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Bandzerewicz A, Howis J, Wierzchowski K, Slouf M, Hodan J, Denis P, Gołofit T, Pilarek M, Gadomska-Gajadhur A. Exploring the application of poly(1,2-ethanediol citrate)/polylactide nonwovens in cell culturing. Front Bioeng Biotechnol 2024; 12:1332290. [PMID: 38558787 PMCID: PMC10978747 DOI: 10.3389/fbioe.2024.1332290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 02/28/2024] [Indexed: 04/04/2024] Open
Abstract
Biomaterials containing citric acid as a building unit show potential for use as blood vessel and skin tissue substitutes. The success in commercializing implants containing a polymer matrix of poly(1,8-octanediol citrate) provides a rationale for exploring polycitrates based on other diols. Changing the aliphatic chain length of the diol allows functional design strategies to control the implant's mechanical properties, degradation profile and surface energy. In the present work, poly(1,2-ethanediol citrate) was synthesized and used as an additive to polylactide in the electrospinning process. It was established that the content of polycitrate greatly influences the nonwovens' properties: an equal mass ratio of polymers resulted in the best morphology. The obtained nonwovens were characterized by surface hydrophilicity, tensile strength, and thermal properties. L929 cell cultures were carried out on their surface. The materials were found to be non-cytotoxic and the degree of porosity was suitable for cell colonization. On the basis of the most important parameters for assessing the condition of cultured cells (cell density and viability, cell metabolic activity and lactate dehydrogenase activity), the potential of PLLA + PECit nonwovens for application in tissue engineering was established.
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Affiliation(s)
| | - Joanna Howis
- Faculty of Chemistry, Warsaw University of Technology, Warsaw, Poland
| | - Kamil Wierzchowski
- Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warsaw, Poland
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czechia
| | - Jiri Hodan
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czechia
| | - Piotr Denis
- Laboratory of Polymers and Biomaterials, Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw, Poland
| | - Tomasz Gołofit
- Faculty of Chemistry, Warsaw University of Technology, Warsaw, Poland
| | - Maciej Pilarek
- Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warsaw, Poland
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Skoupý R, Boltje DB, Slouf M, Mrázová K, Láznička T, Taisne CM, Krzyžánek V, Hoogenboom JP, Jakobi AJ. Robust Local Thickness Estimation of Sub-Micrometer Specimen by 4D-STEM. Small Methods 2023; 7:e2300258. [PMID: 37248805 DOI: 10.1002/smtd.202300258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/21/2023] [Indexed: 05/31/2023]
Abstract
A quantitative four-dimensional scanning transmission electron microscopy (4D-STEM) imaging technique (q4STEM) for local thickness estimation across amorphous specimen such as obtained by focused ion beam (FIB)-milling of lamellae for (cryo-)TEM analysis is presented. This study is based on measuring spatially resolved diffraction patterns to obtain the angular distribution of electron scattering, or the ratio of integrated virtual dark and bright field STEM signals, and their quantitative evaluation using Monte Carlo simulations. The method is independent of signal intensity calibrations and only requires knowledge of the detector geometry, which is invariant for a given instrument. This study demonstrates that the method yields robust thickness estimates for sub-micrometer amorphous specimen using both direct detection and light conversion 2D-STEM detectors in a coincident FIB-SEM and a conventional SEM. Due to its facile implementation and minimal dose reauirements, it is anticipated that this method will find applications for in situ thickness monitoring during lamella fabrication of beam-sensitive materials.
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Affiliation(s)
- Radim Skoupý
- Institute of Scientific Instruments, Czech Academy of Sciences, Brno, 61264, CZ
- Department of Bionanoscience, Delft University of Technology, Delft, 2628 CD, NL
- Kavli Institute of Nanoscience, Delft University of Technology, Delft, 2628 CJ, NL
- Department of Imaging Physics, Delft University of Technology, Delft, 2628 CJ, NL
| | - Daan B Boltje
- Department of Imaging Physics, Delft University of Technology, Delft, 2628 CJ, NL
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, 162 00, CZ
| | - Kateřina Mrázová
- Institute of Scientific Instruments, Czech Academy of Sciences, Brno, 61264, CZ
| | - Tomáš Láznička
- Institute of Scientific Instruments, Czech Academy of Sciences, Brno, 61264, CZ
| | - Clémence M Taisne
- Department of Bionanoscience, Delft University of Technology, Delft, 2628 CD, NL
| | - Vladislav Krzyžánek
- Institute of Scientific Instruments, Czech Academy of Sciences, Brno, 61264, CZ
| | - Jacob P Hoogenboom
- Department of Imaging Physics, Delft University of Technology, Delft, 2628 CJ, NL
| | - Arjen J Jakobi
- Department of Bionanoscience, Delft University of Technology, Delft, 2628 CD, NL
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Krzyzanek V, Slouf M, Skoupy R, Pavlova E, Hrubanova K. Powder Nano-Beam Diffraction in Scanning Electron Microscopy: Possibilities and Limitations for Applications. Microsc Microanal 2023; 29:328-329. [PMID: 37613212 DOI: 10.1093/micmic/ozad067.153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Vladislav Krzyzanek
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Radim Skoupy
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
- Laboratory of Nanoscale Biology, Paul Scherrer Institute, Villigen, Switzerland
| | - Ewa Pavlova
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Prague, Czech Republic
| | - Kamila Hrubanova
- Institute of Scientific Instruments of the Czech Academy of Sciences, Brno, Czech Republic
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Kozisek J, Slouf M, Sloufova I. Factor analysis of the time series of SERS spectra reveals water arrangement and surface plasmon changes in Ag nanoparticle systems. Spectrochim Acta A Mol Biomol Spectrosc 2023; 293:122454. [PMID: 36780740 DOI: 10.1016/j.saa.2023.122454] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 01/19/2023] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
The enhancement of Raman signals of molecules localized in the vicinity of plasmonic nanoparticles, known as surface-enhanced Raman scattering (SERS) effect, is strongly influenced by the selected excitation wavelength. The optimal excitation wavelength in SERS measurements is given by the position of the surface plasmon extinction (SPE) band of the studied system. Even a small change of the SPE band intensity, position and/or shape during the measurement may influence the SERS signal significantly. In this work, we prepared several systems of Ag nanoparticles, which were used for the demonstration how the information about SPE changes can be obtained by multivariate statistical analysis (factor analysis; FA) from SERS spectral sets, and employed in more precise and more comprehensive interpretation of the results. In non-aggregated Ag colloidal systems measured at the excitation wavelength of 445 nm, SPE band changes could be monitored by the analysis of water stretching vibration together with the vibrations in the fingerprint region. The FA of the water stretching band region was shown to provide unique information on both arrangement and disarrangement of water molecules in the vicinity of Ag NPs during the time evolution of these SERS active systems. In addition, the FA of the fingerprint region helped to monitor a rapid metalation of meso-tetrakis(N-methyl-4-pyridyl)porphine in etched SERS systems with Ag+ ions released from the NPs surface. In aggregated Ag colloidal systems measured at the excitation wavelength of 785 nm, the FA of SERS spectral sets enabled us to reveal the contribution of the 2nd electromagnetic enhancement to the overall SERS signal. The reliability of our conclusions was verified by comparing the results obtained from FA of SERS spectral sets with the data obtained from the parallel SPE measurements of the studied systems.
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Affiliation(s)
- Jan Kozisek
- Charles University, Faculty of Science, Department of Physical and Macromolecular Chemistry, Hlavova 2030, 128 40 Prague 2, Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovskeho nam. 2, 162 06 Prague 6, Czech Republic
| | - Ivana Sloufova
- Charles University, Faculty of Science, Department of Physical and Macromolecular Chemistry, Hlavova 2030, 128 40 Prague 2, Czech Republic.
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Hobzova R, Sirc J, Shrestha K, Mudrova B, Bosakova Z, Slouf M, Munzarova M, Hrabeta J, Feglarova T, Cocarta AI. Multilayered Polyurethane/Poly(vinyl alcohol) Nanofibrous Mats for Local Topotecan Delivery as a Potential Retinoblastoma Treatment. Pharmaceutics 2023; 15:pharmaceutics15051398. [PMID: 37242640 DOI: 10.3390/pharmaceutics15051398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 04/27/2023] [Accepted: 04/28/2023] [Indexed: 05/28/2023] Open
Abstract
Local chemotherapy using polymer drug delivery systems has the potential to treat some cancers, including intraocular retinoblastoma, which is difficult to treat with systemically delivered drugs. Well-designed carriers can provide the required drug concentration at the target site over a prolonged time, reduce the overall drug dose needed, and suppress severe side effects. Herein, nanofibrous carriers of the anticancer agent topotecan (TPT) with a multilayered structure composed of a TPT-loaded inner layer of poly(vinyl alcohol) (PVA) and outer covering layers of polyurethane (PUR) are proposed. Scanning electron microscopy showed homogeneous incorporation of TPT into the PVA nanofibers. HPLC-FLD proved the good loading efficiency of TPT (≥85%) with a content of the pharmacologically active lactone TPT of more than 97%. In vitro release experiments demonstrated that the PUR cover layers effectively reduced the initial burst release of hydrophilic TPT. In a 3-round experiment with human retinoblastoma cells (Y-79), TPT showed prolonged release from the sandwich-structured nanofibers compared with that from a PVA monolayer, with significantly enhanced cytotoxic effects as a result of an increase in the PUR layer thickness. The presented PUR-PVA/TPT-PUR nanofibers appear to be promising carriers of active TPT lactone that could be useful for local cancer therapy.
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Affiliation(s)
- Radka Hobzova
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, 162 06 Prague, Czech Republic
| | - Jakub Sirc
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, 162 06 Prague, Czech Republic
| | - Kusum Shrestha
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, 162 06 Prague, Czech Republic
| | - Barbora Mudrova
- Department of Analytical Chemistry, Faculty of Science, Charles University, 128 43 Prague, Czech Republic
| | - Zuzana Bosakova
- Department of Analytical Chemistry, Faculty of Science, Charles University, 128 43 Prague, Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, 162 06 Prague, Czech Republic
| | | | - Jan Hrabeta
- Department of Pediatric Hematology and Oncology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, 150 06 Prague, Czech Republic
| | - Tereza Feglarova
- Department of Pediatric Hematology and Oncology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, 150 06 Prague, Czech Republic
| | - Ana-Irina Cocarta
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, 162 06 Prague, Czech Republic
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Rajbanshi A, Mahmoudi N, Murnane D, Pavlova E, Slouf M, Dreiss C, Cook M. Combining branched copolymers with additives generates stable thermoresponsive emulsions with in situ gelation upon exposure to body temperature. Int J Pharm 2023; 637:122892. [PMID: 37001832 DOI: 10.1016/j.ijpharm.2023.122892] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 03/12/2023] [Accepted: 03/23/2023] [Indexed: 04/03/2023]
Abstract
Branched copolymer surfactants (BCS) containing thermoresponsive polymer components, hydrophilic components, and hydrophobic termini allow the formation of emulsions which switch from liquid at room temperature to a gel state upon heating. These materials have great potential as in situ gel-forming dosage forms for administration to external and internal body sites, where the emulsion system also allows effective solubilisation of a range of drugs with different chemistries. These systems have been reported previously, however there are many challenges to translation into pharmaceutical excipients. To transition towards this application, this manuscript describes the evaluation of a range of pharmaceutically-relevant oils in the BCS system as well as evaluation of surfactants and polymeric/oligomeric additives to enhance stability. Key endpoints for this study are macroscopic stability of the emulsions and rheological response to temperature. The effect of an optimal additive (methylcellulose) on the nanoscale processes occurring in the BCS-stabilised emulsions is probed by small-angle neutron scattering (SANS) to better comprehend the system. Overall, the study reports an optimal BCS/methylcellulose system exhibiting sol-gel transition at a physiologically-relevant temperature without macroscopic evidence of instability as an in situ gelling dosage form.
