Preparation of Zinc-Doped Hydroxyapatite Ceramics and Evaluation of Biocompatibility and Antibacterial Activity

Bacterial resistance and the demand for novel antibacterial strategies represent major challenges in contemporary medicine. In this study, zinc-doped hydroxyapatite (Zn-HA) samples with 3, 5, and 10 wt% Zn(II) were synthesized using wet precipitation synthesis and sintered at 700 and 800 °C. The samples were characterized by X-ray Diffraction, Fourier Transform Infrared Spectroscopy, Raman Spectroscopy, and Scanning Electron Microscopy. The antimicrobial properties of the Zn-HA were tested against four bacterial strains-<i>Staphylococcus aureus</i>, <i>Enterococcus faecalis</i>, <i>Salmonella typhimurium</i>, <i>Escherichia coli</i>-and the fungus Candida albicans. Both 5 wt% and 10 wt% Zn-HA effectively inhibited the growth of all microorganisms. Notably, 10wt% Zn-HA exhibited the best results, with inhibition rates of 50.2% against <i>S. aureus</i>, 36.5% against <i>E. faecalis</i>, 47.5% against <i>P. aeruginosa</i>, 31.8% against <i>E. coli</i>, and 24.7% against <i>C. albicans</i>. There were no significant differences in the growth of adipose mesenchymal stem cells between the prepared samples and the control. For osteogenic differentiation, dye uptake was 1.2 times higher for HA and 5 wt% Zn-HA, and 1.3 times higher for 3 wt% Zn-HA compared to the control. These results suggest that developed ceramics may be effective in regenerative medicine, paving the way for innovative treatments.