Superhydrophilic Lubricating Loach Mucus-Methacryloylated Gelatin Hydrogel.

Resistance from seawater will reduce the speed and increase energy consumption of vessels during navigation. Loach mucus (MC) was extracted for drag reduction testing inspired by the super-lubricating loaches in this research. MC-methacrylated gelatin hydrogels (MC-GelMA) were then fabricated, which showed super-hydrophilic performance with a contact angle of 0°, and a swelling ratio less than 25% in artificial seawater over 7-days. The drag reduction rates of MC-GelMA on surfaces of epoxy resin, aluminum alloy, stainless steel, and glass are 53.6%, 37.7%, 34.1%, and 77.2%, respectively, demonstrating their excellent drag reduction performance. Ciprofloxacin-loaded MC-GelMA endow hydrogels with excellent antimicrobial performance with inhibition zones of 2.84 and 2.65 cm against Staphylococcus aureus and Escherichia coli, respectively, which could prevent the degradation of MC by bacteria within short term, and also improve the antifouling performance. Thus, MC-GelMA have great potential application for drag reduction of vessels.