Magnetogenetic Control of Protein Gradients Inside Living Cells with High Spatial and Temporal Resolution

Tools for controlling the spatial organization of proteins are a major prerequisite for deciphering mechanisms governing the dynamic architecture of living cells. Here, we have developed a generic approach for inducing and maintaining protein gradients inside living cells by meaty of biofunctionalized magnetic nanoparticles (MNPs). For this purpose; we tailored the size and surface properties of MNPs in order to ensure unhindered mobility in the cytosol. These MNPs with a core diameter below 50 nm could be rapidly relocalized in living cells by exploiting biased diffusion at weak magnetic forces in the femto-Newton range. In combination with MNP surface functionalization for specific in situ capturing of target proteins as well as efficient delivery into the cytosplasm, we here present a comprehensive technology for controlling intracellular protein gradients with a temporal resolution of a few tens of seconds.