Nanoheterogeneous multilayer films with perfluorinated domains fabricated using the layer-by-layer method

Nanoheterogenous ultrathin films containing perfluorinated domains were prepared via the layer-by-layer (LbL) electrostatic self-assembly method. The films are constructed from the amphiphilic cationic copolymer with perfluorinated side chains and poly(sodium styrenesulfonate) (PSS). The LbL process was optimized by the application of sonication which allowed linear growth of the film. The resulting film exhibited micellar structure with isolated fluorocarbon hydrophobic domains. The remarkable features of the films were their switchable wettability and friction properties. The obtained water-processable films can find a number of potential applications, e.g., as smart and low friction coatings

Characterization of hydrocarbon and fluorocarbon microdomains formed in aqueous solution of associative polymers: A molecular probe technique

Fluorocarbon associative polymers of the polysoap type were studied using two fluorescent probes, 1-octanoylpyrene (OcPyH) and 1-perfluorooctanoylpyrene (OcPyF). In aqueous solution the polymers formed hydrophobic domains composed of hydrocarbon, fluorocarbon or both types of polymeric side chains, which could solubilize the probes. This resulted in the appearance of new fluorescence emission bands and changes in the fluorescence polarization of the probes. The differences in the solubilization properties of the polymers are discussed. (c) 2005 Elsevier B.V. All rights reserved

Nonclinical evaluation of novel cationically modified polysaccharide antidotes for unfractionated heparin.

Protamine, the only registered antidote of unfractionated heparin (UFH), may produce a number of adverse effects, such as anaphylactic shock or serious hypotension. We aimed to develop an alternative UFH antidote as efficient as protamine, but safer and easier to produce. As a starting material, we have chosen generally non-toxic, biocompatible, widely available, inexpensive, and easy to functionalize polysaccharides. Our approach was to synthesize, purify and characterize cationic derivatives of dextran, hydroxypropylcellulose, pullulan and γ-cyclodextrin, then to screen them for potential heparin-reversal activity using an in vitro assay and finally examine efficacy and safety of the most active polymers in Wistar rat and BALB/c mouse models of experimentally induced arterial and venous thrombosis. Efficacy studies included the measurement of thrombus formation, activated partial thromboplastin time, bleeding time, and anti-factor Xa activity; safety studies included the measurement of hemodynamic, hematologic and immunologic parameters. Linear, high molecular weight dextran substituted with glycidyltrimethylammonium chloride groups at a ratio of 0.65 per glucose unit (Dex40-GTMAC3) is the most potent and the safest UFH inhibitor showing activity comparable to that of protamine while possessing lower immunogenicity. Cationic polysaccharides of various structures neutralize UFH. Dex40-GTMAC3 is a promising and potentially better UFH antidote than protamine