Repair of rat cranial bone defects with nHAC/PLLA and BMP‐2‐related peptide or rhBMP‐2

An ideal artificial substitute has good biocompatibility properties and is able to provide for rapid bone formation. Bone morphogenetic protein‐2 (BMP‐2) is considered as one of the most important growth factors for bone regeneration. In this study, a synthetic BMP‐2‐related peptide (designated P24) corresponding to residues of the knuckle epitope of BMP‐2 was introduced into a bioactive scaffold based on nano‐hydroxyapatite/collagen/poly(L ‐lactic acid) (nHAC/PLLA); its in vitro release kinetics was then measured. A 5 mm diameter cranial bone defect was created in the calvariae of 30 rats and randomly implanted with three groups of biomaterials: Group A (nHAC/PLLA alone); Group B (P24/nHAC/PLLA composite); and Group C (recombinant human BMP‐2 (rhBMP‐2)/nHAC/PLLA composite). The P24/nHAC/PLLA implants significantly stimulated bone growth similarly to the rhBMP‐2/nHAC/PLLA implants based on the radiographic and three‐dimensional CT evaluation and histological examination, thereby confirming the enhanced bone healing rate of these compounds compared with the stand‐alone nHAC/PLLA scaffold material. The osteoinductive ability of 3 mg P24 was similar to that of 1 µg rhBMP‐2. P24/nHAC/PLLA is a promising scaffold biomaterial for bone tissue regeneration. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1745–1752, 2011