Growth factors, cytokines and chemokines are crucial for coordinating multiple cell types during the healing process. Proper wound healing is guided by stringent regulation of these agents as well as a wound environment that favors their activity. As to the acute wound, the healing process is controlled by spatio-temporal action of these growth factors. Cytokines and chemokines will lead through progression of healing, resulting in the re-establishment of the skinís barrier function. Whatís more, the generation of a proteolytic environment by inflammatory cells infiltrating the wound site and the prolonged up-regulation of pro-inflammatory cytokines and chemokines will inhibit normal progression of wound healing.
Growth factors and cytokines released at sites of injury and inflammation play an important role in stimulating endothelial progenitor cell (EPC) migration to these sites. The comparative analysis of literature shows that under neutral in vitro conditions, several growth factors and cytokines influence favorably indices of EPC angiogenic function. While, under acidic conditions, the biological activity of certain growth factors may be impaired, although TPO, SCF and IL-3 were each able to rescue EPCs from acidic exposure apoptosis, a combination of these three factors stimulated cell proliferation and prevented apoptosis. Possible combinations of growth factors and cytokines together with EPC transplantation may provide for a greater extent of vessel repair and new vessel formation.