Imparting ultralow lubricity to double-network hydrogels by surface-initiated controlled radical polymerization under ambient conditions

Hydrogels, especially double-network hydrogels, are attractive candidates as load-bearing biomaterials, e.g., tissue-engineering supports for articular cartilages and bones. In this study, we describe the modification of a hydrogel by introduction third monomer, N-[3-(dimethylamino)propyl]methacrylamide, to network system, which serves reactive site subsequent interfacial reactions surface-initiated controlled radical polymerization under ambient conditions. The as-prepared poly(2-(methacryloyloxy)ethyl trimethylammonium chloride) (PMETAC) polyelectrolyte polymer brush-modified DN exhibited an ultralow coefficient friction (0.001–0.004) high contact pressure—comparable that synovial joint.