Fascinating osteoblast compatibility and antibacterial activity of HA-Ta2O5 composite coating deposited by plasma electrolytic oxidation

Abstract

This study concentrated on improving the characteristics of hydroxyapatite (HA) coatings through the addition of varying concentrations of tantalum pentoxide (Ta₂O₅) nanoparticles, ranging from 0 to 1.5 g/L, to the electrolyte solution. The HA-Ta₂O₅ composite coatings were deposited on the Ti6Al4V metallic implant utilizing the plasma electrolytic oxidation (PEO) method. Although the addition of Ta₂O₅ nanoparticles to the electrolyte did not vary the phase composition of the films, more compact and denser coatings were achieved with the embedded nanoparticles. Energy-dispersive X-ray spectroscopy (EDS) elemental mapping and Fourier transform infrared spectroscopy (FTIR) tests were used to confirm the codeposition of the nanoparticles with the HA matrix, and evaluate the uniformity of the nanoparticle distribution throughout the coating. The compatibility of the coatings with osteoblast cells was determined using the MG-63 osteoblastic cell line. The findings indicated a beneficial effect of the incorporated Ta₂O₅ nanoparticles on osteoblastic cell functions adhered to the composite coatings. Additionally, the antibacterial activity of the coatings against Escherichia coli and Staphylococcus aureus pathogenic bacteria was examined by plate-counting assay, and results indicated that the higher nanoparticle content in the coatings stimulated the more robust antibacterial activity. The adopted strategy is capable of rendering substantial progress in surface modification of the metallic implants.