Igor A. Borovoy

Reactive oxygen species generation in aqueous solutions containing GdVO 4 :Eu 3+ nanoparticles and their complexes with methylene blue

It this letter, we report the study of free radicals and reactive oxygen species (ROS) generation in water solutions containing gadolinium orthovanadate GdVO4:Eu3+ nanoparticles (VNPs) and their complexes with methylene blue (MB) photosensitizer. The catalytic activity was studied under UV-Vis and X-ray irradiation by three methods (conjugated dienes test, OH· radical, and singlet oxygen detection). It has been shown that the VNPs–MB complexes reveal high efficiency of ROS generation under UV-Vis irradiation associated with both high efficiency of OH· radicals generation by VNPs and singlet oxygen generation by MB due to nonradiative excitation energy transfer from VNPs to MB molecules. Contrary to that under X-ray irradiation, the strong OH. radicals scavenging by VNPs has been observed.

Primary cell culture from pig neonatal thyroid gland: Growth, folliculogenesis, and hormone activity

A comprehensive assay of proliferative and hormonal activity in primary cell cultures derived from neonatal pig thyroid was carried out for the first time. Morphology and basal and thyroid-stimulating hormone (TSH)-stimulated secretion of thyroxin were evaluated in cultures, depending on the initial material placed into the culture: single cells or follicular conglomerates. Spontaneous and under chronic TSH stimulation folliculogenesis and formation of dome structures were assessed in culture. It was demonstrated that the cells expressed β-III-tubulin during prolonged cultivation with nerve growth factor.

Estimation of luminescent properties of the derivatives of polymethine probes on their interaction with cells of different types

The spectral and luminescent properties of the derivatives of polymethine probes based on 3,3′-dialkyloxacarbocyanine bromide (H-510) and 1,1′-dialkyl-3,3,3′,3′-tetramethylindodicarbocyanine bromide (D-307) (where alkyl is ethyl or octadecyl groups) on accumulation in bone marrow and liver cells of rats have been compared. The general regularities in the interaction between the probes and the membrane microenvironment have been revealed for each type of the cells. It was found that the structural features of membranes and the length of the chains of alkyl substitutes essentially affect the redistribution of dye molecules in the binding centers of particular types, as evidenced by changes in the spectral characteristics of probes. It has been shown by microfluorimetry that the accumulation of short-chain derivatives in single cells is representative of the distinctions in the parameters of their functional metabolic state, which coincides with the present view of the heterogeneous structure of these cellular populations. The hormonal action and the influence of incubation without serum on the intensity of cellular processes were accompanied by changes in the fluorescence of cells stained with the ethyl derivatives of the probes H-510 and D-307. This fact allows us to consider them as optical indicators of the cellular activity. The dye D-307 was found to be more resistant to photodestruction than H-510 both in single cells and model system.