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Papagiannopoulos A, Sklapani A, Len A, Radulescu A, Pavlova E, Slouf M. Protein-induced transformation of unilamellar to multilamellar vesicles triggered by a polysaccharide. Carbohydr Polym 2023; 303:120478. [PMID: 36657851 DOI: 10.1016/j.carbpol.2022.120478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 12/13/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
We report on the morphological transitions of didodecyldimethylammonium bromide (DDAB) cationic vesicles and hybrid DDAB/hyaluronic acid (HA) vesicles upon addition of BSA at pH 7 where BSA is overall negatively charged. Small angle neutron scattering (SANS) is used to extract the size distributions of the nanovesicles, the thickness of the DDAB bilayers and their lamellarity. Although the HA-decorated DDAB vesicles contain the negatively charged polysaccharide the interaction with BSA appears to be more intense in comparison to bare vesicles. Characteristic peaks in the SANS patterns indicate the presence of multilamellar interfaces while the formation of multilamellar vesicles induced by BSA depends on the amount of added HA. Consequently, higher lamellarities are observed at higher BSA contents. This work demonstrates a simple methodology to tune the encapsulation of globular proteins in vesicular nanoassemblies by affecting their lamellarity and has direct implications on the application of vesicles and liposomes in protein delivery.
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Affiliation(s)
- Aristeidis Papagiannopoulos
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece.
| | - Aggeliki Sklapani
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 11635 Athens, Greece
| | - Adél Len
- Centre for Energy Research, Konkoly-Thege Str., 29-33, 1121 Budapest, Hungary; University of Pécs, Faculty of Engineering and Information Technology, Boszorkány Str., 2, 7624 Pécs, Hungary
| | - Aurel Radulescu
- Jülich Centre for Neutron Science JCNS Forschungszentrum Jülich GmbH, Outstation at Heinz Maier-Leibnitz Zentrum (MLZ), Lichtenbergstraße 1, 85747 Garching, Germany
| | - Ewa Pavlova
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovskeho nam. 2, 16206 Prague, Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovskeho nam. 2, 16206 Prague, Czech Republic
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Slouf M, Gajdosova V, Dybal J, Sticha R, Fulin P, Pokorny D, Mateo J, Panisello JJ, Canales V, Medel F, Bistolfi A, Bracco P. European Database of Explanted UHMWPE Liners from Total Joint Replacements: Correlations among Polymer Modifications, Structure, Oxidation, Mechanical Properties and Lifetime In Vivo. Polymers (Basel) 2023; 15:polym15030568. [PMID: 36771869 PMCID: PMC9921464 DOI: 10.3390/polym15030568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/15/2023] [Accepted: 01/19/2023] [Indexed: 01/24/2023] Open
Abstract
This contribution lays the foundation for the European database of explanted UHMWPE liners from total joint replacements. Three EU countries (Czech Republic, Italy and Spain) have joined their datasets containing anonymized patient data (such as age and BMI), manufacturer data (such as information on UHMWPE crosslinking, thermal treatment and sterilization), orthopedic evaluation (such as total duration of the implant in vivo and reasons for its revision) and material characterization (such as oxidative degradation and micromechanical properties). The joined database contains more than 500 entries, exhibiting gradual growth, and it is beginning to show interesting trends, which are discussed in our contribution, including (i) strong correlations between UHMWPE oxidative degradation, degree of crystallinity and microhardness; (ii) statistically significant differences between UHMWPE liners with different types of sterilization; (iii) realistic correlations between the extent of oxidative degradation and the observed reasons for total joint replacement failures. Our final objective and task for the future is to continuously expand the database, involving researchers from other European countries, in order to create a robust tool that will contribute to the better understanding of structure-properties-performance relationships in the field of arthroplasty implants.
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Affiliation(s)
- Miroslav Slouf
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, 16206 Prague, Czech Republic
- Correspondence: (M.S.); (F.M.); (P.B.)
| | - Veronika Gajdosova
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, 16206 Prague, Czech Republic
| | - Jiri Dybal
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, 16206 Prague, Czech Republic
| | - Roman Sticha
- 1st Orthopedics Clinic of the 1st Faculty of Medicine of Charles University and Motol University Hospital, 15006 Prague, Czech Republic
| | - Petr Fulin
- 1st Orthopedics Clinic of the 1st Faculty of Medicine of Charles University and Motol University Hospital, 15006 Prague, Czech Republic
| | - David Pokorny
- 1st Orthopedics Clinic of the 1st Faculty of Medicine of Charles University and Motol University Hospital, 15006 Prague, Czech Republic
| | - Jesús Mateo
- Department of Orthopaedic Surgery and Traumatology, Miguel Servet University Hospital, 50009 Zaragoza, Spain
- Department of Surgery, Medicine School, University of Zaragoza, 50009 Zaragoza, Spain
| | - Juan José Panisello
- Department of Orthopaedic Surgery and Traumatology, Miguel Servet University Hospital, 50009 Zaragoza, Spain
- Department of Surgery, Medicine School, University of Zaragoza, 50009 Zaragoza, Spain
| | - Vicente Canales
- Department of Orthopaedic Surgery and Traumatology, Royo Villanova Hospital, 50015 Zaragoza, Spain
| | - Francisco Medel
- Department of Mechanical Engineering-Institute of Engineering Research of Aragon, University of Zaragoza, 50018 Zaragoza, Spain
- Correspondence: (M.S.); (F.M.); (P.B.)
| | - Alessandro Bistolfi
- Department of Surgery, Orthopedics and Traumatology, Cardinal Massaia Hospital, 14100 Asti, Italy
| | - Pierangiola Bracco
- Chemistry Department and NIS Centre, University of Torino, 10125 Torino, Italy
- Correspondence: (M.S.); (F.M.); (P.B.)
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Slouf M, Steinhart M, Nemecek P, Gajdosova V, Hodan J. Correlations between Microscale Indentation Creep and Macroscale Tensile Creep of Polymers. Materials (Basel) 2023; 16:834. [PMID: 36676572 PMCID: PMC9866530 DOI: 10.3390/ma16020834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/06/2023] [Accepted: 01/13/2023] [Indexed: 06/17/2023]
Abstract
We compared the results of various microscale indentation creep (microcreep) measurements with macroscale tensile creep (macrocreep) measurements of three common polymers: high-density polyethylene (PE), polypropylene (PP), and polystyrene (PS). The main objective was to verify if the short-term microcreep experiments could predict long-term macrocreep behavior of the selected polymers, whose properties ranged from very soft and ductile (PE) to very hard and brittle (PS). The second objective was to compare several creep predictive schemes: the empirical power law model (PL) and several types of phenomenological elasto-visco-plastic models (EVP). In order to facilitate this task, we developed a universal program package named MCREEP, which fits PL and EVP models to both tensile and indentation creep data. All experimental results and theoretical predictions documented that: (i) regardless of the creep experiment type, both micro- and macrocreep resistance increased in the following order: PE < PP < PS, (ii) the short-term microcreep experiments could be used to predict qualitatively the long-term macrocreep behavior, and (iii) the simple empirical power law model yielded better predictions of long-term creep behavior than the more sophisticated elasto-visco-plastic models.
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Clemente I, D’Aria F, Giancola C, Bonechi C, Slouf M, Pavlova E, Rossi C, Ristori S. Structuring and de-structuring of nanovectors from algal lipids. Part 1: physico-chemical characterization. Colloids Surf B Biointerfaces 2022; 220:112939. [DOI: 10.1016/j.colsurfb.2022.112939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/13/2022] [Accepted: 10/13/2022] [Indexed: 11/27/2022]
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Kutac D, Bohonek M, Landova L, Staskova E, Blahutova M, Malikova I, Slouf M, Horacek JM, Stansbury LG, Hess JR, Seghatchian J. Cryopreservation of apheresis platelets treated with riboflavin and UV light. Transfus Apher Sci 2022; 62:103580. [PMID: 36167613 DOI: 10.1016/j.transci.2022.103580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/23/2022] [Accepted: 09/17/2022] [Indexed: 10/14/2022]
Abstract
BACKGROUND Pathogen reduction technology (PRT) is increasingly used in the preparation of platelets for therapeutic transfusion. As the Czech Republic considers PRT, we asked what effects PRT may have on the recovery and function of platelets after cryopreservation (CP), which we use in both military and civilian blood settings. STUDY DESIGN AND METHODS 16 Group O apheresis platelets units were treated with PRT (Mirasol, Terumo BCT, USA) before freezing; 15 similarly collected units were frozen without PRT as controls. All units were processed with 5-6% DMSO, frozen at - 80 °C, stored > 14 days, and reconstituted in thawed AB plasma. After reconstitution, all units were assessed for: platelet count, mean platelet volume (MPV), platelet recovery, thromboelastography, thrombin generation time, endogenous thrombin potential (ETP), glucose, lactate, pH, pO2, pCO2, HCO3, CD41, CD42b, CD62, Annexin V, CCL5, CD62P, and aggregates > 2 mm and selected units for Kunicki score. RESULTS PRT treated platelet units had lower platelet number (247 vs 278 ×109/U), reduced thromboelastographic MA (38 vs 62 mm) and demonstrated aggregates compared to untreated platelets. Plasma coagulation functions were largely unchanged. CONCLUSIONS Samples from PRT units showed reduced platelet number, reduced function greater than the reduced number would cause, and aggregates. While the platelet numbers are sufficient to meet the European standard, marked platelets activation with weak clot strength suggest reduced effectiveness.
