TC-tuned biocompatible suspension of La0.73Sr0.27MnO3 for magnetic hyperthermia

La(1-x)Sr(x)MnO(3), a ferromagnet with high magnetization and Curie temperature T(C) below 70 degrees C, enables its use for magnetic hyperthermia treatment of cancer with a possibility of in vivo temperature control. We found that La(0.73)Sr(0.27)MnO(3) particles of size range 20-100 nm showed saturation magnetization around 38 emu/g at 20 kOe and a T(C) value of 45 degrees C. Aqueous suspension of these nanoparticles was prepared using a polymer, acrypol 934, and the biocompatibility of the suspension was examined using HeLa cells. A good heating ability of the magnetic suspension was obtained in the presence of AC magnetic field, and it was found to increase with the amplitude of field. The suspension having concentration of 0.66 mg/mL (e.g., 0.66 mg of nanoparticles with acropyl per milliliter of culture media) was observed to be biocompatible even after 96 h of treatment, as estimated by sulforhodamine B and trypan blue dye exclusion assays. Further, the treatment with the aforementioned concentration did not alter the microtubule cytoskeleton or the nucleus of the cells. However, the bare particles (concentration of 0.66 mg of nanoparticles per milliliter of culture media, but without acropyl) decreased the viability of cell significantly. Our in vitro studies suggest that the suspension (concentration of 0.66 mg/mL) may further be analyzed for in vivo studies.