Controlled loading of superparamagnetic nanoparticles in fluorescent nanogels as effective T2-weighted MRI contrast agents

Abstract

Spherical superparamagnetic iron oxide nanoclusters (IONCs) with well-controlled shape and size were fabricated. The formation of IONCs was induced by a solvent template-assisted organization of nanoparticles in a polymeric nanogel. An amphiphilic brush copolymer was chosen as the nanogel material because it had a high density of alkyl side-chains that interdigitate through hydrophobic interactions in water to form a stable nanogel matrix. Additionally, the hydrophilic backbone of the copolymer mixed into the nanogel matrix conferred both colloidal stability and important water swelling properties. The hydrodynamic size of IONCs was well-controlled to