In Vitro Biological Evaluations of Zn Doped CaSiO₃ Synthesized by Sol–Gel Combustion Technique

Abstract

Wollastonite (CaSiO₃) is one of the calcium silicate based material and is widely applied in hard tissue engineering applications. Combustion based sol–gel method was adopted to prepare the phase pure CaSiO₃ with inclusion of Zn ions (1, 3 and 5 wt%) using glycine as a reducing agent. The synthesized pure and Zn doped CaSiO₃ powders were characterized by attenuated total reflectance–Fourier transform infrared spectroscopy (ATR–FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), dynamic light scattering (DLS), scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS), transmission electron microscopy (TEM) analyses to confirm their functional groups, phase composition, thermal stability, particle size, surface morphology and topography, respectively. In vitro biological examinations were carried out to evaluate the biological behaviour of pure and Zn doped CaSiO₃ powders. The antibacterial activity was tested for 1–5 wt% of Zn doped CaSiO₃ powders against E. coli and S. aureus by colony forming unit (CFU) which proved that with increase of Zn concentration, the microbial restriction was found to be enhanced for both pathogens than control and pure CaSiO₃. In vitro apatite layer formation was observed on the surface of Zn doped CaSiO₃ powders with existence of ball like crystals for 14 days. In vitro cytocompatible study revealed that 5 wt% of Zn doped CaSiO₃ powder exhibited good cellular interaction of MG-63 cells at concentrations of 200–1000 µg/ml for 24 h. Thus, these biological studies reveal that the developed Zn doped CaSiO₃ powders could be applied for better clinical applications.