Electrochemically obtained bioactive nanocomposite coating based on hydroxyapatite and chitosan loaded with gentamicin

Abstract

A broad spectrum antibiotic-gentamicin was loaded in a composite coating of hydroxyapatite (HAP) with natural polymer chitosan (CS) using electrophoretic deposition (EPD) technique. EPD was carried out at the constant voltage on pure titanium plates from an aqueous suspension. The aim was to assemble porous homogenous coating with improved mechanical strength and favourable antibacterial properties. HAP/CS/Gent coating was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and field emission scanning electron microscopy (FESEM). Obtained results confirmed the formation of a new composite coating HAP/CS/Gent. In the XRD spectrum of HAP/CS/Gent only characteristic crystal planes of HAP were detected. FTIR analysis confirmed the formation of intermolecular and intramolecular hydrogen bonds in the composite coating. TGA analysis was employed to investigate the thermal stability of HAP/CS/Gent. The bioactivity of HAP/CS/Gent composite coating was proved by SEM analysis. The obtained SEM micrographs indicate the biomimetic growth of a new apatite layer after immersion in SBF. The antibiotic loaded coating (HAP/CS/Gent) exhibited good antibacterial activity against Staphylococcus aureus and Escherichia coli, indicating the high potential for biomedical applications. Additionally, the results have shown that the antibacterial effect of HAP/CS/Gent was more pronounced against S. aureus compared to E. coli.