Antibacterial properties and hemolysis test of co-doped (Na+, Cu2+/Zn2+, CO32-) hydroxyapatite/(Cu/Zn)Fe2O4 composites for biomedical application

This study presents a one-stage synthesis of multifunctional composites based on co-doped hydroxyapatite (HAP) and zinc/copper ferrites via the evaporation of multicomponent aqueous solutions followed by annealing to 600 °C. X-ray diffraction analysis confirmed the formation of HAP and ferrite phases. The biological evaluation revealed that the synthesized composites possess pronounced membrane-stabilizing properties. In vitro hemolysis assays showed a decrease of the maximum hemolysis level from 57 to 37–49% at adding of composites in concentrations of 1–2 mg/ml, effectively prolonging the hemolysis process by up to 20 s. Furthermore, the composites exhibited noticeable antimicrobial activity against opportunistic pathogens. The composite based on co-doped (0.25 mol% Na⁺, 0.25 mol% Zn²⁺, 0.5 mol% CO₃²⁻)-HAP with 25 wt% of CuFe₂O₄ demonstrated the highest efficacy against Gram-positive Staphylococcus aureus, showing up to a 16.4-fold growth inhibition. In contrast, Gram-negative Pseudomonas aeruginosa displayed higher resistance, likely due to its more complex cell wall structure. Obtained results suggest the potential of the developed co-doped (Na⁺, Cu²⁺/Zn²⁺, CO₃²⁻) hydroxyapatite/(Cu/Zn)Fe₂O₄ composites for biomedical application.