h-BN Reinforced Bioactive Glasses for Bone Tissue Engineering: Enhanced Strength and Antibacterial Properties

Bioactive glasses (BGs) have garnered significant attention for their potential to enhance mechanical and biological performance in bone and tissue engineering applications. This study presents the first-ever incorporation of hexagonal boron nitride (h-BN) into BGs derived from the SiO2–K2O–CaO–P2O5 system using the conventional melt-quenching technique. The substitution of h-BN was systematically achieved by reducing the CaO content, leading to distinct changes in the physical, structural, and optical properties of the glass. X-ray diffraction (XRD) confirmed the amorphous nature of the fabricated BGs, while the optimized sample exhibited significantly enhanced density (2.584 g/cm3) and compressive strength (456 MPa). Comprehensive structural investigations were conducted using 2D PASS magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy for 29Si, 11B, and 31P nuclei, elucidating the network structure modifications induced by h-BN inclusion. Biological evaluations revealed improved biocompatibility and cellular interactions with osteoblast-like MG-63 cells, as well as positive responses in Drosophila larvae, indicating their suitability for bone tissue engineering. Furthermore, the h-BN-doped BGs demonstrated pronounced antibacterial activity against both Gram-positive (S. pyogenes, B. subtilis) and Gram-negative (E. coli and P. aeruginosa) bacterial strains. Herein, the novelty of this work lies in exploring the unique role of h-BN, a rarely studied additive in BG matrices, which has been shown to impart superior mechanical strength and antibacterial efficacy. These findings highlight the potential of h-BN-doped BGs as promising candidates for next-generation biomedical applications, offering a novel pathway for the development of multifunctional biomaterials.