“Janus-Featured” Hydrogel with Antifouling and Bacteria-Releasing Properties

“Janus-featured” hydrogels with different structure and function for each layer can be particularly important in diverse application. However, very few studies have been conducted on multifunctional Janus-featured hydrogel, and significant challenge for simple, rapid, and efficient fabrication of such hydrogels remains. Herein, Janus-featured poly(N-hydroxyethyl acrylamide) (polyHEAA) hydrogel loaded with modified silica nanoparticle was fabricated by the supergravity method. Silica nanoparticles grafted with poly(3-(dimethyl(4-vinylbenzyl) ammonio) propyl sulfonate) (polyDVBAPS) were first prepared and then introduced into progel of polyHEAA hydrogel. During the formation of the hydrogel, a supergravity resulting from centrifugation was applied, from which silica nanoparticles moved to one side of the hydrogel, forming Janus-featured hydrogels, i.e., a pristine polyHEAA layer and a composite layer. These two layers showed different properties, where the prinstine polyHEAA layer showed excellent antifouling property by resisting the bacteria adsorption (<106 cells/cm2) for up to 5 days, and the nanoparticle-loaded hydrogel layer showed excellent bacteria-releasing properties by releasing >94% adherent bacteria upon a simple treatment with 2.0 M NaCl solution for 10 min. Based on its superb biocompatibility and low biotoxicity, we expect that our interesting strategy may provide a new assumption for the fabrication of “Janus featured” hydrogel and hopefully offer reference significance for the design of hydrogel-based wound dressing in the near future.