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The effect of cationic polyelectrolyte poly(diallyldimethylammonium chloride), anionic polyelectrolyte potassium lignohumate, and their interpolyelectrolyte complex on the aggregate composition and phytotoxicity of constructozem, an artificially constructed soil, is investigated. The original constructozem is characterized by a wide range of structural aggregates with a high proportion of large particles. Addition of the polycation to the constructozem completely destroys large aggregates, while addition of the polyanion has almost no effect on particle size distribution. The polycomplex sharply reduces the proportion of large particles and blocks the appearance of small particles, thereby significantly increasing the content of agronomically valuable aggregates in the constructozem and, at the same time, stimulating the growth and development of plants.

Interaction of the anionic copolymer of acrylic acid and acrylamide with a molar ratio of monomer units of 75 : 25 and poly(N,N′-diallyl-N,N′-dimethylammonium chloride) in aqueous solution is studied. The interaction is accompanied by the formation of a polycomplex stabilized by multiple salt bonds between oppositely charged groups of both polyelectrolytes. A nonstoichiometric polycomplex with a tenfold excess of anionic groups is present in solution in the form of particles with a diameter of about 300 nm; the particles retain their aggregate stability for 30 days. The application of aqueous solutions of individual polymers and the nonstoichiometric polycomplex on the surface of sand with a particle size of 0.15 ± 0.05 mm is associated with the formation of composite polymer-sand coatings. The highest mechanical strength is possessed by coatings with the participation of an anionic copolymer and a polycomplex. For sand and polycomplex coatings, the weight loss during water treatment is 10%, which is lower than that in the case of traditional polyacrylamide soil stabilizer. The polycomplex at a concentration of up to 0.33 wt % does not exhibit toxicity to microorganisms, thereby indicating that the use of a negatively charged polycomplex is promising for obtaining waterproof protective coatings on the surface of sandy soils.

The review discusses the application of polymers for the control of soil degradation caused by wind and water erosion. The background of the problem, current situation with the soil erosion in the world and Russian Federation, traditional methods for controlling erosion processes, and natural and synthetic soil amendments (soil conditioners) are described. Particular attention is paid to t traditional conditioners, polyacrylamide and its derivatives as well as conditioners obtained from interpolyelectrolyte complexes, the products of interaction of oppositely charged ionic polymers. The results of the laboratory experiments, field tests, and practical application of the conditioners are presented. A new type of soil conditioners based on interpolyelectrolyte complexes is described in detail, and the prospects of their application in antierosion technologies are considered.

Interpolyelectrolyte complexes of a linear cationic polymer poly(diallyldimethylammonium chloride) and anionic microgel particles with carboxyl groups in a pH 6 buffer solution are presented. Dispersions of the microgel and its complexes—negatively charged with a 3-fold molar excess of the anionic groups of the microgel and positively charged with a 3-fold molar excess of the cationic groups of the polycation—retain aggregative stability for six months. When applying 1 wt % dispersions of the microgel and complex on the surface of the soil with a high sand content, polymer-soil coatings with a mechanical strength of 19 to 61 kg/m2 depending on the composition of the dispersion are formed. These indicators significantly exceed those for coatings obtained by applying a 1 wt % solution of a linear anionic polymer, poly(acrylic acid), on the soil surface. Coatings involving microgel and its complexes remain stable at an air flow rate of 190 km/h.

The expression of mRNA genes of Toll-like receptors (TLRs) 2, 4, 7, 9 in the retina, lens, and vitreous body of the eye of 13-, 17-, and 19-week fetuses is shown. The results of this work may indicate the role of these receptors in the processes of proliferation and differentiation in neurogenesis and synaptogenesis of the retina, in the processes of proliferation and elongation of the lens fibers, and their readiness in cases of infection to protect eye tissues from pathogens.

