Functionalization of La_0.7Sr_0.3MnO₃ nanoparticles with polymer: Studies on enhanced hyperthermia and biocompatibility properties for biomedical applications

Now-a-days surface functionalized La_0.7Sr_0.3MnO₃ (LSMO) nanoparticles by different biocompatible polymers are attracted considerable interest in various biomedical applications in general and magnetic fluid hyperthermia treatment of cancer in particular. In this paper La_0.7Sr_0.3MnO₃ nanoparticles are synthesized and functionalized with polymer (dextran, with mean particle size ∼25nm). Magnetic measurements of both coated and uncoated particles reveal the superparamagnetic nature at room temperature. The resulting coated particles form a stable suspension in an aqueous environment at physiological pH and possess a narrow hydrodynamic size distribution. In vitro cytotoxicity of the MNPs has been assessed under Trypan blue dye exclusion and MTT assay on HeLa and L929 cell lines. The results demonstrate that dextran functionalized nanoparticles have no significant effect on cell viability within the tested concentrations (0.2-1mg/mL) as compared to bare LSMO. Magnetic fluid hyperthermia studies have been done in detail; the influence of an applied alternating current (AC) magnetic field on heat generation is presented in brief. Dextran functionalized LSMO has the higher Specific absorption rate (SAR) value than the bare LSMO. After functionalization with dextran the SAR values of LSMO nanoparticles increased from 25 to 51W/g. The study shows that the rise in temperatures by these nanoparticles could be safely controlled around Curie temperature (T_c).