The effects of surface bioactivity and sustained-release of genistein from a mesoporous magnesium-calcium-silicate/PK composite stimulating cell responses in vitro, and promoting osteogenesis and enhancing osseointegration in vivo.

The surface of a mesoporous magnesium-calcium-silicate (m-MCS)/polyetheretherketone (PK) composite (MPC) was modified by sand blasting, and genistein (GS) was loaded inside the nanopores of the m-MCS on the modified MPC (MPCm) surface. The results showed that compared with MPC, the surface roughness and hydrophilcity of MPCm obviously improved with more m-MCS exposed on its surface. Moreover, no obvious differences in surface roughness and hydrophilcity were found between MPCm and GS loaded MPCm (MPCm-Ge), and both of them possessed an improved apatite mineralization ability in simulated body fluid solution (SBF) compared with MPC, indicating excellent surface bioactivity. Moreover, the MPCm obviously stimulated the adhesion, proliferation, differentiation and gene expressions of MC3T3-E1 cells compared with MPC, and the sustained-release of GS from the MPCm-Ge surface further significantly promoted the cell proliferation, differentiation and gene expression. According to the Micro-CT, histological and SEM analysis, the results demonstrated that the MPCm obviously improved osteogenesis and enhanced osseointegration in vivo compared with MPC, and the release of GS from the MPCm-Ge surface further significantly improved osteogenesis and enhanced osseointegration. In summary, the significant promotion of cell responses in vitro, and the improvements of osteogenesis and the enhancement of osseointegration in vivo were attributed to the effects of surface bioactivity and GS sustained-release from the MPCm-Ge surface. Therefore, MPCm-Ge would be a potential candidate for orthopedic and dental applications.