Star-shaped poly(2-methyl-2-oxazoline)-based films: rapid preparation and effects of polymer architecture on antifouling properties

Development of surfaces with antifouling properties is of great interest in biomedical applications. In this paper, the research was aimed at rapid preparation of poly(2-methyl-2-oxazoline)-based antifouling coating. We designed and synthesized a set of well-defined multiarm star copolymers hyperbranched poly(ethylenimine)graft- poly(2-methyl-2-oxazoline) (PEI-g-PMOXA) with different PMOXA grafting ratios and chain lengths. The cytotoxicity of the polymer was tested and the PMOXA-based films were successfully deposited rapidly onto substrates via a simple one-step dopamine-assisted codeposition method. The effect of polymer architecture (linear PMOXA with different molecular weights, star PMOXA with different PMOXA grafting ratios and arm lengths) on deposited films with respect to their deposition kinetics, surface composition, wettability, morphology, cytotoxicity, and antifouling properties was investigated systematically. The antifouling properties of PMOXA-based films were found to be dependent on the surface PMOXA chain densities, which were controlled by the PMOXA grafting ratios and chain lengths. Moreover, the star PMOXA structures gave the surfaces with higher PMOXA chain densities and enhanced antifouling properties compared to the linear ones. Among the star copolymers, PEI-g(70)-PMOXA(5K)/polydopamine and PEI-g(70)-PMOXA(7K)/polydopamine deposited films showed the highest resistance to protein adsorption (96-99% relative to the bare gold surface) and cell attachment (97-99% relative to the bare glass surface), as well as complete inhibition against platelet adhesion. At last, the stability test results showed that the PMOXA-based film exhibited superior stability in long-term applications than the poly(ethylene glycol)-based film.