Synthesis of a pH-Sensitive PEO-Based Block Copolymer and its Application for the Stabilization of Iron Oxide Nanoparticles

PEO-based amphiphilic block copolymers that exhibit a pH responsive phase transition behavior are synthesized. The amphiphilic block copolymers show sharp phase transitions in the physiological pH (7.2) range of aqueous media. The block copolymers were efficient stabilizers for the preparation of superparamagnetic iron oxide nanoparticles in aqueous media. The resulting iron oxide nanoparticles in the size range of 5-30 nm showed a relatively good 7.2 image on the basis of the results on their phantom test. All the materials were characterized by the combination of H-1 NMR spectroscopy, size exclusion chromatography, UV/visible spectroscopic analysis, magnetization, transmission electron microscopy, electron diffraction, and X-ray diffraction pattern analysis.