Tannic acid-inspiration and post-crosslinking of zwitterionic polymer as a universal approach towards antifouling surface

A facile and versatile strategy towards antifouling surfaces is an emerging area of huge potential and with an increasing scientific interest. Herein, a universal approach for fabricating antifouling surfaces was developed based on tannic acid (TA) and a novel reactive zwitterionic polymer. Firstly, a thin layer was formed on polyethersulfone (PES) membranes surface with TA molecules via multivalent anchoring sites in few minutes. Subsequently, a reactive zwitterionic polymer (for the first time reported based on quaternization of PEI) was post-crosslinked on the layer via a convenient dip-coating process at room temperature. The as-prepared surface exhibited excellent hydrophilicity confirmed by water contact angle, and its electrically neutral property was affirmed by zeta potential measurement. The surface displayed prominent antifouling efficacy which was evaluated by proteins adsorption, bacteria attachment and platelets adhesion. Meanwhile, after the post-crosslinking, the stability of the surface was significantly enhanced in either acidic or alkaline condition compared with original TA-coated surface. Benefiting from the universal profile, easy operation and low cost of the TA assembly process, as well as the excellent antifouling ability of the zwitterionic polymer, the proposed strategy provided a universal route in design of antifouling surfaces used in biomedical fields.