Luminescent mesoporous bioactive glass nanoparticles: Samarium-doping for enhanced bone regeneration, antibacterial activity, and bioimaging.

Developing multifunctional bioactive materials capable of promoting bone regeneration while enabling real-time monitoring remains a significant challenge in tissue engineering. In this study, samarium (Sm3+)-doped mesoporous bioactive glass nanoparticles (Sm-MBGNs) were successfully synthesized via a sol-gel method assisted by a microemulsion process to enhance both biological functionality and imaging capability. The incorporation of Sm3+ ions into the silicate network was systematically investigated, revealing improved structural and textural properties, including high specific surface area and well-defined mesoporosity. In vitro bioactivity was evaluated through simulated body fluid (SBF) immersion, where hydroxyapatite formation was observed and confirmed using physicochemical and structural analyses. The evolution of the apatite layer was also monitored through photoluminescence emission, indicating the potential of Sm-MBGNs for fluorescence-based bioactivity tracking. Cytocompatibility assessed using MG-63 osteoblast-like cells via MTT assay, along with hemolysis studies, demonstrated good biocompatibility. The samples exhibited noticeable antibacterial activity against Escherichia coli and Staphylococcus aureus based on inhibition zone measurements. Overall, the results suggest that Sm-MBGNs possess promising bioactivity, antibacterial behavior, and luminescent properties, indicating their potential as multifunctional materials for bone regeneration and bioimaging applications, although further quantitative validation is required.