ORNIDAZOL-BASED APPLICATION SORBENT WITH NANO SILICA AND ITS ANTIMICROBIAL ACTIVITY.

OBJECTIVE: The aim: To investigate the effect of application sorbent based on ornidazole with nanosilicon in experiment and clinic. PATIENTS AND METHODS: Materials and methods: In order to study the effectiveness of the Ornidasil application sorbent for the treatment of purulent wounds, we conducted an experimental study in rats. Also, we studied the effectiveness of the Ornidasil in the clinic for the treatment of patients with diabetic foot syndrome and to prevent the suppuration of postoperative wounds in patients with purulent peritonitis in toxic and terminal stages. RESULTS: Results: The formation of active substance complexes with hydroxylated matrices is due to hydrogen bonds between the oxygen atom of the silanol group of the silica surface and the hydrogen atom of the alcohol group of the ornidazole molecule. This promotes the gradual release of ornidazole from the surface of such a matrix into the wound exudate. Thus, on day 13, 9 experimental rats of group I healed completely, 11 rats had a small wound surface, complete healing occurred on day 15. We also investigated the effectiveness Ornidasil in the clinic. In the comparison group, postoperative wound suppuration occurred in 6 patients (31.6%), and in the main group - in 3 patients (12.5%). CONCLUSION: Conclusions: A study of the effectiveness Ornidasil in the complex treatment of Diabetic foot syndrome showed that in the experimental groups, wound healing occurred 1.6 -1.9 times faster. The use of polyurethane wound protector in combination with Ornidasil reduced the suppuration of postoperative wounds in patients of the main group by 2.5 times relative to patients in the comparison group.

Graphene oxide nanoflakes prevent reperfusion injury of Langendorff isolated rat heart providing antioxidative activity in situ.

Carbon materials possess powerful antioxidant activity that might be promising for the development of new generation treatment of cardiovascular diseases, ischemic conditions, and reperfusion injury. The present study aimed to characterize the structure of nanosized graphene oxide (GrO) sample and evaluate the antioxidant efficacy of GrO in situ models of oxidative stress widely used in pre-clinical studies. The structure and surface chemistry of the initial samples were analyzed via LDS, RAMAN, LDI, TPD-MS, and FTIR methods. The GrO showed a strong ability to scavenge DPPH, hydroxyl, and superoxide anion free radicals and have a total antioxidant capacity. The DFT quantum-chemical calculation demonstrated the radical scavenging effect of GrO proceeding due to the physical adsorption of the free radical on the surface. For evaluation of the antioxidant effect of GrO in situ, we used the model of ischemia-reperfusion (I/R) of Langendorff isolated rat heart. We revealed that intravenous pretreatment of Wistar male rats with GrO significantly increased resistance of myocardium to I/R, improved restoration of heart function, prevented non-effective oxygen utilization, and I/R-induced reactive oxygen species production in cardiac tissue. Thus, our data demonstrate the perspective of further use of GrO for the development of antiischemic therapy.

Effect of Charge Distribution in a Modified tRNA Substrate on Pre-Reaction Protein-tRNA Complex Geometry.

An important aspect of molecular mechanics simulations of a protein structure and ligand binding often involves the generation of reliable force fields for nonstandard residues and ligands. We consider the aminoacyl-tRNA synthetase (AaRS) system that involves nucleic acid and amino acid derivatives, obtaining force field atomic charges using the restrained electrostatic potential (RESP) approach. These charges are shown to predict observed properties of the post-transfer editing reaction in this system, in contrast to simulations performed using approximate charges conceived based upon standard charges for related systems present in force field databases. In particular, the simulations predicted key properties induced by mutation. The approach taken for generating the RESP charges retains established charges for known fragments, defining new charges only for the novel chemical features present in the modified residues. This approach is of general relevance for the design of force fields for pharmacological applications, and indeed the AaRS target system is itself relevant to antibiotics development.

A theoretical study on ascorbic acid dissociation in water clusters.

Dissociation of ascorbic acid in water has been studied by using a cluster model. It was examined by density functional theory (DFT) with the В3LYP, M06, and wB97XD functionals and a 6-311++G(d,p) basis set. The thermodynamic and kinetic characteristics of proton transfer from ascorbic acid molecule to water clusters were calculated as well as the equilibrium constants (pK a ) for the related processes. The used functionals in the DFT method together with continuum solvent models provided results close to the experimental data for the dissociation constant of ascorbic acid in aqueous solution.