Paper Title
A Facile Electrodeposition Of Poly (3,4-Ethylenedioxypyrrole)/Strontium, Magnesium Substituted Hydroxyapatite Bilayer Coating On Surgical Grade Stainless Steel For Biomedical Applications

Abstract
Hydroxyapatite (HA) is the most commonly used calcium phosphate based coating material for metallic implants like 316L SS due to its excellent biocompatibility and similar composition and structure to the human hard tissues. The biological performance of HA might be improved by the addition of bioactive ions such as strontium, magnesium, etc. Though the coating of strontium, magnesium substituted HA (Sr,Mg-HA) on 316L SS improves the biocompatibility, the component metal ions of the substrate may be oxidised and will release toxic ions. In order to improve the corrosion resistance and biological performance of the implant, we have fabricated the PEDOP/Sr,Mg-HA bilayer on 316L SS by electrodeposition. The as-developed bilayer coatings were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), high resolution scanning electron microscopy (HRSEM) and energy dispersive X-ray analysis (EDAX). The corrosion resistance of the obtained coating is also investigated in Ringer�s solution by electrochemical techniques. Also, the mechanical property of the PEDOP/Sr,Mg-HA bilayer coating is analyzed. The in-vitro bioactivity of the bilayer coating was investigated. Thus, the PEDOP/Sr,Mg-HA bilayer coated 316L SS can serve as a prospective biomaterial for orthopaedic applications. Index Terms�Electropolymerization, Poly (3,4-ethylenedioxypyrrole), Stainless steel; Substituted hydroxyapatite