Description
Flyer: Prof. Guosong Hong Flyer
Title: Seeing the Sound: An Ultrasound-Mediated Intravascular Light Source Enabled by Mechanoluminescent Materials
Abstract: Light is used in a wide range of methods in chemistry, biology, and medicine, fluorescence imaging, optogenetics, photoactivatable gene editing, light-controlled immunotherapy, and photochemotherapy for treating cancers and viral infections. A critical challenge for all light-based methods in live biological tissues arises from the poor penetration of photons, largely due to scattering and absorption. This limitation frequently necessitates invasive procedures, such as physical sectioning of the tissue, insertion of optical fibers and endoscopes, as well as surgical removal of overlying tissues (e.g., craniotomy). To address these challenges, our lab has developed an ultrasound-mediated intravascular light source, leveraging the deep-tissue penetration of focused ultrasound. We capitalized on mechanoluminescent nanotransducers (MLNTs), which are colloidal nanoparticles of mechanoluminescent materials synthesized via a biomineral-inspired suppressed dissolution approach. These MLNTs can be delivered intravenously into blood circulation and emit light locally at the ultrasound focus. Owing to the deep penetration and fast temporal kinetics of ultrasound, we have demonstrated that this method can produce on-demand and dynamically programmable light emission patterns at elevated depths in different organs of live mice with millisecond precision. This ultrasound-mediated intravascular light source has allowed us to perform noninvasive “sono-optogenetic” neuromodulation in live mice, as well as brain-wide “scanning optogenetics” that activate different brain regions of the same mouse brain. I will conclude my talk by presenting an outlook on how advances in photonic materials may facilitate the development of next-generation brain-machine interfaces.
