Experimental models in wound healing

Abstract Tissue injury resulting in irreversible cell death and connective tissue disruption initiates the repair process. The number of causes that produce tissue injury and tissue loss outnumber the responses the host has to repair the defect. In a superficial injury, where only the epidermal surface is damaged and destroyed (such as a sun burn), the repair process is limited to cellular replacement. Through a process of epidermal cell migration and duplication, the defect is resurfaced in a regen erative manner in the absence of scarring. In contrast, with deeper tissue loss where the connective tissue matrix is de stroyed, healing occurs by scarring with the introduction of new cell populations residing in a newly constructed connec tive tissue matrix and having a new blood supply.