Synthesis and characterization of nHA-PLA composite coating on stainless steel 316L by dip-coating process for biomedical applications

316L stainless steel is the most commonly used metallic material in the manufacture of orthopedic implants. To achieve better properties metal implants are often coated with biocomposites. A sol–gel method was used for coating Poly lactic acid (PLA)/Hydroxyapatite nanopowder (nHA) on stainless steel 316L substrate. 10g PLA was added to 100 gr chloroform and stirred for 2 h at 60 °C. Then 0.5g nHA was added and continued to stir for 30 min at 60 °C to form a jelly-like solution. Afterwards, the substrate was immersed into the solution and kept for 2, 5, and 15 minutes and withdrawn from the bath solution at a prescribed withdrawal velocity. The X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were utilized in order to evaluate the phase composition and the functional groups of PLA/nHA coatings. Morphology and thickness of the nanocomposites coating of samples were evaluated using scanning electron microscope (SEM). Cell viability asses and eventually corrosion resistance were evaluated by MTT and potentiostat test, respectively. SEM result shows that the deposition rate is measured (in terms of coating thickness) as a function of immersion/soaking time. The results of XRD and FTIR tests confirmed the presence of phase of PLA/nHA nanocomposites in the coated samples. Furthermore, the corrosion resistance of coated samples was increased with immersion or soaking time in the solution bath of PLA/nHA nanocomposites and was higher than the uncoated sample.