A Study of the Cytotoxic Effect of Microcapsules and Their Constituent Polymers on Macrophages and Tumor Cells.

We studied the effect of different concentrations of polyelectrolytes poly(allylamine hydrochloride) (PAH) and polystyrene sulfonate (PSS) as well as the effects of microcapsules coated with these polymers on survival of Ehrlich ascites carcinoma cells and mouse peritoneal macrophages and on ROS production by phagocytes. PAH reduced viability of Ehrlich ascites carcinoma in a concentration-dependent manner (LD50=12-15 µg/ml). This effect was presumably determined by its ability to bind phosphates, thereby depleting the culture medium. At the same time, PAH did not affect the viability of macrophages. PSS produced no cytotoxic effect on the examined cells. Polyelectrolyte capsules with the shell architectonics (PAH/PSS)3 and (PAH/PSS)3PAH in the examined concentration range had no effect on the viability of macrophages and tumor cells. PAH microcapsules with positively charged surface much more rapidly and more intensively activated macrophages. The chemiluminescence response directly depended on the amount of capsules in the solution.

Effects of Polyelectrolyte Microcapsules with Different Surface Charge on Erythrocyte Sedimentation Rate.

Relationship between changes in the erythrocyte sedimentation rate in rats and concentration and charge of polyelectrolyte microcapsules was studied by the Panchenkov method. Positively charged microcapsules reduced erythrocyte sedimentation rate in a concentrationdependent manner. This effect was related to a decrease in the content of high-molecularweight proteins in the plasma due to their adsorption in positively charged microcapsules with polyacrylamide surface layer.

[DYNAMICS OF NITROGEN OXIDE METABOLITES IN THE PLASMA AND ASCITES DURING ZAJDEL HEPATOMA GROWTH IN VIVO].

The dynamics of extracellular nitrogen oxide metabolites localized in the plasma and ascites during Zajdel ascites hepatoma growth in the abdominal cavity has been investigated. An increase in peroxynitrite concentration was found by the levels of nitrotyrosine (up to 10-11 nM) in blood plasma at the initial stage of tumor cell development. In the course of further tumor development, an oxidative stress developed, which might cause oxidation of protein components including tyrosine. All these processes may cause a decrease in the accessible amount of tyrosine for nitration and lead to a fall in nitrotyrosine level (to 3-6 nM) at the final stages of tumor growth. Nitrotyrosine dynamics in the region of tumor growth is essentially analogous to that in the plasma because proteins during tumor growth cames from the blood plasma of tumor bearer. In studying the dynamics of nitrosylation of sulfur-bearing protein groups, an increase in the concentration of S-nitrosothyols was found to occur in the blood plasma for up to 6 days of the experiment, subsequently their concentration decreased. In the ascites, where protein R-SNO arrives, the mean concentration of nitrosothyols upon tumor growth is lower compared to that of the plasma. In studying the dynamics of final stable nitrogen oxide decay products--nitrites/nitrates, it has been found that during tumor development the concentration of these metabolites in the plasma varies only moderately within some range and sharply increases at the final stage of the experiment. In the area of tumor growth, an analogous trend in the behavior of nitrites/nitriaes has been registered (noted, marked), but with a higher background level, which might be due to both the functioning of immunocompetent cells, microphages in particular, and a decreased rate of utilization of substances from the ascites. Based on the aforesaid, it has been concluded that the nitrosylating stress in the organism of the bearer of a tumor is being developed along with the oxidative stress.

[Effect of Zajdela ascite hepatoma growth on the extracellular antioxidant system of tumor bearer].

The influence of tumor development on the blood plasma antioxidant system in the area of tumor growth has been studied. Zajdela ascite hepatoma transplanted to the abdominal cavity of Vistar rats was used as a model of tumor growth. It hase been found that tumor development produced and imbalance between pro- and antioxidant systems in the organism of tumor bearer. Besides, a sharp decrease in tocopherol and uric acid concentrations (twice), as well as in the concentration of protein SH-groups (seven times) was noted. In the tumor growth area, along with the tocopherol level decrease, a 5-7 fold increase in the concentrations of uric acid and protein SH-groups was observed. As the concentration of low-molecular antioxidants decreases, the major part is played by protein components which bind or oxidize ions of variable valence. Thus, the level of transferrin (Tf, which is responsible for the transport of iron ions, is reduced in 2.5 to 3 times (from 5.0 to 1.6 mg/ml) in the blood plasma, whereas the Tf level in the ascitic fluid increased from 1.5 to 2.7 mg/ml. The concentration dynamics of the other protein functioning together with Tf, ceruloplasmin (Cp), had opposite (inverse) tendencies. Thus, the Cp concentration in the blood plasma increased 1.5-2 times (from 0.55 to 1.1 mg/ml) whereas it decreased from 0.55 mg/ml to 0.35 mg/ml in the ascites.

[Effects of a nitric oxide donor, the substratum of NO-synthase, and an inhibitor of NO-synthase on the ROS-generation activity of phagocytes in the course of ascites tumor growth].

