Cartilage-inspired surface textures for improved tribological performance of orthopedic implants. (February 2023)

• Record Type: Journal Article
• Authors: Soltani-Kordshuli, Firuze; Choudhury, Dipankar; Goss, Josue A.; Campbell, Mara; Smith, Evelyn; Sonntag, Steven; Niyonshuti, Isabelle I.; Okyere, Deborah; Smeltzer, Mark S.; Chen, Jingyi; Zou, Min
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 138(2023)
• Publication Date: 2023-02
• Subjects: Micro-dimple -- Orthopedic implant -- Titanium -- Durability -- Bacterial colonization; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2022.105572
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: Joint replacements have become one of the most common orthopedic procedures due to the significant demands of retaining functional mobility. While these procedures are of great value to patients, there are some limitations. Durability is the most important limitation associated with joint replacement that needs to be addressed due to the increasing number of younger patients. Titanium is a commonly used implant material which has high biocompatibility, high strength-to-density ratio, and high corrosion resistance. However, current titanium implants have poor wear resistance which shortens their lifespan. In this study, microscale dimples with four different dimple shapes (circular, triangular, square, and star) of similar sizes to the pores found in natural articular cartilage were fabricated on titanium disks to improve implant lubrication and reduce wear. Biotribology tests were performed on dimpled and non-dimpled titanium disks in a condition similar to that inside of a patient's body. It was shown that dimpling the titanium disks optimized the lubricant film formation and decreased the wear rate significantly while also reducing the coefficient of friction (COF). The star-shaped dimples had the lowest COF and almost no detectable wear after 8 h of testing. To investigate whether dimpling increased bacterial colonization due to increased surface area, and to determine whether any increase could be limited by coating with antibacterial materials, bacterial colonization with Staphylococcus aureus was tested with non-dimpled and star-shaped dimpled titanium disks with and without coating with polydopamine (PDA), silver (Ag) nanoparticles (NPs), and PDA + Ag NPs. It was found that dimpling did not increase bacterial colonization, and that coating with PDA, Ag NPs, or PDA + Ag NPs did not decrease bacterial colonization. Nevertheless, we conclude that star-shaped dimpled titanium surfaces have potential utility as more durable orthopedic implants. Highlights: Micro dimples with different shapes were chemically etched on titanium disks. Biotribilogy tests were performed in a simulated synovial fluid. Dimpling enhanced lubrication, reduced friction, and decreased wear rate notably. Dimpling did not increase bacterial colonization despite increasing surface area. Star-shaped dimples have the potential to prolong the life of orthopedic implant.