Magnetic Nanoparticle Transducers for Magnetogenetics: Materials Design, Biointerfaces, and Transduction Mechanisms

Over the years, magnetic nanoparticles (MNPs) have evolved from passive imaging and delivery agents into active transducers that convert externally applied magnetic fields into localized biological stimuli. This transition has created opportunities for magnetogenetics, in which MNPs serve as remotely controlled biointerfaces for regulating cellular activity, tissue function, and therapeutic responses. In this review, we discuss MNP transducers for magnetogenetics from the perspective of materials design, biointerface engineering, and transduction mechanisms. We start with magnetothermal transduction, where nanoparticles dissipate heat under alternating magnetic fields (AMFs) to activate thermosensitive ion channels such as TRPV1, enabling wireless neuronal activation, deep brain stimulation (DBS), regenerative signaling, and disease therapy. We then discuss magnetomechanical transduction, where nanoparticles, nano/micro-discs, nanochains, etc., generate forces, torques, oscillations, or matrix deformation to activate mechanosensitive channels, integrin-mediated pathways, stem cell differentiation, immune modulation, and tumor inhibition. Next, we examine magnetoelectric transduction, where magnetostrictive-piezoelectric materials convert magnetic inputs into local electric fields or surface potentials for neural stimulation, DBS, nerve regeneration, and wound healing. Across these modalities, biological outcomes are governed by intrinsic magnetic properties and several other factors, including particle geometry, anisotropy, surface chemistry, protein corona formation, tissue retention, field waveform, and proximity to the biological target. We further comment on key design principles, including mechanism-specific dosimetry, geometry-field co-design, biointerface localization, targeting specificity, clearance, and chronic safety. Finally, we highlight opportunities for purpose-built, programmable, and closed-loop magnetic biointerfaces that integrate material architecture, magnetic-field input, and biological target selection for precise control of cellular and tissue function.