Alternating magnetic field pretreatment promotes cellular endocytosis to enhance the efficacy of magnetic hyperthermia

Magnetic hyperthermia (MH) relies on the heat generated by magnetic nanoparticles (MNPs) under an alternating magnetic field to kill tumor cells. However, the thermal barrier of the cell membrane hinders the transfer of heat generated by MNPs into cells, thereby limiting their therapeutic efficacy. Enhancing MNPs endocytosis is a promising way to overcome this limitation. The modification of physicochemical properties of MNPs and the pretreatment with electrical field can enhance the endocytosis. As an alternative, here, the effect of alternating magnetic field (AMF) pretreatment was explored. The AMF stimulation increases nanoparticle uptake by 1.62-fold and improves magnetic hyperthermia efficacy by 33 %. AMF stimulation induces F-actin depolymerization, leading to a reduction in cellular elastic modulus. This decreases the elastic deformation energy required for endocytosis, thereby facilitating the formation of membrane ruffles essential for macropinocytosis.