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Affiliation(s)
- Dominik Kutac
- Department of Hematology and Blood Transfusion, Military University Hospital Prague, Czech Republic; Department of Military Internal Medicine and Military Hygiene, Faculty of Military Health Sciences, University of Defence in Brno, Hradec Kralove, Czech Republic.
| | - Milos Bohonek
- Department of Hematology and Blood Transfusion, Military University Hospital Prague, Czech Republic; Faculty of Biomedical Engineering, Czech Technical University in Prague, Czech Republic
| | - Ludmila Landova
- Department of Hematology and Blood Transfusion, Military University Hospital Prague, Czech Republic
| | - Eva Staskova
- Department of Hematology and Blood Transfusion, Military University Hospital Prague, Czech Republic
| | - Marie Blahutova
- Department of Hematology and Blood Transfusion, Military University Hospital Prague, Czech Republic
| | - Ivana Malikova
- Institute of Medical Biochemistry and Laboratory Diagnostics, Faculty of Medicine, Charles University of Prague and the General University Hospital in Prague, Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Czech Republic
| | - Jan M Horacek
- Department of Internal Medicine IV - Hematology, University Hospital Hradec Kralove, Czech Republic
| | - Lynn G Stansbury
- Harborview Injury Prevention Research Center, Harborview Medical Center, Seattle, WA, USA; Department of Anesthesia and Pain Medicine, University of Washington, Seattle, WA, USA
| | - John R Hess
- Harborview Injury Prevention Research Center, Harborview Medical Center, Seattle, WA, USA; Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA, USA
| | - Jerard Seghatchian
- International Consultancy in Blood Components Quality/Safety, Audit/Inspection and DDR Strategy, London, UK
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Kolouchova K, Cernochova Z, Groborz O, Herynek V, Koucky F, Jaksa R, Benes J, Slouf M, Hruby M. Multiresponsive Fluorinated Polymers as a Theragnostic Platform Using 19F MRI. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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13
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Ivan’kova E, Kasatkin I, Vaganov G, Elokhovskiy V, Bugrov A, Yudin V, Pavlova E, Slouf M. Morphological Transformation in Polymer Composite Materials Filled with Carbon Nanoparticles: Part 1.—SEM and XRD Investigations. Materials 2022; 15:ma15103531. [PMID: 35629560 PMCID: PMC9147559 DOI: 10.3390/ma15103531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/10/2022] [Accepted: 05/12/2022] [Indexed: 12/04/2022]
Abstract
HDPE-based nanocomposite fibers have been extruded from a melt and drawn up to draw ratio DR = 8. Two kinds of carbon nanodiscs (original ones and those exposed to additional annealing) have been used as fillers. Obtained nanocomposite fibers have been investigated with the help of different experimental methods: rheology, SEM and WAXS. It has been demonstrated that the annealed carbon nanodiscs possess a nucleation ability that finally leads to strong transformation of the material morphology.
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Affiliation(s)
- Elena Ivan’kova
- Institute of Biosystems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, Polytechnicheskaya ul. 29, 195251 St. Petersburg, Russia
- Institute of Macromolecular Compounds, Russian Academy of Sciences, V.O., Bol’shoy pr. 31, 199004 St. Petersburg, Russia; (G.V.); (V.E.); (A.B.); (V.Y.)
- Correspondence:
| | - Igor Kasatkin
- Research Centre for X-ray Diffraction Studies, Saint Petersburg State University, Universitetskaya nab. 7-9, 199034 St. Petersburg, Russia;
| | - Gleb Vaganov
- Institute of Macromolecular Compounds, Russian Academy of Sciences, V.O., Bol’shoy pr. 31, 199004 St. Petersburg, Russia; (G.V.); (V.E.); (A.B.); (V.Y.)
| | - Vladimir Elokhovskiy
- Institute of Macromolecular Compounds, Russian Academy of Sciences, V.O., Bol’shoy pr. 31, 199004 St. Petersburg, Russia; (G.V.); (V.E.); (A.B.); (V.Y.)
| | - Alexander Bugrov
- Institute of Macromolecular Compounds, Russian Academy of Sciences, V.O., Bol’shoy pr. 31, 199004 St. Petersburg, Russia; (G.V.); (V.E.); (A.B.); (V.Y.)
- Department of Physical Chemistry, Saint Petersburg Electrotechnical University (ETU “LETI”), ul. Professora Popova 5, 197022 St. Petersburg, Russia
| | - Vladimir Yudin
- Institute of Macromolecular Compounds, Russian Academy of Sciences, V.O., Bol’shoy pr. 31, 199004 St. Petersburg, Russia; (G.V.); (V.E.); (A.B.); (V.Y.)
| | - Ewa Pavlova
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 16206 Prague, Czech Republic; (E.P.); (M.S.)
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského nám. 2, 16206 Prague, Czech Republic; (E.P.); (M.S.)
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14
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Ujcic A, Fortelny I, Krejcikova S, Pavlova E, Hodan J, Slouf M. Effects of thermal treatment and nucleating agents on crystallinity, toughness, and stiffness of PLA/PCL blends. EXPRESS POLYM LETT 2022. [DOI: 10.3144/expresspolymlett.2022.18] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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15
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Slouf M, Skoupy R, Pavlova E, Krzyzanek V. High Resolution Powder Electron Diffraction in Scanning Electron Microscopy. Materials (Basel) 2021; 14:ma14247550. [PMID: 34947146 PMCID: PMC8708290 DOI: 10.3390/ma14247550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 11/16/2022]
Abstract
A modern scanning electron microscope equipped with a pixelated detector of transmitted electrons can record a four-dimensional (4D) dataset containing a two-dimensional (2D) array of 2D nanobeam electron diffraction patterns; this is known as a four-dimensional scanning transmission electron microscopy (4D-STEM). In this work, we introduce a new version of our method called 4D-STEM/PNBD (powder nanobeam diffraction), which yields high-resolution powder diffractograms, whose quality is fully comparable to standard TEM/SAED (selected-area electron diffraction) patterns. Our method converts a complex 4D-STEM dataset measured on a nanocrystalline material to a single 2D powder electron diffractogram, which is easy to process with standard software. The original version of 4D-STEM/PNBD method, which suffered from low resolution, was improved in three important areas: (i) an optimized data collection protocol enables the experimental determination of the point spread function (PSF) of the primary electron beam, (ii) an improved data processing combines an entropy-based filtering of the whole dataset with a PSF-deconvolution of the individual 2D diffractograms and (iii) completely re-written software automates all calculations and requires just a minimal user input. The new method was applied to Au, TbF3 and TiO2 nanocrystals and the resolution of the 4D-STEM/PNBD diffractograms was even slightly better than that of TEM/SAED.
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Affiliation(s)
- Miroslav Slouf
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovsky Sq. 2, 16206 Prague, Czech Republic;
- Correspondence: (M.S.); (V.K.)
| | - Radim Skoupy
- Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 61264 Brno, Czech Republic;
| | - Ewa Pavlova
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovsky Sq. 2, 16206 Prague, Czech Republic;
| | - Vladislav Krzyzanek
- Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 61264 Brno, Czech Republic;
- Correspondence: (M.S.); (V.K.)
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16
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Cao Y, Dhahad HA, El-Shorbagy MA, Alijani HQ, Zakeri M, Heydari A, Bahonar E, Slouf M, Khatami M, Naderifar M, Iravani S, Khatami S, Dehkordi FF. Green synthesis of bimetallic ZnO-CuO nanoparticles and their cytotoxicity properties. Sci Rep 2021; 11:23479. [PMID: 34873281 PMCID: PMC8648779 DOI: 10.1038/s41598-021-02937-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 11/24/2021] [Indexed: 01/14/2023] Open
Abstract
In this study, a simple and green strategy was reported to prepare bimetallic nanoparticles (NPs) by the combination of zinc oxide (ZnO) and copper oxide (CuO) using Sambucus nigra L. extract. The physicochemical properties of these NPs such as crystal structure, size, and morphology were studied by X-ray diffraction (XRD), field emission gun scanning electron microscopy (FEG-SEM), and transmission electron microscopy (TEM). The results suggested that these NPs contained polygonal ZnO NPs with hexagonal phase and spherical CuO NPs with monoclinic phase. The anticancer activity of the prepared bimetallic NPs was evaluated against lung and human melanoma cell lines based on MTT assay. As a result, the bimetallic ZnO/CuO NPs exhibited high toxicity on melanoma cancer cells while their toxicity on lung cancer cells was low.
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Affiliation(s)
- Yan Cao
- School of Mechatronic Engineering, Xi'an Technological University, Xi'an, 710021, China
| | - Hayder A Dhahad
- Mechanical Engineering Department, University of Technology, Baghdad, Iraq
| | - M A El-Shorbagy
- Department of Mathematics, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj, 11942, Saudi Arabia
- Department of Basic Engineering Science, Faculty of Engineering, Menoufia University, Shebin El-Kom, 32511, Egypt
| | - Hajar Q Alijani
- Department of Biotechnology, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Mana Zakeri
- Department of Biology, Islamic Azad University, Tehran Medical Branch, Tehran, Iran
| | - Abolfazl Heydari
- Polymer Institute of the Slovak Academy of Sciences, Dúbravská Cesta 9, 845 41, Bratislava, Slovakia
| | - Ehsan Bahonar
- Faculty of Chemical and Petroleum Engineering, Sahand University of Technology, Tabriz, Iran
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovskeho nam. 2, 162 06, Prague 6, Czech Republic
| | - Mehrdad Khatami
- Noncommunicable Diseases Research Center, Bam University of Medical Sciences, Bam, Iran.
| | - Mahin Naderifar
- Faculty of Nursing & Midwifery, Zabol University of Medical Sciences, Zabol, Iran
| | - Siavash Iravani
- Faculty of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Sanaz Khatami
- Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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17
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Pokhrel S, Sigdel A, Lach R, Slouf M, Sirc J, Katiyar V, Bhattarai DR, Adhikari R. Starch-based biodegradable film with poly(butylene adipate- co-terephthalate): preparation, morphology, thermal and biodegradation properties. Journal of Macromolecular Science, Part A 2021. [DOI: 10.1080/10601325.2021.1920838] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Shanta Pokhrel
- Department of Chemistry, Tri-Chandra Multiple Campus, Tribhuvan University, Kathmandu, Nepal
| | - Amrita Sigdel
- Department of Chemistry, Tri-Chandra Multiple Campus, Tribhuvan University, Kathmandu, Nepal
| | - Ralf Lach
- PolymerService GmbH Merseburg, Merseburg, Germany
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Jakub Sirc
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Vimal Katiyar
- Department of Chemical Engineering, Indian Institute of Technology (IIT), Guwahati, India
| | - Dhruba Raj Bhattarai
- National Outreach Research Centre, Nepal Agricultural Research Council (NARC), Lalitpur, Nepal
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18
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Kolouchova K, Groborz O, Cernochova Z, Skarkova A, Brabek J, Rosel D, Svec P, Starcuk Z, Slouf M, Hruby M. Thermo- and ROS-Responsive Self-Assembled Polymer Nanoparticle Tracers for 19F MRI Theranostics. Biomacromolecules 2021; 22:2325-2337. [PMID: 33881829 DOI: 10.1021/acs.biomac.0c01316] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Fluorine-19 magnetic resonance imaging (19F MRI) enables detailed in vivo tracking of fluorine-containing tracers and is therefore becoming a particularly useful tool in noninvasive medical imaging. In previous studies, we introduced biocompatible polymers based on the hydrophilic monomer N-(2-hydroxypropyl)methacrylamide (HPMA) and the thermoresponsive monomer N-(2,2-difluoroethyl)acrylamide (DFEA). These polymers have abundant magnetically equivalent fluorine atoms and advantageous properties as 19F MRI tracers. Furthermore, in this pilot study, we modified these polymers by introducing a redox-responsive monomer. As a result, our polymers changed their physicochemical properties once exposed to an oxidative environment. Reactive oxygen species (ROS)-responsive polymers were prepared by incorporating small amounts (0.9-4.5 mol %) of the N-[2-(ferrocenylcarboxamido)ethyl]acrylamide (FcCEA) monomer, which is hydrophobic and diamagnetic in the reduced electroneutral (Fe(II), ferrocene) state but hydrophilic and paramagnetic in the oxidized (Fe(III), ferrocenium cation) state. This property can be useful for theranostic purposes (therapy and diagnostic purposes), especially, in terms of ROS-responsive drug-delivery systems. In the reduced state, these nanoparticles remain self-assembled with the encapsulated drug but release the drug upon oxidation in ROS-rich tumors or inflamed tissues.
