It has been shown that amphiphilic polymers (AP) (Pluronic F108 and polyvinylpyrrolidone) increase the activity of rose bengal (RB) in the photogeneration of (1)O(2)in vitro and in vivo conditions. In particular, in the presence of AP, the intensity of luminescence of O-1(2) generated by exited RB increased. Perhaps RB forms loosely bound complexes with AP, which promotes disaggregation of the dye. According to x-ray diffraction data, the degree of crystallinity of pluronic decreases during crystallization from joint solutions with RB and a large period in the packing of its crystallites is disrupted. This may indicate the localization of the dye in the intercrystalline amorphous regions of pluronic due to complexation RB + F108. In vitro experiments showed that the phototoxicity of the dye against A549 lung carcinoma cells increases in the presence of F108 and PVP. Under photodynamic exposure to model wounds in rats using the RB + F108 complex as a PS, there was an increase in reparative processes in the wounds, while pluronic F108 weakened the negative impact of RB on microvessels and prevented the development of a local hemorrhagic reaction. Thus, the photosensitizing systems based on RB + AP complexes are promising for treating local foci of oncological and non-oncological nature using PDT.

Composite film samples of polylactide-natural rubber with a rubber content of 5, 10, and 15 wt

The structure and chemical composition of nanocomposite films based on poly(p-xylylene) with cadmium sulphide (CdS) as a filler were studied by X-ray diffraction and IR-spectroscopy. The films were synthesized by co-deposition of p-xylylene monomer and CdS vapors on quartz and silicon substrates, had a thickness of ~0.2 and ~1.5 µm and contained 5–90 vol. % of CdS. The effect of filler content and film thickness on polymer matrix and filler structure was demonstrated. Differences in the chemical compositions of films with thicknesses of ~0.2 and ~1.5 µm were revealed, caused by their partial oxidation upon contact with air after synthesis. The possible influence of hydroxyl groups on the formation of CdS crystalline structures in films was discussed. A correlation was established between structural transformations upon changes in the CdS content with the previously obtained dependences of dark conductivity and photoconductivity for films with a thickness of ~0.2 μm.

The structure and chemical composition of nanocomposite films based on poly(p-xylylene) with cadmium sulfide (CdS) as a filler were studied by X-ray diffraction and infrared (IR) spectroscopy. The films were synthesized by the codeposition of p-xylylene monomer and CdS vapors on quartz and silicon substrates, had a thickness of 0.2 and 1.5 µm and contained 5–90 vol

This work studied biocomposites based on a blend of low-density polyethylene (LDPE) and the ethylene–vinyl acetate copolymer (EVA), filled with 30 wt.% of cellulosic components (microcrystalline cellulose or wood flour). The LDPE/EVA ratio varied from 0 to 100%. It was shown that the addition of EVA to LDPE increased the elasticity of biocomposites. The elongation at break for filled biocomposites increased from 9% to 317% for microcrystalline cellulose and from 9% to 120% for wood flour (with an increase in the EVA content in the matrix from 0 to 50%). The biodegradability of biocomposites was assessed both in laboratory conditions and in open landfill conditions. The EVA content in the matrix also affects the rate of the biodegradation of biocomposites, with an increase in the proportion of the copolymer in the polymer matrix corresponding to increased rates of biodegradation. Biodegradation was confirmed gravimetrically by weight loss, an X-ray diffraction analysis, and the change in color of the samples after exposition in soil media. The prepared biocomposites have a high potential for implementation due to the optimal combination of consumer properties.

The X-ray diffraction technique was used to study oriented films prepared from chloroform solutions of egg phosphatidylcholine, synthetic hybrid antioxidant ICHPHAN-10-C-10 and their mixtures containing 12.5 wt % and 32 wt % ICHPHAN. The air-dry films prepared from phosphatidylcholine and ICHPHAN were multiphase and in addition to non-bilayer lipid phases, they contained a crystalline phase of ICHPHAN. Increasing a degree of hydration of such films contributed to the formation of one lamellar phase containing lipids and ICHPHAN. The formation and disappearance of ICHPHAN crystalline phase in the films upon alteration of their degree of hydration was reversible. Electron density profiles of lipid membranes calculated at ~1.2 nm resolution showed that membrane thickness and lipid hydrocarbon chain ordering decrease in presence of ICHPHAN. The results obtained demonstrate that ICHPHAN can incorporate from crystalline phase into lipid membranes at high concentration.

