Titanium incorporated Zinc-Phosphate bioactive glasses for bone tissue repair and regeneration: Impact of Ti4+on physico-mechanical and in vitro bioactivity

A novel glass system 8ZnO–22Na2O–(24-x)CaO–46P2O5–xTiO2 (x = 0.2, 0.4, 0.6, 0.8 and 1 mol%) was fabricated and investigated in detail for the appropriateness in the use of bone repair and regeneration applications. In this context, we explored the structural, thermal, mechanical, degradation, pH evaluation along with antibacterial assay, cytocompatability and cell proliferation by various characterization techniques like X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Energy dispersive spectrometry (EDS) and differential thermal analysis (DTA), Vickers hardness, cell counting kit (CCK8) method and agar plates method. The obtained results of density, thermal stability and Vickers hardness increase with the increasing content of TiO2 leads to the densification of glass structure dueto formation new linkages P–O–Ti and enters into the network in the form of either TiO4 or TiO5/6 structural units. The formation of a rich crystalline hydroxyl apatite (HAp) layer on the samples with incubation time (3, 7, 14 and 21days) and content of TiO2 up to 0.6 mol% in simulated body fluid (SBF) were confirmed by in vitro analysis. Interestingly, no inhibitory effects on HAp layer formation with the addition of titanium up to 1 mol% were noticed. Lower degradation rate and pH values endorsed to hydration resistant with Ti4+ inclusion, leads to controlled ion leaching. The rat mesenchymal stem cells (rMSCs) growth on glass samples showed the enhanced biocompatibility and proliferation without toxicity. In addition, all glasses possess good antimicrobial properties against bacterial species Escherichia coli (E.coli). Finally, the results revealed that the 0.6 mol% of TiO2 glass (T.6) showed abundant performance for bone generation applications.