The initial-stage dynamics of flocculation of positively charged latex particles induced by polyelectrolytes (PEs) and polyelectrolyte complexes (PECs), composed of linear polyacrylic acid (PAA) and a PAA-based hydrophilic microgel (PAA#) with a small amount of a linear polycation, was comparatively analyzed by applying the standardized colloidal mixing procedure. Based on the rate of flocculation, this method allows us to investigate the dynamics of flocculation immediately after the onset. In addition to confirming the prediction made regarding the initial rate of flocculation with linear polyanions-which was mostly similar to that observed in negatively charged colloids with positively charged PEs-we have confirmed two important new results regarding the microgel: (1) the increase of the initial rate is less markedly affected by the microgel concentration than by the linear polymer concentration, which can be explained by the fact that the three-dimensional (3D) cross-linked structure of the microgel that does not deform as easily as the linear structure upon touching the colloidal surface; and (2) there is a remarkable increase of the initial rate due to the contribution of instant aggregation of the negatively charged microgel induced by the polycation adsorption. These results suggest the significance of state and formation dynamics of PECs prior to reaching the surface of targeted colloidal particles for the intension of effective flocculation. These aspects are not treated so far in the dynamic process of flocculation.

Wide usage of clay-based materials in industry requires investigations concerning efficient modification techniques to control their mechanical behavior in aqueous media. The challenging problem in this field involves minimization of the modifying agent content to provide marked changes in the operating characteristics of the material. In this work, the physicochemical, mechanical and structural aspects of the interaction of capillary water-saturated kaolinite with polyelectrolytes were studied. Modification of kaolinite with a negligible amount (0.1 wt.%) of hydrophilic and amphiphilic polyelectrolytes provides the control for rheological parameters of kaolinite suspensions such as storage and loss modulus in the range of three orders of magnitude. The results obtained reveal the wide possibilities for the production of a spectrum of clay materials using minor amounts of polymer modifying agents.

Studies of the photonics of dyes in structurally organized systems are of great fundamental and applied importance. In this regard, the search for simple and convenient methods for analyzing the composition and studying structurally organized systems based on biomolecules (proteins, nucleic acids, etc.) using dye probes is highly relevant. meso-substituted polymethine (carbocyanine) dyes can serve as such probes, as such dyes have a unique set of spectral-fluorescent and photochemical properties that are sensitive to the molecular environment. In structurally organized systems, the photonics of these dyes changes drastically, which allows them to be used in studies of such systems. One peculiarity of these dyes is the mobile equilibrium between the trans- and cis-isomers, which differently interact with biomolecules. The interaction of the dyes with components of structurally organized systems leads to an increase in fluorescence and intersystem crossing to the triplet state. We have developed and put into practice spectral-fluorescent and photochemical probes based on meso-substituted carbocyanines. In particular, we widely used one of the anionic carbocyanines as a probe in biological systems containing serum albumin and collagens. This review is devoted to the works of the authors on the interaction of meso-substituted carbocyanine dyes with biomolecules and the photonics of meso-substituted carbocyanines in complexes with biomolecules. The works on the use of these dyes as probes in biological systems are also considered.

The preparation of electrostatic complexes between a cationic polymer, poly(diallyldimethylammonium chloride), and natural polyanions, potassium humates, is described. The polycomplexes remain stable in the aqueous solution for a long time (up to 3 months) or form precipitates that can be easily resuspended when the sample is shaken. When aqueous solutions/suspensions of polycomplexes are applied on the sand surface, polymer-sand coatings (crusts) are formed, the mechanical strength of which increases with increasing content of poly(diallyldimethylammonium chloride) in the polycomplex. The greatest resistance to water (water resistance) is exhibited by crusts with a high proportion of mutually neutralized sections of both polymers. For such crusts, sand loss during watering is in the range from 0 to 2%. The developed multicomplex formulations can be used to stabilize soil and ground against water and wind erosion.

Spectral-fluorescent properties of polymethine dye probes anionic 3,3'-di(sulfopropyl)-4,5,4',5'-dibenzo-9-ethylthiacarbocyanine-betaine (DEC) and cationic 3,3',9-trimethylthiacarbocyanine iodide (Cyan 2) in the presence of biological surfactants, bile salts sodium cholate (NaC), sodium deoxycholate (NaDC) and sodium taurocholate (NaTC), as well as sodium dodecyl sulfate (SDS), have been studied in a wide range of surfactant concentrations. When a surfactant is introduced into a solution of DEC, changes of the spectral-fluorescent properties are observed due to decomposition of dye dimers into cis-monomers and cis-trans conversion of the resulting monomers. In the presence of SDS, both processes occur in parallel, caused by noncovalent interaction of dye monomers with micelles, and mainly occur near the critical micelle concentration (CMC). In contrast, upon the introduction of increasing concentrations of bile salts, decomposition of dye dimers into the monomers begins at lower concentrations than cis-trans conversion. The former process is almost completed at concentrations close to CMC of secondary micelles (CMC2), while the latter process occurs even at concentrations of bile salts much higher than CMC2. Hence, DEC can serve as a probe that permits estimating the value of CMC2 and is indicative of reorganization of secondary micelles upon an increase in bile salt concentration. Aggregation of DEC and Cyan 2 on bile salts is also observed. Since it is observed at relatively low concentrations of bile salts (CMC2), the aggregation probably occurs on monomeric molecules of bile salts and their small associates and primary micelles. Decomposition of the aggregates formed begins at concentrations of bile salts above CMC2 (that is, upon the interaction with secondary micelles).

