Nanostructured heterojunctions for magnetoelectric efficiency enhancement and the wireless electrical stimulation in neurogenesis

Abstract

Wireless deep brain stimulation mediated by magnetoelectric (ME) nanoparticles (NPs) has emerged as a promising alternative to traditional neuromodulation for neurological disorders. However, it is a great challenge to achieve a highly efficient treatment of neural injuries via limited ME conversion efficiency, which highlights the opportunity for further material optimization. Here, we propose a robust strategy to improve the ME efficiency by introducing Au NPs onto the surface of coreshell CoFe₂O₄@BaTiO₃ NPs to build Schottky junctions, thereby promoting the separation of electronhole pairs. Moreover, Schottky junctions can be modulated by the piezoelectric field generated by the piezoelectric shell of ME NPs under a magnetic field, allowing electrons to flow continuously. On this basis, we established a wireless ME modulation platform by integrating heterojunction-reinforced ME NPs with a hydrogel matrix that mimics key biochemical and mechanical properties of neural tissue, supporting long-term magnetoelectric stimulation of neural stem cells (NSCs) and promoting their neuronal differentiation in vitro. Furthermore, the therapeutic potential of the ME platform was demonstrated in a traumatic brain injury (TBI) model, in which it significantly enhanced NSC migration and neuronal differentiation, promoted the reconstruction of neural networks, and improved cognitive and memory functions. Overall, this strategy provides new insights for the development of brain stimulation strategies as well as neural tissue repair following injury.