Development of ultra-high molecular weight polyethylene-functionalized carbon nano-onions composites for biomedical applications

Abstract Herein, carbon nano-onions (CNOs) were covalently functionalized with mercaptophenyl methacrylate (MPMA) and ultra-high molecular weight polyethylene/functionalized carbon nano-onions (UHMWPE/f-CNOs) nanocomposites were prepared for the first time. UHMWPE/f-CNOs composites were fabricated by solution mixing followed by hydraulic pressing. The surface chemical structure of f-CNOs, morphology, microstructural properties, thermal stability, and decomposition, crystallinity, mechanical and cytotoxicity of the nanocomposites were evaluated. Biocompatibility assessments of these nanocomposites were studied with the human osteoblast cells. In vitro results displayed excellent cell growth and viability on the surface of nanocomposites over 14 days of incubation without significant cytotoxicity. The cytotoxicity of f-CNOs to osteoblast was depended on its concentration. Increasing the concentration of f-CNOs (0.1 wt%) in UHMWPE improved the biocompatibility of the nanocomposite surface to bone cells. In addition, at a high concentration of f-CNOs (0.1 wt%), the nanocomposite showed the highest improvement in tensile strength 83% as compared to neat UHMWPE. Increasing f-CNOs content also leads to enhancement in yield strength, elastic modulus, fracture toughness, and tensile strength. The strengthening of UHMWPE/f-CNOs systems was significantly influenced by the concentration of f-CNOs, which revealed its extent of polymer wrapping and degree of dispersion. The elastic deformation process was influenced by the fraction of f-CNOs oriented along with the tensile axis, whereas the deformation performance in the plastic regime was controlled by the wrapping of polymer and polymer-f-CNOs interfacial strength. Nevertheless, these nontoxic UHMWPE/f-CNOs nanocomposites would pave the way for the manufacture of artificial implants for potential arthroplasty and other biomedical applications.