A novel impedimetric sensor based on N-acetyl-L-cysteine for the determination of hydroxyl radicals in cell cultures in vitro.

We report a novel impedimetric sensor based on a graphite electrode impregnated with polyethylene and paraffin under vacuum (IGE) modified with electrochemically deposited gold and a self-assembled monolayer of N-acetyl-L-cysteine (NAC/Au/IGE) for selective and sensitive determination of extracellular hydroxyl radicals (OH•) generated by living cells. The application of a sulphur-containing molecule oxidized by OH• predicts the high selectivity of the sensor, and the utilization of the non-faradaic impedance spectroscopy for recording an analytical response makes it possible to achieve superior sensitivity with a detection limit of 0.01 nM and a linear dynamic range of 0.08-8 nM. Meanwhile, NAC/Au/IGE demonstrated a strong potential of detecting OH• generated by biological objects via successful determination of extracellular hydroxyl radicals generated by normal fibroblast cells and prostate carcinoma cells.

[Comparison of neurotropic and antioxidant activity of Cytoflavin and etilmetilgydroxypiridine succinat in patients with chronic brain ischemia]. / Sravnitel'naya kharakteristika neirotropnoi i antioksidantnoi aktivnosti Tsitoflavina i etilmetilgidroksipiridina suktsinata u patsientov s khronicheskoi ishemiei golovnogo mozga.

OBJECTIVE: Determination of the total antioxidant activity of blood serum (AOA) of patients with chronic cerebral ischemia (CCI) I-II st. against the background of treatment with Cytoflavin or ethylmethylhydroxypyridine succinate (EMGPS) and evaluation of the effect of drugs on the state of cognitive functions and emotional sphere of patients. MATERIAL AND METHODS: The main group consisted of 12 women with CCI I-II st., treated on an outpatient basis with Cytoflavin 1 tablet 2 times/day as part of complex therapy for 1 month; 12 patients with CCI I-II st., treated as part of complex therapy with EMGPS 125 mg 2 times/day for 1 month we made a comparison group. The groups are comparable in age, gender, the nature of risk factors, the severity of neurological manifestations, and the nature of basic therapy. The state of AOA, the severity and nature of cognitive and emotional disorders were assessed. RESULTS: It was found that the inclusion of Cytoflavin or EMGPS in complex therapy equally increased the AOA of patients. The decrease in the severity of neurological deficit during treatment consisted in improving spatio-temporal gnosis by improving the relationships in the cortex and synchronizing the activity of its different departments with the rate of nervous activity and neurophysiological characteristics different for each drug. The use of both drugs led to a decrease in the selection reaction time and the number of errors in recognizing the angular velocity of movement. Cytoflavin increased the selectivity of perception and attention in patients, while EMGPS did not affect this indicator. CONCLUSION: The use of Cytoflavin and EMGPS leads to an increase in AOA, has various effects on the cognitive functions of patients with CCI.

Human Mesenchymal Stem Cells as a Carrier for a Cell-Mediated Drug Delivery.

A number of preclinical and clinical studies have demonstrated the efficiency of mesenchymal stromal cells to serve as an excellent base for a cell-mediated drug delivery system. Cell-based targeted drug delivery has received much attention as a system to facilitate the uptake a nd transfer of active substances to specific organs and tissues with high efficiency. Human mesenchymal stem cells (MSCs) are attracting increased interest as a promising tool for cell-based therapy due to their high proliferative capacity, multi-potency, and anti-inflammatory and immunomodulatory properties. In particular, these cells are potentially suitable for use as encapsulated drug transporters to sites of inflammation. Here, we studied the in vitro effects of incorporating synthetic polymer microcapsules at various microcapsule-to-cell ratios on the morphology, ultrastructure, cytokine profile, and migration ability of human adipose-derived MSCs at various time points post-phagocytosis. The data show that under appropriate conditions, human MSCs can be efficiently loaded with synthesized microcapsules without damaging the cell's structural integrity with unexpressed cytokine secretion, retained motility, and ability to migrate through 8 µm pores. Thus, the strategy of using human MSCs as a delivery vehicle for transferring microcapsules, containing bioactive material, across the tissue-blood or tumor-blood barriers to facilitate the treatment of stroke, cancer, or inflammatory diseases may open a new therapeutic perspective.

Electrochemical, quantum-chemical and antioxidant properties of antipyrine and its derivatives.

Electrochemical, quantum-chemical and antioxidant properties of antipyrine and its derivatives have been investigated in this work. New quantum-chemical parameter such as difference of formation heats of a molecule and its cation radical (delta deltaH(cat)) has been used in order to describe properties of the investigated substances. Electrochemical properties (oxidation, reduction potentials) have been investigated. Correlation between the calculated delta deltaH(cat) and the experimentally obtained oxidation potentials for antipyrine and its derivatives has been found.

Antioxidant and electrochemical properties of calcium and lithium ascorbates.

The calcium and lithium pharmaceutical products have been widely used in medicine, especially at diseases of the mind. Bioactivity and toxically of novel complex ascorbates of calcium and lithium were considered in this work. Study of antioxidant properties of new forms of the compounds was carried out by differential pulse voltammetry. Cyclic voltammetry was used for investigation of their electrochemical properties in order to obtain information about electron-transfer reactions. The influence of these substances on the electrochemical oxygen reduction and its kinetic was also studied. As a result, the kinetic parameters interaction between reactive oxygen species and ascorbates of calcium and lithium were evaluated.

Study of antioxidant properties of a water-soluble Vitamin E derivative-tocopherol monoglucoside (TMG) by differential pulse voltammetry.

Study of antioxidant properties of tocopherol monoglucoside (TMG), a water-soluble Vitamin E derivative, by differential pulse voltammetry has been carried out in this work. The pH influence on the antioxidant properties of TMG has been also investigated. It was observed that the antioxidant activity of TMG is greater at 6.90

Investigation of antioxidant and catalytic properties of some biologically active substances by voltammetry.

Antioxidants play a major role in protecting biological systems against many incurable diseases. The biological activity of 12 plant aqueous-alcohol extracts, some standard antioxidants (vitamin C, glucose, resorcinol, and catechol), Na(2)SO(3), humic acids, phthalocyanines, and chlorophyll have been investigated in this work together with evaluation of their influence on the kinetics of the oxygen electroreduction. Finally the use of these substances for prophylactic purposes has been recommended.