A Magnetoresponsive Drug Delivery System via /spl beta/-Cyclodextrin Functionalized Magnetic Polymer Brushes

A novel approach to thermo- and magnetoresponsive drug delivery is presented, using magnetic nanoparticles decorated with a β-cyclodextrin (β -CD) containing polymer brush shell. The iron oxide based magnetic cores with a diameter of 10-12 nm can be used for remote controlled magnetic heating by AC fields. The polymer shell is created by atom transfer radical copolymerization of 2-(2-methoxyethoxy)ethyl methacrylate (MEEMA), oligo(ethylene glycol) methyl ether methacrylate (OEGMA) and the β -CD functional monomer 3-(6-desoxy)-β-cyclodextrin-3H-1,2,3-triazol-4-yl) methylmethacrylate (CDMA). The β-CD units are responsible for a thermosensitive complex formation equilibrium with hydrophobic probes, demonstrated here for the case of phenolphthalein as a model substance. The probe release induced by magnetic heating is greatly enhanced at the lower critical solution temperature (LCST) of the polymer shell. In this work the synthesis and complex formation behavior of the β-CD functional magnetic carriers is investigated with respect to the thermally and magnetically influenced drug release.