Semiconducting Polymer Nanobioconjugates for Targeted Photothermal Activation of Neurons

Optogenetics provides powerful means for precise control of neuronal activity; however, the requirement of transgenesis and the incapability to extend the neuron excitation window into the deep-tissue-penetrating near-infrared (NIR) region partially limit its application. We herein report a potential alternative approach to optogenetics using semiconducting polymer nanobioconjugates (SPNs_bc) as the photothermal nanomodulator to control the thermosensitive ion channels in neurons. SPNs_bc are designed to efficiently absorb the NIR light at 808 nm and have a photothermal conversion efficiency higher than that of gold nanorods. By virtue of the fast heating capability in conjunction with the precise targeting to the thermosensitive ion channel, SPNs_bc can specifically and rapidly activate the intracellular Ca²⁺ influx of neuronal cells in a reversible and safe manner. Our study provides an organic nanoparticle based strategy that eliminates the need for genetic transfection to remotely regulate cellular machinery.