In-vitro performance of titania reinforced hydroxyapatite nanopowders-a microstudy

Bioinert cum bioactive titania reinforced hydroxyapatite (T-HAP) nanopowders (NPs) have been receiving great attention in load-bearing orthopedic and dental implant applications. This study comprehensively evaluated the in vitro performance of T-HAP NPs immersed in SBF for different durations for 7 and 30 days. Duration of immersion had little effect on phase constitution of phase pure and T-HAP NPs as suggested by XRD analysis. Rietveld refinement suggested that with the increase in duration of immersion, inter-atomic distance between atoms of HAP phase and crystallinity of NPs decreased, whereas lattice parameters, cell volume, crystal size, and microstrain in T-HAP NPs increased. FTIR supported XRD phase analysis and suggested bone-like apatitic formation in all NPs. SEM indicated the agglomeration of NPs composed of particles of irregular shapes and sizes. EDX results corroborated with XRD and FTIR results. Hydrodynamic diameter measured using DLS were compared to be significantly bigger than crystal sizes (Rietveld and Scherrer) calculated using XRD data. During in vitro study, pH measurement of SBF suggested the bioactive nature of all NPs and also revealed the higher rate of solubility of T-HAP NPs. All T-HAP NPs gained weight after respective days of immersion in SBF. Hence, this study systematically and minutely evaluated the in vitro performance of T-HAP NPs immersed for different durations in SBF.