Effects of functional groups on the structure, physicochemical and biological properties of mesoporous bioactive glass scaffolds.

Functionalization of biomaterials with specific functional groups is one of the most straightforward strategies to induce specific cell responses to biomaterials. In this study, thiol (SH) and amino (NH) functional groups have been successfully modified on the surfaces of mesoporous bioactive glass (MBG) scaffolds to form thiol-functionalized MBG (SH-MBG) and amino-functionalized MBG (NH-MBG) scaffolds by a post-grafting technique. The effects of the functional groups on the structure, physicochemical and biological properties of MBG scaffolds were systematically investigated. The results showed that the functionalization of MBG scaffolds did not change their structures, and the SH-MBG and NH-MBG scaffolds still had hierarchical pore architecture (macropores of 300-500 μm and mesopores of 3.5-4 nm) and high porosity (84-86%), similar to the MBG scaffolds. Furthermore, the SH-MBG and NH-MBG scaffolds possessed similar apatite mineralization ability and biocompatibility compared to the MBG scaffolds. Importantly, the SH-MBG and NH-MBG scaffolds significantly stimulated adhesion, proliferation and differentiation of human bone marrow-derived mesenchymal stem cells (hBMSCs). Therefore, functionalization of MBG scaffolds with SH and NH functional groups would be a viable way to tailor the surface characteristics for stimulating biological responses of hBMSCs, and the functionalized MBG scaffolds would be a promising bioactive material for bone tissue engineering applications.