High performance nano hydroxyapatite coating on zinc for biomedical applications

Abstract

AbstractZinc and its alloys have been given promising consideration as a new biodegradable implant for use in the human body. Compact and uniform nano hydroxyapatite coatings containing chitosan were successfully deposited onto zinc substrate in an aqueous solution utilizing microwave-assisted process in about 10 min. The quick composite coatings are derived by microwave heating compared with the coatings derived by electrodeposition. The as-deposited coatings formed by electrodeposition synthesis were known as brushite, which was converted to hydroxyapatite after 1 h of immersion (post treated) in 1 M aqueous sodium hydroxide solutions at 100 °C. The incorporation of chitosan (from 0.01–0.05 g/l) into the coating composition results in a smooth and uniform coating structure. SEM, EDS, and an X-ray diffractometer were utilized to analyze coated samples' surfaces to evaluate their surface morphology, chemical composition, and crystalline structures. The in vitro degradation behavior of the composite-coated samples in simulated body fluid at pH 7.4 and 37 °C was evaluated using electrochemical impedance spectroscopy and potentiodynamic polarization. The outcomes showed that microwave-derived coatings provided superior corrosion resistance for zinc implants as compared to electrodeposited coatings. Furthermore, the use of chitosan in hydroxyapatite coatings increased electrochemical corrosion performance. Low chitosan concentrations (0.01–0.03 g/l) exhibit superior anti-corrosion properties than higher concentrations (0.05 g/l). Against Staphylococcus aureus, the coatings demonstrated strong antibacterial efficacy. These corrosion outcomes and the fruitful deposition of a hydroxyapatite/chitosan composite coating on zinc substrate indicate that the coating is efficient for the creation of new composite coatings for either functional implants or regenerative medicine. The resultant coating may be an excellent option for bone implants.