Robust hierarchical porous MBG scaffolds with promoted biomineralization ability

Although bioactive glasses have been traditionally used in the clinical practice for a long period, their uncontrollable architecture and poor mechanical robustness remains a neck bottle for further biomedical applications. In this study, we firstly developed a series of mesoporous bioactive glass (MBG) nanorods with different aspect ratios and adjustable pore sizes via a thermal-mediation approach. The nanorods were then dispersed in MBG sol, followed by impregnation with sponge and in situ gelation. After sinter treatment, the sponge template was removed to offer interconnected macroporous structure, while the intercross-linked MBG nanorods afford meso- and micro- pores. The resulting scaffolds presented a 2-fold reinforcement in compressive strength (1.03 MPa) which is matchable to that of cancellous bone. When their mesopore size was tuned to 7.38 nm, the scaffolds enabled an optimal protein adsorption capacity and sustainable release property. Upon 3-day incubation in simulated body fluid, the scaffolds with macro/meso/micro porous structure present more needle-like hydroxyapatites, indicating their promoted biomineralization capacity. After culture with rat bone marrow stromal cells for 1 day, the hierarchical porous scaffolds displayed good cell attachment and proliferation ability, suggesting their potential as a kind of scaffolds for tissue engineering.