In silico design, building and gas adsorption of nano-porous graphene scaffolds
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22.01.2021 |
Bellucci L.
Delfino F.
Tozzini V.
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Nanotechnology |
10.1088/1361-6528/abbe57 |
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© 2020 The Author(s). Published by IOP Publishing Ltd Printed in the UK Graphene-based nano-porous materials (GNM) are potentially useful for all those applications needing a large specific surface area (SSA), typical of the bidimensional graphene, yet realized in the bulk dimensionality. Such applications include for instance gas storage and sorting, catalysis and electrochemical energy storage. While a reasonable control of the structure is achieved in micro-porous materials by using nano-micro particles as templates, the controlled production or even characterization of GNMs with porosity strictly at the nano-scale still raises issues. These are usually produced using dispersion of nano-flakes as precursors resulting in little control on the final structure, which in turn reflects in problems in the structural model building for computer simulations. In this work, we describe a strategy to build models for these materials with predetermined structural properties (SSA, density, porosity), which exploits molecular dynamics simulations, Monte Carlo methods and machine learning algorithms. Our strategy is inspired by the real synthesis process: starting from randomly distributed flakes, we include defects, perforation, structure deformation and edge saturation on the fly, and, after structural refinement, we obtain realistic models, with given structural features. We find relationships between the structural characteristics and size distributions of the starting flake suspension and the final structure, which can give indications for more efficient synthesis routes. We subsequently give a full characterization of the models versus H2 adsorption, from which we extract quantitative relationship between the structural parameters and the gravimetric density. Our results quantitatively clarify the role of surfaces and edges relative amount in determining the H2 adsorption, and suggest strategies to overcome the inherent physical limitations of these materials as adsorbers. We implemented the model building and analysis procedures in software tools, freely available upon request.
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Poly(3-hydroxybutyrate)/hydroxyapatite/alginate scaffolds seeded with mesenchymal stem cells enhance the regeneration of critical-sized bone defect
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01.09.2020 |
Volkov A.V.
Muraev A.A.
Zharkova I.I.
Voinova V.V.
Akoulina E.A.
Zhuikov V.A.
Khaydapova D.D.
Chesnokova D.V.
Menshikh K.A.
Dudun A.A.
Makhina T.K.
Bonartseva G.A.
Asfarov T.F.
Stamboliev I.A.
Gazhva Y.V.
Ryabova V.M.
Zlatev L.H.
Ivanov S.Y.
Shaitan K.V.
Bonartsev A.P.
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Materials Science and Engineering C |
10.1016/j.msec.2020.110991 |
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© 2020 Elsevier B.V. A critical-sized calvarial defect in rats is employed to reveal the osteoinductive properties of biomaterials. In this study, we investigate the osteogenic efficiency of hybrid scaffolds based on composites of a biodegradable and biocompatible polymer, poly(3-hydroxybutyrate) (PHB) with hydroxyapatite (HA) filled with alginate (ALG) hydrogel containing mesenchymal stem cells (MSCs) on the regeneration of the critical-sized radial defect of the parietal bone in rats. The scaffolds based on PHB and PHB/HA with desired shapes were prepared by two-stage salt leaching technique using a mold obtained by three-dimensional printing. To obtain PHB/HA/ALG/MSC scaffolds seeded with MSCs, the scaffolds were filled with ALG hydrogel containing MSCs; acellular PHB/ALG and PHB/ALG filled with empty ALG hydrogel were prepared for comparison. The produced scaffolds have high porosity and irregular interconnected pore structure. PHB/HA scaffolds supported MSC growth and induced cell osteogenic differentiation in a regular medium in vitro that was manifested by an increase in ALP activity and expression of the CD45 phenotype marker. The data of computed tomography and histological studies showed 94% and 92%, respectively, regeneration of critical-sized calvarial bone defect in vivo at 28th day after implantation of MSC-seeded PHB/HA/ALG/MSC scaffolds with 3.6 times higher formation of the main amount of bone tissue at 22–28 days in comparison with acellular PHB/HA/ALG scaffolds that was shown at the first time by fluorescent microscopy using the original technique of intraperitoneal administration of fluorescent dyes to living postoperative rats. The obtained in vivo results can be associated with the MSC-friendly microstructure and in vitro osteogenic properties of PHB/HA base-scaffolds. Thus, the obtained data demonstrate the potential of MSCs encapsulated in the bioactive biopolymer/mineral/hydrogel scaffold to improve the bone regeneration process in critical-sized bone defects.
