Stable, polymer-directed and SPION-nucleated magnetic amphiphilic block copolymer nanoprecipitates with readily reversible assembly in magnetic fields.

The formation of inorganic-organic magnetic nanocomposites using reactive chemistry often leads to a loss of super-paramagnetisim when conducted in the presence of iron oxide nanoparticles. We present here a low energy and chemically-mild process of co-nanoprecipitation using SPIONs and homopolymers or amphiphilic block copolymers, of varying architecture and hydrophilic/hydrophobic balance, which efficiently generates near monodisperse SPION-containing polymer nanoparticles with complete retention of magnetism, and highly reversible aggregation and redispersion behaviour. When linear and branched block copolymers with inherent water-solubility are used, a SPION-directed nanoprecipitation mechanism appears to dominate the nanoparticle formation presenting new opportunities for tailoring and scaling highly functional systems for a range of applications.

Poly[2-(methacryloyloxy)ethylphosphorylcholine]-coated iron oxide nanoparticles: synthesis, colloidal stability and evaluation for stem cell labelling.

Poly[2-(methacryloyloxy)ethylphosphorylcholine]-coated SPIONs were prepared through ATRP and amidation coupling reactions. The coated SPIONs exhibited high stability and re-dispersability in phosphate buffered saline and uptake in a stem cell line, with high T(2) relaxivity.