Atom Transfer Radical Polymerization of 2-Isopropenyl-2-Oxazoline in Solution and from the Surface of Carbonyl Iron Particles toward Fabrication of a Cytocompatible Magneto-Responsive Hybrid Filler

Atom transfer radical polymerization (ATRP) of 2-isopropenyl-2-oxazolinewas optimized both in solution and initiated from carbonyl iron (CI)particle surface (SI-ATRP) in order to obtain polymers with well-definedmolar mass and narrow dispersity. The polymerization procedure wasthoroughly investigated by size exclusion chromatography and H-1 NMR and optimized from the point of view type of initiator,ligand, copper catalyst, and solvent. Finally, the poly-(2-isopropenyl-2-oxazoline)(PIPOx) with controlled molar masses up to 20,000 g/mol and dispersityin the range of 1.2-1.5 were successfully prepared, while highconversions could be reached. Polymerization conditions using halogenexchange leading to well-defined PIPOx were also developed and usedfor SI-ATRP. SI-ATRP was finally applied for synthesis of magneticCI-PIPOx core-shell particles with two various molar massesof the grafted PIPOx. Finally, as a proof of applicability of suchhybrid particles, the particles were dispersed in the phosphate buffersaline and glycerol to obtain the magnetorheological fluid with blood-likecharacteristics. Magnetorheological and cytotoxicity investigationsproved that non-cytotoxic CI-PIPOx core-shell particles providedthe system with sufficient yield stress values to act as an embolizationagent.