Thermosensitive magnetic polymer particles as contactless controllable drug carriers

Spherically shaped thermosensitive micro and nanoparticles based on N-isopropylacrylamide were synthesized using a novel inverse suspension polymerization technique which enables a bead formation within minutes. In addition to the rapidity, the suspension procedure provides an effective platform for the encapsulation of magnetic colloids and simultaneous drug analogous substances. The presence of the magnetic colloids allows an inductive heating of the particles using an alternating magnetic field above the polymer transition temperature (> 35 degrees C). This results in a pronounced de-swelling accompanied by a release of the encapsulated substances. The potential of this technology for a new contactless controllable drug releasing approach is exemplarily demonstrated using rhodamine B and methylene blue as drug analogous substances. (c) 2006 Elsevier B.V. All rights reserved.