Sol-Gel Synthesis and Characterisation of Nano-sized Hydroxyapatite Powders and Hydroxyapatite/ Poly(D,L-lactide-co-glycolide) Composite Scaffolds

Nano-sized hydroxyapatite (NHA) powders were prepared from calcium nitrate Ca(NO ₃ ) ₂ •4H ₂ O and phosphorus pentoxide using a sol–gel approach. The effects of processing parameters on the composition granularity, and morphologies of hydroxyapatite powders were investigated by thermo-gravimetry/differential scanning calorimetry, X-ray diffraction Fourier Transform-infrared spectroscopy, laser particle analysis and transmission electron microscopy. High purity HA powders with particle size of 30–100 nm were obtained by calcining HA gel at 600 °C. The granularity had a narrow distribution and the particles were dispersed well at 600 °C. Hydroxyapatite/poly(D,L-lactide-co-glycolide) (NHA/PLGA) composite scaffolds were prepared by thermally induced phase separation. The compressive strength and water absorption of the scaffolds were investigated. Their mechanical strength increased significantly with the addition of NHA. The composites with 25 wt.% of NHA exhibited good mechanical properties with an average compressive strength of 2.53 MPa. The hydrophilicity increased with the addition of NHA too. NHA/PLGA scaffolds could be a candidate for tissue engineering.