ИСТИНА

Among a wide variety of cyanine dyes (CD) biscarbocyanine dyes occupy a special place (BCD). Here we report a synthesis and properties of the BCD series with different substituents (n= 1, 2 ; R1, R2 = CH3, (CH2)5CH3, (CH2)4SO3, CH2COOMe, (CH2)10COOH, (CH2)10COOEt, (CH2)4P(O)(OEt)2, (CH2)4SO3). The interaction between two coupled chromophore systems leads to the splitting of the singlet state energy level and the appearance of the absorption band in the near infra-red region of the spectrum. Comparing to single-chromophore dyes, BCD has a higher yield of intersystem crossing. BCD demonstrate the ability to accumulate in cancer cells, its fluorescence in the NIR range effectively passes through the tissues and allows imaging. Spectral and photochemical properties in aqueous and organic media were studied for the synthesized dyes. Due to the triplet state formation under IR irradiation compound BCDC was chosen. Radical anion BCDC was formed as a result of the electron phototransfer reaction from the donor, N,N-dimethylaniline, to the dye’s triplet state. Fluorescence of the dye in cells was registered. Photoexcitation of BCDC in cancer MCF7 cells leads to superoxide radical anion generation. The formation mechanism of superoxide anion includes phototransfer of electron from intracellular protein structures to the BCDC triplet state, which leads to oxidative stress in cells. The formation of BCDC complexes with albumin increases the quantum yield of dye fluorescence, and its mechanism was determined by spectral-kinetic methods. The possible interactions between the BCD molecule and HSA (PDB: 4L9Q) were analyzed by means of semirigid molecular docking. Synthesized BCDC can be considered as a promising compound for theranostics.