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Affiliation(s)
- Kristyna Kolouchova
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského sq. 2, 16206 Prague 6, Czech Republic.,Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, 12800 Prague 2, Czech Republic
| | - Ondrej Groborz
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského sq. 2, 16206 Prague 6, Czech Republic.,Department of Organic Chemistry, Faculty of Science, Charles University, Hlavova 8, 12800 Prague 2, Czech Republic.,Institute of Biophysics and Informatics, Charles University, First Faculty of Medicine, Salmovská 1, 12000 Prague 2, Czech Republic
| | - Zulfiya Cernochova
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského sq. 2, 16206 Prague 6, Czech Republic
| | - Aneta Skarkova
- Department of Cell Biology, Charles University, Viničná 7, 12843 Prague, Czech Republic.,Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (BIOCEV), Průmyslová 595, 25242 Vestec u Prahy, Czech Republic
| | - Jan Brabek
- Department of Cell Biology, Charles University, Viničná 7, 12843 Prague, Czech Republic.,Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (BIOCEV), Průmyslová 595, 25242 Vestec u Prahy, Czech Republic
| | - Daniel Rosel
- Department of Cell Biology, Charles University, Viničná 7, 12843 Prague, Czech Republic.,Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (BIOCEV), Průmyslová 595, 25242 Vestec u Prahy, Czech Republic
| | - Pavel Svec
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského sq. 2, 16206 Prague 6, Czech Republic.,Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, 12800 Prague 2, Czech Republic
| | - Zenon Starcuk
- Institute of Scientific Instruments, Czech Academy of Sciences, Královopolská 147, 61264 Brno, Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského sq. 2, 16206 Prague 6, Czech Republic
| | - Martin Hruby
- Institute of Macromolecular Chemistry, Czech Academy of Sciences, Heyrovského sq. 2, 16206 Prague 6, Czech Republic
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19
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Slouf M, Krajenta J, Gajdosova V, Pawlak A. Macromechanical and micromechanical properties of polymers with reduced density of entanglements. POLYM ENG SCI 2021. [DOI: 10.1002/pen.25699] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Miroslav Slouf
- Institute of Macromolecular Chemistry, Czech Academy of Sciences Prague 6 Czech Republic
| | - Justyna Krajenta
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences Lodz Poland
| | - Veronika Gajdosova
- Institute of Macromolecular Chemistry, Czech Academy of Sciences Prague 6 Czech Republic
| | - Andrzej Pawlak
- Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences Lodz Poland
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20
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Slouf M, Skoupy R, Pavlova E, Krzyzanek V. Powder Nano-Beam Diffraction in Scanning Electron Microscope: Fast and Simple Method for Analysis of Nanoparticle Crystal Structure. Nanomaterials (Basel) 2021; 11:962. [PMID: 33918700 PMCID: PMC8070269 DOI: 10.3390/nano11040962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2021] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 02/05/2023]
Abstract
We introduce a novel scanning electron microscopy (SEM) method which yields powder electron diffraction patterns. The only requirement is that the SEM microscope must be equipped with a pixelated detector of transmitted electrons. The pixelated detectors for SEM have been commercialized recently. They can be used routinely to collect a high number of electron diffraction patterns from individual nanocrystals and/or locations (this is called four-dimensional scanning transmission electron microscopy (4D-STEM), as we obtain two-dimensional (2D) information for each pixel of the 2D scanning array). Nevertheless, the individual 4D-STEM diffractograms are difficult to analyze due to the random orientation of nanocrystalline material. In our method, all individual diffractograms (showing randomly oriented diffraction spots from a few nanocrystals) are combined into one composite diffraction pattern (showing diffraction rings typical of polycrystalline/powder materials). The final powder diffraction pattern can be analyzed by means of standard programs for TEM/SAED (Selected-Area Electron Diffraction). We called our new method 4D-STEM/PNBD (Powder NanoBeam Diffraction) and applied it to three different systems: Au nano-islands (well diffracting nanocrystals with size ~20 nm), small TbF3 nanocrystals (size < 5 nm), and large NaYF4 nanocrystals (size > 100 nm). In all three cases, the STEM/PNBD results were comparable to those obtained from TEM/SAED. Therefore, the 4D-STEM/PNBD method enables fast and simple analysis of nanocrystalline materials, which opens quite new possibilities in the field of SEM.
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Affiliation(s)
- Miroslav Slouf
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic;
| | - Radim Skoupy
- Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 612 64 Brno, Czech Republic;
| | - Ewa Pavlova
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic;
| | - Vladislav Krzyzanek
- Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 612 64 Brno, Czech Republic;
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21
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Galeziewska M, Lipinska M, Mrlik M, Ilcikova M, Gajdosova V, Slouf M, Achbergerová E, Musilová L, Mosnacek J, Pietrasik J. Polyacrylamide brushes with varied morphologies as a tool for control of the intermolecular interactions within EPDM/MVQ blends. POLYMER 2021. [DOI: 10.1016/j.polymer.2021.123387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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22
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Ilcikova M, Galeziewska M, Mrlik M, Osicka J, Masar M, Slouf M, Maslowski M, Kracalik M, Pietrasik R, Mosnacek J, Pietrasik J. The effect of short polystyrene brushes grafted from graphene oxide on the behavior of miscible PMMA/SAN blends. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.123088] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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23
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Bucknall C, Altstädt V, Auhl D, Buckley P, Dijkstra D, Galeski A, Gögelein C, Handge UA, He J, Liu CY, Michler G, Piorkowska E, Slouf M, Vittorias I, Wu JJ. Structure, processing and performance of ultra-high molecular weight polyethylene (IUPAC Technical Report). Part 3: deformation, wear and fracture. PURE APPL CHEM 2020. [DOI: 10.1515/pac-2019-0406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Three grades of polyethylene, with weight-average relative molar masses,
M
‾
W
${\bar{M}}_{\text{W}}$
, of approximately 0.6 × 106, 5 × 106, and 9 × 106, were supplied as compression mouldings by a leading manufacturer of ultra-high molecular weight polyethylene (UHMWPE). They were code-named PE06, PE5, and PE9, respectively. Specimens cut from these mouldings were subjected to a wide range of mechanical tests at 23 °C. In tensile tests, deformation was initially elastic and dominated by crystallinity, which was highest in PE06. Beyond the yield point, entanglement density became the dominant factor, and at 40 % strain, the rising stress–strain curves for PE5 and PE9 crossed the falling PE06 curve. Fracture occurred at strains above 150 %. Differences in stress–strain behaviour between PE5 and PE9 were relatively small. A similar pattern of behaviour was observed in wear tests; wear resistance showed a marked increase when
M
‾
W
${\bar{M}}_{\text{W}}$
was raised from 0.6 × 106 to 5 × 106, but there was no further increase when it was raised to 9 × 106. It is concluded that the unexpected similarity in behaviour between PE5 and PE9 was due to incomplete consolidation during moulding, which led to deficiencies in entanglement at grain boundaries; they were clearly visible on the surfaces of both tensile and wear specimens. Fatigue crack growth in 10 mm thick specimens was so severely affected by inadequate consolidation that it forms the basis for a separate report – Part 4 in this series.
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Affiliation(s)
- Clive Bucknall
- School of Aerospace, Transport & Manufacturing B 61 , Cranfield University , Bedford, MK43 0AL , UK
| | - Volker Altstädt
- Department of Polymer Engineering , Universität Bayreuth , Bayreuth , Germany
| | - Dietmar Auhl
- Fakultät III – Werkstoffwissenschaft Technische , Universität Berlin , Berlin, D-10623 , Germany
| | - Paul Buckley
- Department of Engineering Science , University of Oxford , Oxford, OX1 3PJ , UK
| | | | - Andrzej Galeski
- Centre for Molecular and Macromolecular Sciences , Polish Academy of Sciences , Lodz , Poland
| | | | - Ulrich A. Handge
- Institute of Polymer Research , Helmholtz-Zentrum Geesthacht , Max-Planck-Strasse 1 , 21502, Geesthacht , Germany
| | - Jiasong He
- Chinese Academy of Sciences, Laboratory of Polymer Science and Materials , Beijing , China, 100190
| | - Chen-Yang Liu
- Chinese Academy of Sciences, Laboratory of Polymer Science and Materials , Beijing , China, 100190
| | - Goerg Michler
- Martin-Luther-Universität , Halle-Wittenberg , Germany
| | - Ewa Piorkowska
- Centre for Molecular and Macromolecular Sciences , Polish Academy of Sciences , Lodz , Poland
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry CAS , Prague , Czech Republic
| | - Iakovos Vittorias
- Omya International AG , Baslerstrasse 42 , CH-4665, Oftringen , Switzerland
| | - Jun Jie Wu
- Department of Engineering , Durham University , Stockton Road , Durham, DH1 3LE , UK
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24
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Bucknall C, Altstädt V, Auhl D, Buckley P, Dijkstra D, Galeski A, Gögelein C, Handge UA, He J, Liu CY, Michler G, Piorkowska E, Slouf M, Vittorias I, Wu JJ. Structure, processing and performance of ultra-high molecular weight polyethylene (IUPAC Technical Report). Part 2: crystallinity and supra molecular structure. PURE APPL CHEM 2020. [DOI: 10.1515/pac-2019-0403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Test methods including OM, SEM, TEM, DSC, SAXS, WAXS, and IR were used to characterise supra-molecular structure in three batches of polyethylene (PE), which had weight-average relative molar masses
M
¯
w
${\overline{M}}_{\text{w}}$
of approximately 0.6 × 106, 5 × 106, and 9 × 106. They were applied to compression mouldings made by the polymer manufacturer. Electron microscopy showed that powders formed in the polymerization reactor consisted of irregularly shaped grains between 50 and 250 μm in diameter. Higher magnification revealed that each grain was an aggregate, composed of particles between 0.4 and 0.8 μm in diameter, which were connected by long, thin fibrils. In compression mouldings, lamellar thicknesses ranged from 7 to 23 nm. Crystallinity varied between 70 and 75 % in reactor powder, but was lower in compression mouldings. Melting peak temperatures ranged from 138 to 145 °C, depending on processing history. DMTA showed that the glass transition temperature θ
g was −120 °C for all three grades of polyethylene. IR spectroscopy found negligibly small levels of oxidation and thermal degradation in mouldings. Optical microscopy revealed the presence of visible fusion defects at grain boundaries. It is concluded that relatively weak defects can be characterized using optical microscopy, but there is a need for improved methods that can detect less obvious fusion defects.
