polyoxazolines; nanogel; hydrogel; responsiveness; crystallization; LCST; aldehyde; protein repellent; cytotoxicity
Abstract :
[en] 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).
