Synergistic Effect of Strontium Doping and Surfactant Addition in Mesoporous Bioactive Glass for Enhanced Osteogenic Bioactivity and Advanced Bone Regeneration

Polymers (Basel). 2025 Jan 14;17(2):187. doi: 10.3390/polym17020187.

Abstract

Mesoporous bioactive glass (MBG) is an advanced biomaterial widely recognized for its application in bone regenerative engineering. This study synthesized an MBG powder (80 mol% SiO2, 5 mol% P2O5, and 15 mol% CaO) using a facile sol-gel method with the non-ionic surfactant Pluronic® P123, which acted as a pore-forming agent. MBGs form bioactive surfaces that facilitate HA formation, and the presence of Pluronic® P123 increases the surface area and promotes HA nucleation. Various percentages of strontium (Sr) doping were examined to improve bioreactivity, biological response, and bone formation, with 3SMBG (3 mol% Sr) showing the highest specific surface area. In vitro biocompatibility tests revealed HA formation on all glass surfaces after immersion in simulated body fluid (SBF), indicated by sheet-like HA morphologies, the presence of PO43- and CO32- functional groups, and the amorphous structure along with SrCO3 crystalline phases corresponding to HA and Sr-HA structures. Sr doping resulted in delayed initial degradation and sustained release of Sr2+, achieving over 95% cell viability. Surfactant-induced mesoporous structure and Sr incorporation synergistically enhance osteocyte induction and formation in vitro. These findings suggest that Sr-doped MBG, particularly with P123-assisted Sr/Ca substitution, optimizes the material's properties for advanced bone regenerative applications.

Keywords: P123; bone tissue engineering; hydroxyapatite; mesoporous bioactive glass; strontium.