'Smart' Polymer Sandwiches From Hydrogel Nanocoatings Attached to Stimuli-Responsive Grafted Brush Coatings: Changing the Cell Behavior.

In an effort to provide a universal platform for remotely controlling the behavior of various cell lines, we present a strategy for fabricating 'smart' polymer sandwiches using a nanogel attached to temperature-responsive grafted brush coatings. These coatings can be easily modified to meet the requirements of specific cell types while preserving responsiveness. First, temperature-responsive grafted copolymer brush coatings of poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) with a small amount of hydroxyethyl methacrylate (HEMA) were synthesized on glass surfaces. Subsequent modifications involved using multifunctional alcohols, amines, or their combinations with proteins to react with divinyl sulfone, forming a cross-linked polymer matrix with a surface nanogel structure attached to grafted copolymer brushes containing hydroxyl groups. The resulting sandwich coatings were comprehensively characterized, revealing maintained temperature-responsiveness for various structures of the grafted nanogel. Compared with P(OEGMA-co-HEMA) brushes, these temperature-responsive sandwich coatings exhibited improved biocompatibility while retaining the ability to regulate cell morphology and detachment of dermal fibroblasts through external temperature control. Rheological analysis of live cells was performed on the developed platforms to reveal their impact on cellular behavior. The application of these new materials opens exciting possibilities for tissue engineering.