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Surdo S, Barillaro G. Voltage- and Metal-assisted Chemical Etching of Micro and Nano Structures in Silicon: A Comprehensive Review. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2400499. [PMID: 38644330 DOI: 10.1002/smll.202400499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 03/12/2024] [Indexed: 04/23/2024]
Abstract
Sculpting silicon at the micro and nano scales has been game-changing to mold bulk silicon properties and expand, in turn, applications of silicon beyond electronics, namely, in photonics, sensing, medicine, and mechanics, to cite a few. Voltage- and metal-assisted chemical etching (ECE and MaCE, respectively) of silicon in acidic electrolytes have emerged over other micro and nanostructuring technologies thanks to their unique etching features. ECE and MaCE have enabled the fabrication of novel structures and devices not achievable otherwise, complementing those feasible with the deep reactive ion etching (DRIE) technology, the gold standard in silicon machining. Here, a comprehensive review of ECE and MaCE for silicon micro and nano machining is provided. The chemistry and physics ruling the dissolution of silicon are dissected and similarities and differences between ECE and MaCE are discussed showing that they are the two sides of the same coin. The processes governing the anisotropic etching of designed silicon micro and nanostructures are analyzed, and the modulation of etching profile over depth is discussed. The preparation of micro- and nanostructures with tailored optical, mechanical, and thermo(electrical) properties is then addressed, and their applications in photonics, (bio)sensing, (nano)medicine, and micromechanical systems are surveyed. Eventually, ECE and MaCE are benchmarked against DRIE, and future perspectives are highlighted.
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Affiliation(s)
- Salvatore Surdo
- Dipartimento di Ingegneria dell'Informazione, Università di Pisa, via G. Caruso 16, Pisa, 56122, Italy
| | - Giuseppe Barillaro
- Dipartimento di Ingegneria dell'Informazione, Università di Pisa, via G. Caruso 16, Pisa, 56122, Italy
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Zhang L, Liao W, Chen S, Chen Y, Cheng P, Lu X, Ma Y. Towards a New 3Rs Era in the construction of 3D cell culture models simulating tumor microenvironment. Front Oncol 2023; 13:1146477. [PMID: 37077835 PMCID: PMC10106600 DOI: 10.3389/fonc.2023.1146477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 03/22/2023] [Indexed: 04/05/2023] Open
Abstract
Three-dimensional cell culture technology (3DCC) sits between two-dimensional cell culture (2DCC) and animal models and is widely used in oncology research. Compared to 2DCC, 3DCC allows cells to grow in a three-dimensional space, better simulating the in vivo growth environment of tumors, including hypoxia, nutrient concentration gradients, micro angiogenesis mimicism, and the interaction between tumor cells and the tumor microenvironment matrix. 3DCC has unparalleled advantages when compared to animal models, being more controllable, operable, and convenient. This review summarizes the comparison between 2DCC and 3DCC, as well as recent advances in different methods to obtain 3D models and their respective advantages and disadvantages.
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Affiliation(s)
- Long Zhang
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Weiqi Liao
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Shimin Chen
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yukun Chen
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Pengrui Cheng
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial International Cooperation Base of Science and Technology (Organ Transplantation), The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xinjun Lu
- Department of Biliary-Pancreatic Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yi Ma
- Organ Transplant Center, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial Key Laboratory of Organ Donation and Transplant Immunology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- Guangdong Provincial International Cooperation Base of Science and Technology (Organ Transplantation), The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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Regulating MDA-MB-231 breast cancer cell adhesion on laser-patterned surfaces with micro- and nanotopography. Biointerphases 2022; 17:021002. [PMID: 35291767 DOI: 10.1116/6.0001564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Breast cancer is the most common type of cancer observed in women. Communication with the tumor microenvironment allows invading breast cancer cells, such as triple negative breast cancer cells, to adapt to specific substrates. The substrate topography modulates the cellular behavior among other factors. Several different materials and micro/nanofabrication techniques have been employed to develop substrates for cell culture. Silicon-based substrates present a lot of advantages as they are amenable to a wide range of processing techniques and they permit rigorous control over the surface structure. We investigate and compare the response of the triple negative breast cancer cells (MDA-MB-231) on laser-patterned silicon substrates with two different topographical scales, i.e., the micro- and the nanoscale, in the absence of any other biochemical modification. We develop silicon surfaces with distinct morphological characteristics by employing two laser systems with different pulse durations (nanosecond and femtosecond) and different processing environments (vacuum, SF6 gas, and water). Our findings demonstrate that surfaces with microtopography are repellent, while those with nanotopography are attractive for MDA-MB-231 cell adherence.
