Synthesis, characterization, and antimicrobial properties of hydroxyapatite/montmorillonite composite enriched with strontium

This study aims to develop a new composite based on hydroxyapatite/montmorillonite enriched with strontium (HAP/Sr-MMT) with enhanced properties for bone tissue engineering applications. Composites HAP/Sr-MMT were in-situ synthesized via co-precipitation method with a Ca/P molar ratio of 1.67 and different percentages of Sr-MMT (1, 5, 10, 20, 30wt.%). Techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) were used to evaluate the physico-chemical properties of the prepared composites. The antimicrobial properties of the composites were also evaluated. The XRD analysis of dried composites confirmed the presence of apatite and clay mineral phases. After calcination, the decomposition of the HAP structure prepared with a higher amount of Sr-MMT and the formation of β and α-Ca3(PO4)2 phases was shown. FT-IR analysis confirmed the existence of surface interactions between apatitic structure and modified clay. SEM observations demonstrated the effect of added clay on the morphology of the particle composites. Antimicrobial tests showed that the composites exhibited enhanced antimicrobial properties against the tested strains. These results suggest that the new obtained composite materials with good antimicrobial properties can potentially serve as biomaterials for bone tissue engineering applications.