Study of nanohydroxyapatite composites loaded with gentamicin sulfate and silver nanoparticles

The aim of the work is to compare the properties of nanohydroxyapatite coatings containing antibiotic - gentamicin or silver nanoparticles. The coatings were obtained using the electrophoretic deposition method (EDP). The additives were introduced by the immersion method. Evaluation of the coating was performed by using a Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectrometer (EDX), and a drop shape analyzer. Antibacterial properties were examined by assessing the surface after incubation in a bacterial solution for 30 days. The corrosion properties of the materials were also assessed. Silver nanoparticles and the antibiotic were successfully incorporated into the nanohydroxyapatite coating. The wettability test shows the hydrophilic behavior of the coatings that contains an antibiotic. Furthermore, the average contact angle (CA) value for nanohydroxyapatite doped with silver nanoparticles increased to 120°. The highest surface roughness was observed for the coating containing silver. All nanohydroxapatite modifications improved the corrosion resistance of the titanium alloy, but the best results were obtained by nanohydroxapatite with AgNPs, where the Icorr parameter was 15.5 ± 3.9 μA/cm², Ecorr showed the most positive value of 25.6 ± 1.7 mV, and Rpol was 8.1 ± 0.2 kΩ cm². For comparison, the corresponding values for the nHAp coating are: 41.7 ± 1.9 μA/cm², -56.1 ± 1.6 mV, 3.6 ± 0.4 kΩ cm². It was found that both the coating with added AgNPs and the one with a higher concentration of gentamicin exhibited antibacterial properties. It can be stated that the silver-containing coating shows greater potential for combating perioperative infections due to the combination of good corrosion resistance and broad-spectrum antibacterial properties.