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Trych-Wildner A, Wildner K, Sosinowski P. Feasibility Study of a Piezo Actuator as a Potential Standard in Calibration for Roundness Instruments. SENSORS (BASEL, SWITZERLAND) 2022; 22:9312. [PMID: 36502014 PMCID: PMC9741474 DOI: 10.3390/s22239312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/24/2022] [Accepted: 11/24/2022] [Indexed: 06/17/2023]
Abstract
The paper presents experimental data that show the possible application of a piezo actuator in the role of calibration standard that can serve as an alternative route to currently available methods like gauge blocks or flick standards. First, the experimental setups for interferometric and roundness instruments measurements were described. Next, the experiments using an interferometer for calibration of the piezo actuator were shown. Finally, the application of a piezo actuator to calibrate the roundness instrument, to state the correction factor for the roundness probe, and to relate it to the unit of metre, assuring the traceability of future measurements was performed. Detailed procedures of simulating grooves and then processing the data were described and the calibration curve was obtained using regression analysis. The estimation of uncertainty provided by different factors during the measurements was given to fulfil as closely as possible real calibration procedures taken up in the measurement laboratories. Finally, the limitations of the presented procedures were presented and discussed.
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Affiliation(s)
- Anna Trych-Wildner
- Central Office of Measures, Time and Length Department, Precise Geometric Measurements Laboratory, Elektoralna 2, 00-139 Warsaw, Poland
| | - Krzysztof Wildner
- Warsaw University of Technology, Faculty of Mechatronics, Institute of Metrology and Biomedical Engineering, A. Boboli 8, 02-525 Warsaw, Poland
| | - Piotr Sosinowski
- Central Office of Measures, Time and Length Department, Precise Geometric Measurements Laboratory, Elektoralna 2, 00-139 Warsaw, Poland
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2
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Lachaize V, Peña B, Ciubotaru C, Cojoc D, Chen SN, Taylor MRG, Mestroni L, Sbaizero O. Compromised Biomechanical Properties, Cell-Cell Adhesion and Nanotubes Communication in Cardiac Fibroblasts Carrying the Lamin A/C D192G Mutation. Int J Mol Sci 2021; 22:9193. [PMID: 34502098 PMCID: PMC8431729 DOI: 10.3390/ijms22179193] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 11/16/2022] Open
Abstract
Clinical effects induced by arrhythmogenic cardiomyopathy (ACM) originate from a large spectrum of genetic variations, including the missense mutation of the lamin A/C gene (LMNA), LMNA D192G. The aim of our study was to investigate the biophysical and biomechanical impact of the LMNA D192G mutation on neonatal rat ventricular fibroblasts (NRVF). The main findings in mutated NRVFs were: (i) cytoskeleton disorganization (actin and intermediate filaments); (ii) decreased elasticity of NRVFs; (iii) altered cell-cell adhesion properties, that highlighted a strong effect on cellular communication, in particular on tunneling nanotubes (TNTs). In mutant-expressing fibroblasts, these nanotubes were weakened with altered mechanical properties as shown by atomic force microscopy (AFM) and optical tweezers. These outcomes complement prior investigations on LMNA mutant cardiomyocytes and suggest that the LMNA D192G mutation impacts the biomechanical properties of both cardiomyocytes and cardiac fibroblasts. These observations could explain how this mutation influences cardiac biomechanical pathology and the severity of ACM in LMNA-cardiomyopathy.
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Affiliation(s)
- Veronique Lachaize
- Department of Engineering and Architecture, University of Trieste, Via Valerio 10, 34127 Trieste, Italy;
| | - Brisa Peña
- CU-Cardiovascular Institute, University of Colorado Anschutz Medical Campus, 12700 E. 19th Ave., Aurora, CO 80045, USA; (B.P.); (S.N.C.); (M.R.G.T.); (L.M.)
