Автореферат

Настоящая работа посвящена комплексному исследованию в области синтеза потенциально биологически активных веществ на основе гидразидов и нитрилов α-( и β-)-аминопропановых кислот, установлению закономерностей их гетероциклизации и изучению биологической активности новых производных гидразидов и нитрилов α-( и β-)- аминокислот

Removal of Cd2+ from water by use of super-macroporous cryogels and comparison to commercial adsorbents

In this study amphoteric cryogels were synthesized by the use of free-radical co-polymerization of acrylate-based precursors (methacrylic acid and 2-acrylamido-2-methyl-1-propansulfonic acid) with allylamine at different ratios. The physico-chemical characteristics of the cryogels were examined using SEM/EDX, FT-IR, XPS and zeta potential measurements. The cryogels were tested toward Cd 2+ removal from aqueous solutions at various pH and initial concentrations. Equilibrium studies revealed a maximum sorption capacity in the range of 132–249 mg/g. Leaching experiments indicated the stability of Cd 2+ in the cryogel structure. Based on kinetics, equilibrium and characterization results, possible removal mechanisms are proposed, indicating a combination of ion exchange and complexation of Cd 2+ with the cryogels’ surface functional groups. The cryogels were compared to commercially available adsorbents (zeolite Y and cation exchange resin) for the removal of Cd 2+ from various water matrices (ultrapure water, tap water and river water) and the results showed that, under the experimental conditions used, the cryogels can be more effective adsorbents

Synthesis of trans-porphyrin dimers for nonlinear optics

Following the development of the idea of octupolar molecules as nonlinear optical materials a variety of compounds have been reported. Trans-porphyrins have a great potential to self-order into octupolar symmetry. Nonlinear optical properties can be tuned by using strong donor-acceptor groups in porphyrins as well as extention of conjugation. Here we report the syntheses of trans-A2D2-porphyrins and their dimerization into cubic octupoles by lanthanides and organic bidentate ligands. Bulky groups are employed to induce non-centrosymmetric eclipsed or staggered conformations. Effect of donor acceptor groups, dimerization conditions and crystal packing of dimers are studied.Research Grant of Ministry of Education and Science of Kazakhsta

A cryogel-based bioreactor for water treatment applications

The aim of this study was to develop and test a non-diffusion limited, high cell density bioreactor for biodegradation of various phenol derivatives. The bioreactor was obtained using a straightforward one-step preparation method using cryostructuration and direct cross-linking of bacteria into a 3D structured (sponge-like) macroporous cryogel composite material consisting of 11.6% (by mass) cells and 1.2–1.7% polymer, with approximately 87% water (in the material pores). The macroporous cryogel composite material, composed of live bacteria, has pore sizes in the range of 20–150 μm (confirmed by SEM and Laser Scanning Confocal Microscopy). The enzymatic activity of bacteria within the cryogel structure and the effect of freezing on the viability of the cross-linked cells was estimated by MTT assay. Cryogels based on Pseudomonas mendocina, Rhodococcus koreensis and Acinetobacter radioresistens were exploited for the effective bioremediation of phenol and m-cresol, and to a lesser extent 2-chlorophenol and 4-chlorophenol, utilising these phenolic contaminants in water as their only source of carbon. For evaluation of treatment scalability the bioreactors were prepared in plastic “Kaldnes” carriers to improve their mechanical properties and allow application in batch or fluidised bed water treatment modes.</p

One-step formation of three-dimensional macroporous bacterial sponges as a novel approach for the preparation of bioreactors for bioremediation and green treatment of water

