Fabrication, characterisation and assessment of bioactivity of poly(d,l lactid acid) (PDLLA)/TiO2 nanocomposite films

This study deals with the fabrication and characterisation of polymer matrix composites containing titanium dioxide (TiO2) nanoparticles. Poly(d,l lactid acid) (PDLLA) films incorporated with different percentages (0, 5, 20 wt%) of TiO2 nanoparticles were prepared by solvent casting and characterised by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The in vitro bioactive properties of the films were assessed after immersion in simulated body fluid (SBF) for up to 21 days. No hydroxyapatite (HA) formation was observed on the surfaces, neither for pure PDLLA samples nor for PDLLA samples filled with TiO2 nanoparticles. This confirms that under simulated physiological conditions, TiO2 nanoparticles do not impart bioactivity to the PDLLA matrix. The present study provides an analytical method for the assessment of the suitability of titanium dioxide nanoparticles to be used as filler in resorbable polymer matrices for biomedical applications.