Magnetic nanoparticles-induced endosomal rupture for cytosolic antibody delivery and intracellular labeling

Abstract

Antibodies (Ab’) and their derivatives are powerful tools for intracellular diagnostics and targeting. But the cell membrane barrier limited the intracellular applications of antibodies. Many strategies have been developed to solve these problems, but a vast majority of them may bring about safety concerns or show poor clinical prospect. Here we report a cytosolic antibody delivery strategy by the combination of magnetic nanoparticles (MNPs) and commercial permanent magnets. Firstly, the positive-charged MNPs and antibodies were premixed to form MNP-Ab’ complex. After cell incubation of the complex and magnet enrichment, cell uptake of the complex was considerably enhanced. The static parallel magnetic field (MF) treatment was then realized by placing two parallel commercial magnets onto the culture plate. Robust endosomal rupture and antibody endosomal escape were induced due to this treatment. Finally, the antibody molecules were effectively released into the cytosols for live-cell intracellular labeling. This strategy also exhibits superb performance for the co-labeling of intracellular targets. MNP-induced endosomal rupture is a promising strategy for cytosolic antibody delivery, intracellular diagnosis and specific targeting in live cells.