Work

Bioactive borate glass-hydroxyapatite composites: Influence of the sintering temperature on structural properties and in vitro bioactivity

Year: 2025

Type: article

Abstract: Recent research efforts have focused on combining hydroxyapatite (HA) with various bioactive glasses to create composite materials for biomedical applications. This research aimed to develop a new group of hydroxyapatite/borate glass composites and to investigate the influence of sintering temperature in the structural properties and in vitro bioactivity. The composites were synthesized using two concentrations (25/75 wt% and 50/50 wt% - bioactive glass/hydroxyapatite) and two sintering temperatures (530 and 1000 °C). The composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), in vitro bioactivity tests in simulated body fluid (SBF), and pH measurements. XRD and FT-IR analyses were performed before and after immersion in SBF solution. Before immersion in SBF, the composites, heat-treated at 530 °C, do not present additional phase formation. However, at 1000 °C, the composites present an NaCaPO 4 additional phase, due to the hydroxyapatite decomposition. XRD and FT-IR results, after immersion in SBF, confirmed the interaction between the ions from the composite and the ions present in the SBF solution. Composite 50BG_530 showed a silver chloride phase, indicating a potential antibacterial activity. 25BG_1000 presented an increase in the crystallinity of the HA phase, as a function of soaking time. Composite 50BG_1000 showed a decrease of NaCaPO 4 phase and an increase of HA's phase, improving the in vitro bioactivity. Based in these results, all composites presented good potential to be applied in bone regeneration. • Novel bioactive borate glass-hydroxyapatite composites. • Glass content and sintering temperature change the structure of the composites. • Composite 50BG_530 showed a potential antibacterial activity. • Composite 50BG_1000 exhibited an increase in the HA phase. • All composites presented good potential to be applied in bone regeneration.

Source: Next Materials

DOI: 10.1016/j.nxmate.2025.100589