A prodrug according to formula (I) wherein R2 is a residue of a drug, said drug having a hydroxyl group by which the COOR2 group is formed Z is O or NH m is 0 or 1 and R3 is an organic moiety comprising a lipophilic group or a residue of a polymer, provided that Z is 0 if the polymer is carboxymethyl dextran. A system includes a plurality of magnetic nanoparticles including a prodrug as described above, a stent and a source of uniform magnetic field capable of producing temporary magnetization of the stent and/or the magnetic nanoparticles. A method of treating a medical condition with a drug includes administering to a patient in need of the drug a prodrug as described above, the prodrug being capable of releasing the drug in the patient after the administration step.
