Biomimetic study of a polymeric composite material for joint repair applications

A longer lifespan is still being sought for biomaterials used for joint repair. We developed a new nanocomposite material of polytrimethylene carbonate (PTMC), hydroxyapatite (HAP), and multiwalled carbon nanotubes (MWNT) to mimic real cartilage. Experimental results were compared with those of natural cartilage and the conventional joint replacement material ultrahigh-molecular-weight polyethylene (UHMWPE). Friction experiments showed that our developed composite material had a coefficient of friction close to that of articular cartilage. Nanoindentation experiments indicated that the surface elastic behavior was similar to that of cartilage. The surface attraction forces on a silicon atomic force microscope tip were much higher for cartilage than those for the other two materials. These results hold promise for this artificial cartilage composite material’s performance in vivo, following further experimental investigations and chemical modifications.