Platelet releasate treatment improves skin healing in diabetic rats through endogenous growth factor secretion

Although impaired skin wound healing in diabetes is a well established phenomenon, virtually nothing is known of its underlying mechanism. We have demonstrated that diabetic skin exhibited a significant deficiency in total mitogenic activity, notably a diminution in FGF1, FGF2 and TGFbeta-like molecules. We postulated that impaired skin healing could be explained by a decreased expression of endogenous growth factors that could be compensated by a platelet releasate (PR) added in situ. Histological studies showed that PR treatment improved tissue repair and restored disturbed healing steps observed in untreated diabetic rat skin although reepithelialization was not altered. Our data demonstrate that PR treatment induces important modulations of the quantity and the kinetic of secretion of endogenous growth factors in the wounds. Although exogenous factors present in PR could no longer be quantified in the wounds after 3 days, our results indicated that factors contained in PR may have: 1) a direct and immediate effect on the growth of neodermal cells, combined to 2) a long term stimulation of endogenous growth factor synthesis in situ during cutaneous wound healing in diabetic rats.