Tissue engineering for cutaneous wounds: selecting the proper time and space for growth factors, cells and the...

Currently, autografts are the best treatment to any substantial cutaneous injury, and their success is well known as a burn therapy. However, autografts have been less successful in the treatment of chronic ulcers, and are usually a last-resort therapy because of infection at the injured site, high surgical expense, additional morbidity and engraftment failure. In addition, patients with burns covering more than 50% of their skin have limited donor sites for autograft harvest. Therefore, there is a great need for a cost-effective, user-friendly, tissue-engineered construct (TEC) that can provide successful treatments to both acute and chronic wounds in a wider repertoire of patients, including diabetics and the elderly. One approach to the challenge is to create a substitute for skin in vitro that can integrate into the engraftment site in vivo. An alternative is to engineer a biocompatible, resorbable matrix that can recruit the proper, native tissue cells to the injured site and induce them to heal the wound without scarring. This chapter reviews the 3 essential components of cutaneous wound healing, that is, cells, extracellular matrix molecules and bioactive molecules, that must be considered for designing TECs to potentially enhance the healing process. In nature, a 'dynamic reciprocity' exists amongst cells and extracellular matrix that is mediated by bioactive molecules at the site of injury. Thus, it is important to examine the interplay of all 3 components when engineering a TEC. This chapter also includes examples of commercially available products to highlight how researchers have already begun to find success in tissue engineering.