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Effect of Tryptophan-Derived AhR Ligands, Kynurenine, Kynurenic Acid and FICZ, on Proliferation, Cell Cycle Regulation and Cell Death of Melanoma Cells-In Vitro Studies. Int J Mol Sci 2020; 21:ijms21217946. [PMID: 33114713 PMCID: PMC7663343 DOI: 10.3390/ijms21217946] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/20/2020] [Accepted: 10/24/2020] [Indexed: 12/18/2022] Open
Abstract
Tryptophan metabolites: kynurenine (KYN), kynurenic acid (KYNA) and 6-formylindolo[3,2-b]carbazole (FICZ) are considered aryl hydrocarbon receptor (AhR) ligands. AhR is mainly expressed in barrier tissues, including skin, and is involved in various physiological and pathological processes in skin. We studied the effect of KYN, KYNA and FICZ on melanocyte and melanoma A375 and RPMI7951 cell toxicity, proliferation and cell death. KYN and FICZ inhibited DNA synthesis in both melanoma cell lines, but RPMI7951 cells were more resistant to pharmacological treatment. Tested compounds were toxic to melanoma cells but not to normal human adult melanocytes. Changes in the protein level of cyclin D1, CDK4 and retinoblastoma tumor suppressor protein (Rb) phosphorylation revealed different mechanisms of action of individual AhR ligands. Importantly, all tryptophan metabolites induced necrosis, but only KYNA and FICZ promoted apoptosis in melanoma A375 cells. This effect was not observed in RPMI7951 cells. KYN, KYNA and FICZ in higher concentrations inhibited the protein level of AhR but did not affect the gene expression. To conclude, despite belonging to the group of AhR ligands, KYN, KYNA and FICZ exerted different effects on proliferation, toxicity and induction of cell death in melanoma cells in vitro.
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Cutarelli A, Ghio S, Zasso J, Speccher A, Scarduelli G, Roccuzzo M, Crivellari M, Maria Pugno N, Casarosa S, Boscardin M, Conti L. Vertically-Aligned Functionalized Silicon Micropillars for 3D Culture of Human Pluripotent Stem Cell-Derived Cortical Progenitors. Cells 2019; 9:E88. [PMID: 31905823 PMCID: PMC7017050 DOI: 10.3390/cells9010088] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/18/2019] [Accepted: 12/23/2019] [Indexed: 02/06/2023] Open
Abstract
Silicon is a promising material for tissue engineering since it allows to produce micropatterned scaffolding structures resembling biological tissues. Using specific fabrication methods, it is possible to build aligned 3D network-like structures. In the present study, we exploited vertically-aligned silicon micropillar arrays as culture systems for human iPSC-derived cortical progenitors. In particular, our aim was to mimic the radially-oriented cortical radial glia fibres that during embryonic development play key roles in controlling the expansion, radial migration and differentiation of cortical progenitors, which are, in turn, pivotal to the establishment of the correct multilayered cerebral cortex structure. Here we show that silicon vertical micropillar arrays efficiently promote expansion and stemness preservation of human cortical progenitors when compared to standard monolayer growth conditions. Furthermore, the vertically-oriented micropillars allow the radial migration distinctive of cortical progenitors in vivo. These results indicate that vertical silicon micropillar arrays can offer an optimal system for human cortical progenitors' growth and migration. Furthermore, similar structures present an attractive platform for cortical tissue engineering.