Experiments in vitro were performed to investigate the effects of the nitric oxide donor (SNP), the substratum of NO-synthase (L-arginine), and the inhibitor of NO-synthase (nitroarginine) on the ROS-generating activity of blood plasma polymorphonuclear leucocytes and ascitic fluid macrophages isolated at different times of tumor (Zaidel hepatoma) growth in animal organism. It was found that in the initial period of tumor growth the nitric oxide donor at a concentration of 8 x 10(-5) M reduced the potential ROS-generating activity of macrophages by 38.5 +/- 9.0% and that of polymorphic-nuclear leucocytes of plasma by 27.6 +/- 7.0 %. However, the dynamics of this process during tumor growth was conservative: variations in the production of ROS by phagocytes were 10 +/- 3.0%. L-arginine induced a decrease in the ROS-generating activity of granulocytes and mononucleares by 25-30%. This fact points to an inducible inhibiting effect of NO-synthase on the ROS-generating activity of NADPH-oxidase in the course of tumor growth. The inhibitor of NO-synthase, nitroarginine, produced a monotonous increase in the ROS-generating activity of phagocytes isolated from the tumor at different periods of its growth. The use NO-synthase inhibitors for increasing ROS levels in the region of tumor growth may favor the suppression of tumor cell growth in vivo.

Effects of a nanocomplex containing antioxidant, lipid, and amino acid on thermal burn wound surface.

Dihydroquercetin (flavonoid of plant origin) immobilized with an amino acid in lecithin nanoparticles promotes reduction of inflammatory reactions in the wound after thermal burn. The use of a liposomal complex in burn injury stabilizes endogenous antioxidant system and limits the secondary necrotic zone in the wounds. The treatment was associated with intensification of skin regeneration processes and reparation of hairy follicles and sebaceous glands.

[Beneficial action of the liposomal form of dihydroquercetin on the process of skin regeneration after thermal burn].

It was found that the flavonoid of plant origin, dihydroquercetin, being localized in lecitin nanoparticles in the presence of amino acid, reduced inflammatory reactions in the wound zone after thermal burn. Application of the liposomal complex on burn trauma stabilized the endogenous antioxidant system and minimized the area of the secondary necrosis in burn wound. Also, intensification of skin regeneration and repair of hair follicles and sebaceous glands were observed.

[Variations in cell population size and reactive oxygen species level in the blood and the ascites liquid of tumor carrier].

Using Seidel ascites hepatoma as a model, we studied in detail changes in cell population size and in the level of reactive oxygen species in the tumor growth zone and in the blood plasma of tumor carrier. It was found that reduction-oxidation conditions in the blood plasma and in the tumor growth zone were different. Thus, because of hyperactivity and increase in the number of leukocytes, the blood plasma exhibited strong oxidative stress inducing damage to healthy cells, whereas the tumor growth zone showed the decrease in macrophage concentration, as well as in oxygen and ROS levels. These conditions favor intensive growth of tumor cells.

Effect of liposomes containing antioxidant, phospholipid, and amino acid on skin regeneration after chemical burn.

Liposomes containing natural flavonoid dihydroquercetin, phospholipid lecithin, and zwitterionic amino acid glycine were used for the therapy of glacial acetic acid-induced chemical burn. No inflammatory reaction was observed in the region of wound. The area of postburn injury did not increase in time. Planimetry and histological studies showed that improved skin regeneration was accompanied by repair of hair follicles and sebaceous glands.

[A comparison of antioxidant properties of hypoxen and duroquinone by the method of chemiluminescence].

The antioxidant activity of duroquinone and hypoxen was compared with that of alpha-tocopherol and vitamin C in a model system (luminol-peroxidase-H2O2), and their influence on the level of reactive oxygen species in systems containing polymorphonuclear leukocytes of healthy and tumor-bearing animals was studied. It was shown that, in a model chemical system, the concentrations of antioxidants (the inverse of antioxidant activity) necessary to decrease twice the intensity of the chemiluminescence answer (C50%) are arranged in the following order: alpha-tocopherol > duroquinone > hypoxen > ascorbic acid. In this case, the concentrations of the hydrophobic antioxidants (C50% for alpha-tocopherol and duroquinone 10-30 mkM) should be 20-50 times higher than for hydrophilic antioxidants (C50% for vitamin C and hypoxen 0.5-0.6 mkM). It was revealed that the generation of reactive oxygen species by blood phagocytes of tumor-bearing animals is 2-2.5 times higher than by phagocytes of healthy animals. The antioxidant concentration necessary to decrease the chemiluminescence answer in the cellular system should be one order of magnitude higher than in the model chemical system. The distribution of a hydrophobic antioxidant between water/lipid phases promotes an increase in the concentration of the antioxidant necessary to decrease the level of reactive oxygen species twice. Thus, the major factor influencing the antioxidant activity is the constant of distribution of these compounds in a water/lipid system.

[Cytotoxicity of amyloid fibrils of X-protein].

It is known that amyloid oligomers, protofibrils, and fibrils induce cell death, and antibiotic tetracycline inhibits the fibrillization of beta amyloid peptides and other amyloidogenic proteins and disassembles their pre-formed fibrils. Earlier we have demonstrated that sarcomeric cytoskeletal proteins of the titin family (X-, C-, and H-proteins) are capable to form in vitro amyloid fibrils, and tetracycline effectively destroys these fibrils. Here we show that the viability of polymorphonuclear leukocytes in the presence of X-protein amyloids depends on the concentration of amyloid fibrils of X-protein and the time of incubation. In addition to the disaggregation of X-protein fibrils, tetracycline eliminated the cytotoxic effect of the protein. The antibiotic itself did not show a toxic effect, and the cell viability in its presence even increased. Our results evidence the potential of this approach for evaluating the effectiveness of drugs preventing or treating amyloidoses.

[The use of a modelling method in craniometry]. / Ispol'zovanie metoda modelirovaniia v kraniometrii.

Laser interferometry is proposed for accurate measurements of the external parameters and fixation of the relief of human skull surface. This method creates a detailed three-dimensional computer model of the object of investigation, which can be used in automated systems of personality identification based on investigation of the skull and life-time photos. Further development of the method opens new vistas in automation of the trassological and ballistic identification.