Magnetic Nanoprobes for Spatio-Mechanical Manipulation in Single Cells

Abstract Magnetic nanoparticles (MNPs) are widely known as valuable agents for biomedical applications. Yet, for their successful application within cells they need to fulfill a variety of demands such as monodispersity, biocompatibility or sufficient magnetic response. Given these prerequisites, MNPs may be used for remote, non-invasive manipulation, where their spatial redistribution or force response in a magnetic field provides a fine-tunable stimulus to a cell. Here, we investigate the properties of two different MNPs and their suitability for spatio-mechanical manipulations: semisynthetic magnetoferritin nanoparticles and fully synthetic ‘nanoflower’-shaped iron-oxide nanoparticles. Next to characterizing their structure, surface potential and magnetic response, we monitor the MNP performance in a living cell environment using fluorescence microscopy and confirm their biocompatibility. We then demonstrate their capability to spatially redistribute and to respond to magnetic force gradients inside a cell. Our remote manipulation assays present these tailored magnetic materials as suitable agents for applications in magnetogenetics, biomedicine or nanomaterial research.