A Tough, Slippery, and Anticoagulant Double-Network Hydrogel Coating

Blood contact medical devices require a lubricant and anticoagulant surface to reduce tissue trauma, thrombosis, and other complications. Hydrogel coating is a promising strategy but usually shows poor adhesion and weak mechanical properties, leading to the failure of the coating by delamination or fracture during clinical applications. Herein, we report a tough and slippery hydrogel coating through the procedures of photoinitiator entrapment, pregel solution dip-coating, and UV-curing. The surface-embedded initiator and in situ polymerization attribute to the robust interfacial bonding, and double-network (DN) hydrogel formulation improves the toughness of the hydrogel coating itself. We characterize the morphology, composition, thickness, lubrication, and anticoagulant capabilities of the coating. Furthermore, we confirm the toughness of the coating by sonicating, soaking, repeated friction, tension, and the bending test. Results show that the DN hydrogel coating has a low coefficient of friction (∼0.03) after 3000 cycles of friction with a 20 N load (∼33 kPa). This coating method may bring clinical benefits in the use of vascular catheters as well as other interventional devices.