Multipurpose Antifouling Coating of Solid Surfaces with the Marine‐Derived Polymer Fucoidan

The control of biofouling, which is the unwanted adsorption of biomolecules and organisms on solid surfaces, is a prerequisite for wider applicability of the functional materials that are currently being used in biomedical industries. One of the frequently used methods for controlling biofouling is the use of surface coatings with antifouling materials. Herein, fucoidan, which is a marine‐derived polysaccharide, is reported as a new type of antifouling material that is safe and broadly applicable. Fucoidan is conjugated with catechols, which are known to act as adhesives for grafting functional molecules onto solid substrates. Fucoidan catechol (FD‐C) is subsequently utilized for robust fucoidan coatings of solid substrates, and the FD‐C‐coated surfaces show excellent antifouling capability for fouling organisms, including platelets and bacteria. The FD‐C coating is also confirmed to be nonirritating upon skin contact, demonstrating its potential use in public places for inhibiting contagions. A multipurpose antifouling is developed using the marine‐derived natural polymer, fucoidan. Fucoidan‐coated solid surfaces show excellent resistance to platelet, bacteria, and marine diatom adhesions. The skin compatibility of the coating is confirmed by skin irritation tests using an animal model, demonstrating its potential use in public places for inhibiting contagions.