Fast-polymerized lubricant and antibacterial hydrogel coatings for medical catheters

Medical catheters are highly susceptible to friction and infection when intervening or implanting in the body, and to thrombosis when in contact with blood. Coating medical catheters with lubricant and antibacterial hydrogel is an effective strategy but struggle to achieve. Here, hydrogel coating on the catheter surface with lubrication and antibacterial properties was constructed by the rapid polymerization of acrylamide (AAM) and sulfobetaine methacrylate (SBMA) in the presence of quaternary ammonium chitosan (QCS) based on the redox-based cross-linking method. First, the medical catheter surface was decorated with a polyethyleneimine (PEI) adhesive layer. The pre-gel solution was then applied to the catheter surface, followed by immersion in an aqueous FeSO4·7H2O solution, where a large amount of SO4-• was generated by a redox reaction between ammonium persulfate (APS) and Fe2+, which rapidly triggered the monomer to cross-link to form the coating. Polyelectrolyte PEI as the adhesive layer could bind the coating to the substrate through hydrogen bonding interactions and confer antimicrobial properties to the coating with the assistance of QCS (antibacterial rate of 95.88 % against E. coli and 97.11 % against B. subtilis). The hydrogel coatings exhibited outstanding lubricity with a low coefficient of friction (COF ≈ 0.053) and excellent antifouling properties (resists non-specific protein adsorption, inhibits platelet adhesion and prevents thrombosis (The clotting time was extended from 25.6 s to 74.7 s)) based on the integration of SBMA. This work shed new light on the design of hydrogel coatings to achieve modification of the substrate surface.