- Consortium for Fibrosis Research & Translation, Anschutz Medical Campus, University of Colorado, 12700 E. 19th Ave., Aurora, CO 80045, USA
- Bioengineering Department, University of Colorado Denver Anschutz Medical Campus, Bioscience 2 1270 E. Montview Ave., Suite 100, Aurora, CO 80045, USA
| | - Catalin Ciubotaru
- Institute of Materials, National Research Council of Italy (CNR_IOM), Area Science Park Basovizza, 34149 Trieste, Italy; (C.C.); (D.C.)
| | - Dan Cojoc
- Institute of Materials, National Research Council of Italy (CNR_IOM), Area Science Park Basovizza, 34149 Trieste, Italy; (C.C.); (D.C.)
| | - Suet Nee Chen
- CU-Cardiovascular Institute, University of Colorado Anschutz Medical Campus, 12700 E. 19th Ave., Aurora, CO 80045, USA; (B.P.); (S.N.C.); (M.R.G.T.); (L.M.)
| | - Matthew R. G. Taylor
- CU-Cardiovascular Institute, University of Colorado Anschutz Medical Campus, 12700 E. 19th Ave., Aurora, CO 80045, USA; (B.P.); (S.N.C.); (M.R.G.T.); (L.M.)
| | - Luisa Mestroni
- CU-Cardiovascular Institute, University of Colorado Anschutz Medical Campus, 12700 E. 19th Ave., Aurora, CO 80045, USA; (B.P.); (S.N.C.); (M.R.G.T.); (L.M.)
| | - Orfeo Sbaizero
- Department of Engineering and Architecture, University of Trieste, Via Valerio 10, 34127 Trieste, Italy;
- CU-Cardiovascular Institute, University of Colorado Anschutz Medical Campus, 12700 E. 19th Ave., Aurora, CO 80045, USA; (B.P.); (S.N.C.); (M.R.G.T.); (L.M.)
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3
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Short-Term Degradation of Bi-Component Electrospun Fibers: Qualitative and Quantitative Evaluations via AFM Analysis. J Funct Biomater 2018; 9:jfb9020027. [PMID: 29601499 PMCID: PMC6023316 DOI: 10.3390/jfb9020027] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/28/2018] [Accepted: 03/20/2018] [Indexed: 12/21/2022] Open
Abstract
Electrospun polymeric fibers are currently used as 3D models for in vitro applications in biomedical areas, i.e., tissue engineering, cell and drug delivery. The high customization of the electrospinning process offers numerous opportunities to manipulate and control surface area, fiber diameter, and fiber density to evaluate the response of cells under different morphological and/or biochemical stimuli. The aim of this study was to investigate—via atomic force microscopy (AFM)—the chemical and morphological changes in bi-component electrospun fibers (BEFs) during the in vitro degradation process using a biological medium. BEFs were fabricated by electrospinning a mixture of synthetic-polycaprolactone (PCL)-and natural polymers (gelatin) into a binary solution. During the hydrolytic degradation of protein, no significant remarkable effects were recognized in terms of fiber integrity. However, increases in surface roughness as well as a decrease in fiber diameter as a function of the degradation conditions were detected. We suggest that morphological and chemical changes due to the local release of gelatin positively influence cell behavior in culture, in terms of cell adhesion and spreading, thus working to mimic the native microenvironment of natural tissues.
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Smolyakov G, Dague E, Roux C, Seguelas MH, Galés C, Senard JM, Arvanitis DN. Nanoscale structural mapping as a measure of maturation in the murine frontal cortex. Brain Struct Funct 2017; 223:255-265. [PMID: 28779306 DOI: 10.1007/s00429-017-1486-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 07/26/2017] [Indexed: 01/01/2023]
Abstract
Atomic force microscopy (AFM) is emerging as an innovative tool to phenotype the brain. This study demonstrates the utility of AFM to determine nanomechanical and nanostructural features of the murine dorsolateral frontal cortex from weaning to adulthood. We found an increase in tissue stiffness of the primary somatosensory cortex with age, along with an increased cortical mechanical heterogeneity. To characterize the features potentially responsible for this heterogeneity, we applied AFM scan mode to directly image the topography of thin sections of the primary somatosensory cortical layers II/III, IV and V/VI. Topographical mapping of the cortical layers at successive ages showed progressive smoothing of the surface. Topographical images were also compared with histochemically derived morphological information, which demonstrated the deposition of perineuronal nets, important extracellular components and markers of maturity. Our work demonstrates that high-resolution AFM images can be used to determine the nanostructural properties of cortical maturation, well beyond embryonic and postnatal development. Furthermore, it may offer a new method for brain phenotyping and screening to uncover topographical changes in early stages of neurodegenerative diseases.
