Advanced protein-based hydrophilic coatings for anti-biofouling applications: A review

Biofouling-the undesirable accumulation of proteins, microorganisms, and biofilms on surfaces-remains a persistent challenge that compromises the performance and safety of marine equipment, biomedical devices, food packaging, and water treatment systems. Traditional antifouling approaches, often dependent on toxic biocides or non-degradable polymers, raise significant environmental and biocompatibility concerns. To address these limitations, this review presents an original, mechanism-oriented framework for understanding and advancing protein-based hydrophilic coatings. Unlike previous studies, we establish a novel classification system that categorizes these coatings into three groups-native protein coatings, phase-transitioned protein (PTP) coatings, and polyphenol-mediated protein (PMP) self-assembly coatings and systematically link their molecular architectures to antifouling mechanisms, stability, and functional performance. Furthermore, by conducting a comparative analysis with polymeric, inorganic, and nanostructured coatings, we uniquely highlight the multifunctionality, intrinsic biocompatibility, and environmental advantages of protein-based systems. Finally, we identify unresolved challenges-such as durability, substrate adhesion, and large-scale manufacturability and propose forward-looking design strategies, including hybrid architectures and multifunctional integration, to guide the development of next-generation antifouling coatings. This work thus provides a distinctive conceptual contribution by unifying classification, mechanistic insight, and translational guidance, offering a clear roadmap for future innovations in sustainable antifouling technologies.