A lubricated and antibacterial hydrogel coating based on polyelectrolyte adhesion for medical catheters

Surface modification of silicone tubing could significantly improve its medical applications. Nevertheless, customizing the surface of silicone tubing for better interfacial adhesion and multifunctionality through simple methods is still a significant challenge. Here, in situ growth of hydrogel coatings with antimicrobial and lubricating functions on silicone tubes was achieved by the introduction of polyelectrolytes. The interfacial adhesion between the substrate and the hydrogel was achieved by electrostatic interactions as well as hydrogen bonding. The flexibility of the hydrogel coating was provided by hydrogen bonding formed between polyvinylpyrrolidone (PVP) chains and poly(acrylic acid-acrylamide) (P(AAc-AAm)) chains. At the same time, the lactam group in the molecular structure of PVP and the amide group in the molecular structure of P(AAc-AAm) endowed the hydrogel coating with good hydrophilicity (WCA ≈ 26.7°) and excellent lubricating properties (COF ≈ 0.129). Furthermore, the synergistic effect of PEI and PHMB provided the hydrogel with efficient antimicrobial properties (the OD600 value of E. coli decreased by 77.2% and that of S. aureus decreased by 85.2%). This work provides a new idea for the design of hydrogel coatings for surface modification of catheters.