Antibacterial activity of carbonate hydroxyapatite-based honeycomb scaffolds doped with zinc for medical implants

BackgroundThe utilization of bioceramics for medical implants necessitates the incorporation of antibacterial properties to mitigate post-surgical inflammation of bone tissue.ObjectiveIn this research, Zn²⁺ ions were introduced as an antibacterial agent into carbonate-hydroxyapatite-based honeycomb Scaffold bioceramics (CHA/HCB), with varying doping concentrations, to investigate the impact of Zn²⁺ on the antibacterial activity of CHA/HCB against Staphylococcus aureus and Pseudomonas aeruginosa.MethodsCHA was synthesized from abalone shells through the co-precipitation method, followed by the fabrication of a CHA-based scaffold with HCB using the porogen leaching technique. Subsequently, the Zn ion doping process was executed through the ion exchange method, using concentrations of 0.05 M, 0.1 M, 0.15 M, and 0.2 M. The samples were characterized using XRF and antibacterial test.ResultsThe XRF results revealed that the Ca/P ratio of CHA/HCB was within the range of 1.48-1.85, indicating a declining trend with the introduction of Zn²⁺ as a dopant. Nevertheless, these results remained within acceptable ranges, ensuring compatibility with bone tissue. In terms of antibacterial activity, the measured inhibition zone diameters increased alongside the increase of Zn concentration. The zone diameters ranged from 14.3 to 22.0 mm against Staphylococcus aureus and 13.7 to 21.4 mm against Pseudomonas aeruginosa.ConclusionThe findings suggest that Zn doping in CHA/HCB bioceramics has a potential an antibacterial agent in CHA scaffolds as well as potential for practical applications, particularly in reducing the risk of postoperative infection in bone tissue implantation.