Initial assessment of nitrogen-doped reduced graphene oxide-enhanced 76S mesoporous bioactive glass: structural, mechanical, and biological analysis

Silica-based mesoporous bioactive glass (MBG) has attracted significant attention due to its excellent bioactivity, biodegradability, and biocompatibility, making it highly suitable for biomedical applications, particularly as scaffolds for tissue engineering. However, its limited antibacterial and mechanical properties remain major drawbacks. In this study, these limitations were achieved by incorporating nitrogen-doped reduced graphene oxide (N-rGO) into 76S MBG. The results demonstrated that the addition of N-rGO (up to 3 wt%) could enhance both the elastic modulus and hardness by approximately 11.33 GPa and 0.06 GPa, respectively, as confirmed by nanoindentation, while maintaining adequate cytocompatibility ( > 79.52 % cell viability). Furthermore, increasing the N-rGO content led to progressively higher antibacterial activity against E. coli . However, in vitro bioactivity decreased with increasing N-rGO content after 14 days of immersion in SBF, likely due to a reduction in surface area and pore volume. Furthermore, in vitro cytotoxicity assays indicated that higher N-rGO loading reduced the viability of MC3T3-E1 osteoblast cells.