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Affiliation(s)
- Alessandro Cutarelli
- Laboratory of Stem Cell Biology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (A.C.); (J.Z.)
| | - Simone Ghio
- Fondazione Bruno Kessler-Center for Material and Microsystem, 38123 Trento, Italy; (S.G.); (M.C.)
| | - Jacopo Zasso
- Laboratory of Stem Cell Biology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (A.C.); (J.Z.)
| | - Alessandra Speccher
- Laboratory of Neural Development and Regeneration, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (A.S.); (S.C.)
| | - Giorgina Scarduelli
- Advanced Imaging Facility, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (G.S.); (M.R.)
| | - Michela Roccuzzo
- Advanced Imaging Facility, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (G.S.); (M.R.)
| | - Michele Crivellari
- Fondazione Bruno Kessler-Center for Material and Microsystem, 38123 Trento, Italy; (S.G.); (M.C.)
| | - Nicola Maria Pugno
- Laboratory of Bio-Inspired and Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, 38123 Trento, Italy;
- School of Engineering and Materials Science, Queen Mary University of London, London E1 4NS, UK
- Ket-Lab, Edoardo Amaldi Foundation, via del Politecnico snc, I-00133 Roma, Italy
| | - Simona Casarosa
- Laboratory of Neural Development and Regeneration, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (A.S.); (S.C.)
| | - Maurizio Boscardin
- Fondazione Bruno Kessler-Center for Material and Microsystem, 38123 Trento, Italy; (S.G.); (M.C.)
| | - Luciano Conti
- Laboratory of Stem Cell Biology, Department of Cellular, Computational and Integrative Biology-CIBIO, University of Trento, 38123 Trento, Italy; (A.C.); (J.Z.)
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Torsello B, De Marco S, Bombelli S, Chisci E, Cassina V, Corti R, Bernasconi D, Giovannoni R, Bianchi C, Perego RA. The 1ALCTL and 1BLCTL isoforms of Arg/Abl2 induce fibroblast activation and extra cellular matrix remodelling differently. Biol Open 2019; 8:bio.038554. [PMID: 30837227 PMCID: PMC6451347 DOI: 10.1242/bio.038554] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The fibrotic tissue and the stroma adjacent to cancer cells are characterised by the presence of activated fibroblasts (myofibroblasts) which play a role in creating a supportive tissue characterised by abundant extracellular matrix (ECM) secretion. The myofibroblasts remodel this tissue through secreted molecules and modulation of their cytoskeleton and specialized contractile structures. The non-receptor protein tyrosine kinase Arg (also called Abl2) has the unique ability to bind directly to the actin cytoskeleton, transducing diverse extracellular signals into cytoskeletal rearrangements. In this study we analysed the 1ALCTL and 1BLCTL Arg isoforms in Arg−/− murine embryonal fibroblasts (MEF) cell line, focusing on their capacity to activate fibroblasts and to remodel ECM. The results obtained showed that Arg isoform 1BLCTL has a major role in proliferation, migration/invasion of MEF and in inducing a milieu able to modulate tumour cell morphology, while 1ALCTL isoform has a role in MEF adhesion maintaining active focal adhesions. On the whole, the presence of Arg in MEF supports the proliferation, activation, adhesion, ECM contraction and stiffness, while the absence of Arg affected these myofibroblast features. This article has an associated First Person interview with the first author of the paper. Summary: The non-receptor tyrosine kinase Arg and its isoforms modulate the extra cellular matrix production that is relevant in fibrosis and tumour growth, this may open future novel therapeutic approaches.
