Silver@Hydroxyapatite functionalized calcium carbonate composites: characterization, antibacterial and antibiofilm activities and cytotoxicity

Silver@Hydroxyapatite functionalized calcium carbonate composites have been prepared through different
sustainable methods, without involving the use of organic solvents and additional reagents. The composites were
characterized by X-ray powder diffraction, field emission scanning electron microscopy, transmission electron
microscopy, spectrophotometric measurements and X-ray photoemission spectroscopy. From the characterization
techniques, the obtained nanoparticles resulted constituted essentially by Ag3PO4 nanostructures, whose size
varied from 70 to 100 nm and were uniformly distributed on the calcium carbonate surface. Upon VIS irradiation,
the formation of plasmonic nanostructures with a more defined dimensional distribution and reduced size
could be obtained, as a prove of a partial silver reduction. All composites exhibited good antimicrobial and
antibiofilm activities against Staphylococcus aureus and Pseudomonas aeruginosa whereas they showed low
cytotoxicity effects towards human skin keratinocytes and human fibroblasts. These results enable these composites
to be promising candidates for biomedical and pharmaceutical applications.