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Affiliation(s)
- Clive Bucknall
- School of Aerospace, Transport & Manufacturing B 61 , Cranfield University , Bedford, MK43 0AL , UK
| | - Volker Altstädt
- Department of Polymer Engineering , Universität Bayreuth , Bayreuth , Germany
| | - Dietmar Auhl
- Fakultät III – Werkstoffwissenschaft Technische Universität Berlin , D-10623, Berlin , Germany
| | - Paul Buckley
- Department of Engineering Science , University of Oxford , OX1 3PJ, Oxford , UK
| | | | - Andrzej Galeski
- Centre for Molecular and Macromolecular Sciences , Polish Academy of Sciences , Lodz , Poland
| | | | - Ulrich A. Handge
- Institute of Polymer Research , Helmholtz-Zentrum Geesthacht , Max-Planck-Strasse 1 , 21502, Geesthacht , Germany
| | - Jiasong He
- Chinese Academy of Sciences , Laboratory of Polymer Science and Materials , Beijing, 100190 , China
| | - Chen-Yang Liu
- Chinese Academy of Sciences , Laboratory of Polymer Science and Materials , Beijing, 100190 , China
| | - Goerg Michler
- Martin-Luther-Universität Halle-Wittenberg , Germany
| | - Ewa Piorkowska
- Centre for Molecular and Macromolecular Sciences , Polish Academy of Sciences , Lodz , Poland
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry CAS , Prague , Czech Republic
| | - Iakovos Vittorias
- Omya International AG , Baslerstrasse 42 , CH-4665, Oftringen , Switzerland
| | - Jun Jie Wu
- Department of Engineering , Durham University , Stockton Road , Durham, DH1 3LE , UK
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25
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Bucknall C, Altstädt V, Auhl D, Buckley P, Dijkstra D, Galeski A, Gögelein C, Handge UA, He J, Liu CY, Michler G, Piorkowska E, Slouf M, Vittorias I, Wu JJ. Structure, processing and performance of ultra-high molecular weight polyethylene (IUPAC Technical Report). Part 4: sporadic fatigue crack propagation. PURE APPL CHEM 2020. [DOI: 10.1515/pac-2019-0408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Fatigue tests were carried out on compression mouldings supplied by a leading polymer manufacturer. They were made from three batches of ultra-high molecular weight polyethylene (UHMWPE) with weight-average relative molar masses,
M
¯
W
${\overline{M}}_{\mathrm{W}}$
, of about 0.6 × 106, 5 × 106 and 9 × 106. In 10 mm thick compact tension specimens, crack propagation was so erratic that it was impossible to follow standard procedure, where crack-tip stress intensity amplitude, ΔK, is raised incrementally, and the resulting crack propagation rate, da/dN, increases, following the Paris equation, where a is crack length and N is number of cycles. Instead, most of the tests were conducted at fixed high values of ΔK. Typically, da/dN then started at a high level, but decreased irregularly during the test. Micrographs of fracture surfaces showed that crack propagation was sporadic in these specimens. In one test, at ΔK = 2.3 MPa m0.5, there were crack-arrest marks at intervals Δa of about 2 μm, while the number of cycles between individual growth steps increased from 1 to more than 1000 and the fracture surface showed increasing evidence of plastic deformation. It is concluded that sporadic crack propagation was caused by energy-dissipating crazing, which was initiated close to the crack tip under plane strain conditions in mouldings that were not fully consolidated. By contrast, fatigue crack propagation in 4 mm thick specimens followed the Paris equation approximately. The results from all four reports on this project are reviewed, and the possibility of using fatigue testing as a quality assurance procedure for melt-processed UHMWPE is discussed.
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Affiliation(s)
- Clive Bucknall
- B 61 School of Aerospace, Transport & Manufacturing , Cranfield University , Bedford, MK43 0AL , UK
| | - Volker Altstädt
- Department of Polymer Engineering , Universität Bayreuth , Bayreuth , Germany
| | - Dietmar Auhl
- Fakultät III – Werkstoffwissenschaft Technische , Universität Berlin , D-10623, Berlin , Germany
| | - Paul Buckley
- Department of Engineering Science , University of Oxford , Oxford, OX1 3PJ , UK
| | | | - Andrzej Galeski
- Centre for Molecular and Macromolecular Sciences , Polish Academy of Sciences , Lodz , Poland
| | | | - Ulrich A. Handge
- Institute of Polymer Research , Helmholtz-Zentrum Geesthacht , Max-Planck-Strasse 1 , Geesthacht, 21502 , Germany
| | - Jiasong He
- Chinese Academy of Sciences , Laboratory of Polymer Science and Materials , Beijing , China
| | - Chen-Yang Liu
- Chinese Academy of Sciences , Laboratory of Polymer Science and Materials , Beijing , China
| | - Goerg Michler
- Martin-Luther-Universität Halle-Wittenberg , Halle-Wittenberg , Germany
| | - Ewa Piorkowska
- Centre for Molecular and Macromolecular Sciences , Polish Academy of Sciences , Lodz , Poland
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry CAS , Prague , Czech Republic
| | - Iakovos Vittorias
- Omya International AG , Baslerstrasse 42 , CH-4665, Oftringen , Switzerland
| | - Jun Jie Wu
- Department of Engineering , Durham University , Stockton Road , Durham, DH1 3LE , UK
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Bucknall C, Altstädt V, Auhl D, Buckley P, Dijkstra D, Galeski A, Gögelein C, Handge UA, He J, Liu CY, Michler G, Piorkowska E, Slouf M, Vittorias I, Wu JJ. Structure, processing and performance of ultra-high molecular weight polyethylene (IUPAC Technical Report). Part 1: characterizing molecular weight. PURE APPL CHEM 2020. [DOI: 10.1515/pac-2019-0405] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
The aim of this project was to study the efficacy of current methods of quality control and quality assurance for ultra-high molecular weight polyethylene (UHMWPE) products, and find improvements where possible. Intrinsic viscosity (IV) tests were performed on three grades of polyethylene with weight average relative molar masses
M
̅
$̅{M}$
w of about 6 × 105, 5.0 × 106 and 9.0 × 106. Results from three laboratories showed substantial scatter, probably because different methods were used to make and test solutions. Tensile tests were carried out to 600 % extension at 150 °C under both constant applied load and constant Hencky strain rate, on compression mouldings made by a leading manufacturer of ultra-high molecular weight polyethylene. They gave low values of
M
̅
$̅{M}$
w, suggesting incomplete entanglement at ‘grain boundaries’ between powder particles. Results from conventional melt-rheology tests are presented, and their relevance to quality control and assurance is discussed. Attempts to calculate molecular weights from these data met with limited success because of extended relaxation times. Suggestions are made for improving international standards for IV testing of UHMWPE, by investigating the various factors that can cause significant errors, and by introducing methods for checking the homogeneity (and hence validity) of the solutions tested. Part 2 addresses characterization of crystallinity and structure. Part 3 covers mechanical properties, and Part 4 focuses on the sporadic crack propagation behaviour exhibited by all three grades of UHMWPE in fatigue tests on 10 mm thick compact tension specimens.
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Affiliation(s)
- Clive Bucknall
- B 61 School of Aerospace, Transport & Manufacturing , Cranfield University , Bedford , MK43 0AL , UK
| | - Volker Altstädt
- Department of Polymer Engineering , Universität Bayreuth , Bayreuth , Germany
| | - Dietmar Auhl
- Fakultät III - Werkstoffwissenschaft Technische Universität Berlin , Berlin , D-10623 , Germany
| | - Paul Buckley
- Department of Engineering Science , University of Oxford , Oxford , OX1 3PJ , UK
| | | | - Andrzej Galeski
- Centre for Molecular and Macromolecular Sciences , Polish Academy of Sciences , Lodz , Poland
| | | | - Ulrich A. Handge
- Institute of Polymer Research , Helmholtz-Zentrum Geesthacht , Max-Planck-Strasse 1 , Geesthacht , 21502 , Germany
| | - Jiasong He
- Chinese Academy of Sciences , Laboratory of Polymer Science and Materials , Beijing , 100190 , China
| | - Chen-Yang Liu
- Chinese Academy of Sciences , Laboratory of Polymer Science and Materials , Beijing , 100190 , China
| | - Goerg Michler
- Martin-Luther-Universität Halle-Wittenberg , Halle , Germany
| | - Ewa Piorkowska
- Centre for Molecular and Macromolecular Sciences , Polish Academy of Sciences , Lodz , Poland
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry CAS , Prague , Czech Republic
| | - Iakovos Vittorias
- Omya International AG , Baslerstrasse 42 , Oftringen , CH-4665 , Switzerland
| | - Jun Jie Wu
- Department of Engineering , Durham University , Stockton Road , Durham , DH1 3LE , UK
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Rohiwal SS, Dvorakova N, Klima J, Vaskovicova M, Senigl F, Slouf M, Pavlova E, Stepanek P, Babuka D, Benes H, Ellederova Z, Stieger K. Polyethylenimine based magnetic nanoparticles mediated non-viral CRISPR/Cas9 system for genome editing. Sci Rep 2020; 10:4619. [PMID: 32165679 PMCID: PMC7067791 DOI: 10.1038/s41598-020-61465-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 02/17/2020] [Indexed: 01/09/2023] Open
Abstract
Clustered regularly interspaced short palindromic repeats-associated protein (CRISPR/Cas9) system has become a revolutionary tool for gene editing. Since viral delivery systems have significant side effects, and naked DNA delivery is not an option, the nontoxic, non-viral delivery of CRISPR/Cas9 components would significantly improve future therapeutic delivery. In this study, we aim at characterizing nanoparticles to deliver plasmid DNA encoding for the CRISPR-Cas system in eukaryotic cells in vitro. CRISPR/Cas9 complexed polyethylenimine (PEI) magnetic nanoparticles (MNPs) were generated. We used a stable HEK293 cell line expressing the traffic light reporter (TLR-3) system to evaluate efficient homology- directed repair (HDR) and non-homologous end joining (NHEJ) events following transfection with NPs. MNPs have been synthesized by co-precipitation with the average particle size around 20 nm in diameter. The dynamic light scattering and zeta potential measurements showed that NPs exhibited narrow size distribution and sufficient colloidal stability. Genome editing events were as efficient as compared to standard lipofectamine transfection. Our approach tested non-viral delivery of CRISPR/Cas9 and DNA template to perform HDR and NHEJ in the same assay. We demonstrated that PEI-MNPs is a promising delivery system for plasmids encoding CRISPR/Cas9 and template DNA and thus can improve safety and utility of gene editing.
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Affiliation(s)
- S S Rohiwal
- The PIGMOD center, Institute of Animal Physiology and Genetics, v. v. i., The Czech Academy of Sciences, Libechov, Czech Republic
| | - N Dvorakova
- The PIGMOD center, Institute of Animal Physiology and Genetics, v. v. i., The Czech Academy of Sciences, Libechov, Czech Republic
| | - J Klima
- The PIGMOD center, Institute of Animal Physiology and Genetics, v. v. i., The Czech Academy of Sciences, Libechov, Czech Republic
| | - M Vaskovicova
- The PIGMOD center, Institute of Animal Physiology and Genetics, v. v. i., The Czech Academy of Sciences, Libechov, Czech Republic
| | - F Senigl
- Institute of Molecular Genetics, The Czech Academy of Sciences, Praha 4, Czech Republic
| | - M Slouf
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
| | - E Pavlova
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
| | - P Stepanek
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
| | - D Babuka
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
| | - H Benes
- Institute of Macromolecular Chemistry CAS, Heyrovského nám. 2, 162 06, Prague 6, Czech Republic
| | - Z Ellederova
- The PIGMOD center, Institute of Animal Physiology and Genetics, v. v. i., The Czech Academy of Sciences, Libechov, Czech Republic.
| | - K Stieger
- Department of Ophthalmology, Justus-Liebig-University, 35392, Giessen, Germany.
