Photocrosslinkable hydrogels based on hyaluronic acid are promising biomaterials high in demand in tissue engineering. Typically, hydrogels are photocured under the action of UV or blue light strongly absorbed by biotissues, which limits prototyping under living organism conditions. To overcome this limitation, we propose the derivatives of well-known photosensitizers, namely chlorin p6, chlorin e6 and phthalocyanine, as those for radical polymerization in the transparency window of biotissues. Taking into account the efficiency of radical generation and dark and light cell toxicity, we evaluated water miscible pyridine phthalocyanine as a promising initiator for the intravital hydrogel photoprinting of hyaluronic acid glycidyl methacrylate (HAGM) under irradiation near 670 nm. Coinitiators (dithiothreitol or 2-mercaptoethanol) reduce the irradiation dose required for HAGM crosslinking from similar to 405 J cm-2 to 80 J cm-2. Patterning by direct laser writing using a scanning 675 nm laser beam was performed to demonstrate the formation of complex shape structures. Young's moduli typical of soft tissue (similar to 270-460 kPa) were achieved for crosslinked hydrogels. The viability of human keratinocytes HaCaT cells within the photocrosslinking process was shown. To demonstrate scaffolding across the biotissue barrier, the subcutaneously injected photocomposition was crosslinked in BALB/c mice. The safety of the irradiation dose of 660-675 nm light (100 mW cm-2, 15 min) and the non-toxicity of the hydrogel components were confirmed by histomorphologic analysis. The intravitally photocrosslinked scaffolds maintained their shape and size for at least one month, accompanied by slow biodegradation. We conclude that the proposed technology provides a lucrative opportunity for minimally invasive scaffold formation through biotissue barriers.

A number of drugs based on recombinant erythropoietin contain human serum albumin as an auxiliary component. The presence of this protein hinders the proper control of the drug quality in accordance with the requirements of regulating agencies. We propose the novel method for separation of recombinant erythropoietin (epoetin beta) and human serum albumin. It is based on the subsequent use of hydrophobic sorbent and anion exchange resin placed in gravity flow columns (without the use of spin-columns). The proposed approach makes it possible to concentrate and purify the preparations containing the epoetin beta both at high and at minimal concentrations (the ratio of the amount of albumin and erythropoietin in the used preparations can reach 125:1). The average yield of epoetin beta after the use of hydrophobic sorbent and anion exchange resin was 75% and 97%, respectively. It was shown that the determined conditions of sample preparation had no affect on the content of the epoetin beta in the product.

Maxillofacial defects, arising from trauma, oncological disease or congenital abnormalities, detrimentally affect daily life. Prosthetic repair offers the aesthetic and functional reconstruction with the help of materials mimicking natural tissues. 3D polymer printing enables the design of patient-specific prostheses with high structural complexity, as well as rapid and low-cost fabrication on-demand. However, 3D printing for prosthetics is still in the early stage of development and faces various challenges for widespread use. This is because the most suitable polymers for maxillofacial restoration are soft materials that do not have the required printability, mechanical strength of the printed parts, as well as functionality. This review focuses on the challenges and opportunities of 3D printing techniques for production of polymer maxillofacial prostheses using computer-aided design and modeling software. Review discusses the widely used polymers, as well as their blends and composites, which meet the most important assessment criteria, such as the physicochemical, biological, aesthetic properties and processability in 3D printing. In addition, strategies for improving the polymer properties, such as their printability, mechanical strength, and their ability to print multimaterial and architectural structures are highlighted. The current state of the prosthetic retention system is presented with a focus on actively used polymer adhesives and the recently implemented prosthesis-supporting osseointegrated implants, with an emphasis on their creation from 3D-printed polymers. The successful prosthetics is discussed in terms of the specificity of polymer materials at the restoration site. The approaches and technological prospects are also explored through the examples of the nasal, auricle and ocular prostheses, ranging from prototypes to end-use products.

