Biocompatibility of platinum-based bulk metallic glass in orthopedic applications.

Bulk Metallic Glasses (BMGs) are a class of amorphous metals that exhibit high strength, ductility paired with wear and corrosion resistance. These properties suggest that they could serve as an alternative to conventional metallic implants that suffer wear and failure. In the present study, we investigated Platinum (Pt)-BMG biocompatibility in bone applications. Specifically, we investigated osteoclast formation on flat and nanopatterned Pt57.5Cu14.7Ni5.3P22.5 (atomic percent) as well as titanium (control). Specifically, RANKL-induced murine bone marrow derived mononuclear cell fusion was measured on multiple nanopatterns and was found to be reduced on nanorods (80 and 200 nm in diameter) and was associated with reduced TRAP and MMP9 expression. Evaluation of MSC to osteoblast differentiation on nanopatterned Pt-BMG showed significant reduction in comparison to flat, suggesting that further exploration of nanopatterns is required to have simultaneous induction of osteoblasts and inhibition of osteoclasts. In vivo studies were also pursued to evaluate the biocompatibility of Pt-BMG in comparison to titanium. Rods of each material were implanted in the femurs of mice and evaluated by X-ray, mechanical testing, micro-CT, and histological analysis. Overall, Pt-BMG showed similar biocompatibility with titanium suggesting that it has the potential to improve outcomes by further processing at the nanoscale.