Studies on enhanced colloidal stability and heating ability of glycine functionalized LSMO nanoparticles for cancer hyperthermia therapy

Magnetic nanoparticles offer potential advances in cancer treatment. In the present research, La0.7Sr0.3MnO3 (LSMO) nanoparticles were synthesized via a facile combustion method. A novel bilayer coating of glycine was used for stabilization. The as-prepared, monolayer and bilayer coated nanoparticles were characterized by X-ray diffractometry, Fourier transform infrared spectroscopy, transmission electron microscopy, dynamic light scattering, zeta potential measurement and vibrating sample magnetometry studies. The aqueous suspensions of bilayer coated LSMO showed good colloidal stability even after a long period of time. Magnetic measurements showed negligible coercivity and remanence values at room temperature implying superparamagnetic behaviour of the LSMO magnetic nanoparticles. The specific absorption rates of these magnetic nanoparticles are found to be 26-75 W g(-1) in different physiological media such as phosphate buffered saline (PBS), glucose, NaCl and bovine serum albumin (BSA) protein, and their values are suitable for hyperthermia treatment of cancer cells under an alternating current (AC) magnetic field. The cytotoxicity of magnetic nanoparticles coated with monolayer and bilayer glycine was studied in a MCF-7 cell culture. The potential for using bilayer functionalized LSMO nanoparticles in cancer cells was studied, and the cell viability of these nanoparticles against MCF-7 breast cancer cells is significantly enhanced as compared to monolayer and non-functionalized LSMO nanoparticles. Such nanoparticles with enhanced cell viability and enhanced specific absorption rates hold great promise for use in the intracellular hyperthermia treatment of cancer tumors.