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BACKGROUND:Owing to improvement of the molecular diagnostic methods using purified preparations of nucleic acids (NAs), the development of effective methods providing the isolation of DNA is still relevant. The sorption properties of magnetic multi-walled carbon nanotubes (MWCNTs), oxidized MWCNTs and MWCNTs (pristine and oxidized) modified with polydiallyldimethylammonium chloride (pDADMAC) with respect to double strained DNA have been studied.RESULTS:It was shown that in the presence of MWCNTs/pDADMAC particles the DNA molecules were reversibly retained by the particle's surface. The optimal conditions for each step of DNA extraction from model solutions using the obtained material were selected. A comparative evaluation of the effectiveness of the proposed method for DNA isolation based on the results of spectrophotometry and real-time PCR was carried out. It was shown that the desorbed DNA was efficiently amplified in PCR, inhibition of polymerase did not occurred. Probable mechanisms of DNA retention due to the influence of residual impurities of catalysts in the MWCNT composition, as well as the surface charge of nanotubes are proposed.CONCLUSION:Sequentially oxidized and coated with pDADMAC magnetically susceptible CNTs are seemed to be a promising material for development of low-cost systems proving an easy isolation, storage, and subsequent use of dsDNA in molecular diagnostics. The sorption properties of such systems are determined with highly developed specific surface area and their chemical composition.

Wide application of chitosan in modern technologies is limited by the lack of reliable and low-cost techniques to prepare size-tuned constructs with a complex surface morphology, improved optical and mechanical properties. We report a new simple method for preparation of transparent thermoreversible chitosan alcogels from chitosan/H2O/ethanol ternary systems. This method, termed "low temperature thermally induced phase separation under non-freezing conditions" (LT-TIPS-NF), fine tunes gelation by adjusting only temperature (from 5 to -25 °C) and varying the initial content of chitosan (from 0.5 to 2.0 wt%) and ethanol (from 28.5 to 47.5 vol%). Transparent non-swelling final constructs of complex shape are prepared by fixing the pre-formed alcogels with a base solution. The size of the gel constructs is limited only by the dimensions of the mold and the cooling chamber. The LT-TIPS-NF is applicable both in injection molding and 3D printing techniques. The in vitro and in vivo experiments show the absence of prominent cytotoxicity and well-defined cell adhesion on the obtained hydrogels. Thus, this facile and scalable technique provides the multifunctional chitosan gel preparation with easily controlled properties exploiting inexpensive, renewable, and environmentally friendly source polysaccharide. These materials have prospects for a variety of uses, especially for biomedical applications.

The method providing one-step isolation of DNA from soil extracts was developed. Isolation of nucleic acids from the biological objects presenting in a soil usually is carried out by in situ lysis of the sample followed by DNA purification. The purification step is complicated by the fact that about 60% of all soil organic substances are humic substances (HSs), which are powerful inhibitors of the polymerase. The currently known methods of DNA isolation from soil samples are usually laborious and multistage. In our opinion, a promising approach to solve this problem could be based on the use of a two-component bioseparating element. The first component of such element is a special sorbent demonstrating the effect of "negative selection" in relation to DNA (when DNA is not retained by the sorbent while the admixtures are effectively held), and the second polymeric component exhibits high selectivity in binding of HSs. The effectiveness of the use of such two-component system for one-step isolation of DNA from soil extracts with simultaneous purification of DNA from HSs was confirmed by spectroscopic, electrophoretic, and chromatographic methods. The developed element was represented as a compact spin-cartridge containing two layers of different sorbents. In particular, polyaniline-modified silica effectively retained proteins, and polymer alginate particles provided the retention of hydrophobic (similar to 98%) and hydrophilic (>75%) fractions of HSs. The both used components did not retain DNA. Achieved purity of the isolated DNA provided the possibility of its direct use in PCR analysis. The yield of purified DNA estimated by the model experiments was more than 90% .