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Spermatogenesis induction of spermatogonial stem cells using nanofibrous poly(l-lactic acid)/multi-walled carbon nanotube scaffolds and naringenin
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01.12.2019 |
Ghorbani S.
Eyni H.
Khosrowpour Z.
Salari Asl L.
Shabani R.
Nazari H.
Mehdizadeh M.
Ebrahimi Warkiani M.
Amjadi F.
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Polymers for Advanced Technologies |
10.1002/pat.4733 |
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© 2019 John Wiley & Sons, Ltd. Spermatogenesis is a process in which animals generate spermatozoa from spermatogonial stem cells (SSCs). Successful in vitro differentiation of SSCs towards spermatids holds a significant promise for regeneration of impaired spermatogenesis. The present study aims to evaluate the efficiency of a 3D culture containing naringenin on proliferation and differentiation potentials of mouse SSCs. In this study, multi-walled carbon nanotubes (MWCNTs) were incorporated into poly(l-lactic acid) (PLLA) fibers via electrospinning technique. The fibrous PLLA/MWCNTs were studied by Fourier-transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), water contact angle measurements, electrical conductivity, and mechanical properties. Next, the SSCs were seeded into the PLLA/MWCNTs scaffolds and exhibited preferable survival and differentiation efficiency to subsequent cell lines. To shed more light on this matter, the immunocytochemistry, reverse-transcription polymerase chain reaction (RT-PCR), and qRT-PCR results showed that the aforementioned cells on the 3D fabrics overexpressed the C-kit and SYCP3 proteins. In addition, the reactive oxygen species (ROS) measurement data demonstrated that naringenin, an effective antioxidant, plays an important role in in vitro spermatogenesis. Taken together, the results of this study revealed the synergistic effects of 3D scaffolds and naringenin for efficient spermatogenesis in laboratories.
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Extracellular matrix-based hydrogels obtained from human tissues: A work still in progress
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01.10.2019 |
Gazia C.
Tamburrini R.
Asthana A.
Chaimov D.
Muir S.
Marino D.
Delbono L.
Villani V.
Perin L.
Di Nardo P.
Robertson J.
Orlando G.
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Current Opinion in Organ Transplantation |
10.1097/MOT.0000000000000691 |
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© 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.
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Flexible polycaprolactone and polycaprolactone/graphene scaffolds for tissue engineering
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01.09.2019 |
Evlashin S.
Dyakonov P.
Tarkhov M.
Dagesyan S.
Rodionov S.
Shpichka A.
Kostenko M.
Konev S.
Sergeichev I.
Timashev P.
Akhatov I.
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Materials |
10.3390/ma12182991 |
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© 2019 by the authors. Developing bone scaffolds can greatly improve the patient's quality of life by accelerating the rehabilitation process. In this paper, we studied the process of composite polycaprolactone supercritical foaming for tissue engineering. The influence of graphene oxide and reduced graphene oxide on the foaming parameters was studied. The structural and mechanical properties were studied. The scaffolds demonstrated mechanical flexibility and endurance. The co-culturing and live/dead tests demonstrated that the obtained scaffolds are biocompatible. Different composite scaffolds induced various surface cell behaviors. The experimental data demonstrate that composite foams are promising candidates for in vivo medical trials.
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Cellulose-based scaffolds for fluorescence lifetime imaging-assisted tissue engineering
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15.10.2018 |
O'Donnell N.
Okkelman I.
Timashev P.
Gromovykh T.
Papkovsky D.
Dmitriev R.
