A new sterically hindered trialkyl-substituted o-benzoquinone, 4,6-di-tert-butyl-3-[(3,5-di-tert-butyl-1H-pyrazol-1-yl)methyl]cyclohexane-3,5-diene-1,2-dione was synthesized. Its spectral, electronic, and structural characteristics were determined, which were found to be similar to those for analogous 3,6- and 3,5-di-tert-butyl-o-benzoquinones. The following sequence was observed for the reactivity in the photoreduction reaction in the presence of N,N-dimethylaniline (DMA): 3,6-di-tert-butyl-o-benzoquinone > 4,6-di-tert-butyl-3-[(3,5-di-tert-butyl-1H-pyrazol-1-yl)methyl]cyclohexane-3,5-diene-1,2-dione > 3,5-di-tert-butyl-o-benzoquinone. The new quinone, like 3,6- and 3,5-di-tert-butyl-o-benzoquinones, in combination with DMA was found to initiate radical polymerization under the irradiation by LED sources in the range from 395 to 630 nm. It was found that the introduction of the pyrazole-containing fragment at position 6 of the quinonoid ring of 3,5-di-tert-butyl-o-benzoquinone led to a sharp increase in the activity of the new compound as a photoinitiator compared to 3,5-di-tert-butyl-o-benzoquinone and made the new quinone comparable with 3,6-di-tert-butyl-o-benzoquinone in the photoinitiating activity. At the same time, a photopolymerizable composition containing a photoinitiating system based on 4,6-di-tert-butyl-3-[(3,5-di-tert-butyl-1H-pyrazol-1-yl)methyl]cyclohexane-3,5-diene-1,2-dione was found to be more stable than the photoinitiating system based on 3,6-di-tert-butyl-o-benzoquinone.

The photolysis of a phenanthroline-containing imidazole in a DMSO solution and the initiating ability of the compound in the photopolymerization of multifunctional (meth)acrylates under LED irradiation (λ = 395 nm) in aerobic conditions have been studied for the first time. The relationship between the kinetic parameters of photopolymerization and light intensity and the chemical structure and viscosity of multifunctional monomers has been established.

A norbornene-substituted cationic iridium(III) complex containing 1-phenylisoquinoline cyclometalating ligands and an additional phenylimidazophenanthroline ligand was synthesized. On the base of this complex, water-soluble polymers were obtained by ring-opening metathesis polymerization (ROMP). The resulting polymers showed oxygen-dependent phosphorescence in the orange spectral region and high cytotoxicity against HCT116 cancer cells.

Alginate is one of the well-studied natural polysaccharides that is most commonly used for the encapsulation of biological objects. Alginate hydrogels exhibit good biocompatibility and are often used to create shells around pancreatic islets of Langerhans in order to produce stable transplants, making possible long-term normoglycemia, and to prevent fatal hypoglycemia in absolute insulin deficient diseases. However, there exists the problem of rejection and loss of an encapsulated transplant owing to immune response. One of the lines of research into reduction of rejection and increase in the compatibility and stability of an alginate shell is the chemical modification of alginate. At present, a large number of chemically functionalized alginates are available for different purposes. This makes it possible to gain insight into relationship between the character of modification and the properties of modified alginates. The review highlights techniques and features of the chemical modification of sodium alginate designed for the microencapsulation of insulin producing cells.

The review includes the results of analytical research on the problem of application of pancreatic islet encapsulation technologies for compensation of type 1 diabetes. We present a review of modern encapsulation technologies, approaches to encapsulation strategies, insulin replacement technologies: auto-, allo- and xenotransplantation; prospects for cell therapy for insulin-dependent conditions; modern approaches to β-cell encapsulation, possibilities of optimization of encapsulation biomaterials to increase survival of transplanted cells and reduce adverse consequences for the recipient. The main problems that need to be solved for effective transplantation of encapsulated islets of Langerhans are identified and the main strategies for translating the islet encapsulation technology into medical reality are outlined.

The homophase polymerization of acrylic acid is carried out in a solution of poly(butyl acrylate) trithiocarbonate (PBATC) in a mixed solvent 2-propanol–water. The phase diagram of the three-component PBATC-2-propanol–water system at 22°C is obtained. The homophase region of the compositions of semidilute solutions is determined. The homophase polymerization of AA in the three-component system at 70°C, in which the mixed solvent with respect to PBATC is similar in thermodynamic quality to the θ-solvent at 22°, yields solutions of the narrowly dispersed block copolymer butyl acrylate–acrylic acid. The content of the block copolymer in solutions is 15–23%, the MW of the copolymer is 10–20 × 103, and the polydispersity coefficient is 1.12–1.16. As evidenced by dynamic light scattering, under normal conditions, the solutions contain nanoparticles with a diameter of up to 50 nm with a narrow size distribution.

A procedure was developed for preparing poly(methyl methacrylate) nanoparticles of 15–50 nm size from coarser (200–300 nm) polymer latex particles prepared by emulsifier-free emulsion polymerization. The hydrodynamic radii of the macromolecules in the t -BuOH (85 vol %)-H 2 O (15 vol %) mixture at 30°C and in the i -PrOH (80 vol %)-H 2 O (20 vol %) mixture at 25°C were determined by dynamic light scattering: R h = 5.94 × 10 −2 M w 0.3733 ( R 2 = 0.9525) and R h = 2.12 × 10 −2 M w 0.4641 ( R 2 = 0.9673), respectively.

