Semiconducting polymers are light nanotransducers in eyeless animals

Current implant technology uses electrical signals at the electrode-neural interface. This rather invasive approach
presents important issues, in terms of performance, tolerability, and overall safety of the implants. Inducing light sensitivity
in living organisms is an alternative method that provides groundbreaking opportunities in neuroscience.
Optogenetics is a spectacular demonstration of this, yet is limited by the viral transfection of exogenous genetic
material. We propose a nongenetic approach toward light control of biological functions in living animals. We show
that nanoparticles based on poly(3-hexylthiophene) can be internalized in eyeless freshwater polyps and are fully biocompatible.
Under light, the nanoparticles modify the light response of the animals, at twodifferent levels: (i) they enhance
the contraction events of the animal body, and (ii) they change the transcriptional activation of the opsin3-like gene. This
suggests the establishment of a seamless and biomimetic interface between the living organism and the polymer nanoparticles
that behave as light nanotransducers, coping with or amplifying the function of primitive photoreceptors.