A study of the degradation profiles of drugs based on recombinant monoclonal antibodies under stress conditions made it possible to determine the dynamics and mechanisms of degradation processes, to identify drug degradation products, and to reveal differences in the stability of biosimilar drugs for relatively short times. A strategy for accelerated (35 d) stability assessment under stress conditions of the original product Soliris® (Switzerland) and its biosimilar PRK-001 (Russia) was proposed. Their degradation profiles after exposure to extreme pH, oxidative stress, and UV radiation were studied. Antibody fragments were analyzed using size-exclusion chromatography, capillary isoelectric focusing, electrophoresis, and mass spectrometry. Both products showed similar degradation profiles and similar changes in isoform contents.

The review considers the role that nanotechnologies play in the development of sample preparation methods for molecular diagnostic, focusing on the methods to isolate nucleic acids (NAs) from biological samples and the underlying physicochemical processes. Methods based on reversible adsorption (that is, solid-phase selective extraction) are the most efficient and allow miniaturization and automatization of the related processes. In the approach most commonly used until recently, NAs from biological samples are bound with a sorbent and then eluted (positive selection). The review analyzes the potential and advantages of an alternative one-step NA isolation method. Sorbents utilized in the method bind proteins and other components of biological samples, but are inert towards NAs in terms of absorption (negative selection). Consideration is given to the methods used to produce nanostructured composite sorbents on the basis of solid matrices (porous silica, glass multicapillaries, and synthetic membranes) via modification with nano-thick polymer layers to achieve negative selection toward NAs. Primary attention is payed to fluoropolymers and polyanilines, their applications, and fields of their alternative use.

Polyaniline (PANI) is a polyconjugated polymer that attracts the attention of scientists for many years because of the possibility of its use in both organic electronics and as material for biomedical and electrophysical application, thanks to its high conductivity, chemical stability, the ability of redox and non-oxidative doping, biocompatibility and selective affinity for different types of biopolymers. However, volatility of physical and chemical properties of PANI limits its wide practical application as a component of composites. Those drawbacks could be overcome by the use of aniline oligomers that demonstrate reliable control and adjustment of their structure, better solubility and processability. In this research, we examined physical and chemical properties of phenyl end-capped tetraaniline (TANI) and its films, which are the lowest molecular weight derivatives of aniline in comparison with PANI. Self-organized thin film structures of TANI with well-defined morphology were prepared via transfer of Langmuir films obtained on the water-air interface. The behavior of TANI as bioseparating material as studied with spectral correlation technique on the examples of separation of nucleic acids and proteins was shown to be similar to PANI?s behavior. In particular, TANI demonstrates sorption inertness towards double strained nucleic acids and binds the proteins depending on their isoelectric points and hydrophobicity (?negative selection?).

Objectives. Developing reliable and accurate analytical methods is necessary for comparative pharmaceutical analysis using physicochemical, biological (in vitro), preclinical, and clinical trials. The main objective of this study was to develop and validate an in vitro method for determining the specific activity of the recombinant monoclonal antibody eculizumab.Methods. The method of indirect enzyme immunoassay was used in the study.Results. A method for determining the specific activity of the humanized recombinant monoclonal antibody eculizumab was described and validated for the first time. A comparative evaluation of the specific activity of Soliris® (Alexion Pharmaceuticals Inc., USA), and its biosimilar PRK-001 (Pharmapark, Russia) was performed using the developed method.Conclusions. The similarity of PRK-001 and the original Soliris® in relation to their specific activity, that is, binding to the human complement system C5 protein, was proved.

Drug elution profiles must be studied in vitro to optimize a polymer-drug formulation during development of drug-eluting stents (DESs). Results from HPLC assays of drug contents and elution kinetics from a biodegradable sirolimus coating and a stable zotarolimus coating on coronary DESs are presented. Drug contents were assessed for crimped stents on the delivery system and expanded stents. The drug coating morphology and elution kinetics were demonstrated to be associated. Significant coating morphological defects were shown to cause deviations in the drug elution profile.