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Acta Biomaterialia |
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6 |
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© 2018 Acta Materialia Inc. Quantitative measurement of pH and metabolite gradients by microscopy is one of the challenges in the production of scaffold-grown organoids and multicellular aggregates. Herein, we used the cellulose-binding domain (CBD) of the Cellulomonas fimi CenA protein for designing biosensor scaffolds that allow measurement of pH and Ca2+ gradients by fluorescence intensity and lifetime imaging (FLIM) detection modes. By fusing CBD with pH-sensitive enhanced cyan fluorescent protein (CBD-ECFP), we achieved efficient labeling of cellulose-based scaffolds based on nanofibrillar, bacterial cellulose, and decellularized plant materials. CBD-ECFP bound to the cellulose matrices demonstrated pH sensitivity comparable to untagged ECFP (1.9–2.3 ns for pH 6–8), thus making it compatible with FLIM-based analysis of extracellular pH. By using 3D culture of human colon cancer cells (HCT116) and adult stem cell-derived mouse intestinal organoids, we evaluated the utility of the produced biosensor scaffold. CBD-ECFP was sensitive to increases in extracellular acidification: the results showed a decline in 0.2–0.4 pH units in response to membrane depolarization by the protonophore FCCP. With the intestinal organoid model, we demonstrated multiparametric imaging by combining extracellular acidification (FLIM) with phosphorescent probe-based monitoring of cell oxygenation. The described labeling strategy allows for the design of extracellular pH-sensitive scaffolds for multiparametric FLIM assays and their use in engineered live cancer and stem cell-derived tissues. Collectively, this research can help in achieving the controlled biofabrication of 3D tissue models with known metabolic characteristics. Statement of Significance: We designed biosensors consisting of a cellulose-binding domain (CBD) and pH- and Ca2+-sensitive fluorescent proteins. CBD-tagged biosensors efficiently label various types of cellulose matrices including nanofibrillar cellulose and decellularized plant materials. Hybrid biosensing cellulose scaffolds designed in this study were successfully tested by multiparameter FLIM microscopy in 3D cultures of cancer cells and mouse intestinal organoids.
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Advanced laser technologies for regenerative medicine
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13.08.2018 |
Timashev P.
Minaev N.
Bagratashvili V.
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Proceedings - International Conference Laser Optics 2018, ICLO 2018 |
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© 2018 IEEE. This presentation will discusses recent studies on two photon polymerization process and examples of its application in TE.
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Applying LIFT-technology for vasculature formation in tissue and organ engineering
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13.08.2018 |
Antoshin A.
Fedyakov M.
Sobolevskaya M.
Churbanov S.
Minaev N.
Shpichka A.
Timashev P.
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Proceedings - International Conference Laser Optics 2018, ICLO 2018 |
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1 |
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© 2018 IEEE. This study aimed to develop the approach to the vasculature formation using LIFT-technology for tissue and organ engineering.
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Combined endovascular treatment of acute coronary syndrome with bioresorbable scaffolds and angioplasty in patient with critical lower limb ischemia – Hybrid treatment in multidisciplinary hospital
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01.01.2018 |
Zagorulko A.
Kolosov R.
Sidelnikov A.
Korzheva Y.
Koledinsky A.
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Rational Pharmacotherapy in Cardiology |
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© 2018 Stolichnaya Izdatelskaya Kompaniya. All rights reserved. The key to successful treatment in patients with acute coronary syndrome is maximally early revascularization of the coronary arteries. Treatment of multifocal atherosclerosis with lesions of the coronary and peripheral arteries requires coordinated work of the multidisciplinary team of doctors. Critical ischemia of the lower limbs requires urgent revascularization in order to prevent limb amputation. However, it is not always possible to perform revascularization using specialists of the same profile – endovascular or surgical. The use of hybrid methods of treatment (surgical and endovascular) allows to significantly improve the prognosis in saving the limb. The article presents a clinical observation of successful multistep treatment of a patient with acute coronary syndrome in combination with critical ischemia of the lower limb. The first stage was performed by multiple stenting of the coronary arteries with bioabsorptive scaffolds; the second stage was the hybrid treatment – femoral-tibial bypass with simultaneous recanalization and angioplasty of the lower leg arteries with good postoperative and long-term outcome.
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Optical properties of porous polylactide scaffolds
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01.01.2018 |
Yusupov V.
Sviridov A.