Multiliposomal containers obtained by the successive adsorption of cationic polypeptide poly(L-lysine) and anionic liposomes on the surface of anionic magnetic microgels—the products of γ-Fe2O3 (maghemite) synthesis in the matrix of natural anionic polysaccharide—the mixed Na/Ca salt of alginic acid—are presented. The composition and morphology of magneto-sensitive microgels are studied by X-ray analysis, FTIR spectroscopy, Mossbauer spectroscopy, magnetometry, and transmission electron microscopy. The size of particles of multiliposomal containers with the ultimate liposome content in the physiological solution is about 400 nm. They are not cytotoxic up to a poly(L-lysine) concentration of 600 μM. It is shown that these objects filled with antitumor antibiotic—doxorubicin—are able to move in a suspension under application of an external magnetic field with the integrity of liposomes in the container being preserved. The obtained containers are promising for the controlled delivery of bioactive substances (drugs).

The bilirubin content in the vitreous body of the eye of human fetuses of gestation week 17-31 was measured. During gestation weeks 17-19, the mean bilirubin concentration was 8.67 μmol/liter; then, decreased to 1.37 μmol/liter (gestation weeks 20 to 31). Bilirubin, being an endogenous antioxidant, is probably involved in protection of the retina and lens from LPO processes that intensively develop in retinal neurons and lens fibers.

The expression of Toll-like receptors TLR2 and TLR4 in the human retina during early prenatal development is shown for the first time. It was found that the development and differentiation of the retina is accompanied by specific spatial changes in the location of these receptors. TLR2 and TLR4 expression was detected in both neuroblastic retinal layers in gestation week 9. At subsequent developmental stages, the immunohistochemical staining for TLR2 and TLR4 gradually shifted towards the inner and outer plexiform layers of the retina and the nerve fiber layer. Our results suggest a possible involvement of these receptors in the regulation of neurogenesis and axonogenesis and the formation of synaptic connections between neurons and axons. The presence of TLR receptors in the endothelial cells forming retinal vessel walls does not exclude their role in the blood–retina barrier in pathogen infection.

A synthetic procedure is described for preparation of magneto-sensitive nanocomposites from maghemite nanoparticles and a natural polysaccharide, sodium alginate cross-linked with calcium ions. With this procedure, a series of nanocomposites was synthesized and characterized by spectrophotometry, transmission electron microscopy, X-ray diffraction, Mössbauer spectroscopy, Fourier transform IR-spectroscopy and magnetometry with the following main conclusions: (a) The nanocomposites retain their solubility in water unless the iron content exceeds 18.1±0.2 wt%. (b) Only γ-Fe2O3 nanoparticles are included in the nanocomposite. (c) Size of nanoparticles lies within a 4–20 nm range with a dominant diameter of 7±1 nm. (d) Maghemite nanoparticles bind to the alginate matrix via formation of electrostatic and coordination contacts between the surface Fe3+ maghemite ions and functional alginate groups. (e) The nanocomposites exhibit properties which are characteristic for soft magnetic materials since they have a low coercive force. (f) Magnetic characteristics of the nanocomposites, saturation magnetization and residual magnetization, are effectively controlled by the maghemite content. (g) An external magnetic field causes the nanocomposites to move in an aqueous dispersion.

The presence of alpha-fetoprotein (AFP) was shown in the retina and lens of the human fetal eye at different stages of prenatal development. PCR analysis revealed AFP mRNA neither in the retina nor in the lens, whereas in the fetal liver (control) AFP mRNA was found to be expressed. The data obtained indicate that AFP is not synthesized in retinal and lens cells of the human fetal eye but is imported from elsewhere to be taken up by these cells. The presence of AFP in the retina and lens implies its involvement in early morphogenesis and differentiation of these ocular tissues during prenatal human development.