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Affiliation(s)
- Barbara Torsello
- School of Medicine & Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Sofia De Marco
- School of Medicine & Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Silvia Bombelli
- School of Medicine & Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Elisa Chisci
- School of Medicine & Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Valeria Cassina
- School of Medicine & Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Roberta Corti
- School of Medicine & Surgery, University of Milano-Bicocca, 20900 Monza, Italy.,Department of Materials Science, University of Milano-Bicocca, 20125 Milan, Italy
| | - Davide Bernasconi
- School of Medicine & Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Roberto Giovannoni
- School of Medicine & Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Cristina Bianchi
- School of Medicine & Surgery, University of Milano-Bicocca, 20900 Monza, Italy
| | - Roberto A Perego
- School of Medicine & Surgery, University of Milano-Bicocca, 20900 Monza, Italy
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Widyaya VT, Riga EK, Müller C, Lienkamp K. Sub-micrometer Sized, 3D-Surface-attached Polymer Networks by Microcontact Printing: Using UV-Crosslinking Efficiency to Tune Structure Height. Macromolecules 2018; 54:1409-1417. [PMID: 34404958 PMCID: PMC7611507 DOI: 10.1021/acs.macromol.7b02576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The lateral dimensions of micro- and nanostructures obtained by microcontact printing (μCP) can be easily varied by selecting stamps with the desired spacing and pattern. However, the height of these structures cannot be tuned as easily, and in most cases only 2D structures are obtained. Here, we show how the chemical cross-linking properties of polymer inks designed for μCP can be used to obtain 3D structures with heights ranging from 3 to 750 nm using the same μCP stamps. This is technologically relevant because the ink concentration affects the quality and resolution of the printed image, and therefore can only be varied in a certain range. By exploiting the cross-linking efficiency to tune the height, an additional parameter is available to reach the desired structure height without compromising the image quality. The inks were made from copolymers containing a low percentage of different UV cross-linkable repeat units: nitrobenzoxadiazole (NBD), coumarin (COU), and/or benzophenone (BP). The base polymer of the here presented model system was an antimicrobially active poly(oxanorbornene) (SMAMP), however the concept should be transferable to many other polymer backbones. We describe the fabrication and characterization of the printed micro- and nanostructures made from pure SMAMP, NBD-SMAMP, coumarin-SMAMP, BP-SMAMP, BP-NBD-SMAMP and BP-coumarin-SMAMP polymer inks. The photo-dimerization of COU during UV irradiation at λ = 254 nm was confirmed by UV-Vis spectroscopy. Since NBD and COU are fluorescent, the polymer could be visualized by fluorescence microscopy. Additionally, their height profiles were measured by atomic force microscopy (AFM). The heights of the 3D surface-attached polymer networks obtained from the here presented polymer inks correlated with the gel-content of the corresponding unstructured polymer layers, and thus with the cross-linking efficiency of the NBD, COU and BP cross-linkers. Due to being covalently cross-linked, these 3D-surface attached polymer structures were solvent-stable and stable in aqueous surroundings.
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Affiliation(s)
- Vania Tanda Widyaya
- Bioactive Polymer Synthesis and Surface Engineering Group, Department of Microsystems Engineering (IMTEK) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 105, 79110 Freiburg, Germany
| | - Esther K. Riga
- Bioactive Polymer Synthesis and Surface Engineering Group, Department of Microsystems Engineering (IMTEK) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 105, 79110 Freiburg, Germany
| | - Claas Müller
- Laboratory for Process Technology, Department of Microsystem Engineering (IMTEK), Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany
| | - Karen Lienkamp
- Bioactive Polymer Synthesis and Surface Engineering Group, Department of Microsystems Engineering (IMTEK) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT), Albert-Ludwigs-Universität Freiburg, Georges-Köhler-Allee 105, 79110 Freiburg, Germany
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Abstract
In these last few decades the great explosion of the molecular approaches has casted a little shadow on the DNA quantitative analysis. Nevertheless DNA cytochemistry represented a long piece of history in cell biology since the advent of the Feulgen reaction. This discovery was really the milestone of the emerging quantitative cytochemistry, and scientists from all over the world produced a very large literature on this subject. This first era of quantitation (histochemistry followed by cytochemistry) started by means of absorption measurements (histophotometry and cytophotometry). The successive introduction of fluorescence microscopy gave a great boost to quantitation, making easier and faster the determination of cell components by means of cytofluorometry. The development of flow cytometry further contributed to the importance of quantitative cytochemistry. At its beginning, the mission of flow cytometry was still DNA quantitation. For a decade the Feulgen reaction had been the reference methodology for both conventional and flow cytofluorometry; the advent of Shiff-type reagents contributed to expand the variety of possible fluorochromes excitable in the entire visible spectrum as well as in the ultraviolet region. The fluorescence scenario was progressively enriched by new probes among which are the intercalating dyes which made DNA quantitation simple and fast, thus spreading it worldwide. The final explosion of cytofluorometry was made possible by the availability of a large variety of probes directly binding DNA structure. In addition, immunofluorescence allowed to correlate the cell cycle-related DNA content to other cell markers. In the clinical application of flow cytometry, this promoted the introduction of multiparametric analyses aimed at describing the cytokinetic characteristics of a given cell subpopulation defined by a specific immunophenotype setting.
