Organic/inorganic bioactive materials part IV: In vitro assessment of bioactivity of gelatin-calcium phosphate silicate/wollastonite hybrids

Biohybrids consisting of gelatin (G) and calcium phosphate silicate/wollastonite (CPS/W) have not been prepared so far. In this work our results are focused on the possibility of obtaining G-CPS/W bioactive hybrids in vitro. XRD, FTIR, SEM/EDS techniques were employed to characterize the synthesized hybrid materials. FTIR shows that before immersion in 1.5 SBF the “red shift” of COO- band for pure G is observed. The presence of this bond could be attributed to the formation of COO-Ca²⁺ via non-biomimetic route. After immersion in 1.5 SBF, FTIR shows the presence of A- and B-type carbonate containing hydroxyapatite (A/B-CO₃HA). ESD and FTIR show that small amount of calcite (CaCO₃) are present after in vitro test in 1.5 SBF for 3 days. XRD reveals that CO₃HA and small amounts of CaCO₃ can be detected after in vitro test. SEM results obtained for immersed samples show that hydroxyapatite (HA) particles fully covered the surface of the hybrids by a layer composed of spherulites. At higher magnification, very small elongated crystallites could be observed.