Polyaniline (PANI) and polyaramides deposited on the surfaces of glass slides and particulate silica were studied as adsorbents of nucleic acids and proteins by flow-through spectral correlation interferometry and solid-state extraction using spin-cartridges. Double stranded DNA from E. coli as well as pepsin, bovine serum albumin and lysozyme were the analytes studied in contact with the polymer nanolayers in phosphate buffer solution, pH 7.2. None of the coated glass slides could bind the DNA, which passed them practically without adsorption. In contact with polyaramides, the proteins of pI > 4 reversibly formed the 0.2-2.5 nm-thick adsorption layers decomposing on further rinsing with the protein-free eluent. In contact with PANI, the proteins formed stable adsorption layers at pH 7.2, which needed the pH 3.0 to be eluted. Thus, in a neutral aqueous medium optimal for separation of biopolymers, polyaramides, although did not retain DNA, had a weaker affinity to proteins as compared to PANI. Since the recovery of DNA passed through the PANI-coated silica was the maximal among the particulate adsorbents, the PANI-modified composites were preferred as the carriers for the single-step isolation of nucleic acids from complex biological mixtures. (C) 2017 Elsevier B.V. All rights reserved.

Sorption properties of composite silica sorbents modified with nanolayers of fluoropolymers; polyanilines and polyaramides containing aromatic nitrogen; fluorine; as well as donor and acceptor fragments; with respect to nucleic acids (DNA and RNA) and proteins differing in molecular weight and pI are considered. The use of the investigated sorbents in the sample preparation for molecular diagnostics (in particular; in the PCR analysis) not only provides a one-step isolation of nucleic acids; but also allows the isolation and simultaneous purification of protein compounds from the impurities presented in the initial mixture. For the first time; the properties of these materials are compared in the static sorption regime using the compact spin-columns and in the regime of dynamic sorption by the method of spectral-correlation interferometry. The effect of the chemical composition; morphology; and surface charge of these polymer coatings on their sorption properties was studied. Possible mechanisms of sorption of biopolymers on the investigated sorbents are discussed. The use of the developed approaches to the analysis of properties of the sorbents as well as the obtained data open new possibilities for the synthesis of composite sorbents with specific properties. PANI and polyaramides were shown to demonstrate the similar sorption properties when interacting with nucleic acids; but they differ in a various extent in the retention of various proteins. In a neutral aqueous medium (optimal for separation of biopolymers) polyaramides; although did not retain DNA; had a weaker affinity to proteins as compared to PANI. Since the recovery of DNA passed through the PANI-coated silica was the maximal among the particulate adsorbents; the PANI-modified composites were preferred as the carriers for the single-step isolation of nucleic acids from complex biological mixtures. The article cites the results of systematic studies of the authors in the development of sorbents for one-step separation and isolation of biopolymers from complex biological mixtures.Forcitation:Liaw D.-J.; Zybin D.I.; Prostyakova A.I.; Yagudaeva E.Yu.; Vikhrov A.A.; Ishchenko A.A.; Zubov V.P.; Kapustin D.V. Static and dynamic sorption of nucleic acids and proteins on surface of sorbents modified with nanolayers of polymers. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 1. P. 4-22

The effect of chemical composition and morphology of the surface layers of new polyaramide-containing sorbents on the mechanism of selective sorption of nucleic acids and proteins was investigated as compared to the previously studied sorbents modified with fluoropolymers and polyaniline (high-throughput materials providing one-step isolation of DNA from biological mixtures). A series of silica-based sorbents modified with polyaramides having consistently varying structure and containing the set of "key" structural elements (aromatic units and nitrogen atoms in the backbone, fluorinated groups), and various donor and acceptor moieties was prepared. The chemical composition of the polymer coatings was evaluated by X-ray photoelectron spectroscopy. The surface morphology was studied by scanning probe microscopy. The sorption properties were investigated by passing the mixtures containing DNA, RNA and proteins of different nature through the cartridges containing the obtained sorbents. All the investigated materials weakly retain double-stranded DNA but effectively retain RNA and proteins. The sorption capacity of the sorbents depends on the protein nature. The observed sorption behavior was shown to be determined by the chemical structure and not by the morphology of the polymer coating. It was proposed that similarity of the sorption properties of the series of chemically different polymers could be determined by similar total input of different sorption mechanisms.