The morphology and structure of polylactide film samples obtained from a melt and from a solution in chloroform are studied. The crystallization process of polylactide takes place under nonisothermal conditions. It is determined that the melting and crystallization points of the polylactide sample obtained from the solution are, respectively, 2 and 4°C lower than the sample obtained from the melt. Using optical polarization microscopy, it is shown that the sample obtained from the solution has a spherulite structure, while spherulites are not detected in the polylactide sample obtained from the melt. The X-ray diffraction patterns of the polylactide samples crystallized from the solution and melt are different. Well-defined reflexes characteristic of the crystalline modification of the α-form are recorded on the diffractogram of the sample obtained from the solution. The pressed polylactide sample has an initially X-ray amorphous structure, which partially transforms into a crystalline structure during annealing for 60 min at 90°C. X-ray diffraction analysis revealed differences in the degree of crystallinity over the thickness of the polylactide sample obtained from the solution.

В работе изучены морфология и структура пленочных образцов полилактида, полученных из расплава и из раствора в хлороформе. Процесс кристаллизации полилактида протекал в неизотермических условиях. Определено, что температуры плавления и кристаллизации образца полилактида, полученного из раствора, ниже соответственно на 2 и 4 °С, чем образца, полученного из расплава. Методом оптической поляризационной микроскопии показано, что образец, полученный из раствора, имеет сферолитную структуру, а в образце полилактида, полученном из расплава, сферолиты не выявляются. Рентгеновские дифрактограммы образцов полилактида, полученных из раствора и расплава, различны. На дифрактограмме образца, полученного из раствора, присутствуют четкие рефлексы, характерные для кристаллической α-формы. Полилактид, полученный из расплава, имеет изначально рентгеноаморфную структуру, которая частично переходит в кристаллическую при отжиге (90 °С, 60 мин). Методом рентгенодифракционого анализа выявлены различия в степени кристалличности по толщине образца полилактида, полученного из раствора.

The structure of nanocomposite films based on poly( p -xylylene) (PPX) and cadmium sulfide (CdS) is investigated. The films are synthesized on silicon substrates by the vapor-phase codeposition of p ‑xylylene monomer and CdS; the films are ~1.5 µm thick and contain 5 to 90 vol % CdS. The absence of other chemical compounds (except for PPX and CdS) in the films is confirmed by infrared (IR) spectroscopy in the range of 4000–600 cm –1 . The X-ray diffraction data show that the structures of both the polymer matrix and the filler change with an increase in the CdS content in the films. The polymer matrix has an unoriented amorphous-crystal structure at a CdS content of 5 vol % and an X-ray amorphous structure at 10–70 vol % CdS (with a preferred orientation at 30–70 vol % CdS). At 80 and 90 vol % CdS, no diffraction pattern from PPX is observed. The presence of CdS in the films is not revealed by the X-ray diffraction method at its content of ≤50 vol %, which is indicative of the molecular dispersed or very small cluster form of CdS in these films. The films containing 60, 70, or 80 vol % CdS exhibit an unoriented X-ray amorphous CdS structure with a nanoparticle size of no more than ~3 nm (according to published data). At 90 vol % CdS, ~9-nm oriented CdS nanoparticles with an imperfect crystal structure are formed in the film.

The results of research on the structural, thermodynamic, and physicochemical properties of normal maize starch subjected to mechanical processing in a ball mill for different time intervals are presented. It is shown that in the process of mechanical processing, abrasion and splitting of starch granules, the formation of roughness and cracks on their surface, and an increase in size of the granules occur. During the treatment, the crystalline regions of the structure are destroyed and completely disappear after 8 h of treatment. The observed changes are a consequence of the destruction of the structure of the crystalline lamellae of amylopectin. The mechanically processed starch is characterized by lower values of temperature, enthalpy, and the level of cooperativity of the melting process. At the same time, mechanically modified starch has higher rates of water solubility, water absorption, and enzymatic availability than native starch. The mechanical processing of starch granules in a ball mill for various periods of time can be used to modify the physicochemical properties of maize starch within specified limits.

Solid-phase photosensitizing systems active in the generation of singlet oxygen (1O2) are obtained from fluorinated tetraphenylporphyrin (FTPP) immobilized on polysaccharide aerogels (chitosan and calcium alginate). Immobilization is carried out in a supercritical carbon dioxide (SC–CO2), or by planting FTPP on an aerogel (AEG) from a solution in chloroform. The kinetic parameters of the oxidation of tryptophan in an aqueous medium and anthracene in SC–CO2 are found using these photocatalytic systems. It is shown that the immobilization of porphyrin on a chitosan aerogel does not affect the effective rate constant of photooxidation. Active photocatalytic systems for FTPP immobilized on AG of calcium alginate are obtained only by impregnating the polymer with FTPP molecules in SC–CO2. It is found that FTPP immobilized on both chitosan and calcium alginate aerogels retains its functional activity for 3–4 cycles in model photooxidation processes. Differential thermal analysis is used to explain the differences between the photocatalytic activity of solid-phase aerogel systems containing porphyrin photosensitizers. Treatment with chloroform in particular has almost no effect on the thermooxidative destruction of the FTPP–chitosan aerogel system. A change in the thermooxidative destruction of the catalyst after treating the FTPP–AG system of calcium alginate with chloroform testifies to a change in structure of the system. It is concluded that photostable photosensitizing systems based on aerogels of calcium alginate or chitosan containing fluorinated tetraphenylporphyrins can be used for the photooxidation of organic substrates in both aqueous solutions and a supercritical medium.

