Surface modification of bioactive glasses for successful incorporation with poly(lactic-co-glycolic acid) (PLGA)†

Bioactive glass (BG)–polymer composites are promising materials for bone grafting in bone tissue regeneration. BG provides rigidity and can initiate bone growth, whereas the polymer matrix provides flexibility and biocompatibility. However, due to the complex composition of BG, incorporation into the polymer matrix is difficult and often leads to unwanted porosity and low interface strength between both components. In this study, we investigate the surface treatment of commercially available micronized melt-derived BG with varying compositions (45S5 and 1393) to improve its incorporation into a poly(lactic-co-glycolic acid) (PLGA) matrix by improving surface roughness, surface charge and active sites on the BG. The surfaces of BG are modified by treatment in simulated body fluid (SBF) for 3 days prior to composite production. This leads to the formation of carbonated hydroxyapatite on the surface of both BG types, as demonstrated by XRD, FTIR, XPS and EDX. This also leads to a change in surface texture and an increase in specific surface area from initially 3 to 116 m² g⁻¹ and from 2 to 65 m² g⁻¹ for 45S5 and 1393, respectively. Subsequently, composite PLGA–BG microspheres are fabricated using a probe-ultrasonication assisted solid-in-oil-in-water emulsion method. Additionally, the surface interaction of bioactive glasses with PLGA is discussed in detail.