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Affiliation(s)
- Alena Kalendova
- Polymer Engineering Department, Faculty of TechnologyTomas Bata University in Zlin, Vavreckova 275 760 01 Zlin Czech Republic
| | - Jiri Smotek
- Polymer Engineering Department, Faculty of TechnologyTomas Bata University in Zlin, Vavreckova 275 760 01 Zlin Czech Republic
| | - Petr Stloukal
- Environmental Protection Engineering Department, Faculty of TechnologyTomas Bata University in Zlin, Vavreckova 275 76001 Zlin Czech Republic
| | - Milan Kracalik
- Institute of Polymer ScienceJohannes Kepler University Linz, Altenberger Str. 69, KG 604 4040 Linz Austria
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry AS CR, Heyrovskeho nam. 2 162 06 Prague 6 Czech Republic
| | - Stephan Laske
- Polymer ProcessingZentrum für Kunststofftechnik Leoben, Montanuniversität Leoben, Otto‐Glöckel‐Straße 2/III 8700 Leoben Austria
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29
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Skoupy R, Nebesarova J, Slouf M, Krzyzanek V. Quantitative STEM imaging of electron beam induced mass loss of epoxy resin sections. Ultramicroscopy 2019; 202:44-50. [PMID: 30953993 DOI: 10.1016/j.ultramic.2019.03.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/26/2019] [Accepted: 03/29/2019] [Indexed: 10/27/2022]
Abstract
In sample preparation of biological samples for electron microscopy, many types of embedding media are widely used. Unfortunately, none of them is perfectly resistant to beam induced damage. The article is focused on mass loss measuring of pure epoxy resin EMbed 812 that replaced Epon - the most widely used embedding resin for biological electron microscopy, in a form of ultrathin sections with thicknesses ranging from 30 to 100 nm. The STEM imaging was performed in a quantitative way which allowed us to estimate the mass loss directly up to the total dose of 3000 e-/nm2. For data acquisition we used SEM equipped with a commercial STEM detector working at a relatively low acceleration voltage of 30 kV. In this study we estimated the influence of various factors which can affect the endurance of the epoxy resin EMbed 812 ultrathin sections under an electron beam, such as the sample aging, differences between storing the samples in forms of ultrathin sections and whole blocks, ultrathin sections thicknesses, temperature of the sample, probe current, and one or two-sided carbon coating of ultrathin sections. The aim of this work is to investigate beam induced mass loss at electron energies of SEM and find out how to reduce the mass loss.
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Affiliation(s)
- Radim Skoupy
- Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 612 64 Brno, Czech Republic
| | - Jana Nebesarova
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branisovska 31, 370 05 Ceske Budejovice, Czech Republic; Faculty of Science, Charles University in Prague, Vinicna 7, 128 44 Prague 2, Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic
| | - Vladislav Krzyzanek
- Institute of Scientific Instruments of the Czech Academy of Sciences, Kralovopolska 147, 612 64 Brno, Czech Republic.
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30
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Bulatović VO, Grgić DK, Slouf M, Ostafinska A, Dybal J, Jozinović A. Biodegradability of blends based on aliphatic polyester and thermoplastic starch. Chem Pap 2018. [DOI: 10.1007/s11696-018-0663-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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31
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Kolouchova K, Sedlacek O, Jirak D, Babuka D, Blahut J, Kotek J, Vit M, Trousil J, Konefał R, Janouskova O, Podhorska B, Slouf M, Hruby M. Self-Assembled Thermoresponsive Polymeric Nanogels for 19F MR Imaging. Biomacromolecules 2018; 19:3515-3524. [PMID: 30011367 DOI: 10.1021/acs.biomac.8b00812] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Magnetic resonance imaging using fluorinated contrast agents (19F MRI) enables to achive highcontrast in images due to the negligible fluorine background in living tissues. In this pilot study, we developed new biocompatible, temperature-responsive, and easily synthesized polymeric nanogels containing a sufficient concentration of magnetically equivalent fluorine atoms for 19F MRI purposes. The structure of the nanogels is based on amphiphilic copolymers containing two blocks, a hydrophilic poly[ N-(2-hydroxypropyl)methacrylamide] (PHPMA) or poly(2-methyl-2-oxazoline) (PMeOx) block, and a thermoresponsive poly[ N(2,2difluoroethyl)acrylamide] (PDFEA) block. The thermoresponsive properties of the PDFEA block allow us to control the process of nanogel self-assembly upon its heating in an aqueous solution. Particle size depends on the copolymer composition, and the most promising copolymers with longer thermoresponsive blocks form nanogels of suitable size for angiogenesis imaging or the labeling of cells (approximately 120 nm). The in vitro 19F MRI experiments reveal good sensitivity of the copolymer contrast agents, while the nanogels were proven to be noncytotoxic for several cell lines.
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Affiliation(s)
- Kristyna Kolouchova
- Institute of Macromolecular Chemistry AS CR , v.v.i., Heyrovského sq. 2 , Prague 6 162 06 , Czech Republic
| | - Ondrej Sedlacek
- Institute of Macromolecular Chemistry AS CR , v.v.i., Heyrovského sq. 2 , Prague 6 162 06 , Czech Republic.,Department of Organic and Macromolecular Chemistry , Ghent University , Krijgslaan 281-S4 , 9000 Ghent , Belgium
| | - Daniel Jirak
- Institute for Clinical and Experimental Medicine , Vídeňská 9 , Prague 4 140 21 , Czech Republic.,Institute of Biophysics and Informatics, First Medicine Faculty , Charles University , Salmovská 1 , Prague 120 00 , Czech Republic
| | - David Babuka
- Institute of Macromolecular Chemistry AS CR , v.v.i., Heyrovského sq. 2 , Prague 6 162 06 , Czech Republic
| | - Jan Blahut
- Department of Inorganic Chemistry, Faculty of Science , Charles University , Hlavova 8 , Prague 2 128 00 , Czech Republic
| | - Jan Kotek
- Department of Inorganic Chemistry, Faculty of Science , Charles University , Hlavova 8 , Prague 2 128 00 , Czech Republic
| | - Martin Vit
- Institute for Clinical and Experimental Medicine , Vídeňská 9 , Prague 4 140 21 , Czech Republic.,TU Liberec, Faculty of mechatronics, informatics and interdisciplinary studies , Studentská 1402/2 , Liberec 1 461 17 , Czech Republic
| | - Jiri Trousil
- Institute of Macromolecular Chemistry AS CR , v.v.i., Heyrovského sq. 2 , Prague 6 162 06 , Czech Republic.,Department of Analytical Chemistry, Faculty of Science , Charles University , Hlavova 8 , Prague 2 128 43 , Czech Republic
| | - Rafał Konefał
- Institute of Macromolecular Chemistry AS CR , v.v.i., Heyrovského sq. 2 , Prague 6 162 06 , Czech Republic
| | - Olga Janouskova
- Institute of Macromolecular Chemistry AS CR , v.v.i., Heyrovského sq. 2 , Prague 6 162 06 , Czech Republic
| | - Bohumila Podhorska
- Institute of Macromolecular Chemistry AS CR , v.v.i., Heyrovského sq. 2 , Prague 6 162 06 , Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry AS CR , v.v.i., Heyrovského sq. 2 , Prague 6 162 06 , Czech Republic
| | - Martin Hruby
- Institute of Macromolecular Chemistry AS CR , v.v.i., Heyrovského sq. 2 , Prague 6 162 06 , Czech Republic
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32
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Vetrik M, Parizek M, Hadraba D, Kukackova O, Brus J, Hlidkova H, Komankova L, Hodan J, Sedlacek O, Slouf M, Bacakova L, Hruby M. Porous Heat-Treated Polyacrylonitrile Scaffolds for Bone Tissue Engineering. ACS Appl Mater Interfaces 2018; 10:8496-8506. [PMID: 29437373 DOI: 10.1021/acsami.7b18839] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Heat-treated polyacrylonitrile (HT-PAN), also referred to as black orlon (BO), is a promising carbon-based material used for applications in tissue engineering and regenerative medicine. To the best of our knowledge, no such complex bone morphology-mimicking three-dimensional (3D) BO structure has been reported to date. We report that BO can be easily made into 3D cryogel scaffolds with porous structures, using succinonitrile as a porogen. The cryogels possess a porous morphology, similar to bone tissue. The prepared scaffolds showed strong osteoconductive activity, providing excellent support for the adhesion, proliferation, and mitochondrial activity of human bone-derived cells. This effect was more apparent in scaffolds prepared from a matrix with a higher content of PAN (i.e., 10% rather than 5%). The scaffolds with 10% of PAN also showed enhanced mechanical properties, as revealed by higher compressive modulus and higher compressive strength. Therefore, these scaffolds have a robust potential for use in bone tissue engineering.
