Injectable Black Phosphorus Nanosheets for Wireless Nongenetic Neural Stimulation.

Neurons can be modified to express light-sensitive proteins for enabling stimulation with a high spatial and temporal resolution, but such techniques require gene transfection and systematical implantation. Here, a black phosphorus nanosheet-based injectable strategy is described for wireless neural stimulation both in vitro and in vivo without cell modifications. These nanosheets, with minimal invasiveness, high biocompatibility, and biodegradability, are anchored on cell membranes as miniature near-infrared (NIR) light transducers to create local heating for neural activity excitation. Based on cultured multielectrode-array recording, in vivo electrophysiology analysis, and open field behavioral tests, it is demonstrated that remotely applied NIR illumination can reliably trigger spiking activity in cultured neurons and rat brains. Excitingly, reliable regulation of brain function to control animal behaviors is also described. Moreover, this approach has shown its potential for future clinical use by successful high-frequency stimulation in cells and animals in this proof-of-concept study. It is believed that this new method will offer a powerful alternative to other neural stimulation solutions and potentially be of independent value to the healthcare system.