The efficiency of one-step and multi-step protocols of DNA isolation from lysed sputum samples containing the Mycobacterium tuberculosis complex has been compared. DNA was isolated using spin-cartridges containing a special silica-based sorbent modified with fluoroplast and polyaniline, or using an automated isolation system. One-step isolation using the obtained sorbent has been shown to ensure a significantly lower DNA loss and higher sensitivity in the PCR detection of Mycobacterium tuberculosis as compared to a system based on sorption and desorption of nucleic acids during the isolation.

A composite sorbent modified with fluorinated aromatic polyamide, for single-step isolation of DNA from biological mixtures is developed. The sorbent is prepared by the polymer deposition from solution onto the surface of porous silica. It is shown that the polymer coating with a thickness of 4 nm is formed not only on the outer surface of the carrier particles but also on the inner pore surfaces. It is found that the material produced largely retained porosity of the pristine support and the material is selective in a one-step separation of nucleic acids and proteins by passing the bacterial lysate through a sorbent. The degree of purification of the isolated preparations of DNA is sufficient to be used directly in PCR analysis.

Aims: To demonstrate the effectiveness of application of the adsorbent successively modified with nano-layers of fluoroplast and polyaniline for one-step isolation of DNA of hepatitis B virus and transfusion-transmitted virus from human serum. Materials & Methods: The technique is based on the application of the spin-cartridges containing porous adsorbent for one-step viral DNA isolation from serum followed by polymerase chain reaction. Results: The developed adsorbent was shown to be effective for one-step isolation of viral DNA from serum samples for polymerase chain reaction diagnostics. Conclusion: The effectiveness of the developed adsorbent application for isolation of viral DNA from serum for polymerase chain reaction diagnostics was confirmed in comparison with standard methods. Thus, the facile sample preparation method of viral DNA isolation was elaborated.

The essence of modern biotechnology, in particular, chemical, biological and medical biotechnology, has been changed drastically, first due to development of recombinant DNA technology. Thus, so called molecular biotechnology has been arisen. This new discipline is based on the integrated use of methods borrowed from molecular and cell biology, microbiology, genetics, biochemistry and chemical engineering. These methods together with classical microbiological and immunological methods are widely used, for instance for laboratory diagnostics of infection diseases. The new fine technologies now used not only in scientific laboratories but also in routine medical practice, are connected with development of artificial multiple copying of DNA, i.e. the method known as polymerase chain reaction (PCR). However, along with many advantages of PCR-diagnostics there is a serious problem relating to an optimal choice of the techniques for the sample preparation. At present, there is no single universal approach for DNA isolation from different sources (e.g. from bacterial lysate or blood). To solve this specific aim the special adsorbents should be used depending on physical-chemical and sorption properties of the target compound. Thus, the success of biomedical biotechnology is to a large extent determined by availability of new effective materials and more universal approaches for biopolymer isolation and purification. As we will show below an optimal approach is based on the use of solid (porous) matrices coated with specific polymers providing the selective sorption of biopolymers. Special attention should be paid not only to retaining of functional activity of isolated substances, but also to elimination of laborand time-consuming protocols as well as to development of scalable and automatable techniques. Therefore, the reasons of necessity in new multipurpose matrices are evident. Such matrices should not induce irreversible denaturation of biopolymers and, at the same time, they should provide effective separation of the components contained in the complicated mixture (such as clinical sample). The development of biocompatible composites modified with fluoropolymerand polyaniline-based modifiers is in the scope of this work. Both the polytetrafluoroethylene (PTFE) and the polyaniline (PANI) were shown to be effective for one-step DNA isolation