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Affiliation(s)
- Giuliano Mazzini
- Institute of Molecular Genetics, CNR, Via Abbiategrasso 207, 27100, Pavia, Italy. .,Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Pavia, Italy.
| | - Marco Danova
- Department of Medicine, Azienda Socio-Sanitaria Territoriale of Pavia, Pavia, Italy
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Fernández-Castillejo S, Formentín P, Catalán Ú, Pallarès J, Marsal LF, Solà R. Silicon microgrooves for contact guidance of human aortic endothelial cells. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:675-681. [PMID: 28462069 PMCID: PMC5372752 DOI: 10.3762/bjnano.8.72] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Accepted: 02/27/2017] [Indexed: 05/09/2023]
Abstract
Background: Micro- and nanoscale substrates have been fabricated in order to study the influence of the topography on the cellular response. The aim of this work was to prepare different collagen-coated silicon substrates displaying grooves and ridges to mimic the aligned and elongated endothelium found in linear vessels, and to use them as substrates to study cell growth and behaviour. Results: The influence of groove-shaped substrates on cell adhesion, morphology and proliferation were assessed, by comparing them to flat silicon substrates, used as control condition. Using human aortic endothelial cells, microscopy images demonstrate that the cellular response is different depending on the silicon surface, when it comes to cell adhesion, morphology (alignment, circularity and filopodia presence) and proliferation. Moreover, these structures exerted no cytotoxic effect. Conclusion: The results suggest that topographical patterning influences cell response. Silicon groove substrates can be used in developing medical devices with microscale features to mimic the endothelium in lineal vessels.
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Affiliation(s)
- Sara Fernández-Castillejo
- Unit of Lipids and Atherosclerosis Research, Department of Medicine and Surgery, Universitat Rovira I Virgili, Sant Llorenç 21, 43201 Reus, Tarragona, Spain
| | - Pilar Formentín
- Nano-electronic and Photonic Systems, Departament d’Enginyeria Electrònica, Elèctrica i Automàtica, Universitat Rovira I Virgili, Països Catalans 26, 43007 Tarragona, Spain
| | - Úrsula Catalán
- Unit of Lipids and Atherosclerosis Research, Department of Medicine and Surgery, Universitat Rovira I Virgili, Sant Llorenç 21, 43201 Reus, Tarragona, Spain
| | - Josep Pallarès
- Nano-electronic and Photonic Systems, Departament d’Enginyeria Electrònica, Elèctrica i Automàtica, Universitat Rovira I Virgili, Països Catalans 26, 43007 Tarragona, Spain
| | - Lluís F Marsal
- Nano-electronic and Photonic Systems, Departament d’Enginyeria Electrònica, Elèctrica i Automàtica, Universitat Rovira I Virgili, Països Catalans 26, 43007 Tarragona, Spain
| | - Rosa Solà
- Unit of Lipids and Atherosclerosis Research, Department of Medicine and Surgery, Universitat Rovira I Virgili, Sant Llorenç 21, 43201 Reus, Tarragona, Spain
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