Loading of BMP‐2‐related peptide onto three‐dimensional nano‐hydroxyapatite scaffolds accelerates mineralization in critical‐sized cranial bone defects

Extrusion free‐forming, as a rapid prototyping technique, is extensively applied in fabricating ceramic material in bone tissue engineering. To improve the osteoinductivity of nano‐hydroxyapatite (nHA) scaffold fabricated by extrusion free‐forming, in this study, we incorporated a new peptide (P28) and optimized the superficial microstructure after shaping by controlling the sintering temperature. P28, a novel bone morphogenic protein 2 (BMP‐2)‐related peptide, was designed in this study. Analysis of the structure, physicochemical properties and release kinetics of P28 from nHA sintered at temperatures ranging from 1000 °C to 1400 °C revealed that nHA sintered at 1000 °C had higher porosity, preferable pore size and better capacity to control P28 release than that sintered at other temperatures. Moreover, the nHA scaffold sintered at 1000 °C with P28 showed improved adhesion, proliferation and osteogenic differentiation of MC3T3‐E1 cells compared with scaffolds lacking P28 or BMP‐2. In vivo, nHA scaffolds sintered at 1000 °C with P28 or BMP‐2 induced greater bone regeneration in critical‐sized rat cranial defects at 6 and 12 weeks post‐implantation compared with scaffolds lacking P28 or BMP‐2. Thus, nHA scaffolds sintered at 1000 °C and loaded with P28 may be excellent biomaterials for bone tissue engineering. Copyright © 2016 John Wiley & Sons, Ltd.