Titanium dioxide (TiO(2)) nanoparticles filled poly(D,L lactid acid) (PDLLA) matrix composites for bone tissue engineering

Titanium dioxide (TiO(2)) nanoparticles were investigated for bone tissue engineering applications with regard to bioactivity and particle cytotoxicity. Composite films on the basis of poly(D,L lactid acid) (PDLLA) filled with 0, 5 and 30 wt% TiO(2) nanoparticles were processed by solvent casting. Bioactivity, characterised by formation of hydroxyapatite (HA) on the materials surface, was investigated for both the free TiO(2) nanoparticles and PDLLA/TiO(2) composite films upon immersion in supersaturated simulated body fluid (1.5 SBF) for up to 3 weeks. Non-stoichiometric HA nanocrystals (ns-HA) with an average diameter of 40 nm were formed on the high content (30 wt% TiO(2)) composite films after 2 weeks of immersion in 1.5 SBF. For the pure PDLLA film and the low content composite films (5 wt% TiO(2)) trace amounts of ns-HA nanocrystals were apparent after 3 weeks. The TiO(2) nanopowder alone showed no bioactivity. The effect of TiO(2) nanoparticles (0.5-10,000 microg/mL) on MG-63 osteoblast-like cell metabolic activity was assessed by the MTT assay. TiO(2) particle concentrations of up to 100 microg/mL had no significant effect on MG-63 cell viability.