Thermosensitive Ion Channel Activation in Single Neuronal Cells by Using Surface‐Engineered Plasmonic Nanoparticles

Controlling cell functions using external photoresponsive nanomaterials has enormous potential for the development of cell‐engineering technologies and intractable disease therapies, but the former currently requires genetic modification of the target cells. We present a method using plasma‐membrane‐targeted gold nanorods (pm‐AuNRs) prepared with a cationic protein/lipid complex to activate a thermosensitive cation channel, TRPV1, in intact neuronal cells. Highly localized photothermal heat generation mediated by the pm‐AuNRs induced Ca²⁺ influx solely by TRPV1 activation. In contrast, the use of previously reported cationic AuNRs that are coated with a conventional synthetic polymer also led to photoinduced Ca²⁺ influx, but this influx resulted from membrane damage. Our method provides an optogenetic platform without the need for prior genetic engineering of the target cells and might be useful for novel TRPV1‐targeted phototherapeutic approaches.