posted on 2024-01-19, 19:33authored byYuriy N. Luponosov, Alexander N. Solodukhin, Nikolay A. Aseyev, Tatyana I. Rokitskaya, Darya E. Kolotova, Elena A. Kotova, Tikhon S. Kurkin, Liya A. Poletavkina, Yulia A. Isaeva, Yuri N. Antonenko, Pavel M. Balaban, Sergey A. Ponomarenko
Organic
semiconductor materials with a unique set of properties
are very attractive for interfacing biological objects and can be
used for noninvasive therapy or detection of biological signals. Here,
we describe the synthesis and investigation of a novel series of organic
push–pull conjugated molecules with the star-shaped architecture,
consisting of triphenylamine as a branching electron donor core linked
through the thiophene π-spacer to electron-withdrawing alkyl-dicyanovinyl
groups. The molecules could form stable aqueous dispersions of nanoparticles
(NPs) without the addition of any surfactants or amphiphilic polymer
matrixes with the average size distribution varying from 40 to 120
nm and absorption spectra very similar to those of human eye retina
pigments such as rods and green cones. Variation of the terminal alkyl
chain length of the molecules forming NPs from 1 to 12 carbon atoms
was found to be an efficient tool to modulate their lipophilic and
biological properties. Possibilities of using the NPs as light nanoactuators
in biological systems or as artificial pigments for therapy of degenerative
retinal diseases were studied both on the model planar bilayer lipid
membranes and on the rat cortical neurons. In the planar bilayer system,
the photodynamic activity of these NPs led to photoinactivation of
ion channels formed by pentadecapeptide gramicidin A. Treatment of
rat cortical neurons with the NPs caused depolarization of cell membranes
upon light irradiation, which could also be due to the photodynamic
activity of the NPs. The results of the work gave more insight into
the mechanisms of light-controlled stimulation of neuronal activity
and for the first time showed that fine-tuning of the lipophilic affinity
of NPs based on organic conjugated molecules is of high importance
for creating a bioelectronic interface for biomedical applications.