— The structure of poly- p -xylylene–cadmium sulfide (PPX–CdS) nanocomposite films of different thickness (~0.2, ~0.5, and ~1 μm) is studied by X-ray diffraction in a wide range of CdS concentrations, as well as the structure of single-component CdS and PPX films of different thickness. The films are obtained by solid-phase cryochemical synthesis on optical quartz and single-crystal silicon substrates. The results of the study show that CdS nanoparticles in PPX-CdS films with a thickness of ~ 0.2 μm with filler content of C ~ 10.5–13.5 vol % and in a CdS film of the same thickness have a crystal structure of a wurtzite type with an average size of coherent scattering regions of ~30 nm in PPX–CdS and ~60 nm in CdS films. For nanocomposite films with a thickness of ~0.2 μm ( C ~ 8 vol %), ~0.5 and ~1 μm ( C ~ 5–90 vol %), as well as for a CdS film with a thickness of ~1 μm, only diffusive diffraction maxima are observed, on the basis of which the conclusion is drawn that the CdS nanoparticles in these films have an amorphous or defective crystal structure and a size of ~1–3 nm. The PPX matrix in all studied nanocomposite films has a low-ordered (amorphous) structure, as in a single-component film of this polymer with a thickness of ~0.5 μm.

The structure of the samples of polymer porphyrin-containing photosensitizing systems with different contents of chlorin e6 trisodium salt (Ce6Na), sodium alginate, and polyvinylpyrrolidone was investigated by X-ray diffraction and atomic force microscopy (AFM). The samples were obtained in the form of films by evaporation of aqueous solutions containing these compounds in different proportions. X‑ray diffraction studies show that, in two-component films Ce6Na–sodium alginate, a separate phase of the first substance and the phase of the second substance with the same structure as in the one-component films of this polymer are formed. At the same time, in two-component films Ce6Na–polyvinylpyrrolidone and three-component films Ce6Na–sodium alginate–polyvinylpyrrolidone, as evidenced by X-ray diffraction, the main part of Ce6Na does not form a separate phase, but the structure of polyvinylpyrrolidone changes in comparison with the one-component films of this polymer. In addition, X-ray diffraction studies show that, in the films containing sodium alginate and polyvinylpyrrolidone, these polymers form two separate phases. This conclusion also follows from the AFM data, although no significant influence of Ce6Na on the surface structure of the films obtained using sodium alginate, polyvinylpyrrolidone, and their mixture is revealed by AFM.

Poly(p-xylylene)—CdS (PPX—CdS) nanocomposite films with different thicknesses (∼0.2, ∼0.5, ∼1, and ∼1.5 μm) and concentrations of CdS from 5 to 90 vol.%, as well as single-component CdS and PPX films with various thicknesses were studied by X-ray diffraction. The films were synthesized on polished silicon or quartz substrates by low-temperature vapor deposition method. It was shown that CdS nanoparticles in PPX—CdS films, depending on their thickness and CdS content, can have an X-ray amorphous structure, a defect crystal structure (RCP structure), or a wurtzite-type crystal structure. Similar structures were observed for single-component CdS films of the corresponding thickness. The sizes of the coherent scattering regions of CdS were determined for some nanocomposite and single-component films. Poly(p-xylylene) in the studied nanocomposite films was characterized by an X-ray amorphous structure.

The creation of new highly productive forms of potato by genetic engineering methods raises the question about the quality of transgenic tubers, which first of all relates to the properties of important storage compound such as starch. The article presents the results of studies aiming to the analysis of morphology, structure, and thermodynamic parameters of starch extracted from the potato tubers expressing thetms1auxin biosynthesis gene fromAgrobacterium tumefaciensand characterized by increased productivity in vitro. The transformed and control plants were cultivated in vitro on artificial sterile medium, as well as in vivo in the soil. The methods of scanning electron microscopy, wide-angle X-ray scattering, and differential scanning microcalorimetry were used in the work. It was established that the transformation of plants with the construction with thetms1gene under the control of the patatin gene promoter causes significant changes in a number of thermodynamic parameters of starch, first of all an increase in the thickness of crystalline lamella and melting temperature, which apparently reflects the increase in the structural ordering of the main starch fraction (approximately 90%) in the tubers of these transformants. Along with this, the effect of accumulating fractions with a less ordered structure in the starch composition, correlating with the ectopic expression of thetms1auxin biosynthesis gene, was established. At the same time, the B type of the polymorphic structure of starch remains unchanged. However, the detected changes mainly affected starch of the plants, cultivated in vitro. The starch of transgenic plants cultivated in the soil differs little in its basic characteristics from the starch of nontransgenic control plants.