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Affiliation(s)
- G Smolyakov
- LAAS-CNRS, Université de Toulouse, CNRS, Toulouse, France
- ITAV-CNRS, Université de Toulouse, CNRS, Toulouse, France
| | - E Dague
- LAAS-CNRS, Université de Toulouse, CNRS, Toulouse, France.
- ITAV-CNRS, Université de Toulouse, CNRS, Toulouse, France.
| | - C Roux
- LAAS-CNRS, Université de Toulouse, CNRS, Toulouse, France
- ITAV-CNRS, Université de Toulouse, CNRS, Toulouse, France
- Laboratoire Des IMRCP, Université de Toulouse, CNRS UMR 5623, Université de Toulouse, 118 Route de Narbonne, 31062, Toulouse Cedex 9, France
- Institut Des Maladies Métaboliques Et Cardiovasculaires, INSERM, UMR1048, Université de Toulouse, 118 Route de Narbonne, 31062, Toulouse Cedex 9, France
| | - M H Seguelas
- Institut Des Maladies Métaboliques Et Cardiovasculaires, INSERM, UMR1048, Université de Toulouse, 118 Route de Narbonne, 31062, Toulouse Cedex 9, France
| | - C Galés
- ITAV-CNRS, Université de Toulouse, CNRS, Toulouse, France
- Institut Des Maladies Métaboliques Et Cardiovasculaires, INSERM, UMR1048, Université de Toulouse, 118 Route de Narbonne, 31062, Toulouse Cedex 9, France
| | - J M Senard
- Institut Des Maladies Métaboliques Et Cardiovasculaires, INSERM, UMR1048, Université de Toulouse, 118 Route de Narbonne, 31062, Toulouse Cedex 9, France
| | - D N Arvanitis
- Institut Des Maladies Métaboliques Et Cardiovasculaires, INSERM, UMR1048, Université de Toulouse, 118 Route de Narbonne, 31062, Toulouse Cedex 9, France.
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5
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Smolyakov G, Cauquil M, Severac C, Lachaize V, Guilbeau-Frugier C, Sénard JM, Galés C, Dague E. Biophysical properties of cardiomyocyte surface explored by multiparametric AFM. J Struct Biol 2017; 198:28-37. [PMID: 28263874 DOI: 10.1016/j.jsb.2017.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 12/10/2016] [Accepted: 03/01/2017] [Indexed: 11/30/2022]
Abstract
PeakForce Quantitative Nanomechanical Mapping (PeakForce QNM) multiparametric AFM mode was adapted to qualitative and quantitative study of the lateral membrane of cardiomyocytes (CMs), extending this powerful mode to the study of soft cells. On living CM, PeakForce QNM depicted the crests and hollows periodic alternation of cell surface architecture previously described using AFM Force Volume (FV) mode. PeakForce QNM analysis provided better resolution in terms of pixel number compared to FV mode and reduced acquisition time, thus limiting the consequences of spontaneous living adult CM dedifferentiation once isolated from the cardiac tissue. PeakForce QNM mode on fixed CMs clearly visualized subsarcolemmal mitochondria (SSM) and their loss following formamide treatment, concomitant with the interfibrillar mitochondria climbing up and forming heaps at the cell surface. Interestingly, formamide-promoted SSM loss allowed visualization of the sarcomeric apparatus ultrastructure below the plasma membrane. High PeakForce QNM resolution led to better contrasted mechanical maps than FV mode and provided correlation between adhesion, dissipation, mechanical and topographical maps. Modified hydrophobic AFM tip enhanced contrast on adhesion and dissipation maps and suggested that CM surface crests and hollows exhibit distinct chemical properties. Finally, two-dimensional Fast Fourier Transform to objectively quantify AFM maps allowed characterization of periodicity of both sarcomeric Z-line and M-band. Overall, this study validated PeakForce QNM as a valuable and innovative mode for the exploration of living and fixed CMs. In the future, it could be applied to depict cell membrane architectural, mechanical and chemical defects as well as sarcomeric abnormalities associated with cardiac diseases.
