Slow-release lubrication effect of graphene oxide/poly(ethylene glycol) wrapped in chitosan/sodium glycerophosphate hydrogel applied on artificial joints.

The artificial joints would go through serious wear after implantation surgery due to the poor lubrication of the body fluid, and the biomimetic lubricants directly injected in vitro is easy to be absorbed by human tissues, and after a period of time, it will lose its lubrication effect. However, the composite hydrogel with slow-release lubrication effect provides a new way for the lubrication of artificial joints. In this study, Graphene oxide/Poly(ethylene glycol) (GO/PEG) composites were prepared to improve the artificial joint lubrication, and through wrapped in the Chitosan/Sodium glycerophosphate (CS/GP) hydrogel, the GO/PEG lubricant will be released under the squeezing action, thus to prolong the service time of biomimetic lubricants. The friction experimental results showed that GO/PEG had better lubrication effect, and the average friction coefficient of the slow-release solution was below 0.03, especially with the pressure increasing. GO, PEG and small molecule GP in the slow-release solution through hydrogen-bond interaction might form a particular structure, which led to the good lubricating effect. The experiments of cell and acute toxicity in vivo showed that GO and its composite hydrogel had good biocompatibility.