Potential of pigment epithelium-derived factor (PEDF) as a bone regenerative biopharmaceutical

Bone is very much a dynamic tissue, capable of various functions not limited to protection of the marrow, serving as a reservoir for calcium, maintaining posture and facilitating mobility. It is also a tissue that is fully capable of regenerating itself at most stages of life, with a diminishing capacity with increasing age. Bone defects can arise from a variety of factors not limited to bone tumours and fractures. At present, clinically, most diseased bone is removed and the patient fitted with prosthetics, with use of certain factors such as bone morphogenetic proteins (BMPs) to aid healing. Recently, the protein pigment epithelium-derived factor (PEDF) has been found to have favourable effects on bone regeneration, which is reviewed here. Numerous studies have shown the potential of PEDF in vitro, with increasing reports of success in small animal models of bone trauma. This review puts forward the advantages, and some disadvantages, in the use of PEDF as a biopharmaceutical for bone regeneration.