Репозиторий Университета

© 2019 Wolters Kluwer Health, Inc. Purpose of reviewThe current review summarizes contemporary decellularization and hydrogel manufacturing strategies in the field of tissue engineering and regenerative medicine.Recent findingsDecellularized extracellular matrix (ECM) bioscaffolds are a valuable biomaterial that can be purposed into various forms of synthetic tissues such as hydrogels. ECM-based hydrogels can be of animal or human origin. The use of human tissues as a source for ECM hydrogels in the clinical setting is still in its infancy and current literature is scant and anecdotal, resulting in inconclusive results.SummaryThus far the methods used to obtain hydrogels from human tissues remains a work in progress. Gelation, the most complex technique in obtaining hydrogels, is challenging due to remarkable heterogeneity of the tissues secondary to interindividual variability. Age, sex, ethnicity, and preexisting conditions are factors that dramatically undermine the technical feasibility of the gelation process. This is contrasted with animals whose well defined anatomical and histological characteristics have been selectively bred for the goal of manufacturing hydrogels.

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. The physicochemical and technological properties of an interpolymer complex of polymethyacrylic acid and polyethylene glycol, known under its commercial name “Polymer Carrier Composition” (FGUP Science Research Institute of Polymers, Russia), were studied. This polymer is an excipient substance used in the technology of solid dosage forms as a matrix former and as a film-forming agent for making long-acting and slow-release formulations. With the aim of widening the potential uses of the polymer carrier composition, the solubility of the polymer in aqueous solutions and organic solvents was studied, along with the technological and surfactant properties of the polymer; the critical gel-forming concentration was also determined. Experimental samples of tablets and oral gels of model substances with similar physicochemical properties were prepared, based on different concentrations of the Polymer Carrier Composition, and the technological, rheological, and biopharmaceutical properties of these were studied. The potential for using the polymer in both hard and soft dosage forms to obtain prolonged-release medicinal formulations is demonstrated.

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. Articular hyaline cartilage is extensively hydrated, but it is neither innervated nor vascularized, and its low cell density allows only extremely limited self-renewal. Most clinical and research efforts currently focus on the restoration of cartilage damaged in connection with osteoarthritis or trauma. Here, we discuss current clinical approaches for repairing cartilage, as well as research approaches which are currently developing, and those under translation into clinical practice. We also describe potential future directions in this area, including tissue engineering based on scaffolding and/or stem cells as well as a combination of gene and cell therapy. Particular focus is placed on cell-based approaches and the potential of recently characterized chondro-progenitors; progress with induced pluripotent stem cells is also discussed. In this context, we also consider the ability of different types of stem cell to restore hyaline cartilage and the importance of mimicking the environment in vivo during cell expansion and differentiation into mature chondrocytes.

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Research results supporting the manufacturing technology for floating prolonged-release oral tablets based on a hydrophilic matrix with the nonselective α-adrenoblocker proroxan are presented.Wet granulation of the effervescent ingredients with the matrix produced tablets with the required buoyancy lag-time, float time, and proroxan release kinetics.

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Our study confirmed the capacity of S. pyogenes strains to form biofilms on abiotic surfaces. Chains of streptococci surrounded by bluish film were seen under a microscope after alcian blue staining of the preparations grown on slides. On ultrathin sections in transmission electron microscope, the extracellular matrix (indicator of biofilm maturity) became visible after staining with alcian blue. Microscopy of the sections shows structures characteristic of a biofilm in spaces between the cells. Scanning electron microscopy also demonstrates the presence of a biomembrane. Importantly that type 1M strain forming in fact no membranes when cultured on plastic plates (Costar) formed biofilms on the glass. It seems that the conditions for the biofilm formation on the plastic and on the glass differ, due to which the exopolymeric matrices formed on different surfaces vary by biochemical composition.

© 2018, Springer Science+Business Media, LLC, part of Springer Nature. We created an anisotropic material based on collagen sponge and reactive polylactide structured by laser photopolymerization. The combination of collagen with reactive polylactide improves the resistance of the formed matrices to biodegradation in comparison with collagen sponge, while the existence of sites with different mechanical characteristics and cell affinity on the matrix provides directed cell growth during their culturing. It was shown that reinforcement of the collagen sponges 7-fold increased the mean Young’s modulus for the hybrid matrix without affecting its cytotoxicity. The developed matrix provides cell adhesion and proliferation along reinforcement lines and can be used for fabrication of tissue engineering constructs.

