Molecular Design of Thermoresponsive Poly(oligoethylene glycol)vinyl Esters for the Generation of Polymer Brush-Based Biointerfaces

Vinyl polymers bearing oligoethylene glycol (OEG) side chains have emerged as starting materials for the generation of biointerfaces and thermoresponsive systems. Here, we report the molecular design of thermoresponsive poly(oligoethylene glycol)vinyl esters (POEGVEs) and evaluate their behavior in solution as well as their performance as surface-grafted polymer brushes. POEGVEs bearing one and two ethylene glycol units were synthesized via RAFT/MADIX polymerization and directly compared to the corresponding polyacrylate analogues. Despite their closely related compositions, POEGVEs exhibited markedly higher LCST values in water, indicating stronger polymer–water interactions associated with the higher polarity of the vinyl ester backbone. When assembled as polymer brush layers on model Au surfaces, POEGVEs displayed enhanced hydration, higher swelling ratios, and lower water contact angles relative to those of the corresponding poly(oligoethylene glycol)acrylate (POEGA) brushes. This increased hydration translated into significantly improved resistance to nonspecific protein adsorption from full human serum (FHS). Collectively, these findings identify OEG-functional poly(vinyl ester)s as a promising and previously overlooked platform for the design of thermoresponsive and antifouling polymer biointerfaces.