The one-step synthesis of water-soluble composites from maghemite (γ-Fe2O3) nanoparticles with a diameter of 12 ± 4 nm and a biocompatible polysaccharide, namely, sodium salt of carboxymethyl cellulose, is described. The role of the polymer matrix consists in stabilization of the resulting nanoparticles by the electrostatic interaction of polymer carboxyl groups with the surface atoms of iron in the (3+) oxidation state. The dissolution of the composites in water affords aggregatively stable dispersions responding to the external magnetic field. The content of the magnetic phase (iron oxide) in the formulation of the maghemite–carboxymethyl cellulose composite is defined by the ratio of components during the synthesis.

Bilayer lipid vesicles (liposomes) composed of zwitter-ionic (electroneutral) egg yolk lecithin and anionic phosphatidylserine were loaded with a water-soluble antitumor antibiotic Dox and electrostatically adsorbed onto the surface of thermo-sensitive microgels synthesized from 3-(N,N-dimethylamino)propylmethacrylamide, N,N-methylenebisacrylamide and 2,2′-azobis(2-methylpropionamidine) dihydrochloride. The resulting saturated microgel-liposomes complex with ultimately adsorbed 40 liposomes retains encapsulated drug in water solution at 25 °C. An increase in temperature induces a collapse of the microgel core and squeezing of the liposome shell, followed by liposome disruption and a release of encapsulated Dox. An intensive Dox leakage begins when temperature reaches 39 °C; a maximum amount of Dox is released within 5 min after starting the temperature trigger. The results are of importance for constricting of thermo-sensitive drug carries and developing protocols for the most productive drug release.

A novel one-step procedure is described for synthesizing water soluble biocompatible nanocomposites from maghemite nanoparticles and carboxymethyl cellulose (CMC). The procedure allows the magneto-sensitive nanocomposites with a controlled content of the inorganic phase. The maghemite formation has been proved by X-ray diffraction analysis and Mossbauer spectroscopy. An average diameter of the maghemite nanoparticles is equal to 11nm according to transmission electron microscopy. As shown by FTIR spectroscopy, the nanoparticles bind to the polymer matrix via electrostatic and coordination interactions. The diameter of the nanocomposites in dilute aqueous solutions vary from 50nm at the iron content of 2-4.3wt.% to 140nm at the iron content of 5.2-8.6wt.%. The study of specific magnetization of the nanocomposites vs. applied magnetic field indicates their ferromagnetic properties. The saturation magnetization and coercive force of the sample with the maximum maghemite content (8.6wt.%) are 11.5emu/g and 30.08Oe, respectively. The nanocomposite motion has been shown to be controlled by an external magnetic field. The biocompartible maghemite-CMC nanocomposites seem to be promising for encapsulation and delivery of biologically active compounds.

This paper describes electrostatic interaction (complexation) of two oppositely charged linear polyelectrolytes, an anionic poly(acrylic acid) and a cationic poly(diallyldimethylammonium chloride). In the excess of the anionic polymer, the complexation results in formation of non-stoichiometric interpolyelectrolyte complex (NIPEC) which is actually a block copolymer with hydrophilic regions represented by free (unbound) anionic units and hydrophobic fragments of mutually neutralized anionic and cationic units. A negative charge renders the colloidal stability to NIPEC species in aqueous solutions while ensuring their binding to heavy metal ions and positive dispersed particles. In the lab test, a NIPEC formulation (a NIPEC species aqueous solution), being deposited over a top of sod-podzolic soil with the aggregate size of 0.2 mm and less, ensures a protective NIPEC-soil layer (crust) via electrostatic and hydrophobic interactions of NIPEC species with the soil aggregates. The hardness of the NIPEC-soil crust is as more as 40 times higher than the hardness of the initial (untreated) soil, while the crust does not prevent water infiltration. These findings make NIPEC formulations promising binders for stabilization of the soil at a wind speed of 10–12 m/s. The crust seems to sustain water erosion as well. Additionally, NIPECs show a great capacity to heavy metal ions.

