2-Oxazolines are known to be popular building blocks for the controlled synthesis of self-assembling polymer systems. Due to the structure similar to poly(amino acids) and peptides, this polymers exhibit a good biocompatibility and immunogenicity. By variation of the monomer structure one can obtain hydrophilic, hydrophobic or stimuli-responsive polymers or blocks. The most widely studied thermoresponsive poly(2-oxazolines) are poly(2-n-propyl-2-oxazoline) (Tcloud~ 25 °C) and poly(2-iso-propyl-2-oxazoline) (Tcloud~35 °C). The cloud point temperature of resulting polymer can be tuned by polymer chain length as well as by copolymerization with other 2-oxazolines. Here we present the synthesis and characterization of novel 2-oxazoline copolymers with hydrophilic, fluorophilic, and thermoresponsive fragments. All polymers were synthesized by Cationic Ring-Opening Polymerization (CROP). In absence of moister and other nucleophilic impurities, the CROP proceeds in a living mode allowing us to control precisely the blocks ratio and, thus, obtain well-defined polymers. The solution behaviour of all copolymers was studied by a series of physico-chemical methods such as dynamic light scattering, small angle X-ray scattering, transmission electron microscopy, etc.. The presence of hydrophobic fluorinated block contributed to self-assembly of all copolymers in aqueous milieu, whereas the presence of 2-n-propyl-2-oxazoline block made these systems responsive to heating (Figure 1). The obtained fluorine containing poly-2-oxazolines represent a potential platform for utilization as 19F magnetic resonance imaging contrast agents.

Fluorine containing poly-2-oxazolines as contrast agents for 19F MRI: Quest for the structure

2019 Spring National Meeting

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