Magnetic particle composition for therapeutic hyperthermia

Magnetic nanoparticle compositions are provided which provide an inherent temperature regulator for use in magnetic heating, particularly for use in magnetic hyperthermia medical treatments. The composition includes magnetic nanoparticles having a Curie temperature of between 40 and 46° C., preferably about 42° C., and may further include a polymeric material and optionally a drug or radiosensitizing agent. Methods of hyperthermia treatment of a patient in need thereof are provided which include the steps of administering to the patient a composition comprising magnetic nanoparticles having a Curie temperature of between 40 and 46° C.; and exposing the magnetic nanoparticles in the patient to an alternating magnetic field effective to generate hysteresis heat in the nanoparticles.