Smart flower like MgO/Tb,Eu-substituted hydroxyapatite dual layer coating on 316L SS for enhanced corrosion resistance, antibacterial activity and osteocompatibility

Abstract

To promote and enhance the biological responses of implant hydroxyapatite (HAP) coatings, these are modified by substitution with various ions for the development of bioactive bone implants. In the present work, we have fabricated a MgO/Tb,Eu-HAP dual substituted hydroxyapatite coating on borate passivated 316L stainless steel (316L SS) by the electrodeposition method. The MgO/Tb,Eu-HAP dual substituted hydroxyapatite coating on borate passivated 316L SS was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffractometry (XRD), high resolution scanning electron microscopy (HRSEM) with an energy dispersive X-ray (EDAX) analysis. Also, the mechanical property of the MgO/Tb,Eu-HAP dual layer coating was evaluated using adhesion and Vickers micro-hardness tests. The corrosion performance of MgO/Tb,Eu-HAP dual layer coating was investigated in Ringer's solution. The antibacterial activity of dual layer coating was evaluated against Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria) bacterial strains. The alkaline phosphate activity of MC3T3-E1 osteoblasts on the MgO/Tb,Eu-HAP dual layer coating was tested in order to examine their differentiation phase, which is a quantitative marker of osteogenesis. In addition, the in-vitro biocompatibility of cell proliferation and Live/Dead assay of MgO/Tb,Eu-HAP dual layer coating were investigated on MC3T3-E1 cells. Hence these results improved the anti-corrosion performance, bioactivity and biocompatibility of MgO/Tb,Eu-HAP coating on passivated 316L SS as well. Finally, it is concluded that the MgO/Tb,Eu-HAP dual layer coating can be considered to be a capable candidate for biomedical applications.

Keywords

• 316L stainless steel
• MgO/Tb,Eu-HAP
• Corrosion resistance
• Antibacterial activity
• ALP activity
• Bioactivity