The presence of carotenoids in the vitreous body, retina, lens, retinal pigment epithelium together with choroid (hereinafter RPE), and ciliary body and iris together with choroidal stroma (hereinafter CBI) was studied throughout the second trimester of prenatal development of the human eye. It has been found that the vitreous body, retina, and RPE contain lutein and its oxidized forms. Zeaxanthin was not found in the tissues studied. The presence of lutein in the vitreous body is transient and no longer detected after 28 weeks of gestation. Lutein was not detected in the lens and CBI, but its oxidized forms were found. The presence of carotenoids in different tissues of the eye in the course of normal eye development and the antioxidant role of carotenoids are discussed.

We present a smart liposome carrier system for stimulated release, consisting of cationic, thermo-responsive microgels. At low temperature, the swollen microgels adsorb about 200 anionic liposomes, 50 nm in diameter, per microgel. When heated from 39 °C to 41 °C, the microgel–liposome complex particles collapse from approx. 370 nm down to approx. 270 nm. Upon the thermo-induced collapse, the adsorbed liposome satellite layer is squeezed until the initially spherical liposomes explode and release their payload (antitumor drug doxorubicin) into the surrounding. This burst release mechanism, taking place over a narrow temperature range, is newly reported and of possible biomedical importance.

The noncovalent interaction of a number of cationic and anionic meso-substituted polymethine (carbocyanine) dyes with sodium deoxycholate (NaDC) as a biologically important surfactant was studied by spectral-fluorescent methods. The following dyes were studied: 3,3′-di(β-hydroxyethyl)-9-methylthiacarbocyanine-iodide (K1), 3,3′-di(β-hydroxyethyl)-5,5′-dimethoxy-9-ethylthiacarbocyanine iodide (K2), 3,3′,9-trimethylthiacarbocyanine iodide (K3, Cyan 2), 3,3′-di(γ-sulfopropyl)-9-methylthiacarbocyanine-betaine (A1), and 3,3′-di(γ-sulfopropyl)-4,5,4′,5′-dibenzo-9-ethylthiacarbocyanine-betaine (A2, DEC). Upon addition of increasing concentrations of NaDC, the absorption spectra of dyes K1–K3 in aqueous solutions exhibit changes due to the formation of dye aggregates and their subsequent decomposition into monomers. The formation of aggregates of K1–K3 leads to broadening of the absorption spectra and an appearance of additional bands. Upon binding to the surfactant, the cis-monomers of the dyes undergo partial cis–trans conversion, which is accompanied by an increase in the fluorescence intensity. The binding constants of the dyes to NaDC were estimated on the basis of Scatchard and Hill models from the dependences of the absorption and fluorescence spectra on the concentration of NaDC.

In this article we describe the use of novel aqueous polymer formulations for stabilization of sand and soil against wind erosion and retention of water in polymer-treated sand/soil samples. Two series of formulations were prepared. The first consisted of polyacrylic acid (PAA) and two electrostatic complexes of PAA with cationic poly(diallyldimethylammonium chloride): negatively and positively charge; the second included PAA-based cross-linked copolymer (PAA#) which forms microgel particles upon swelling and two its electrostatic complexes with the polycation: negatively and positively charged. 1 mass% formulations showed the stability against aggregation for 3 months excepting the negative complex with PAA which aggregated within half an hour after preparation. The viscosity of 1 mass% formulations, which lies within a (1.6÷320)×10−6 m2/s interval, allowed their deposition over fine-grained sand and loamy sand soil using a conventional spray machine followed by formation of polymer-sand(soil) crusts. Both for sand and soil, the PAA#-based crusts demonstrated a higher resistance to mxechanical loads in comparison with the crusts formed by linear PAA: up to a 42.5 MPa mechanical strength for sand/PAA# crust against a 12.5 MPa strength for sand/PAA crust. Additionally, the PAA#-based crusts was not impacted by airstream, up to a 190 km per hour air speed, while PAA-based crust was destroyed within a minute. Finally, PAA# alone and its negative complex were characterized by a high swelling (degree of swelling up to 195) that allowed them to maintain a high water retention capacity, being bound to sand and soil. The results are promising for preparing anti-erosion and water-saving formulations, especially in areas with insufficient moisture content, and design of sand-based composite materials.

