Photothermal Manipulation of Thermo-Sensitive Ion Channel of Neurons Using Indocyanine Green Loaded PEG-b-PLGA Micelles

Abstract

In this study, we have developed the activation method of thermo-responsive TRPV1 ion channels of neurons using photothermal and biodegradable polymer micelles. Indocyanine Green (ICG) dye was loaded on polymer micelles formed from poly(ethylene glycol) block copolymer possessing poly(lactic-co-glycolic acid) (PEG-b-PLGA) segment. The obtained ICG-loaded micelles showed a photothermal effect under tissue penetrable near-infrared (NIR) light irradiation. In addition, the ICG micelles also displayed biodegradability in acidic conditions. Furthermore, anti-TRPV1 antibody installed ICG-micelles showed specific recognition against TRPV1 on the cell membrane and accelerated Na⁺ influx into the cells was observed under NIR irradiation. Based on these results, the ICG micelles developed in this study are expected to be used as a tool for the remote activation of neurons, and they can be applied for various manipulation and analytical techniques of the nervous system.