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Affiliation(s)
- Georges Smolyakov
- ITAV, Université de Toulouse, CNRS, France; LAAS-CNRS, Université de Toulouse, CNRS, France; Service de Pharmacologie, CHU de Toulouse, Université de Toulouse, Toulouse, France
| | - Marie Cauquil
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Université de Toulouse, France; Service de Pharmacologie, CHU de Toulouse, Université de Toulouse, Toulouse, France
| | | | - Véronique Lachaize
- ITAV, Université de Toulouse, CNRS, France; LAAS-CNRS, Université de Toulouse, CNRS, France; Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Université de Toulouse, France; Service de Pharmacologie, CHU de Toulouse, Université de Toulouse, Toulouse, France
| | - Céline Guilbeau-Frugier
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Université de Toulouse, France; Centre de Microscopie Électronique Appliquée à la Biologie, Université de Toulouse, France; Service de Pharmacologie, CHU de Toulouse, Université de Toulouse, Toulouse, France
| | - Jean-Michel Sénard
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Université de Toulouse, France; Service de Pharmacologie, CHU de Toulouse, Université de Toulouse, Toulouse, France
| | - Céline Galés
- ITAV, Université de Toulouse, CNRS, France; Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Université de Toulouse, France; Service de Pharmacologie, CHU de Toulouse, Université de Toulouse, Toulouse, France.
| | - Etienne Dague
- ITAV, Université de Toulouse, CNRS, France; LAAS-CNRS, Université de Toulouse, CNRS, France; Service de Pharmacologie, CHU de Toulouse, Université de Toulouse, Toulouse, France.
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6
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Smolyakov G, Formosa-Dague C, Severac C, Duval R, Dague E. High speed indentation measures by FV, QI and QNM introduce a new understanding of bionanomechanical experiments. Micron 2016; 85:8-14. [DOI: 10.1016/j.micron.2016.03.002] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 03/03/2016] [Accepted: 03/05/2016] [Indexed: 12/31/2022]
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7
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Dague E, Genet G, Lachaize V, Guilbeau-Frugier C, Fauconnier J, Mias C, Payré B, Chopinet L, Alsteens D, Kasas S, Severac C, Thireau J, Heymes C, Honton B, Lacampagne A, Pathak A, Sénard JM, Galés C. Atomic force and electron microscopic-based study of sarcolemmal surface of living cardiomyocytes unveils unexpected mitochondrial shift in heart failure. J Mol Cell Cardiol 2014; 74:162-72. [PMID: 24839910 DOI: 10.1016/j.yjmcc.2014.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/07/2014] [Accepted: 05/08/2014] [Indexed: 10/25/2022]
Abstract
Loss of T-tubules (TT), sarcolemmal invaginations of cardiomyocytes (CMs), was recently identified as a general heart failure (HF) hallmark. However, whether TT per se or the overall sarcolemma is altered during HF process is still unknown. In this study, we directly examined sarcolemmal surface topography and physical properties using Atomic Force Microscopy (AFM) in living CMs from healthy and failing mice hearts. We confirmed the presence of highly organized crests and hollows along myofilaments in isolated healthy CMs. Sarcolemma topography was tightly correlated with elasticity, with crests stiffer than hollows and related to the presence of few packed subsarcolemmal mitochondria (SSM) as evidenced by electron microscopy. Three days after myocardial infarction (MI), CMs already exhibit an overall sarcolemma disorganization with general loss of crests topography thus becoming smooth and correlating with a decreased elasticity while interfibrillar mitochondria (IFM), myofilaments alignment and TT network were unaltered. End-stage post-ischemic condition (15days post-MI) exacerbates overall sarcolemma disorganization with, in addition to general loss of crest/hollow periodicity, a significant increase of cell surface stiffness. Strikingly, electron microscopy revealed the total depletion of SSM while some IFM heaps could be visualized beneath the membrane. Accordingly, mitochondrial Ca(2+) studies showed a heterogeneous pattern between SSM and IFM in healthy CMs which disappeared in HF. In vitro, formamide-induced sarcolemmal stress on healthy CMs phenocopied post-ischemic kinetics abnormalities and revealed initial SSM death and crest/hollow disorganization followed by IFM later disarray which moved toward the cell surface and structured heaps correlating with TT loss. This study demonstrates that the loss of crest/hollow organization of CM surface in HF occurs early and precedes disruption of the TT network. It also highlights a general stiffness increased of the CM surface most likely related to atypical IFM heaps while SSM died during HF process. Overall, these results indicate that initial sarcolemmal stress leading to SSM death could underlie subsequent TT disarray and HF setting.
