The utility of collagen-based vehicles in delivery of growth factors for hard and soft tissue wound repair.

Bovine demineralized bone powder and reconstituted bovine dermal collagen have been effectively utilized during the past several years to deliver a variety of growth factors in animal models of hard and soft tissue wound repair. Bone morphogenetic proteins have been delivered in a demineralized bone powder matrix to promote ectopic bone formation in the rat subcutaneous model with the objective of studying the process of endochondral bone formation and evaluating the utility of such factors in promoting repair of hard tissue defects. Reconstituted bovine dermal collagen gels and sponges, including composites of collagen and heparin, have been utilized to deliver growth factors such as platelet-derived growth factor (PDGF), transforming growth factor-beta (TGF-beta) and fibroblast growth factor (FGF) to study their effects in subcutaneous and incisional models of dermal wound repair. The results of these experimental animal studies have provided convincing evidence that the rheological properties, biocompatibility and resorbable nature of type I collagen make it an excellent delivery vehicle for evaluation of a variety of growth factors in human clinical studies of hard and soft tissue would repair.