Immobilisation of bacteria on or into a polymer support is a common method for the utilisation of bacteria as biocatalysts for many biotechnological, medical and environmental applications. The main challenge in this approach is the time taken for the formation of stable biofilms, and the typically low percentage of bacterial cells present on or in the polymer matrix. In this work we propose a novel method for producing a porous bacteria based structure with the properties of a sponge (bacterial sponge) that we then use as a bioreactor for water treatment. Cryogelation has been used as a tool to create macroporous (i.e. with pores in the range 10–100 mm), highly permeable systems with low diffusion constraints and high bacterial content (more than 98% to total material content). A novel crosslinking system was used to form stable bacterial sponges with a high percentage of live bacteria organized in a 3D porous structure. The bacterial sponge was produced in a one step process and can be made from one or several bacterial strains (in this case, two bacterial strains Pseudomonas mendocina and Rhodoccocus koreensis (and a mixture of both) were used)

ANTIMICROBIAL PROPERTIES OF THE TRICLOSAN-LOADED POLYMERIC COMPOSITE BASED ON UNSATURATED POLYESTER RESIN: SYNTHESIS, CHARACTERIZATION AND ACTIVITY

The manufacturing of sanitary and household furniture on a large scale with inherently antimicrobial properties is an essential field of research. This work focuses on the synthesis of polymer composites based on the unsaturated polyester of resin loaded with 5 wt.%-Triclosan produced by a co-mixing approach on automated technological complex with a potential for broad applications. According to findings, the polymer composite has a non-porous structure (surface area < 1.97 m2/g) suitable for sanitary applications to reduce the growth of bacteria. The chemical composition confirmed the presence of major elements, and the inclusion of Triclosan was quantitatively confirmed by the appearance of chlorine on XRF (1.67 wt.%) and EDS (1.62 wt.%) analysis. Thermal analysis showed the difference of 5 wt.% in weight loss, which confirms the loading of Triclosan into the polymer matrix. The polymer composite completely inhibited the strains of S. aureus 6538-P, S. aureus 39, S. epidermidis 12228, and Kl. Pneumoniae 10031 after 5-min contact time. The antimicrobial effects against Kl. pneumoniae 700603, Ps. aeruginosa 9027 and Ps. aeruginosa TA2 strains were 92.7%, 85.8% and 18.4%, respectively. The inhibition activity against C. albicans 10231 and C. albicans 2091 was 1.6% and 82.4%, respectively; while the clinical strain of C. albicans was inhibited by 92.2%. The polymer composite loaded with 5 wt.%-Triclosan displayed a stability over the period that illustrates the possibility of washing the composite surface

Synthetic amphoteric cryogels as an antidote against acute heavy metal poisoning

The effectiveness of an amphoteric cryogel (AAC) as an oral sorbent (enerosorbent) for the treatment of acute poisoning of small animals (rats) with heavy metals (HMs) was studied in in vivo experiments. The morphological structure of the cryogel was examined using scanning electron microscopy/energy-dispersive X-ray analysis and confocal microscopy. The use of the cryogel in the treatment of rats administered an LD50 dose of Cd(NO3)2, CsNO3, Sr(NO3)2, or HgCl2 in aqueous solution showed their high survival rate compared to the control group, which did not receive such treatment. The histological and chemical analysis of internal tissues and the biochemical analysis of the blood of the experimental animals showed the effectiveness of the cryogel in protecting the animals against the damaging effect of HMs on the organism comparable with unithiol, a chelating agent based on 2,3-dimercapto-1-propane sulfonic acid sodium salt (DMPS) approved for the treatment of acute poisoning with some heavy metals

Gold nanoparticles incorporated into cryogel walls for efficient nitrophenol conversion

