Tailoring LaSrMnO (0.25 ≤x≤ 0.35) nanoparticles for self-regulating magnetic hyperthermia therapy: an in vivo study.

A careful design of LaSrMnO (0.25 ≤x≤ 0.35) nanoparticles (NPs) was made to prepare a self-controlled heating agent for magnetic hyperthermia therapy (MHT). The results showed that the magnetic properties and heating efficacy of the tailored LaSrMnO NPs are strongly dependent on the doping level of La/Sr cations, so that LaSrMnO NPs possessed the highest saturation magnetization and heating efficacy in response to safe alternating magnetic fields used in biomedical applications (H = 3.4-5.0 mT and f = 120 kHz). Furthermore, to improve the biocompatibility of the LaSrMnO NPs, the surface of the NPs was coated with a thin silica shell, and then the therapeutic efficacy of MHT using the silica-coated LaSrMnO NPs was investigated using a typical animal model of breast cancer. The results showed that in the control group, the mean tumor volume increased up to 300% over 6 days, while in the MHT group, the mean tumor volume decreased about 85% during the same period of time (P = 0.002). The outcomes of this study indicate that silica-coated LaSrMnO NPs are a promising tool for self-regulating MHT.