Investigating the biomedical potential of MgO-45S5 bioglass/hydroxyapatite nanocomposite scaffolds: In vitro degradation, surface mineralization, biocompatibility and osteogenesis

The development of a hydroxyapatite (HA)-based scaffold with high degradability and bioactivity was essential for advancing bone defect repair. In this study, HA, MgO/HA and MgO-45S5 bioglass/HA scaffolds were fabricated via spark plasma sintering, and a comprehensive comparative analysis was conducted on their degradation behavior, surface mineralization, biocompatibility and osteogenesis. The results showed that the addition of MgO and BG enabled the HA-based scaffolds to maintain a nanocrystalline structure. Compared with HA and MgO/HA scaffolds, the MgO-45S5 bioglass/HA scaffold demonstrated an increased porosity of 77.15% and improved pore interconnectivity. Moreover, the composite scaffolds exhibited higher degradation rate (75.42%) after 12 weeks, and substantial apatite deposition was detected on its scaffold surface as early as 1 day. In vitro cell assays indicated that the scaffold displayed excellent biocompatibility and enhanced osteogenic characteristics ( P  <  0.0001 ). Fundamentally, the enhanced degradability was attributed to the increased surface reactivity associated with the nanocrystalline structure and high porosity. Meanwhile, it facilitated the substantial release of Mg²⁺, Si⁴⁺, Ca²⁺ and PO₄³⁻ ions, which promoted surface mineralization and activated cellular responses. These findings suggest that the co-addition of MgO and 45S5 bioglass markedly improves the functional properties and potential of the scaffold for biomedical applications. Download: Download high-res image (316KB) Download: Download full-size image