Large-pore mesoporous Ca–Si-based bioceramics with high in vitro bioactivity and protein adsorption capability for bone tissue regeneration

Abstract

Mesoporous Ca–Si-based bioceramics represented by mesoporous bioactive glasses (MBG) have attracted much attention in the field of bone tissue regeneration due to their excellent bioactivity, biocompatibility and osteoconductivity. However, the small mesopores (<7 nm) have greatly hindered their ability to encapsulate macromolecular proteins with ability to significantly induce bone growth. To solve this problem, a novel type of large-pore mesoporous silica (LPMS) was first synthesized using a simple one-step method at high temperatures. Solid reactions were then carried out to synthesize large-pore mesoporous Ca–Si-based bioceramics (LPMSCs) using LPMS as both the template and silicon source, and Ca(NO₃)₂ as the calcium source. The prepared LPMSCs not only displayed large-diameter (>15 nm) mesopores, but also high in vitro bioactivities. Bovine serum albumin (BSA) was used as a model protein to evaluate the adsorption capacity and release properties of our synthesized products for proteins. The results demonstrated that BSA could be encapsulated into the LPMSCs, with a slow and sustained release behaviour. Furthermore, in vitro cell tests showed the LPMSCs to have a favourable effect on proliferation and osteogenetic differentiation. These findings indicate that LPMSCs could be used as a bioactive protein adsorption and release system for preparation of bone implant materials.