The adsorption of bone‐related proteins on calcium phosphate ceramic particles with different phase composition and its adsorption kinetics

Calcium phosphate (CaP) ceramics, especially hydroxyapatite and biphasic calcium phosphate (BCP), have attracted significant interest in bone tissue engineering because of their compositional similarities to bone mineral and excellent biocompatibility. The purpose of this study is to investigate the effect of phase compositions of CaP ceramics on their bone morphogenetic protein‐2 (BMP‐2) adsorption behaviours in phosphate‐buffered saline. The BCP material surface probably has more adsorption sites which can adsorb more BMP‐2 molecules. Langmuir, Frundlich, and Temkin isotherm models were used to describe the adsorption of BMP‐2 onto CaP ceramics. The Langmuir isotherm model fit the equilibrium data better than the Frundlich and Temkin isotherm models. The pseudo‐first‐order kinetic model is suitable for the description of the adsorption kinetics, and 240 min is thought to be the optimal adsorption time. A possible adsorption mechanism has been proposed. The electrostatic interaction plays an important role in the adsorption processes. In addition, the BMP‐2 could be adsorbed to the surface which showed slight conformational changes analysed by Fourier transform infrared spectroscopy. Copyright © 2016 John Wiley & Sons, Ltd.