Promoting filopodial elongation in neurons by membrane-bound magnetic nanoparticles

What is the role of mechanical tension in promoting filopodia elongation and axon growth? Here we induce filopodia elongation using superparamagnetic iron oxide nanoparticles (SPIONs) functionalized with molecules that bind neuronal membranes and direct SPIONs to the neuronal growth cone. In response to applied magnetic fields, SPIONs exerted mechanical tension at the filopodia tip and induced filopodia elongation. This technique permitted us to answer questions about whether filopodia tension and elongation are sufficient to induce axon growth.72