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Affiliation(s)
- Miroslav Vetrik
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences , Heyrovsky Sq. 2 , 162 06 Prague 6 , Czech Republic
| | - Martin Parizek
- Institute of Physiology of the Czech Academy of Sciences , Videnska 1083 , 14220 Prague 4 , Czech Republic
| | - Daniel Hadraba
- Institute of Physiology of the Czech Academy of Sciences , Videnska 1083 , 14220 Prague 4 , Czech Republic
| | - Olivia Kukackova
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences , Heyrovsky Sq. 2 , 162 06 Prague 6 , Czech Republic
| | - Jiri Brus
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences , Heyrovsky Sq. 2 , 162 06 Prague 6 , Czech Republic
| | - Helena Hlidkova
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences , Heyrovsky Sq. 2 , 162 06 Prague 6 , Czech Republic
| | - Lucie Komankova
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences , Heyrovsky Sq. 2 , 162 06 Prague 6 , Czech Republic
| | - Jiri Hodan
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences , Heyrovsky Sq. 2 , 162 06 Prague 6 , Czech Republic
| | - Ondrej Sedlacek
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences , Heyrovsky Sq. 2 , 162 06 Prague 6 , Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences , Heyrovsky Sq. 2 , 162 06 Prague 6 , Czech Republic
| | - Lucie Bacakova
- Institute of Physiology of the Czech Academy of Sciences , Videnska 1083 , 14220 Prague 4 , Czech Republic
| | - Martin Hruby
- Institute of Macromolecular Chemistry of the Czech Academy of Sciences , Heyrovsky Sq. 2 , 162 06 Prague 6 , Czech Republic
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33
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Ostafinska A, Vackova T, Slouf M. Strong synergistic improvement of mechanical properties in HDPE/COC blends with fibrillar morphology. POLYM ENG SCI 2017. [DOI: 10.1002/pen.24805] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Aleksandra Ostafinska
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2; Prague 6 162 06 Czech Republic
| | - Tatana Vackova
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2; Prague 6 162 06 Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2; Prague 6 162 06 Czech Republic
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34
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Sedlacek O, Kucka J, Monnery BD, Slouf M, Vetrik M, Hoogenboom R, Hruby M. The effect of ionizing radiation on biocompatible polymers: From sterilization to radiolysis and hydrogel formation. Polym Degrad Stab 2017. [DOI: 10.1016/j.polymdegradstab.2017.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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35
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Brezaniova I, Hruby M, Kralova J, Kral V, Cernochova Z, Cernoch P, Slouf M, Kredatusova J, Stepanek P. Temoporfin-loaded 1-tetradecanol-based thermoresponsive solid lipid nanoparticles for photodynamic therapy. J Control Release 2016; 241:34-44. [DOI: 10.1016/j.jconrel.2016.09.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Revised: 09/08/2016] [Accepted: 09/09/2016] [Indexed: 12/15/2022]
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36
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Rabyk M, Hruby M, Vetrik M, Kucka J, Proks V, Parizek M, Konefal R, Krist P, Chvatil D, Bacakova L, Slouf M, Stepanek P. Modified glycogen as construction material for functional biomimetic microfibers. Carbohydr Polym 2016; 152:271-279. [DOI: 10.1016/j.carbpol.2016.06.107] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 06/21/2016] [Accepted: 06/28/2016] [Indexed: 12/16/2022]
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37
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Vacková T, Kratochvíl J, Ostafinska A, Krejčíková S, Nevoralová M, Slouf M. Impact of particle morphology on structure, crystallization kinetics, and properties of PCL composites with TiO2-based particles. Polym Bull (Berl) 2016. [DOI: 10.1007/s00289-016-1723-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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38
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Bajsić EG, Mijović B, Penava NV, Grgurić TH, Slouf M, Zdraveva E. The effect of UV irradiation on the electrospun PCL/TiO2composites fibers. J Appl Polym Sci 2016. [DOI: 10.1002/app.43539] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Emi Govorčin Bajsić
- Faculty of Chemical Engineering and Technology; Department of Polymer Engineering and Organic Chemical Technology, University of Zagreb; Marulicev trg 19 Zagreb HR-10000 Croatia
| | - Budimir Mijović
- Faculty of Textile Technology; Department of Basic, Natural and Technical Sciences, University of Zagreb; Prilaz baruna Filipovica 28 a Zagreb HR-10000 Croatia
| | - Nina Vranješ Penava
- Faculty of Chemical Engineering and Technology; Department of Polymer Engineering and Organic Chemical Technology, University of Zagreb; Marulicev trg 19 Zagreb HR-10000 Croatia
| | - Tamara Holjevac Grgurić
- Faculty of Metallurgy; Department of Physical Metallurgy, University of Zagreb; Aleja narodnih heroja 3 Sisak HR-44103 Croatia
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry of the as CR; v.v.i, Heyrovskeho nam. 2 16206 Czech Republic
| | - Emilija Zdraveva
- Faculty of Textile Technology; Department of Basic, Natural and Technical Sciences, University of Zagreb; Prilaz baruna Filipovica 28 a Zagreb HR-10000 Croatia
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Slouf M, Vacková T, Zhigunov A, Sikora A, Piorkowska E. Nucleation of Polypropylene Crystallization with Gold Nanoparticles. Part 2: Relation between Particle Morphology and Nucleation Activity. J MACROMOL SCI B 2016. [DOI: 10.1080/00222348.2016.1153402] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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40
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Biani A, Dorigato A, Bonani W, Slouf M, Pegoretti A. Mechanical behaviour of cyclic olefin copolymer/exfoliated graphite nanoplatelets nanocomposites foamed through supercritical carbon dioxide. EXPRESS POLYM LETT 2016. [DOI: 10.3144/expresspolymlett.2016.91] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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41
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Stloukal P, Pekařová S, Kalendova A, Mattausch H, Laske S, Holzer C, Chitu L, Bodner S, Maier G, Slouf M, Koutny M. Kinetics and mechanism of the biodegradation of PLA/clay nanocomposites during thermophilic phase of composting process. Waste Manag 2015; 42:31-40. [PMID: 25981155 DOI: 10.1016/j.wasman.2015.04.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 03/20/2015] [Accepted: 04/09/2015] [Indexed: 06/04/2023]
Abstract
The degradation mechanism and kinetics of polylactic acid (PLA) nanocomposite films, containing various commercially available native or organo-modified montmorillonites (MMT) prepared by melt blending, were studied under composting conditions in thermophilic phase of process and during abiotic hydrolysis and compared to the pure polymer. Described first order kinetic models were applied on the data from individual experiments by using non-linear regression procedures to calculate parameters characterizing aerobic composting and abiotic hydrolysis, such as carbon mineralization, hydrolysis rate constants and the length of lag phase. The study showed that the addition of nanoclay enhanced the biodegradation of PLA nanocomposites under composting conditions, when compared with pure PLA, particularly by shortening the lag phase at the beginning of the process. Whereas the lag phase of pure PLA was observed within 27days, the onset of CO2 evolution for PLA with native MMT was detected after just 20days, and from 13 to 16days for PLA with organo-modified MMT. Similarly, the hydrolysis rate constants determined tended to be higher for PLA with organo-modified MMT, particularly for the sample PLA-10A with fastest degradation, in comparison with pure PLA. The acceleration of chain scission in PLA with nanoclays was confirmed by determining the resultant rate constants for the hydrolytical chain scission. The critical molecular weight for the hydrolysis of PLA was observed to be higher than the critical molecular weight for onset of PLA mineralization, suggesting that PLA chains must be further shortened so as to be assimilated by microorganisms. In conclusion, MMT fillers do not represent an obstacle to acceptance of the investigated materials in composting facilities.
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Affiliation(s)
- Petr Stloukal
- Centre of Polymer Systems, Tomas Bata University in Zlín, nám. TGM Sqr. 5555, 760 01 Zlín, Czech Republic; Department of Environmental Protection Engineering, Faculty of Technology, Tomas Bata University in Zlín, nám. TGM 5555, 760 01 Zlin, Czech Republic.
| | - Silvie Pekařová
- Department of Environmental Protection Engineering, Faculty of Technology, Tomas Bata University in Zlín, nám. TGM 5555, 760 01 Zlin, Czech Republic
| | - Alena Kalendova
- Polymer Engineering, Faculty of Technology, Tomas Bata University in Zlín, nám. TGM 5555, 760 01 Zlin, Czech Republic
| | - Hannelore Mattausch
- Department of Polymer Engineering, Chair of Polymer Processing, Montanuniversitaet Leoben, 8700 Leoben, Austria
| | - Stephan Laske
- Department of Polymer Engineering, Chair of Polymer Processing, Montanuniversitaet Leoben, 8700 Leoben, Austria
| | - Clemens Holzer
- Department of Polymer Engineering, Chair of Polymer Processing, Montanuniversitaet Leoben, 8700 Leoben, Austria
| | - Livia Chitu
- Materials Center Leoben GmbH, 8700 Leoben, Austria
| | | | | | - Miroslav Slouf
- Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovského nám. 2, 162 06 Praha 6-Břevnov, Czech Republic
| | - Marek Koutny
- Centre of Polymer Systems, Tomas Bata University in Zlín, nám. TGM Sqr. 5555, 760 01 Zlín, Czech Republic; Department of Environmental Protection Engineering, Faculty of Technology, Tomas Bata University in Zlín, nám. TGM 5555, 760 01 Zlin, Czech Republic
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Dabrowska I, Fambri L, Pegoretti A, Slouf M, Vackova T, Kolarik J. Spinning, drawing and physical properties of polypropylene nanocomposite fibers with fumed nanosilica. EXPRESS POLYM LETT 2015. [DOI: 10.3144/expresspolymlett.2015.25] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Ostafinska A, Fortelny I, Nevoralova M, Hodan J, Kredatusova J, Slouf M. Synergistic effects in mechanical properties of PLA/PCL blends with optimized composition, processing, and morphology. RSC Adv 2015. [DOI: 10.1039/c5ra21178f] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Blending of poly(lactic acid) with poly(ε-caprolactone) can increase the impact strength above the values of the individual components.
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Affiliation(s)
- Aleksandra Ostafinska
- Institute of Macromolecular Chemistry
- Academy of Sciences of the Czech Republic
- 162 06 Prague 6
- Czech Republic
| | - Ivan Fortelny
- Institute of Macromolecular Chemistry
- Academy of Sciences of the Czech Republic
- 162 06 Prague 6
- Czech Republic
| | - Martina Nevoralova
- Institute of Macromolecular Chemistry
- Academy of Sciences of the Czech Republic
- 162 06 Prague 6
- Czech Republic
| | - Jiri Hodan
- Institute of Macromolecular Chemistry
- Academy of Sciences of the Czech Republic
- 162 06 Prague 6
- Czech Republic
| | - Jana Kredatusova
- Institute of Macromolecular Chemistry
- Academy of Sciences of the Czech Republic
- 162 06 Prague 6
- Czech Republic
| | - Miroslav Slouf
- Institute of Macromolecular Chemistry
- Academy of Sciences of the Czech Republic
- 162 06 Prague 6
- Czech Republic
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Filová E, Suchý T, Sucharda Z, Supová M, Zaloudková M, Balík K, Lisá V, Slouf M, Bačáková L. Support for the initial attachment, growth and differentiation of MG-63 cells: a comparison between nano-size hydroxyapatite and micro-size hydroxyapatite in composites. Int J Nanomedicine 2014; 9:3687-706. [PMID: 25125978 PMCID: PMC4130718 DOI: 10.2147/ijn.s56661] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Hydroxyapatite (HA) is considered to be a bioactive material that favorably influences the adhesion, growth, and osteogenic differentiation of osteoblasts. To optimize the cell response on the hydroxyapatite composite, it is desirable to assess the optimum concentration and also the optimum particle size. The aim of our study was to prepare composite materials made of polydimethylsiloxane, polyamide, and nano-sized (N) or micro-sized (M) HA, with an HA content of 0%, 2%, 5%, 10%, 15%, 20%, 25% (v/v) (referred to as N0–N25 or M0–M25), and to evaluate them in vitro in cultures with human osteoblast-like MG-63 cells. For clinical applications, fast osseointegration of the implant into the bone is essential. We observed the greatest initial cell adhesion on composites M10 and N5. Nano-sized HA supported cell growth, especially during the first 3 days of culture. On composites with micro-size HA (2%–15%), MG-63 cells reached the highest densities on day 7. Samples M20 and M25, however, were toxic for MG-63 cells, although these composites supported the production of osteocalcin in these cells. On N2, a higher concentration of osteopontin was found in MG-63 cells. For biomedical applications, the concentration range of 5%–15% (v/v) nano-size or micro-size HA seems to be optimum.
