Hydroxyapatite layer evolution on silica-based (45S10P) bioactive glass-ceramic nanoparticles doped with Zn2+ ions: Augmentation of in vitro bioactivity, antibacterial activity and textural modification for bone regeneration

Zinc-incorporated bioactive glasses (BG) and bioactive glass-ceramic (BGC) nanoparticles (BGC-NPs) represent highly adaptable, biodegradable, and bioactive materials in tissue engineering and regenerative medicine. This study delves into the synthesis, characterization and biomedical implications of Zn²⁺ ions-doped 45S10P spherical BGC-NPs, employing analytical techniques and in vitro assays. The resulting (Zn²⁺+ 45S10P) BGC-NPs, prepared using a modified Strober's method, exhibited spherical morphology with excellent dispersion, as verified by TEM, FE-SEM, and DLS analyses. XRD, FTIR, and FESEM analysis revealed an augmented hydroxyapatite (HAp) layer formation with increasing zinc content. Zeta potential analysis showcased a shift from negative to positive values after immersion in simulated body fluid (SBF), indicating the bioactive potential of the developed BGC-NPs. Hemocompatibility assays indicated the biocompatibility of all BGC-NPs, demonstrating minimal hemolytic effects with incorporating Zn²⁺ ions below a standard threshold (<5 % lysis). Further, the migration assay revealed the potentiality of the BGC-NPs to stimulate the migration of HeLa cells. Cell viability assays employing MG-63 osteoblast-like cells highlighted enhanced cell viability over time, underscoring their non-toxic nature and potential for tissue regeneration. Antibacterial assays displayed significant inhibitory effects against Gram-negative compared to Gram-positive bacteria, underscoring their potential for anti-infection applications. Overall, the results affirm the promising prospects of Zinc incorporation into 45S10P BGC-NPs for bone tissue regeneration applications.