GRAFTING OF MAGNETIC PARTICLES WITH POLY(2-ISOPROPENYL-2-OXAZOLINE)

Magnetic particles play an important role in modern biomedical applications including targeted drug delivery, local embolization of blood veins, hyperthermia etc. Therefore, the development of more effective systems with high biocompatibility is of interest for many researchers. Nevertheless, these magnetic systems have to meet certain criteria necessary for in vivo applications. We have considered key requirements desired from such materials, and we have prepared a promising system based on core-shell particles via surface-initiated atom transfer radical polymerization (ATRP). The finest grade of the carbonyl iron particles was used as a suitable core and the treatment of its surface in acidic environment ensured the presence of hydroxyl groups, which were further coupled with ethoxy groups of (3-Aminopropyl) triethoxysilane. After the functionalization, the immobilization of 2-Bromoisobutyryl bromide, which served as an initiator, was performed. Finally, the initiator-treated particles were grafted with poly(2-isopropenyl-2-oxazoline) (PIPOx) under ATRP conditions as the PIPOx has recently shown a great potential in biomedical applications. The cleaning and washing procedures ensured high purity of the product. The reaction conversion, molar mass and dispersity of PIPOx grafts were investigated using nuclear magnetic resonance and gel permeation chromatography, respectively. The presence of grafted PIPOx was confirmed using Fourier-transform infrared, and energy-dispersive X-ray spectroscopies. The grafted PIPOx layer had negligible effect on particle magnetization as revealed via vibration-sample magnetometry. Synthesized core-shell structures may find utilization as a promising material for local embolization or may serve as a drug delivery system due to the presence of PIPOx bearing the active sites allowing the drug bonding.