© Springer Science+Business Media, LLC 2017.  Sandwich enzyme-linked immunosorbent assay (ELISA) of sulfonamides based on double-competitive interaction between haptenized protein as a captured antigen and analyte for binding to immobilized and enzyme-labeled antibodies was developed. This experimental assay format was examined in analytical properties and matrix effect resistance in comparison with usual ones: indirect, direct antigen-coated and antibody-coated ELISAs. All four assay formats were designed on the basis of interactions between the previously prepared monoclonal antibody and immunizing hapten, 4-(4-(4-aminophenylsulfonamido) phenyl)butanoic acid, providing the uniform output optical signal for correct comparison of each assay characteristic. The sensitivity (IC 50 ) of the developed competitive sandwich assay was rather below 100 ng/ml for 11 sulfonamides which was suitable for their determination in milk, muscles and animal sera at established maximum residue limit concentration. Comparative examination did not reveal changes in assay specificity, and advantages in sensitivity, matrix effect resistance, and procedure duration before commonly used assay formats. Moreover, new design of assay was shown to be three-fold more consumable in antibody reagents in comparison with direct assay formats.

© 2018 Stavropol State Medical University. All Rights Reserved. 57 men and 43 women, aged 22.0±4.2 years were examined to determine the clinical and prognostic value of matrix metalloproteinases in heart remodeling in CTD. Serum concentrations of MMP-1, MMP-9, TIMP-1 were determined by ELI-SA («Cloud-Clone Corp.», China). Imbalance of MMP-1, MMP-9 and their inhibitor - TIMP-1 was revealed in patients with CTD. Significant increase in MMP-1 level was registered in cases of MVP with myxomatous degeneration and mitral regurgitation of II degree. Risk of cardiac remodeling progression at three-year follow-up increases in cases of elevated of MMP-1/TIMP-1 coefficient. Identified changes in the MMPs system in patients with CTD may be used as additional criteria of severity and determination of probability of progression of heart connective tissue structures remodeling.

© 2018 SPIE. In this work, tissue-engineered structures based on a matrix of protein conjugates, chitosan and carbon nanotubes were prepared and studied. Bovine serum albumin (BSA), bovine collagen (BCrossed D sign¡) were used. Two types of single-walled carbon nanotubes (SWCNTs) were used to form a strong internal scaffold in a protein-chitosan matrix under the action of laser radiation. Tissue-engineered structures were created by means of layered deposition and laser evaporation of the initial aqueous dispersion from SWCNT, BSA, BC and chitosan succinate. As sources of laser radiation, a continuous diode laser with a wavelength of 810 nm and a pulsed fiber laser with a wavelength of 1064 nm and frequency of 80 kHz were used. Studies of tissue-engineered structures were carried out using vibrational spectroscopy methods (IR and Raman). The changes in the frequencies and intensities of the corresponding absorption bands and Raman lines of the amide group oscillations were analyzed. IR spectra of tissue-engineered structures demonstrated a high degree of binding of organic (protein, chitosan) and inorganic (SWCNT) components. The structure and defectiveness of the carbon nanotube scaffold were investigated in the Raman spectra.

© 2018 Russian Photodynamic Association. All rights reserved. Currently, reconstructive-plastic surgery is becoming the standard for surgical and combined treatment of breast cancer (BC) patients. With a one-stage reconstruction of the breast, the use of biological implants that can replace muscle autografts and, consequently, reduce trauma, blood loss and operation time, and also to avoid defects in the donor zones is becoming topical. From 2014 to 2017, 151 reconstructive operations on 121 patients with BC (average age 41.5 years) using synthetic and biological materials were carried out in P.Herzen Moscow Oncology Research Institute. 0 stage of BC TisN0M0 was diagnosed in 11 (9.1%) patients, I stage - in 52 (42.9%), IIA - in 41 (33.9%), IIB - in 9 (7.4%), IIIA - in 4 (3.3%), IIIB - in 2 (1.7%), IIIC - in 2 (1.7%). To strengthen the lower slope, a biological implant - Permacol acellular dermal matrix, was used in 34 cases. Cosmetic result was rated as excellent in 20 (58.9%) cases, good in 11 (32.3%), unsatisfactory in 3 (8,8%). Biological materials are an important addition to various options for breast reconstruction. The criterion for selecting the material for strengthening the lower slope of the breast with subcutaneous or cutaneous mastectomy for cancer with a one-stage reconstruction using a silicone endoprosthesis is the pinch-test value.

