Concise Review: Tissue-Engineered Skin and Nerve Regeneration in Burn Treatment

Abstract

Burns not only destroy the barrier function of the skin but also alter the perceptions of pain, temperature, and touch. Different strategies have been developed over the years to cover deep and extensive burns with the ultimate goal of regenerating the barrier function of the epidermis while recovering an acceptable aesthetic aspect. However, patients often complain about a loss of skin sensation and even cutaneous chronic pain. Cutaneous nerve regeneration can occur from the nerve endings of the wound bed, but it is often compromised by scar formation or anarchic wound healing. Restoration of pain, temperature, and touch perceptions should now be a major challenge to solve in order to improve patients' quality of life. In addition, the cutaneous nerve network has been recently highlighted to play an important role in epidermal homeostasis and may be essential at least in the early phase of wound healing through the induction of neurogenic inflammation. Although the nerve regeneration process was studied largely in the context of nerve transections, very few studies have been aimed at developing strategies to improve it in the context of cutaneous wound healing. In this concise review, we provide a description of the characteristics of and current treatments for extensive burns, including tissue-engineered skin approaches to improve cutaneous nerve regeneration, and describe prospective uses for autologous skin-derived adult stem cells to enhance recovery of the skin's sense of touch. STEM CELLS TRANSLATIONAL MEDICINE 2013;2:545-551

The prickly, stressful business of burn pain

“…Four weeks after thermal injury, nerve trunks run perpendicularly to the surface of the scar with a "characteristically varicose appearance", and at 4 months after burn there was no significant difference in axon counts between burned and control skin, though in some cases there may have been an increase in the density of axons in the burned skin (Ward et al, 1998). No studies conducted thus far have determined whether the axonal ingrowth is from regenerating axons that had been injured by the burn or from intact axons innervating neighboring skin which reinnervated the recovered skin by collateral sprouting (Blais et al, 2013;Diamond et al, 1987;Diamond et al, 1992aDiamond et al, , 1992bGloster and Diamond, 1992), though it is most likely both. This concept is schematized in Fig.…”

Minced Tissue in Compressed Collagen: A Cell-containing Biotransplant for Single-staged Reconstructive Repair

“…As collagen is degraded, neovascularization and granulation tissue supports the transplanted minced particles that reorganize, migrate and expand [5][6][7]11,16 . Besides, collagen is a major natural component of the extracellular matrix both in skin and in the bladder and has been used for creation of scaffolds both in vitro and in vivo including wound healing studies and reconstructions in the urogenital system 17,18 .…”

Burns

“…44 This nerve regeneration process is imperfect. It was reported that 71% of extensively burned victims suffer from abnormal sensation and 36% from chronic pain.…”