Bioinspired Polysaccharide‐Derived Zwitterionic Brush‐like Copolymer as an Injectable Biolubricant for Arthritis Treatment

Abstract Developing highly efficient and biocompatible biolubricants for arthritis treatment is extraordinarily demanded. Herein, inspired by the efficient lubrication of synovial joints, a paradigm that combines natural polysaccharide (chitosan) with zwitterionic poly[2‐(methacryloyloxy) ethyl phosphorylcholine] (PMPC), to design a series of brush‐like Chitosan‐g‐PMPC copolymers with highly efficient biological lubrication and good biocompatibility is presented. The Chitosan‐g‐PMPC copolymers are prepared via facile one‐step graft polymerization in aqueous medium without using any toxic catalysts and organic solvents. The as‐prepared Chitosan‐g‐PMPC copolymers exhibit very low coefficient of friction (μ < 0.01) on Ti₆Al₄V alloy substrate in both pure water and biological fluids. The superior lubrication is attributed primarily to the hydrated feature of PMPC side chains, interface adsorption of copolymer as well as to the hydrodynamic effect. In vivo experiments confirm that Chitosan‐g‐PMPC can alleviate the swelling symptom of arthritis and protect the bone and cartilage from destruction. Due to their facile preparation, distinctive lubrication properties, and good biocompatibility, Chitosan‐g‐PMPC copolymers represent a new type of biomimetic lubricants derived from natural biopolymer for promising arthritis treatment and artificial joint lubrication.