[The range and potential contribution of irreversibly adsorbed proteins on the surface of artificial implants]. / Spektr i potentsial'naia rol' neobratimo adsorbirovannykh belkov na poverkhnosti iskusstvennykh implantiruemykh materialov.

Protein adsorption is the first stage of the interaction between prosthetic materials with tissues of the body. They undergo conformational changes depending on the chemical composition and the nanotopography surface. Adsorbed proteins induce adhesion and alter the functional state of migrating cells. Plasma samples from patients were incubated with such matrices as titanium, polypropylene or polyester with fluoropolymer coating meshes. Bound peptides were analyzed by electrophoresis. Qualitative analysis of the peptides extracted from the gel was performed by chromatography-mass spectrometry. Quantitative analysis was performed by the MRM method. More than 60 proteins were identified on the analyzed surfaces. Quantitative analysis showed preferential adsorption of vitronectin, albumin, fibrinogen a-chain, C1ѕ component of the complement system. Vitronectin had the maximum relative protein content. Since biocompatibility of the analyzed materials varies considerably this variability may be attributed to conformational changes occurring with vitronectin during its irreversible adsorption.

Sources of Reactive Oxygen and Nitrogen Species in Tissue Microenvironment of Hernioplasty Materials.

Titanium and polypropylene mesh endoprostheses were implanted into the rat abdominal cavity and the populations of cells migrating to their surface were analyzed. On both materials, the cells were presented mainly by macrophages that proliferated, activated, and fused to form multinuclear cells. Contact with the foreign surface triggered superoxide anion generation and myeloperoxidase synthesis by macrophages (these processes were more intense on polypropylene implants than on titanium ones) and stimulated production of nitric oxide by macrophage. It was hypothesized that the effects of free nitrogen and oxygen radicals lead to oxidation and destruction of the polypropylene endoprosthesis surface.

STUDIES OF SPACEFLIGHT EFFECTS ON A 3D MODEL OF CHONDROBLAST CULTURE.

The effect of long-duration space flight on the vital processes in human chondroblasts in vitro was studied with a number of morphologic, biochemical and optic techniques. Object of investigation was a 3-D porous biocarrier populated by a cell culture in a leak-free vessel completely full of growth medium. The investigation was performed onboard automatic .spacecraft Foton-M4 with the use of research equipment SIGMA. Synchronous experiments were conducted in ground laboratory. The experiment with cell culture prepared of the human hyaline cartilage validated suitability of this model for long-duration experiments with adhesive cells on automatic spacecraft; besides, the experimental results suggest that in spaceflight microgravity adhesive cells exist in the state of suspension.

Antiradical effect of allopurinol at early stages of experimental acute pancreatitis.

Pretreatment with allopurinol partly prevented generation of free oxygen radicals in the pancreas of dogs with experimental acute pancreatitis. Allopurinol holds promise for the prevention of acute postoperative pancreatitis.

Generation of free oxygen radicals in the pathogenesis of experimental acute reflux pancreatitis.

In dogs with acute reflux pancreatitis specific activity of superoxide dismutase in the pancreas rapidly increased (over 15 min). Activation of this enzyme by free oxygen radicals was demonstrated in in vitro experiments. Treatment with allopurinol prevented activation of superoxide dismutase. Our results indicate that superoxide ions are generated in the pancreas at the early stage of acute reflux pancreatitis due to activation of xanthine oxidase.

Free radical oxidation and activity of enzymes catalyzing biotransformation of xenobiotics in the liver of rats with experimental acute pancreatitis.

The development of experimental acute pancreatitis in rats was accompanied by intensification of lipid peroxidation, activation of superoxide dismutase and glutathione reductase, inhibition of glutathione transferase, and deceleration of aniline N-hydroxylation by cytochrome P-450 in the liver. Antioxidants inhibited lipid peroxidation and antioxidant enzymes, but did not prevent inhibition of detoxifying enzymes.