Polymers containing oligoether groups, amino acid fragments, and luminophore complexes of iridium(III) in side chains are synthesized by metathesis polymerization. The photophysical properties of the compounds obtained are studied. The iridium-containing copolymers show intense green, blue-green, and red photoluminescence, and the color is determined by the nature of the iridium(III) complexes contained in polymeric emitters. Polymeric products are soluble in water and form micelles with average sizes of 19–54 nm. The cytotoxicity of the polymers with respect to A431 human epidermoid carcinoma cells is determined.

Copolymers with oligoether units and luminophoric iridium(III) complexes in the side chains have been synthesized via metathesis polymerization. The copolymers containing different luminophoric iridium(III) complexes have exhibited strong green, blue-green, or red photoluminescence. The copolymers are soluble in water, forming micelles with average size 14‒20 nm. The copolymer with red photoluminescence has low cytotoxicity with respect to epidermoid human carcinoma cells (line A431).

New two- and trivalent europium complexes with dithio- and diselenodiphenylphosphinate ligands (S 2 PPh 2 - and Se 2 PPh 2 - ) have been synthesized as precursors for nanoparticles. Two-valent europium compounds have been characterized via X-ray diffraction. Their photoluminescence properties have been studied as well. EuS colloidal nanoparticles have been obtained via the thermolysis of Eu(S 2 PPh 2 ) n ( n = 2, 3) in a hexadecylamine medium at 310°C. The average size of objects is found to be 40–70 nm. As is established, the valent state of a lanthanide in the complex exerts no influence on the size of the forming nanoparticles or on the luminescence spectrum of colloidal solutions.

The mean size of the latex particles formed in emulsion polymerization of methyl methacrylate under definite conditions (water: monomer volume ratio 15: 1, 80°C, potassium persulfate concentration 0.07 wt %) decreases from 200 to 9–10 nm as the concentration of an ionic surfactant (anionic Disponil AES 60, SDS, cationic C19H42BrN) is increased from 0.0 to 1.0 wt %. The nonionic surfactants studied influence the size of the latex particles formed differently: with ALM-10, the particle size decreases from 200 to 150–190 nm, whereas with ALM-7 and ALM-2 it increases from 200 to 320 nm as the surfactant concentration is increased from 0.0 to 1.0 wt %. An increase in the concentration of F127 amphiphilic ternary block copolymer from 0.0 to 1.0 wt % leads to a monotonic decrease in the size of the poly(methyl methacrylate) latex particles formed from 200 to 53 nm.

A series of narrow-MMD polymers with the molecular mass from 33 × 103 to 123 × 103 (polydispersity coefficient 1.08–1.16) were synthesized by bulk polymerization of n-butyl acrylate [2,2′-azobis(isobutyronitrile), 60°C] in the presence of a low-molecular-mass RAFT agent, dibenzyl trithiocarbonate. Then, polymerization of acrylic acid was performed in aqueous-alcoholic solution (ammonium persulfate, 70°C) in the presence of the obtained polymers, and a series of n-butyl acrylate–acrylic acid block copolymers with the molecular masses from 22 × 103 to 81 × 103 (polydispersity coefficient 1.07–1.13) were prepared. In aqueous-alcoholic solutions of the synthesized copolymers, there are nanoparticles whose size varies from 5 tо 65 nm and increases with an increase in the molecular mass of the copolymer and in the concentration of water in the solvent.

The morphology of polymers prepared through the photoinduced polymerization of oligo(carbonate dimethacrylate) in the presence of different nonpolymerizable additives is studied via the method of atomic force microscopy. Depending on the nature and concentration of an additive, the photoinduced polymerization of the above composite systems is shown to be accompanied by microphase separation and formation of a porous polymeric material. In the case of methanol, homogeneous porous structures with characteristic pore sizes of several hundred nanometers are formed. In the case of dinonyl phthalate, the characteristic pore sizes lie below 100 nm. The synthesized porous polymers can sorb both polar and nonpolar solvents. The photoinduced polymerization of an oligomer in the medium of toluene, benzene, or carbon tetrachloride leads to the formation of polymer nano-particles whose dimensions are controlled by the nature of a solvent.

New metal-polymer complexes have been synthesized that combine Eu(III) with a copolymer of N-vinylcarbazole and a methacrylate comonomer-ligand that contains chelate 2-(2-pyridyl)-quinoline groups. The photo- and electroluminescence properties of these metal-polymer complexes, containing from 0.6 to 5 mol% europium (in terms of a link of the copolymer ligand) have been studied. It is shown that the electroluminescence intensity decreases with increasing concentration of europium in these complexes, and this is probably associated with concentration quenching. In this case, the minimum switch-on voltage of the LEDs in which metal-polymer complexes are used as light-emitting layers is less than 6 V. The maximum luminance achieved is 40 cd/m(2). (C) 2011 Optical Society of America.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The morphology of polymers prepared through the photoinduced polymerization of oligo(carbonate dimethacrylate) in the presence of different nonpolymerizable additives (methanol, dinonyl phthalate, hexane, toluene, benzene, and carbon tetrachloride) is studied via the method of atomic force microscopy. Depending on the nature and concentration of an additive, the photoinduced polymerization of the above composite systems is shown to be accompanied by microphase separation and formation of a porous polymeric material. In the case of methanol, homogeneous porous structures with characteristic pore sizes of several hundred nanometers are formed. In the case of dinonyl phthalate, the characteristic pore sizes lie below 100 nm. The synthesized porous polymers can sorb both polar and nonpolar solvents. The photoinduced polymerization of an oligomer in the medium of toluene, benzene, or carbon tetrachloride leads to the formation of polymer nanoparticles whose dimensions are controlled by the nature of a solvent.