Heating ability of La-Sr-Mn-Cu perovskite spheres under an alternating current magnetic field for magnetic hyperthermia mediators

摘要

La_(0.666)Sr_(0.373)Mn_(0.943)Cu_(0.018)O_3 spheres (average diameter: 2.4 mm) were used as magnetic hyperthermia mediators. They were prepared by the polymerized complex method and alginate gelation. A starch paste containing nine such spheres (0.1034 g) was maintained at a constant temperature when it was exposed to an alternating current magnetic field (frequency: 1 MHz; magnetic field strength: 20-55 Oe-rms). After exposure to a magnetic field with a field strength of 55 Oe-rms for 60 min, a temperature of r_(6o)=73.5 ℃ was obtained. T_(60) for field strengths of 40 and 55 Oe-rms differed by only 2.6 ℃. La_(0.666)Sr_(0.373)Mn_(0.943)Cu_(0.018)O_3 spheres satisfy the following important requirements for heating mediators: their amount can be controlled in tumors, their temperature can be controlled without monitoring, and their heating ability is independent of the field strength and direction. Thus, La_(0.666)Sr_(0.373)Mn_(0.943)Cu_(0.018)O_3 spheres are promising heating mediators for inducing magnetic hyperthermia.