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Affiliation(s)
- Etienne Dague
- CNRS, LAAS, F-31400 Toulouse, France; CNRS, ITAV-USR3505, Toulouse, France; Université de Toulouse, ITAV, LAAS, F-31400 Toulouse France.
| | - Gaël Genet
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France
| | | | - Céline Guilbeau-Frugier
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France; Department of Histopathology, Centre Hospitalier Universitaire de Toulouse, 31432 Toulouse, France
| | - Jérémy Fauconnier
- INSERM U1046, Université Montpellier 1, Université Montpellier 2, Montpellier, France
| | - Céline Mias
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France
| | - Bruno Payré
- Centre de Microscopie Électronique Appliquée à la Biologie, Faculté de Médecine Rangueil, 31062 Toulouse, France
| | - Louise Chopinet
- CNRS, LAAS, F-31400 Toulouse, France; CNRS, IPBS-UMR5089, F-31077 Toulouse, France
| | - David Alsteens
- Institute of Life Sciences, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
| | - Sandor Kasas
- Department of Cellular Biology and Morphology, Université de Lausanne, Institut de Physique des Systèmes Biologiques, École Polytechnique Fédérale de Lausanne, Switzerland
| | - Childerick Severac
- CNRS, ITAV-USR3505, Toulouse, France; Université de Toulouse, ITAV, LAAS, F-31400 Toulouse France
| | - Jérôme Thireau
- INSERM U1046, Université Montpellier 1, Université Montpellier 2, Montpellier, France
| | - Christophe Heymes
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France
| | - Benjamin Honton
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France
| | - Alain Lacampagne
- INSERM U1046, Université Montpellier 1, Université Montpellier 2, Montpellier, France
| | - Atul Pathak
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France; Department of Clinical Pharmacology, Centre Hospitalier Universitaire de Toulouse, F-31432 Toulouse, France
| | - Jean-Michel Sénard
- Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France; Department of Clinical Pharmacology, Centre Hospitalier Universitaire de Toulouse, F-31432 Toulouse, France
| | - Céline Galés
- CNRS, ITAV-USR3505, Toulouse, France; Institut des Maladies Métaboliques et Cardiovasculaires, INSERM UMR1048, Toulouse, France.
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8
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Formosa C, Grare M, Jauvert E, Coutable A, Regnouf-de-Vains JB, Mourer M, Duval RE, Dague E. Nanoscale analysis of the effects of antibiotics and CX1 on a Pseudomonas aeruginosa multidrug-resistant strain. Sci Rep 2012; 2:575. [PMID: 22893853 PMCID: PMC3418629 DOI: 10.1038/srep00575] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 07/30/2012] [Indexed: 12/02/2022] Open
Abstract
Drug resistance is a challenge that can be addressed using nanotechnology. We focused on the resistance of the bacteria Pseudomonas aeruginosa and investigated, using Atomic Force Microscopy (AFM), the behavior of a reference strain and of a multidrug resistant clinical strain, submitted to two antibiotics and to an innovative antibacterial drug (CX1). We measured the morphology, surface roughness and elasticity of the bacteria under physiological conditions and exposed to the antibacterial molecules. To go further in the molecules action mechanism, we explored the bacterial cell wall nanoscale organization using functionalized AFM tips. We have demonstrated that affected cells have a molecularly disorganized cell wall; surprisingly long molecules being pulled off from the cell wall by a lectin probe. Finally, we have elucidated the mechanism of action of CX1: it destroys the outer membrane of the bacteria as demonstrated by the results on artificial phospholipidic membranes and on the resistant strain.
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Affiliation(s)
- C Formosa
- Centre National de la Recherche Scientifique, Laboratoire d’Analyse et d’Architecture des Systèmes-LAAS, Toulouse, France
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9
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Clusel M, Corwin EI. Unfolding proteins with an atomic force microscope: force-fluctuation-induced nonexponential kinetics. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:041920. [PMID: 22181188 DOI: 10.1103/physreve.84.041920] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 08/31/2011] [Indexed: 05/31/2023]
Abstract
We show that in experimental atomic force microscopy studies of the lifetime distribution of mechanically stressed folded proteins the effects of externally applied fluctuations cannot be distinguished from those of internally present fluctuations. In certain circumstances this leads to artificially nonexponential lifetime distributions, which can be misinterpreted as a signature of protein complexity. This work highlights the importance of fully characterizing and controlling external sources of fluctuation in mechanical studies of proteins before drawing conclusions on the physics at play on the molecular level.
