Bioactivity and cytotoxicity of LiF-modified bioactive glass ceramics for bone regeneration

Abstract

Bioactive glasses and glass-ceramics have drawn significant attention due to their excellent bone-bonding capabilities and biocompatibility. This study investigates the effects of lithium fluoride (LiF) addition on the microstructure, mechanical properties, and biocompatibility of novel bioactive glass compositions. Glasses with varying LiF contents (1, 2, and 3 wt%) were synthesized using the melt-quenching method and subsequently heat-treated to obtain bioactive glass-ceramics. X-ray diffraction (XRD) analysis revealed an increase in the intensity of hydroxyapatite, fluorapatite, and diopside phases with increasing LiF content, suggesting enhanced crystallization. Vickers hardness measurements showed a significant improvement, with the highest hardness (730 MPa) observed in the K3 composition. Scanning Electron Microscopy (SEM) was used to examine the microstructural morphology, while Energy-Dispersive X-ray Spectroscopy (EDX) was employed to analyze the elemental composition of the samples. Furthermore, in vitro bioactivity assessments in simulated body fluid (SBF) confirmed the apatite-forming ability of all compositions. Cytotoxicity evaluations demonstrated enhanced cell viability in LiF-containing compositions, with K3 exhibiting the highest biocompatibility. The findings suggest that LiF addition optimizes crystallization, mechanical performance, and biocompatibility, making these modified bioactive glass-ceramics promising candidates for biomedical applications.