PMC:4137170 / 30055-30876 JSONTXT

Gelatin release kinetics has indicated that the initial burst of rhBMP-2 is achieved by diffusion [34, 35]. However, in a situation where sustained release primarily occurs, enzymatic degradation is the more important mechanism [35]. As shown in the present study, the porous β-TCP microsphere and hyaluronic acid powder gel composite may not release sufficient amounts of rhBMP-2 in situations where sustained release occurs due to the strong binding of rhBM-2. In fact, the ratio and particle size of the β-TCP microsphere are important in determining the degradation rate [36]. Moreover, the β-TCP used in this study had a particle size ranging from 45 to 75 μm and it was less degraded than a nano-sized β-TCP. Therefore, in order to achieve the maximum efficacy of rhBMP-2, the composite properties must be improved.