constitutes a significant handicap to rehabilitation of burn patients. Our aim was to investigate two different approaches to enhance nerve regeneration in a reconstructed skin transplantated on mice. First, we developed a collagen sponge enriched with 1, 10 or 50μg of laminin in which human fibroblasts and keratinocytes were grown to produce a reconstructed skin, that was then grafted on the back of athymic mice for 120 days. Immunohistochemical studies demonstrated that 10μg of laminin induced a 5 times increase in the number of nerve fibers in the graft, compared to a control. The sense of touch recovery was evaluated by testing A‐Beta, A‐Delta and C sensory nerve fibers with a Neurometer (Neurotron Inc. Baltimore, MD). An improvement in the sensory function was observed for the A‐Beta and A‐Delta nerve fibers on grafts enriched with laminin. In the second approach, we incorporated in the reconstructed skin immature hair follicles obtained from mouse embryos. We observed nerve fibers migrating around these hair follicles only 30 days after graft. The incorporation of laminin, as a global approach, or hair follicles, as a targeted approach to enhance nerve regeneration in a tissue‐engineered autologous skin graft could be an efficient solution to promote a better tactile recovery for patients with deep and extensive burns. This work was supported by the Canadian Institute of Health Research and the Fonds de Recherche en Santé du Québec