Abstract
As the number of annual Total Hip Replacement (THR) surgeries continues to increase, the longevity of metal based hip implants is a major concern. Tribochemical reactions cause the Cobalt-Chromium-Molybdenum (CoCrMo) hip implant to release wear debris that interacts with decomposed proteins to form a tribolayer. We conducted an electrochemical investigation in order to understand the role of molybdenum in the stability of the tribolayer under mechanical wear and electrochemical corrosion. Tribolayers made of a bovine calf serum (BCS) and bovine calf serum with sodium molybdates (BCS-Mo) were electrochemically deposited on high carbon CoCrMo discs and subjected to corrosion and tribocorrosion experiments under potentiodynamic conditions in a hip-simulator. Potentiodynamic-polarization curve, Electrochemical Impedance Spectroscopy (EIS) tests and surface characterization techniques were carried out. The results indicate an increased resistance to corrosion under mechanical wear by BCS-Mo coated surface which is more distinct when Mo is added into the electrolyte. In addition, biocompatibility evaluation using MG63 osteosarcoma cells on BCS and BCS-Mo coated samples did not show any statistically significant difference in cell growth compared to uncoated CoCrMo discs. These findings suggest a pre-formed electrochemical tribolayer with sodium molybdates may be a promising pre-implantation treatment of THRs to extend the longevity of implants in vivo.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 82-91 |
| Number of pages | 10 |
| Journal | Thin Solid Films |
| Volume | 644 |
| DOIs | |
| State | Published - Dec 31 2017 |
Funding
The authors acknowledge financial support from NSF grant ( 1160951 PI: Shull and Mathew) and Craig Fellowship (Mary-M1 UIC Medical student). We are also grateful to Blazer foundation for the Regenerative Medicine and Disability lab at Department of Biomedical Sciences, UIC College of Medicine at Rockford. We are also thankful to Prof. Robert Urban (Rush University Medical Center) for the SEM facility and Carpenter Technology Corporation, PA, for the CoCrMo sample donations. The support of Dr. Pourzal (Rush University Medical Center) and Dr. Elizabeth Martin (Northwestern University) is also acknowledged. We also thank Thermo Fisher Scientific (Rockford) for their funding support of the Summer Science High School Internship (2016) to Annabelle (co-authour).
Keywords
- Cobalt-Chromium-Molybdenum
- Sodium molybdates
- Tribocorrosion
- Tribolayer
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Metals and Alloys
- Materials Chemistry
