Magnesium (Mg) possesses desirable properties for biomedical applications but suffers from limitations in mechanical strength. This study explores Mg-Boron Nitride (BNNS) nanocomposites as a potential solution. We investigate the microhardness and cytocompatibility of these nanocomposites to assess their suitability for biomedical use. Vickers microhardness testing revealed a significant enhancement (1.5 times) in microhardness with the incorporation of 15 vol.% BNNS nanoparticles. This improvement can be attributed to the presence of BNNS nanoparticles at grain boundaries, hindering dislocation movement and twinning within the Mg matrix. Cytotoxicity evaluation using mouse osteocyte cells demonstrated good cytocompatibility for both bare Mg and Mg-BNNS nanocomposites with low BNNS content. The viability improved with increasing dilution, suggesting a dose-dependent response. These findings highlight the potential of Mg-BNNS nanocomposites for biomedical applications. The increased microhardness offers promise for improved mechanical performance, while the good cytocompatibility at low BNNS content indicates biocompatibility. Future research will focus on optimizing BNNS content, exploring surface functionalization strategies for further cytotoxicity mitigation, and conducting long-term biocompatibility studies.

Keywords: Microhardness, Cytocompatibility.