The Role Of Human Serum Albumin On Corrosion Of Orthopedic Biomaterials

摘要

The primary applications of metallic biomaterials are prostheses and fixation devices in medical industry such as total joint replacements, skull plates, nails, screws, nuts, and wires. AISI 316L, wrought Co-28Cr-6Mo, and Ti-6AI-4V are common biomaterials in today's medical industry. These have biocompatible chemical compositions avoiding adverse tissue reactions with high corrosion resistance. The high corrosion resistance of these materials relies on the growth of a surface passive layer. However, biomaterials are not completely inert in the body. For example, protein-surface and cell-surface interactions form micro- and sub-micrometer sized metal products and affect corrosion behavior of the metallic device. In addition, the protein concentration varies at the implant/tissue interface during the healing period after implantation surgeries. Therefore, the hypothesis is that the presence and change of protein concentration can affect the metal dissolution rate and corrosion behavior of metallic bio-implants. In this study, the effect of human serum albumin (HSA) concentrations (from 0 to 2 g/L) in phosphate buffered saline (PBS) on the electrochemical corrosion behavior of AISI 316L, wrought Co-28Cr-6Mo and Ti-6AI-4V was investigated. The advanced electrochemical techniques such as potentiodynamic polarization (PD), electrochemical impedance spectroscopy (EIS), and linear polarization resistance (LPR) were employed. The results showed that Ti-6AI-4V alloy had the highest breakdown potential indicating that its passive layer has the highest resistance compared to 316L and Co-2Cr-6Mo alloys. HSA concentration variations did not show a significant effect on corrosion behavior of Ti-6AI-4V alloy; However, HSA variation affected the passive behavior of 316L and Co-28Cr-6Mo alloys. The corrosion rate of 316L was higher than Co-28Cr-6Mo and Ti-6AI-4V alloys.