Improved bioactivity properties of SiO2-CaO-P2O5 glasses by using calcium l-lactate pentahydrate as calcium oxide precursor

In this work, SiO2-CaO-P2O5 based bioactive glasses were synthesized by the sol-gel method using calcium l-lactate pentahydrate and calcium nitrate tetrahydrate (CaNT) as calcium oxide precursors in order to achieve an improvement of the material bioactivity. The obtained samples were characterized by X-ray diffraction (XRD), FT-IR spectroscopy and scanning electron microscopy, then they were assessed from the perspective of their bioactive properties, while the textural properties were evaluated by Brunauer-Emmett-Teller method. The XRD pattern confirms the amorphous structure for all samples, except the glass synthesized with CaNT, where few crystallization centres associated with apatite phase were identified. A higher specific surface area and pore volume were obtained for the glasses prepared with calcium l-lactate pentahydrate in comparison with those obtained by using CaNT, result that was expected to be favorable in terms of bioactivity. The in vitro bioactivity assessment revealed the occurrence of a more pronounced apatite layer onto the glass' surfaces prepared with calcium l-lactate pentahydrate than as for the samples obtained with CaNT.