Insights into zinc and silver co-substitution over cytotoxicity, antibacterial efficacy, and bone regeneration capabilities of strontium phosphosilicate

Abstract

A series of Zinc and Silver co-substituted Sr5(PO4)2SiO4 samples were developed to evaluate the induction of antibacterial properties within the parent material. Structural evaluation of the powder samples showed a good agreement of diffraction data with respective ICDD data cards, and biocompatible secondary phases were found to be present alongside the parent material. A decrease in crystallite size (<40 nm) was observed as the substitution level increased calculated from Scherrer's equation which was also evident in infrared spectra. 6% molar substitution (Zn-3% & Ag-3%) was found to be optimized concentration for the same based on biocompatibility studies involving Hemolytic and MTT assay against MG-63 cell lines. The samples were identical in morphology to Hydroxyapatite and showed excellent bone regeneration capabilities supported by secondary phases confirmed during SBF treatment studies evaluated using diffraction, IR spectra, and electron microscopy that showed signs of apatite seeding over the particles. Both Qualitative and quantitative antibacterial tests in the form of Media poisoning and CFU calculations proved successful acquisition of antibacterial properties at 6% molar substitution. Hence the proposed system can be deemed antibacterial and biocompatible for human application and further evaluated as a possible substitute for Ca–P ceramics for bone regeneration applications.