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Affiliation(s)
- Elena Filová
- Department of Biomaterials and Tissue Engineering, Institute of Physiology, Prague, Czech Republic
| | - Tomáš Suchý
- Department of Composite and Carbon Materials, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, Prague, Czech Republic ; Laboratory of Biomechanics, Department of Mechanics, Biomechanics and Mechatronics, Faculty of Mechanical Engineering, CTU in Prague, Prague, Czech Republic
| | - Zbyněk Sucharda
- Department of Composite and Carbon Materials, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Monika Supová
- Department of Composite and Carbon Materials, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Margit Zaloudková
- Department of Composite and Carbon Materials, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Karel Balík
- Department of Composite and Carbon Materials, Institute of Rock Structure and Mechanics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Věra Lisá
- Department of Biomaterials and Tissue Engineering, Institute of Physiology, Prague, Czech Republic
| | - Miroslav Slouf
- Department of Morphology and Rheology of Polymer Materials, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Lucie Bačáková
- Department of Biomaterials and Tissue Engineering, Institute of Physiology, Prague, Czech Republic
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Novotný F, Wandrol P, Proška J, Slouf M. In situ WetSTEM observation of gold nanorod self-assembly dynamics in a drying colloidal droplet. Microsc Microanal 2014; 20:385-393. [PMID: 24641815 DOI: 10.1017/s1431927614000208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Direct in situ visualization of nanoparticles in a liquid is an important challenge of modern electron microscopy. The increasing significance of bottom-up methods in nanotechnology requires a direct method to observe nanoparticle interactions in a liquid as the counterpart to the ex situ electron microscopy and indirect scattering and spectroscopy methods. Especially, the self-assembly of anisometric nanoparticles represents a difficult task, and the requirement to trace the route and orientation of an individual nanoparticle is of highest importance. In our approach we utilize scanning transmission electron microscopy under environmental conditions to visualize the mobility and self-assembly of cetyltrimethylammonium bromide (CTAB)-capped gold nanorods (AuNRs) in an aqueous colloidal solution. We directly observed the drying-mediated AuNR self-assembly in situ during rapid evaporation of a colloidal droplet at 4°C and pressure of about 900 Pa. Several types of final AuNR packing were documented including side-by-side oriented chains, tip-to-tip loosely arranged nanorods, and domains of vertically aligned AuNR arrays. The effect of local heating by electron beam is used to qualitatively asses the visco-elastic properties of the formed AuNR/CTAB/water membrane. Local heating induces the dehydration and contraction of a formed membrane indicated either by its rupture and/or by movement of the embedded AuNRs.
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Affiliation(s)
- Filip Novotný
- 1 Department of Physical Electronics, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Břehová 7, 115 19 Prague, Czech Republic
| | - Petr Wandrol
- 2 FEI, Podnikatelská 6, 612 00, Brno, Czech Republic
| | - Jan Proška
- 1 Department of Physical Electronics, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Břehová 7, 115 19 Prague, Czech Republic
| | - Miroslav Slouf
- 3 Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 162 06 Prague 6, Czech Republic
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Fulin P, Pokorny D, Slouf M, Nevoralova M, Vackova T, Dybal J, Pilar J. Quantification of structural changes of UHMWPE components in total joint replacements. BMC Musculoskelet Disord 2014; 15:109. [PMID: 24678698 PMCID: PMC3986646 DOI: 10.1186/1471-2474-15-109] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Accepted: 03/24/2014] [Indexed: 11/17/2022] Open
Abstract
Background At present time the number of implantations of joint replacements as well as their revisions increases. Higher demands are required on the quality and longevity of implants. The aim of this work was to determine the degree of oxidative degradation and the amount of free/residual radicals in selected ultra-high molecular weight polyethylene (UHMWPE) components of the joint replacements and demonstrate that the measured values are closely connected with quality and lifetime of the polymer components. Methods We tested both new (4 samples) and explanted (4 samples) UHMWPE polymers for total joint replacements. The samples were characterized by infrared spectroscopy (IR), electron spin resonance (ESR) and microhardness (MH) test. The IR measurements yielded the values of oxidation index and trans-vinylene index. The ESR measurements gave the free radicals concentration. Results In the group of new polyethylene components, we found oxidation index values ranging from 0.00-0.03 to 0.24. The trans-vinylene index values ranged from 0.044 to 0.080. The value of free radical concentration was zero in virgin and also in sample of Beznoska Company and non-zero in the other samples. In the group of explanted components, the measured values were associated with their history, micromechanical properties and performance in vivo. Conclusions We demonstrated that measuring of oxidative damage may help the orthopaedic surgeon in estimating the quality of UHMWPE replacement component and thus radically to avoid early joint replacement failure due to worse polyethylene quality.
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Affiliation(s)
- Petr Fulin
- Department of Orthopaedics, First Faculty of Medicine, Charles University in Prague, V Úvalu 84, Prague 5 15006, Czech Republic.
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Fulín P, Pokorný D, Slouf M, Vacková T, Dybal J, Sosna A. [Effect of sterilisation with formaldehyde, gamma irradiation and ethylene oxide on the properties of polyethylene joint replacement components]. Acta Chir Orthop Traumatol Cech 2014; 81:33-39. [PMID: 24755055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
PURPOSE OF THE STUDY Each method of sterilisation has some effect on the structure and properties of UHMWPE and thus also on joint replacement longevity. This study was designed to compare, using objective methods of measurement, several kinds of sterilisation and to recommend the one which has the best prospect for making joint replacements last longer. MATERIAL AND METHODS Two groups of UHMWPE samples were tested. Group 1 included virgin GUR 1020 polyethylene, non-modified and non-sterilised (Meditech, Germany). Group 2 comprised of three sets of samples sterilised with formaldehyde, gamma irradiation and ethylene oxide, respectively. In both groups, physicochemical properties were assessed by infrared spectroscopy (IR), and the oxidation (OI) and trans-vinyl (VI) indices, which show the degree of oxidation of a material, were determined. Free-radical concentrations were measured by the method of electron spin resonance (ESR). The mechanical properties of each sample were studied using small punch tests (SPT) and testing microhardness (MH). Any change in mechanical properties can affect, to various degrees, the quality and longevity of a prosthetic joint. RESULTS The samples sterilised by gamma irradiation showed higher values of both the OI (0.37) and the VI index (0.038) than the other samples (OI, 0.02 to 0.05 and VI, 0). Also, the free-radical concentration was detectable only in the gamma-sterilised sample. Values obtained for mechanical properties were as follows: peak load in the range of 58.48 N (gamma irradiation) to 59.60 N (ethylene oxide); ultimate load in the range of 46.69 N (gamma irradiation) to 57.50 N (ethylene oxide); ultimate displacement in the range of 4.29 mm (gamma irradiation) to 4.58 mm (virgin polyethylene and formaldehyde); and work to failure in the range of 185.18 mJ (gamma irradiation) to 205.89 mJ (virgin polyethylene). Microhardness values were obtained in the following ranges: 41.2 to 44.6 MPa (virgin polyethylene); 40.2 to 44.1 MPa (formaldehyde); 46.1 to 49.3 MPa (gamma irradiation); and 40.3 to 44.2 MPa (ethylene oxide). DISCUSSION The samples sterilised with formaldehyde and ethylene oxide have mechanical properties very similar to virgin polyethylene, they are not damaged by oxidation and do not contain free radicals. Owing to these characteristics, the immediate and long-term oxidation stability of the three samples is higher. The sample sterilised by gamma irradiation showed the presence of free radicals and immediate and long-term oxidative degradation. This results in the deterioration of mechanical properties and the growth of crystallinity due to enhanced oxidation and leads to higher polyethylene microhardness. CONCLUSIONS Sterilisation with gamma irradiation results in oxidative degradation and mechanical property deterioration, which is one of the potential risks of a shorter life span of joint replacements. The use of ethylene oxide or formaldehyde does not change polymer properties nor has any effect on oxidation of materials. Therefore, a longer life expectancy of the joint replacements sterilised with ethylene oxide can be expected. The life span of their joint replacements is a key issue for the patients. Prosthetic joint loosening is painful and the patient often requires re-implantation. A higher number of re-implantations is associated with higher costs for the institution involved and, consequently, for the whole health care system. Although this study basically deals with chemical issues, it informs the surgeon of the latest developments leading to the improvement of implanted materials, which can increase the life expectancy of joint replacements and patients' satisfaction.
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Affiliation(s)
- P Fulín
- I. ortopedická klinika 1. LF UK a FN Motol, Praha
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Hajduová J, Procházka K, Slouf M, Angelov B, Mountrichas G, Pispas S, Stěpánek M. Polyelectrolyte-surfactant complexes of poly[3,5-bis(dimethylaminomethyl)-4-hydroxystyrene]-block-poly(ethylene oxide) and sodium dodecyl sulfate: anomalous self-assembly behavior. Langmuir 2013; 29:5443-5449. [PMID: 23590563 DOI: 10.1021/la400583z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Polyelectrolyte-surfactant complexes (PE-S) formed by double hydrophilic cationic polyelectrolyte poly[3,5-bis(dimethylaminomethyl)-4-hydroxystyrene]-block-poly(ethylene oxide) (NPHOS-PEO) and anionic surfactant sodium dodecyl sulfate (SDS) in acidic aqueous solutions were studied by light scattering, SAXS, and scanning transmission electron microcopy in the environmental mode (wet-STEM) for various stoichiometric ratios between the numbers of SDS anions and dimethylaminomethyl groups of NPHOS in the complex. The obtained results show that the NPHOS-PEO/SDS system behaves differently from other systems of double hydrophilic block polyelectrolyte and oppositely charged ionic surfactant because it forms water-insoluble PE-S for compositions close to the zero net charge of the complex. This phase separation occurs, instead of the PE-S rearrangement to core-shell particles, which is hindered due to conformational rigidity of the NPHOS blocks. For the surfactant amounts below and above the precipitation region, large spherical aggregates and their clusters are present in the solution. SAXS measurements indicate that although the NPHOS-PEO/SDS system does not form the core-shell particles with the NPHOS/SDS core and the PEO shell as other PE-S of double hydrophilic polyelectrolytes, the aggregates contain domains of closely packed surfactant micelles which bind to both NPHOS polyelectrolyte blocks and PEO blocks.
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Affiliation(s)
- Jana Hajduová
- Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University of Prague, Prague 2, Czech Republic
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Henke P, Lang K, Kubát P, Sýkora J, Slouf M, Mosinger J. Polystyrene nanofiber materials modified with an externally bound porphyrin photosensitizer. ACS Appl Mater Interfaces 2013; 5:3776-3783. [PMID: 23566280 DOI: 10.1021/am4004057] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Polystyrene ion-exchange nanofiber materials with large surface areas and adsorption capacities were prepared by electrospinning followed by the sulfonation and adsorption of a cationic 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin (TMPyP) photosensitizer on the nanofiber surfaces. The morphology, structure, and photophysical properties of these nanofiber materials were characterized by microscopic methods and steady-state and time-resolved fluorescence and absorption spectroscopies. The externally bound TMPyP can be excited by visible light to form triplet states and singlet oxygen O2((1)Δg) and singlet oxygen-sensitized delayed fluorescence (SODF). The photophysical properties of the nanofibers were strongly dependent on the amount of bound TMPyP molecules and their organization on the nanofiber surfaces. The nanofibers demonstrated photooxidative activity toward inorganic and organic molecules and antibacterial activity against E. coli due to the sensitized formation of O2((1)Δg) that is an effective oxidation/cytotoxic agent. The nanofiber materials also adsorbed heavy metal cations (Pb(2+)) and removed them from the water environment.
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Affiliation(s)
- Petr Henke
- Faculty of Science, Charles University in Prague, Hlavova 2030, 128 43 Praha 2, Czech Republic
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