Minimally invasive neuromodulation using magnetic nanomaterials

<h2>Abstract</h2> Recent advances in neural engineering have deepened our insight into the relationship between neural activity, brain circuits, and behaviour, paving the way for new neuromodulation strategies. Techniques such as optogenetics and chemogenetics, alongside external stimulation techniques such as deep brain stimulation (DBS), have enabled activation and inhibition of neurons. However, these methods are often limited by their invasiveness, potential off-target effects, and challenges in temporal resolution. Existing non-invasive approaches, such as transcranial magnetic stimulation and focused ultrasound (FUS), show clinical promise but are constrained by spatial precision and stimulation depth limitations in the brain. Magnetic nanomaterials offer a promising, minimally invasive alternative by directly interacting with the nervous system at cellular and molecular levels. When exposed to external magnetic fields (MFs), these nanoscale materials can initiate neuronal activity through mechanisms such as localised induced electric polarisation (magnetoelectric), heat dissipation (magnetothermal, or magnetic moment (magnetomechanical), enabling targeted neuronal excitation or inhibition. To advance this technology, future research is needed to optimise nanomaterial biocompatibility, particularly through surface coatings, and on developing compact, wearable systems to replace existing stationary and bulky electronics that drive MFs for minimally invasive neuromodulation.