Articular Cartilage Inspired Bilayer Tough Hydrogel Prepared by Interfacial Modulated Polymerization Showing Excellent Combination of High Load-Bearing and Low Friction Performance.

Articular cartilage is a load-bearing and lubricious tissue covering the ends of articulating bones in synovial joints to reduce friction and wear. It ideally combines the high mechanical property and the ultralow friction performance as a result of biphasic structure and lubricious biomolecules. A biomimicking hydrogel with bilayer structure of thin porous top layer covering a compact and tough hydrogel bulk is fabricated with interfacial modulated polymerization. The top porous layer ensures the ultralow friction toward its contact pairs, while the bottom renders the high load-bearing property. Therefore, with bilayer architecture, hydrogel achieves an outstanding combination of low friction and high load bearing performance with long wear life when sliding against either steel or silicone elastomer counterpair.