Thermosensitive Hydrogel Interface Switching from Hydrophilic Lubrication to Infection Defense

An intervention-induced infection, such as a catheter-associated infection, is one of the most common nosocomial-acquired infections, which causes huge healthcare threats and costs to clinical treatment. This work developed a thermosensitive hydrogel coating on polydimethylsiloxane (PDMS), which smartly switched from hydrophilic lubrication to antimicrobial and antifouling properties. Upon the optimization of the molar ratio of N-isopropylacrylamide versus N,N'-methylenebis(2-propenamide) (NNMBA), the thermosensitive hydrogel coating exhibited hydrophilic lubrication and 2.5-fold and 4.4-fold contact angle hysteresis than those of silicone and PDMS at room temperature, respectively, which provided significant protection to prevent tissue injury during the intervention in vivo. Once reaching body temperature, the hydrogel coating collapsed into a rough morphology with a hydrophobic inlayer and an exposed antibacterial peptide outlayer, which was endowed with an excellent antibacterial adhesion ability, reducing 96.6% of bacterial adherence relative to bare PDMS. The in vivo implantation demonstrated that the coating significantly prevents the infection, which exhibited over 3 × 10³ and 10³ folds of the bacterial number of the surface and surrounding tissue lower than that of the bare implants, respectively. The hydrogel coating had a good biocompatibility with a rare cytotoxicity. This adapted hydrogel interface switching from hydrophilic lubrication to preventing infections offered a surface coating strategy for medical device implantation.