Features of electron beam deposition of polymer coatings with the prolonged release of the drug component.

The first part of the paper provides a comprehensive analysis of the features of electron beam formation of polymer coatings with the prolonged release of the drug compound using ciprofloxacin and clotrimazole as an example. The influence features of the low-energy electron beam on the molecular structure of medicinal chemical preparations have been established. The impossibility of producing the coatings based on medicinal compounds with a complex molecular structure (vancomycin, micafungin, etc.) by a low-energy electron beam has been justified. The second part of the paper introduces a fundamentally new vacuum method for the formation of the composite coatings based on antibiotics and antifungal drugs, accompanied by the prolonged release of the drug component. This method allows the formation of composite coatings based on medicinal compounds with a complex molecular structure. It is effective for modifying implants to prevent the risk of implant-associated infectious complications which are the result of the occurrence of mixed biofilms. The method can be used to form composite layers based on topical antitumor drugs for cancer control.

[Contribution of blue-green pigments to hemolytic activity of Pseudomonas aeruginosa cultural fluid].

AIM: To assess the contribution of blue-green pigments of Pseudomonas aeruginosa to hemolytic activity of its cultural fluid. MATERIALS AND METHODS. Eight hospital strains and reference strain ATCC 15442 were used. Growth dynamics of strains as well as features of accumulation of hemolytic and phospholipase activity were studied. Purified samples of pyoverdin and pyocyanin were extracted by gel-chromatography and chloroform extraction methods. Hemolytic and lecitinase activities of the samples as well as effect of active oxygen scavengers and chelating agents on these activities were studied. RESULTS: Dynamics of accumulation of hemolytic activity significantly differed from that of phospholipase activity when strains were grown in liquid medium. Chromatographic separation of the pigments from cultural fluid supernatants sharply reduced its hemolytic activity. Purified samples of pyoverdin and pyocyanin were capable to lyse erythrocytes and chicken egg lecitin. These characteristics of the pigments were inhibited by nitroblue tetrazolium and sensitive to chelating agents. Conclusion. Pyoverdin and pyocyanin of pathogenic strains of P. aeruginosa are capable to lyse erythrocytes and suspension of purified chicken egg lecitin, they contribute to total hemolytic activity of pathogenic strains of Pseudomonas, which is not determined only by phospholipase C produced by microorganism. Lytic activity of the pigments is blocked by nitroblue tetrazolium and susceptible to some chelating agents. Apparently, this activity is mediated by superoxide radical and determined by presence of metals with transient valence in pigments' molecules.