The electrochemical and in-vitro study on electrophoretic deposition of chitosan/gelatin/hydroxyapatite coating on 316L stainless steel

In the present study, chitosan/gelatin/hydroxyapatite (HA) coating was developed on 316L stainless steel (SS) via electrophoretic deposition (EPD). This type of film exhibits a hierarchical structure consisting of hydroxyapatite particles dispersed in a chitosan/gelatin matrix. An array of different analytical, electrochemical, and bioactive techniques was used to investigate the coatings. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that HA particles are well dispersed in the chitosan/gelatin matrix. X-ray photoelectron spectroscopy (XPS) results revealed that phosphorus is well bonded to the oxygen and well confirmed by the Fourier transform infrared (FTIR) spectrum. The electrochemical studies of the chitosan/gelatin/HA and bare 316L SS were conducted by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The results indicated that corrosion resistance (conducted in simulated body fluid (SBF)) is mainly contributed by the HA particles embedded in the chitosan/gelatin matrix. Moreover, pitting potential of the composite coatings increased compared to that of the bare 316L SS. Chitosan/gelatin/HA developed apatite crystals upon immersion in SBF, thus confirming the bioactive nature of the coating. Furthermore, the coating was cyto-compatible and allows the osteoblast cells to proliferate and grow. The chitosan/gelatin/HA is a suitable candidate for biomedical applications regrading to mechanical and chemical attack.