Pseudohybrid nanoparticles of 800 nm in diameter based on self-assembled high-substituted 2-hydroxypropyl-β-cyclodextrin fabricated in the presence of iron(II) salts were found to be thermally responsive within narrow range of temperature. As-prepared metal-free nanoparticles are stable in aqueous solution at room temperature. However, the increase in temperature results in break-like collapse of nanoparticles to yield species of 400 nm in diameter. On the example of phenolphthalein, it was shown that nanoparticles loaded with model drug decompose to release superficial guest-host inclusion complexes. Local hyperthermia provokes nanoparticles decomposing and drug releasing that allows recognizing focuses of pathology in human body. It might be used for diagnostic medicinal aims and be also considered as basis for the construction of intravascular drug delivery/release systems.

A one-step on air synthesis of water-soluble composites from carboxymethylcellulose sodium salt (CMC) and Cu2O nanoparticles, ca. 10 nm in diameter is described. The polymer matrix stabilizes the nanoparticles against aggregation via electrostatic interaction between carboxyl groups of the polymer and Cu(1+)-ions on the nanoparticle surface. Being dispersed in water, the composites initiate a photocatalytic oxidation of an azo dye Methyl Orange. The oxidation proceeds in the presence of oxygen and accelerates significantly up to a 100 conversion when hydrogen peroxide is added. The Cu2O-CMC composites have potential for photochemical decomposition of organic contaminants in water waste.

Soil erosion is a global problem with grave social, economic and ecological consequences. To stabilize the top soil layer, various approaches have been developed, including the use of synthetic and natural water-soluble polymers capable of binding to soil particles and forming a protective layer (crust) on the topsoil. Individual water-soluble polymers give crusts which lose mechanical stability after re-watering. We describe in the article effective stabilizers of model unstructured soil, sand, “polyelectrolyte complexes” (PECs), composed of two oppositely charged ionic polymers (polyelectrolytes), cationic poly(diallyldimethylammonium chloride) (PDADMAC) and anionic potassium humates (PH). By varying the PDADMAC-to-PH ratio, the total charge of PECs and their solubility in water was adjusted. The PECs as well as PDADMAC and PH were deposited on the surface of monomineral quartz sand, with a mean diameter of particles from 0.15 up to 2.1 mm. After drying, polymer-sand crusts were formed; their mechanical strength increased upon elevating the cationic content in the polymer formulation. Re-watering caused both polyelectrolytes and PECs with a great excess of cationic or anionic groups to be removed from the crusts, which was additionally accompanied by loss of sand and decrease in the mechanical strength of the crust. The slightly positive PECs with a significant degree of mutually neutralized charges (“hydrophobized” blocks) formed the most stable crusts due to electrostatic and hydrophobic contacts with sand particles. A correlation was thus revealed between the PEC composition and the anti-erosion resistance of the polymer-sand crusts. It is shown that the use of non-stoichiometric polycomplexes makes it possible to manipulate the mechanical strength of the resulting coatings. The described approach is promising for fabrication of polymer formulations for environmental protection, conservation/rehabilitation of landfill sites, desertification control, anti-erosion treatment of agricultural land, conservation of mining dumps, treatment of road slopes, etc.

Convenient synthesis path of nanostructured water-soluble microgels (PMG) based on carboxymethylcellulose cross-linked with zinc and ligand N-(5,6-dihydro-4H-1,3-thiazine-2 yl) benzamide and N-(4- isopropyl-phenyl)-N-(1-iminoethyl)piperidine-1-carbothioamide hydrobromides is described. Being insoluble in aqueous solutions the complex of zinc with the ligand acquires the solubility in water when dispersed in nanocontainers of PMG. Microgels were obtained by varying the content of zinc-ions in the reaction mixture. A new method for the determination of zinc in PMG composite using sulfarsazene is proposed. The resulting nanoparticles have been tested for cytotoxicity. It was established cytotoxicity of nanocontainers strongly depends on the concentration of zinc and ligand in composition of PMG.

