Effect of Hyaluronic Acid on the Activity of Methylene Blue in Photogeneration of O.

The effect of a natural polysaccharide (hyaluronic acid (HA)) on the photocatalytic activity of methylene blue (MB) was studied both under model conditions (a tryptophan photooxidation reaction in water) and with in vitro experiments on and bacterial cultures. It was shown spectrophotometrically that, in the presence of HA, an increase in the optical density of the absorption bands λ = 665 nm and 620 nm-which correspond to the monomeric and dimeric forms of the dye, respectively-was observed in the EAS of the dye, while the ratio of the optical density of these bands remained practically unchanged. When adding HA to MB, the intensity of singlet oxygen O photoluminescence and the degree of fluorescence polarization of MB increase.

Effect of Chitosan and Amphiphilic Polymers on the Photosensitizing and Spectral Properties of Rose Bengal.

The influence of chitosan (CS) and amphiphilic polymers (AP: pluronic F108 and polyvinylpyrrolidone (PVP)) on the photocatalytic activity of rose bengal (RB) in a model reaction of tryptophan photo-oxidation in phosphate-buffered saline (PBS) was studied. It was shown that in the presence of CS, the effective rate constant of tryptophan photo-oxidation catalyzed by RB in PBS solution decreases by a factor of two. This is due to the ionic interaction of the RB with the chitosan.

Fabrication of Conductive Tissue Engineering Nanocomposite Films Based on Chitosan and Surfactant-Stabilized Graphene Dispersions.

Chitosan (CS)/graphene nanocomposite films with tunable biomechanics, electroconductivity and biocompatibility using polyvinylpyrrolidone (PVP) and Pluronic F108 (Plu) as emulsion stabilizers for the purpose of conductive tissue engineering were successfully obtained. In order to obtain a composite solution, aqueous dispersions of multilayered graphene stabilized with Plu/PVP were supplied with CS at a ratio of CS to stabilizers of 2:1, respectively. Electroconductive films were obtained by the solution casting method.

Evaluation of Supercritical CO-Assisted Protocols in a Model of Ovine Aortic Root Decellularization.

One of the leading trends in the modern tissue engineering is the development of new effective methods of decellularization aimed at the removal of cellular components from a donor tissue, reducing its immunogenicity and the risk of rejection. Supercritical CO (scCO)-assisted processing has been proposed to improve the outcome of decellularization, reduce contamination and time costs. The resulting products can serve as personalized tools for tissue-engineering therapy of various somatic pathologies.

Multicomponent Non-Woven Fibrous Mats with Balanced Processing and Functional Properties.

The mimicking of the architectonics of native tissue, biodegradable non-woven fibrous mats is one of the most promising forms of scaffolding for tissue engineering. The key properties needed for their successful application in vivo, such as biodegradability, biocompatibility, morphology, mechanical properties, etc., rely on their composition and appropriate 3D structure.

Solid-State Synthesis of Water-Soluble Chitosan-g-Hydroxyethyl Cellulose Copolymers.

Graft copolymers of chitosan with cellulose ether have been obtained by the solid-state reactive mixing of chitin, sodium hydroxide and hydroxyethyl cellulose under shear deformation in a pilot twin-screw extruder. The structure and composition of the products were determined by elemental analysis and IR spectroscopy. The physicochemical properties of aqueous solutions of copolymers were studied as a function of the composition, and were correlated to the mechanical characteristics of the resulting films to assess the performance of new copolymers as coating materials, non-woven fibrous materials or emulsifiers for interface stabilization during the microparticle fabrication process.

Chitosan--oligo/polylactide copolymer non-woven fibrous mats containing protein: from solid-state synthesis to electrospinning.

Graft-copolymers based on bioresorbable synthetic (oligo-/polylactide) and natural (chitosan and collagen/gelatin) components were synthesized through solid-state reactive co-extrusion and used for fabrication of fibrous non-woven mats the electrospinning technique. The effect of the macromolecular features of the initial components on the copolymer characteristics was evaluated using FTIR-spectroscopy, differential scanning calorimetry and elemental analysis. Dynamic light scattering analysis showed that the copolymers have a tendency to form stable ultra-fine dispersions with a mean size of macromolecular aggregates of 150 nm within chlorinated solvents.