Engineering of poly(2-oxazoline)s for a potential use in biomedical applications

Abstract

This PhD work is based on the design of poly(2-oxazoline) (POx) hydrogels and nanogels, by chemical or physical cross-linking, aimed to be used for biomedical applications. Nanogels were first prepared in dilute media and in inverse emulsion based on a statistical copolymer made of 2-ethyl-2-oxazoline and ethylene imine units. These stimuli-responsive nanogels were swelling in acidic media and were cleaved in reductive environment. They proved to be non-cytotoxic and act as protein repellent. Second, a reactive platform based on a statistical POx polymer bearing aldehyde functionalities was engineered, enabling the synthesis of graft and cross-linked POx. Last, a block copolymer made of 2-methyl- and 2-isopropyl-2-oxazoline units, proved to self-assemble into micelles when heated above its LCST, for a short period of time (< 1h30). When annealed for a longer time (> 1h30), crystallization-driven self-assembly led to the formation of different morphologies (fiber rods and cross-linked micelles).