Triblock copolymers of poly(ethylene oxide) and poly(propylene oxide) (so-called pluronics) were shown to influence the aggregation and fusion of atherogenic low density lipoproteins (atLDL) and be able to inhibit these processes. The character of the influence and the degree of the stabilizing effect depended on the structure, relative hydrophobicity, and concentration of the copolymer. Pluronics L61, P85, and L64 characterized by the hydrophilic-lipophilic balance (HLB) value from 3 to 16 had the greatest ability to suppress the aggregation of atLDL. Pluronic L81 with the higher hydrophobicity (HLB = 2) partially inhibited atLDL aggregation at low concentrations but stimulated it at high concentrations. The influence of pluronics did not have a direct connection with their ability for micelle formation, but it was realized through individual macromolecules. We suppose that effects of pluronics could be due to their interaction with the lipid component of LDL and to a possible influence of these copolymers on the structure and hydrophilic-lipophilic characteristics of lipoproteins.

In this paper, we analyzed our own results and published data on the expression of regulatory genes encoding transcription factors Pax6/PAX6, Pitx2/PITX2, Fox1/FOXC1, Prox1/PROX1, Oct4/OCT4, Nanog/NANOG, and TGFβ2 signaling protein during morphogenesis of the cornea in vertebrates. We considered the results obtained for the cornea of model animals, primarily mice, and human fetal cornea. The main possibility of establishing common mechanisms of eye development in vertebrates in health and disease is comparative studies of eye morphogenesis of humans and animal models.

High-substituted 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) was shown to self-assemble in aqueous solutions in the presence of in situ-formed insoluble species of iron. Two different types of water-soluble high-molecular compounds were synthesized at room temperature in aqueous aerated alkaline solutions of (NH4)2Fe(SO4)2•6H2O and high-substituted 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) in the presence of NaH2PO2. These substances called adducts proved to be inorganic-organic hybrid nanospecies of iron species, HP-β-CD and encapsulated inorganic salts (sulfates and phosphates of sodium and ammonium). The adducts were established to show different properties and to have diverse compositions depending on the HP-β-CD: Fe molar ratio in starting solution. The first synthesized adduct (I) is characterized by an unambiguous magnetism with lower solubility in water. It gives a homogeneous solution with particles 400 nm in diameter. The second adduct (II) is not magnetic, more soluble in water, and forms nanoparticles of ∼760 nm in diameter. Both adducts are stable in aqueous solutions but totally destroyed in the presence of H2O2, K2S2O8, and AgNO3. By addition of BaCl2 excess to the aqueous solutions of I and II, the residue of BaSO4 is precipitated and dimensions of the particles of both types decrease up to ∼230 and ∼570 nm in diameter, respectively. Solids I and II were characterized by the data of X-ray diffraction (XRD), Mossbauer spectroscopy, SEM, IR-spectra, and magnetic measurements. Aqueous solutions of I and II were studied by means of mass-spectrometry (MALDI-TOF), dynamic light scattering (DLS) measurements, and analyzed by spectrophotometric titration with phenolphthalein.

A novel one-step procedure is described for synthesizing water soluble biocompatible nanocomposites from maghemite nanoparticles and carboxymethyl cellulose (CMC). The procedure allows the magneto-sensitive nanocomposites with a controlled content of the inorganic phase. The maghemite formation has been proved by X-ray diffraction analysis and Mossbauer spectroscopy. An average diameter of the maghemite nanoparticles is equal to 11nm according to transmission electron microscopy. As shown by FTIR spectroscopy, the nanoparticles bind to the polymer matrix via electrostatic and coordination interactions. The diameter of the nanocomposites in dilute aqueous solutions vary from 50nm at the iron content of 2-4.3wt.% to 140nm at the iron content of 5.2-8.6wt.%. The study of specific magnetization of the nanocomposites vs. applied magnetic field indicates their ferromagnetic properties. The saturation magnetization and coercive force of the sample with the maximum maghemite content (8.6wt.%) are 11.5emu/g and 30.08Oe, respectively. The nanocomposite motion has been shown to be controlled by an external magnetic field. The biocompartible maghemite-CMC nanocomposites seem to be promising for encapsulation and delivery of biologically active compounds.

A comparative study of the noncovalent interaction of the cyanine dye probe 3,3′-di-(γ-sulfopropyl)-4,5,4′,5′-dibenzo-9-ethylthiacarbocyanine betaine with serum albumins of different vertebrates: rat, rabbit, bovine, and human serum albumins (RSA, TSA, BSA, and HSA, respectively) has been performed by spectral and fluorescent methods. It has been shown that, the dye forms only one product, the trans-monomer bound to HSA, by interacting with HSA, whereas other binding products are also formed with other albumins. This is probably explained by a higher interaction energy of the dye with HSA than with other serum albumins.