© The Author(s) 2018. Objective: Chondrospheres represent a variant of tissue spheroids biofabricated from chondrocytes. They are already being used in clinical trials for cartilage repair; however, their biomechanical properties have not been systematically investigated yet. The aim of our study was to characterize chondrospheres in long-term in vitro culture conditions for morphometric changes, biomechanical integrity, and their fusion and spreading kinetics. Results: It has been demonstrated that the increase in chondrospheres secant modulus of elasticity is strongly associated with the synthesis and accumulation of extracellular matrix. Additionally, significant interplay has been found between biomechanical properties of tissue spheroids and their fusion kinetics in contrast to their spreading kinetics. Conclusions: Extracellular matrix is one of the main structural determinants of chondrospheres biomechanical properties during chondrogenic maturation in vitro. The estimation of tissue spheroids’ physical behavior in vitro prior to operative treatment can be used to predict and potentially control fusogenic self-assembly process after implantation in vivo.

© 2018, Nizhny Novgorod State Medical Academy. All rights reserved. The aim of this study was to modify the chemical structure and to optimize the composition of the fibrin gel for effective cell encapsulation. Materials and Methods. We prepared PEGylated fibrin gels using different fibrinogen concentrations (25–50 mg/ml) and PEG-fibrinogen molar ratio 10:1 and 5:1 and characterized them via Fourier transform infrared spectroscopy and differential scanning calorimetry. Within the gels, we encapsulated primary culture of fibroblasts and analyzed using light and laser confocal microscopy. Results. PEGylation of fibrinogen allowed us to achieve the gel transparency and preserve its biocompatibility. We revealed that the gel prepared from PEGylated 5:1 fibrinogen (25 mg/ml) provided the most favorable microenvironment for spreading, growth, and proliferation of fibroblasts. This PEG-fibrin gel can be used for encapsulation of different cell types that is essential for various approaches in tissue engineering and diagnostic systems.

© 2018, Nizhny Novgorod State Medical Academy. All rights reserved. The aim of the study was to demonstrate a good diagnostic potential of atomic force microscopy (AFM) in tracking morphological changes in the extracellular matrix (ECM) of connective tissue due to pathological processes. Here we summarize our experience in AFM application in a number of biomedical studies on the connective tissue disease, both for the research and clinical purposes. Materials and Methods. Depending on the project application (experimental or clinical), the tissue specimens were harvested either from animals, or from patients in the course of their surgical treatment, or post mortem. AFM images of fixed tissue slices on glass slides were acquired with a Solver P47 AFM instrument (NT-MDT, Russia), in the semi-contact mode. For mechanical properties mapping, the images were acquired on air in the PeakForce Quantitative Nanomechanical Mapping mode (PeakForce QNM®), using a MultiMode 8 atomic force microscope (Bruker, USA). The regions of interest for scanning were selected in accordance with the histological assignments for the same sample, based on the view of a sample in the built-in optical microscope of the AFM instrument setup. To quantify the changes in the ECM morphology visualized by AFM imaging, we applied flicker-noise spectroscopy parameterization. Results. AFM has been shown to reveal visible deviations from the normal morphology of the ECM in diseased tissues. We found that AFM and related techniques are capable of tracking disease-related changes at different levels of collagen organization in the ECM. At the microscale, AFM may detect loosening and disorganization of collagen fibers (e.g., in a dysplastic process), or the opposite process of their packing into tight parallel bundles in a fibrotic process. AFM may also monitor the ratio between collagen and non-fibrous material of the ECM, for example, in inflammatory and neoplastic processes. At the level of collagen fibrils, AFM may reveal early signs of the matrix destruction and remodeling not visible at the microscopic level. The flicker-noise spectroscopy parameters provide quantification of the morphological changes visualized by AFM. The PeakForce QNM® and nanoindentation studies give a further insight into the state of ECM via tracking changes in the local mechanical and adhesive properties. All our AFM studies appeared in a good agreement with the histological findings and generally had a superior sensitivity to pathology-related ECM rearrangements. Conclusion. AFM may serve as a valuable complementary diagnostic tool for tracking pathological changes in the connective tissue.