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Affiliation(s)
- Maxime Clusel
- Institut Laue-Langevin, 6 rue Jules Horowitz, Boîte Postale 156X, F-38042 Grenoble Cedex, France.
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10
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Hu Y, Ulstrup J, Zhang J, Molin S, Dupres V. Adhesive properties of Staphylococcus epidermidis probed by atomic force microscopy. Phys Chem Chem Phys 2011; 13:9995-10003. [PMID: 21350761 DOI: 10.1039/c0cp02800b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mapping of the surface properties of Staphylococcus epidermidis and of biofilm forming bacteria in general is a key to understand their functions, particularly their adhesive properties. To gain a comprehensive view of the structural and chemical properties of S. epidermidis, four different strains (biofilm positive and biofilm negative strains) were analyzed using in situ atomic force microscopy (AFM). Force measurements performed using bare hydrophilic silicon nitride tips disclosed similar adhesive properties for each strain. However, use of hydrophobic tips showed that hydrophobic forces are not the driving forces for adhesion of the four strains. Rather, the observation of sawtooth force-distance patterns on the surface of biofilm positive strains documents the presence of modular proteins such as Aap that may mediate cell adhesion. Treatment of two biofilm positive strains with two chemical inhibitor compounds leads to a loss of adhesion, suggesting that AFM could be a valuable tool to screen for anti-adhesion molecules.
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Affiliation(s)
- Yifan Hu
- Department of Chemistry, DTU Chemistry, Building 207, Technical University of Denmark, DK-2800 Lyngby, Denmark
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11
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Azeloglu EU, Costa KD. Atomic force microscopy in mechanobiology: measuring microelastic heterogeneity of living cells. Methods Mol Biol 2011; 736:303-29. [PMID: 21660735 DOI: 10.1007/978-1-61779-105-5_19] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Recent findings clearly demonstrate that cells feel mechanical forces, and respond by altering their -phenotype and modulating their mechanical environment. Atomic force microscope (AFM) indentation can be used to mechanically stimulate cells and quantitatively characterize their elastic properties, providing critical information for understanding their mechanobiological behavior. This review focuses on the experimental and computational aspects of AFM indentation in relation to cell biomechanics and pathophysiology. Key aspects of the indentation protocol (including preparation of substrates, selection of indentation parameters, methods for contact point detection, and further post-processing of data) are covered. Historical perspectives on AFM as a mechanical testing tool as well as studies of cell mechanics and physiology are also highlighted.
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Affiliation(s)
- Evren U Azeloglu
- Cardiovascular Research Center, Mount Sinai School of Medicine, New York, NY, USA
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12
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Sansoz F, Gang T. A force-matching method for quantitative hardness measurements by atomic force microscopy with diamond-tipped sapphire cantilevers. Ultramicroscopy 2010; 111:11-9. [PMID: 21111262 DOI: 10.1016/j.ultramic.2010.09.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 07/28/2010] [Accepted: 09/29/2010] [Indexed: 10/19/2022]
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13
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Yeh MK, Tai NH, Chen BY. Influence of Poisson's ratio variation on lateral spring constant of atomic force microscopy cantilevers. Ultramicroscopy 2008; 108:1025-9. [PMID: 18547729 DOI: 10.1016/j.ultramic.2008.04.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Atomic force microscopy (AFM) can be used to measure the surface morphologies and the mechanical properties of nanostructures. The force acting on the AFM cantilever can be obtained by multiplying the spring constant of AFM cantilever and the corresponding deformation. To improve the accuracy of force experiments, the spring constant of AFM cantilever must be calibrated carefully. Many methods, such as theoretical equations, the finite element method, and the use of reference cantilever, were reported to obtain the spring constant of AFM cantilevers. For the cantilever made of single crystal, the Poisson's ratio varies with different cantilever-crystal angles. In this paper, the influences of Poisson's ratio variation on the lateral spring constant and axial spring constant of rectangular and V-shaped AFM cantilevers, with different tilt angles and normal forces, were investigated by the finite element analysis. When the cantilever's tilt angle is 20 degrees and the Poisson's ratio varies from 0.02 to 0.4, the finite element results show that the lateral spring constants decrease 11.75% for the rectangular cantilever with 1 microN landing force and decrease 18.60% for the V-shaped cantilever with 50 nN landing force, respectively. The influence of Poisson's ratio variation on axial spring constant is less than 3% for both rectangular and V-shaped cantilevers. As the tilt angle increases, the axial spring constants for rectangular and V-shaped cantilevers decrease substantially. The results obtained can be used to improve the accuracy of the lateral force measurement when using atomic force microscopy.