The past several decades have illustrated an enormous interest in noble metal nanoparticles for their superior catalytic activity, however, their industrial use is very restricted due to inefficient recovery leading to potential contamination of products and the environment. Immobilised nanoparticles illustrate promising results for scaling up processes, and can be successfully applied for various catalytic processes including waste industrial water treatment. The aim of the study was to design and study an easy and economically efficient green chemistry approach of preparation of macroporous material, with well distributed gold nanoparticles within the wall of cryogel. Ionic cryogels containing chitosan and tetrachloroaurate complex was reduced by 1.1.3.3-tetramethoxypropane, concurrently allowing chemical cross-linking of the polymer. A mechanism of reduction of noble gold complexes within the cryogel walls by tetramethoxypropane is also studied. Properties of the composite cryogels were evaluated using; differential scanning calorimetry, FT-IR, NMR, compression tests, SEM, TEM), Energy-dispersive X-ray spectroscopy and low temperature nitrogen adsorption. The catalytic activity of the in-situ synthesised gold nanoparticles was comprehensively studied using a model reduction reaction of 4-nitrophenol. Four different concentrations of gold nanoparticles within the cryogel structure were investigated. The turnover number and the turnover frequency parameters for cryogels containing four different concentrations of gold nanoparticles were calculated. The conversion degree of 4-nitrophenol to 4-aminophenol for cryogel containing the lowest of gold nanoparticles reached 96.8% at room temperature. The catalytic activity of incorporated gold nanoparticles for 4-nitrophenol conversion did not decline over 14 consequent testing cycles

Polymeric Materials Used for Immobilisation of Bacteria for the Bioremediation of Contaminants in Water

Bioremediation is a key process for reclaiming polluted soil and water by the use of biological agents. A commonly used approach aims to neutralise or remove harmful pollutants from contaminated areas using live microorganisms. Generally, immobilised microorganisms rather than planktonic cells have been used in bioremediation methods. Activated carbon, inorganic minerals (clays, metal oxides, zeolites), and agricultural waste products are acceptable substrates for the immobilisation of bacteria, although there are limitations with biomass loading and the issue with leaching of bacteria during the process. Various synthetic and natural polymers with different functional groups have been used successfully for the efficient immobilisation of microorganisms and cells. Promise has been shown using macroporous materials including cryogels with entrapped bacteria or cells in applications for water treatment and biotechnology. A cryogel is a macroporous polymeric gel formed at sub-zero temperatures through a process known as cryogelation. Macroporous hydrogels have been used to make scaffolds or supports for immobilising bacterial, viral, and other cells. The production of composite materials with immobilised cells possessing suitable mechanical and chemical stability, porosity, elasticity, and biocompatibility suggests that these materials are potential candidates for a range of applications within applied microbiology, biotechnology, and research. This review evaluates applications of macroporous cryogels as tools for the bioremediation of contaminants in wastewater

Comparative Toxicity of Interferon Beta-1a Impurities of Heavy Metal Ions

Background and Objectives: Providing a proper quality control of drugs is essential for efficient treatment of various diseases minimizing the possible side effects of pharmaceutical active substances and potential impurities. Recent in vitro and in vivo studies have shown that certain heavy metalloids and metals interfere with protein folding of nascent proteins in cells and their biological function can be altered. It is unknown whether the drug impurities including heavy metals may affect the tertiary protein structure. Materials and Methods: ReciGen and Rebif are pharmaceutical interferon beta-1a (IFN&beta;-1a) contained in preparations that are used for parenteral administration. Heavy metal impurities of these samples have been studied by gel electrophoresis, Fourier-transform infrared spectroscopy (FTIR) and inductively coupled plasma mass spectrometry analysis (ICP MS). The concentration of heavy metals including mercury, arsenic, nickel, chromium, iron, and aluminum did not exceed permitted levels established by International Council for Harmonisation guideline for elemental impurities. Results: The ICP MS analysis revealed the presence of heavy metals, moreover zeta potential was significantly different for IFN&beta;-1a, which can be an indirect indication of the difference in composition of ReciGen and Rebif samples, respectively. FTIR analysis revealed very similar amide I and II bonds at 1654 and 1560 cm&minus;1 attributed to the peptide absorption peaks of IFN&beta;-1a in Rebif and ReciGen. Conclusions: It was hypothesized that the IFN&beta;-1a complex binds heavy metals affecting the tertiary protein structure and may lead to some side effects of drug administration. Further testing of IFN&beta;-1a bioequivalence for parenteral application is necessary