Zhigarkov V.
Shubnyy A.
Vorobieva N.
Churbanov S.
Minaev N.
Timashev P.
Rochev Y.
Bagratashvili V.
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Progress in Biomedical Optics and Imaging - Proceedings of SPIE |
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© COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only. Light field intensity distribution in three-dimensional polylactide scaffolds after irradiation with low-intensity light from one side of the samples has been determined in the visible and near-infrared regions of the spectrum. Two different types of scaffolds manufactured by the methods of supercritical fluid foaming and surface selective laser sintering have been investigated. The problem is solved by numerical calculation according to the Monte Carlo method involving experimentally obtained information about effective optical parameters of the scaffold material. Information about intensity distribution of the incident light in the matrix volume is needed to assess the radiation level for the scaffold cells after photobiostimulation. It has been shown that the formation of the light field in case of strongly scattering media, such as polylactide scaffolds, is determined by anisotropy g and the scattering coefficient μs.
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The technology of laser fabrication of cell 3D scaffolds based on proteins and carbon nanoparticles
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01.01.2018 |
Gerasimenko A.
Zhurbina N.
Kurilova U.
Polokhin A.
Ryabkin D.
Savelyev M.
Suetina I.
Mezentseva M.
Ichkitidze L.
Ignatov D.
Garcia-Ramirez M.
Guzman Gonzalez J.
Podgaetsky V.
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Proceedings of SPIE - The International Society for Optical Engineering |
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© 2018 SPIE. The technology of cell 3D scaffolds laser fabrication is developed. 3D scaffolds are designed to repair osteochondral defects, which are poorly restored during the organism's life. The technology involves the use of an installation, the laser beam of which moves along a liquid nanomaterial and evaporates it layer by layer. Liquid nanomaterial consists of the water-protein (collagen, albumin) suspension with carbon nanoparticles (single-walled carbon nanotubes). During laser irradiation, the temperature in the region of nanotubes defects increases and nanotubes are combined into the scaffold. The main component of installation is a continuous laser operating at wavelengh of 810 nm. The laser beam moves along 3 coordinates, which makes it possible to obtain samples of the required geometric shape. The internal and surface structure of the samples at the micro- A nd nanoscale levels were studied using the X-ray microtomography and scanning electron microscopy. In vitro studies of cell growth during 48 and 72 hours demonstrated the ability of cell 3D scaffolds to support the proliferation of osteoblasts and chondroblasts. Using fluorescence and atomic force microscopy, it was found that the growth and development of cells on a sample with a larger concentration of nanotubes occurred faster compared to samples with a smaller concentration of nanotubes.
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Features of primary hippocampal cultures formation on scaffolds based on hyaluronic acid glycidyl methacrylate
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01.01.2018 |
Mishchenko T.
Mitroshina E.
Kuznetsova A.
Shirokova O.
Khaydukov E.
Savelyev A.
Popov V.
Zvyagin A.
Vedunova M.
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Sovremennye Tehnologii v Medicine |
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© 2018, Nizhny Novgorod State Medical Academy. All rights reserved. The aim of the study was to investigate the morphological and metabolic features of primary hippocampal cultures formation on hydrogel films and scaffolds based on hyaluronic acid glycidyl methacrylate. Materials and Methods. Hydrogel films and scaffolds with certain architectonics were developed by micromolding technique on the basis of hyaluronic acid glycidyl methacrylate. Primary hippocampal cells obtained from C57BL/6 mouse embryos (E18) were cultured on the created constructs more than 14 days. Testing cell viability, morphometric assessment, and analysis of spontaneous calcium activity of primary hippocampal cultures were performed on day 14 of cultures development in vitro. Results. This study revealed that the material for the development of scaffolds with given architectonics is non-toxic for the nervous system cells. Dissociated hippocampal cells were actively attached to the scaffold surface and were assembled into cell conglomerates, which exhibited spontaneous calcium activity. Conclusion. Scaffolds designed on the basis of hyaluronic acid glycidyl methacrylate have a high biocompatibility with the nervous system cells. Architectonics and adhesive properties of scaffold contribute to the formation of functionally active cell conglomerates.
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