The noncovalent interaction of the polymethine dye probe 3,3',9-trimethylthiacarbocyanine iodide (Cyan 2) with chondroitin-4-sulfate (C4S) in buffer solutions with different pH and in water in the absence of buffers has been studied by spectral-fluorescent methods. It has been shown that in all media studied, at relatively high concentrations, the dye is bound to C4S mainly as a monomer, which is accompanied by a steep rise of fluorescence (the intermediate formation of dye aggregates on the biopolymer is also observed). From the dependence of the fluorescence quantum yield on the concentration of C4S, the parameters of binding of the dye monomer to C4S were obtained: the effective binding constant K, the number of the monomeric C4S units n per one dye monomer bound to C4S, and the fluorescence quantum yield of the bound dye monomer Φfb. The dependence of Φfb (and K) on рН of the medium is not monotonic: it has a minimum in the region of neutral pH and a growth in the regions of acid and basic pH. This can be explained by changing the charge of a C4S macromolecule as a function of pH and related conformational alterations in the biopolymer, which can affect the rigidity of a dye molecule and the energy of its interaction with the biopolymer.

The noncovalent interaction with hyaluronic acid (HA) of four cyanine dyes having similar structures, 3,3′,9-trimethylthiacarbocyanine (Cyan 2), 3,3′-dimethylthiacarbocyanine (Cyan 45), 3,3′-diethylthiacarbocyanine (DTC), and 3,3′-diethyl-9-methylthiacarbocyanine (DMTC), was studied using the absorption spectra. Dyes Cyan 2, Cyan 45, and DMTC were shown to form H-aggregates in the presence of HA, which is reflected in the appearance of a short-wavelength absorption band with a maximum at 440–450 nm. By the tendency to H-aggregation in the presence of HA, the dyes can be arranged in the series Cyan 2 > Cyan 45 > DMTC > DTC. The aggregation number for Cyan 2 was determined: n = 3. In buffer solutions pH 4.5, 7.0, and 9.1, the absorption spectra of H-aggregates of Cyan 2 have longer wavelengths (with maximums at 460–470 nm) than those in the absence of buffers. Cyan 2 is suggested as a spectral probe to detect HA in biological systems.

The content of serum albumin and alpha-fetoprotein in the vitreous body of the eyes of human fetuses from the 16th through the 24th week was investigated. It was detected that albumin and alpha-fetoprotein in the vitreous body of human eyes are presented in equal molar concentrations in the 16th week. There is 1.5-fold increased concentration of alpha-fetoprotein in comparison to albumin during the 17th week. After the 17th week, there was a reduction in the concentration of both proteins. It was reported that cyanine dye, used for detection of albumin, does not interact with alpha-fetoprotein.

Noncovalent columnar polymers (NCPs) based on cyclodextrins (CD) are polymeric assemblies of molecules that have continuous hollow channels, the width of which is determined by the diameter of the cavity of the initial CDs. The repeating fragment in an NCP is the CD molecule. For NCPs that were obtained by the exclusion of polymer backbone macromolecule from the corresponding inclusion complexes (ICs) based on β-cyclodextrin (NCPexcl), the polymer length, expressed as the number of macrocycles in a single chain (n) is determined by the size of the included ligand, polypropylene glycol (PPG), and is the PPG polymerization degree divided by two. The determination of the molecular weight of an NCP obtained by the precipitation method (NCPprec) is rather difficult, since they are present in the aggregated state rather than in the form of individual molecules in solution. To estimate the molecular weight of NCPprec, an indirect method is used, which is based on the determination of the aggregation rate of the ICs formed as a result of the interaction between an NCP and polypropylene glycol with a fixed molecular weight (MW), in this case PPG 1000. The comparison of the aggregation rates of the inclusion between NCPexcb (which were synthesized using PPGs with different molecular weights) and PPG 1000 with the aggregation rate of the inclusion complex on the basis of NCPprec provided the estimation for the MWs of single polymer chains. The fact that the samples of NCPprec contain ∼30% of the monomeric β-CD was taken into account when constructing the calibration curve. It was demonstrated that the MW of the polypropylene glycol corresponding to NCPprec is 1320 Da. Consequently, ∼11–12 molecules of β-CD are included in the single chains of NCPprec.