Gentamicin-loaded bioceramic composite coating aimed for biomedical use

Abstract

Electrophoretic deposition (EPD) process was successfully used for obtaining composite antibacterial coating of antibiotic gentamicin (Gent), natural polymer chitosan (CS), and hydroxyapatite (HAP). EPD was carried out on pure titanium (Ti) plates in a single step from three-component aqueous suspension. The gentamicin influence was examined through detailed physico-chemical and biological characterization. The formation of composite HAP/CS and HAP/CS/Gent coatings on the titanium surface was confirmed by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron analysis (XPS). Composite HAP/CS and HAP/CS/Gent coatings exhibited homogeneous, porous fracture-free surface, suggesting strong interfacial interactions between HAP and CS. Biological assays pointed to high potential of HAP/CS/Gent coating for medical applications. Test in suspension and agar diffusion method indicated that the gentamicin addition strongly influenced the antibacterial activity of HAP/CS/Gent against Staphylococcus aureus and Escherichia coli. Biocompatibility assays were performed through MTT and DET tests, indicating low cytotoxicity against MRC-5 and L929 tested cell lines. The coating ability to induce and promote osteoconduction was proved by ALP assay suggesting that HAP/CS/Gent coating is an excellent material for bone tissue engineering.