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Affiliation(s)
- Meng-Kao Yeh
- Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan, ROC.
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14
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Mamedov BA. Analytical evaluation of describing functions arising from harmonic balance analysis of tapping mode atomic force microscope. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:056104. [PMID: 18513097 DOI: 10.1063/1.2932345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A new algorithm of harmonic balance analysis of tapping mode atomic force microscopes has been developed. The new algorithm is applicable to analytical evaluation of a large class of common tip-sample interaction potentials. The extensive test calculations show that the proposed algorithm in this work is the efficient one in practical computations. The comparative values presented in tables are acceptable and have the excellent agreement with the numerical results.
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Affiliation(s)
- B A Mamedov
- Department of Physics, Faculty of Arts and Sciences, Gaziosmanpaşa University, Tokat, 60100 Turkey.
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15
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Odorico M, Teulon JM, Berthoumieu O, Chen SWW, Parot P, Pellequer JL. An integrated methodology for data processing in dynamic force spectroscopy of ligand–receptor binding. Ultramicroscopy 2007; 107:887-94. [PMID: 17644254 DOI: 10.1016/j.ultramic.2007.04.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Dynamic force spectroscopy (DFS), using atomic force microscopy (AFM), is a powerful tool to study ligand-receptor binding. The interaction mode of two binding partners is investigated by exploring stochastic behaviors of bond rupture events. However, to define a rupture event from force-distance measurements is not conclusive or unique in literature. To reveal the influence of event identification methods, we have developed an efficient protocol to manage tremendous amount of data by implementing different choices of peak selection from the force-distance curve. This data processing software simplifies routinely experimental procedures such as cantilever spring constant and force-distance curve calibrations, statistical treatments of data, and analysis distributions of rupture events. In the present work, we took available experimental data from a complex between a chelate metal compound and a monoclonal antibody as a study system.
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Affiliation(s)
- M Odorico
- CEA-Valrho, DSV-DIEP-SBTN, BP 17171, Bagnols sur Cèze 30207, France
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16
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Emerson RJ, Bergstrom TS, Liu Y, Soto ER, Brown CA, McGimpsey WG, Camesano TA. Microscale correlation between surface chemistry, texture, and the adhesive strength of Staphylococcus epidermidis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:11311-21. [PMID: 17154620 DOI: 10.1021/la061984u] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Staphylococcus epidermidis is among the most commonly isolated microbes from medical implant infections, particularly in the colonization of blood-contacting devices. We explored the relationships between surface wettability and root-mean-square roughness (Rq) on microbial adhesive strength to a substrate. Molecular-level interactions between S. epidermidis and a variety of chemically and texturally distinct model substrata were characterized using a cellular probe and atomic force microscopy (AFM). Substrata included gold, aliphatic and aromatic self-assembled monolayers, and polymeric and proteinaceous materials. Substrate hydrophobicity, described in terms of the water contact angle, was an insufficient parameter to explain the adhesive force of the bacterium for any of the surfaces. Correlations between adhesion forces and Rq showed weak relationships for most surfaces. We used an alternate methodology to characterize the texture of the surface that is based on a fractal tiling algorithm applied to images of each surface. The relative area as a function of the scale of observation was calculated. The discrete bonding model (DBM) was applied, which describes the area available for bonding interactions over the full range of observational scales contained in the measured substrate texture. Weak negative correlations were obtained between the adhesion forces and the area available for interaction, suggesting that increased roughness decreases bacterial adhesion when nano- to micrometer scales are considered. We suggest that modification of the DBM is needed in order to include discontinuous bonding. The adhesive strength is still related to the area available for bonding on a particular scale, but on some very fine scales, the bacteria may not be able to conform to the valleys or pits of the substrate. Therefore, the bonding between the bacterium and substrate becomes discontinuous, occurring only on the tops of ridges or asperities.
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Affiliation(s)
- Ray J Emerson
- Department of Chemical Engineering, and Bioengineering Institute, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, USA
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