A Janus hydrogel material with lubrication and underwater adhesion

Abstract

Double-layer hydrogel materials combine excellent hydrophilicity, outstanding lubricating properties, high load-bearing modulus, and good biocompatibility, and are often used to achieve high load-bearing (high modulus) and low frictional (low modulus) properties of articular cartilage, but which also makes it difficult for them to form efficient, stable and long-term adhesion underwater. Herein, we constructed a kind of novel underwater Janus hydrogel patches with strong adhesion performance by robustly anchoring mussel-protein-inspired poly (dopamine methacrylamide-co-methoxyethyl acrylate) p(DMA-co-MEA) copolymer onto the surface of poly(acrylic acid-co- acrylamide) p(AAc-co-AAm) hydrogel with bilayer modulus structure analogous to articular cartilage. Due to the coupling of the top lubrication layer and the bottom load-bearing layer, the constructed Janus hydrogel patch not only has fatigue resistance and low friction but also high load-bearing [coefficient of friction (COF) ∼0.0076, 5 N; COF∼0.048, 30 N]. Moreover, the Janus hydrogel also exhibits excellent bonding strength underwater (bonding strength ∼41.6 kPa, Fe substrate). Our strategy for constructing a novel underwater Janus hydrogel patch will provide valuable guidance for the realization of interface bonding of soft material of bionic articular cartilage and promote the practical application of tissue engineering.

Keywords

• Adhesive hydrogels
• Underwater adhesion
• Lubrication and friction
• Articular cartilage