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Ramírez J, Gibson GM, Tassieri M. Optical Halo: A Proof of Concept for a New Broadband Microrheology Tool. MICROMACHINES 2024; 15:889. [PMID: 39064399 PMCID: PMC11278636 DOI: 10.3390/mi15070889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2024] [Revised: 07/04/2024] [Accepted: 07/05/2024] [Indexed: 07/28/2024]
Abstract
Microrheology, the study of material flow at micron scales, has advanced significantly since Robert Brown's discovery of Brownian motion in 1827. Mason and Weitz's seminal work in 1995 established the foundation for microrheology techniques, enabling the measurement of viscoelastic properties of complex fluids using light-scattering particles. However, existing techniques face limitations in exploring very slow dynamics, crucial for understanding biological systems. Here, we present a proof of concept for a novel microrheology technique called "Optical Halo", which utilises a ring-shaped Bessel beam created by optical tweezers to overcome existing limitations. Through numerical simulations and theoretical analysis, we demonstrate the efficacy of the Optical Halo in probing viscoelastic properties across a wide frequency range, including low-frequency regimes inaccessible to conventional methods. This innovative approach holds promise for elucidating the mechanical behaviour of complex biological fluids.
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Affiliation(s)
- Jorge Ramírez
- Departamento de Ingeniería Química, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, 28006 Madrid, Spain;
| | - Graham M. Gibson
- School of Physics and Astronomy, Advanced Research Centre, University of Glasgow, Glasgow G11 6EW, UK;
| | - Manlio Tassieri
- Division of Biomedical Engineering, James Watt School of Engineering, Advanced Research Centre, University of Glasgow, Glasgow G11 6EW, UK
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2
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Domínguez-García P, Pinto JR, Akrap A, Jeney S. Micro-mechanical response and power-law exponents from the longitudinal fluctuations of F-actin solutions. SOFT MATTER 2023; 19:3652-3660. [PMID: 37165665 PMCID: PMC10208217 DOI: 10.1039/d2sm01445a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 04/24/2023] [Indexed: 05/12/2023]
Abstract
We investigate the local fluctuations of filamentous actin (F-actin), with a focus on the skeletal thin filament, using single-particle optical trapping interferometry. This experimental technique allows us to detect the Brownian motion of a tracer bead immersed in a complex fluid with nanometric resolution at the microsecond time-scale. The mean square displacement, loss modulus, and velocity autocorrelation function (VAF) of the trapped microprobes in the fluid follow power-law behaviors, whose exponents can be determined in the short-time/high-frequency regime over several decades. We obtain 7/8 subdiffusive power-law exponents for polystyrene depleted microtracers at low optical trapping forces. Microrheologically, the elastic modulus of these suspensions is observed to be constant up to the limit of high frequencies, confirming that the origin of this subdiffusive exponent is the local longitudinal fluctuations of the polymers. Deviations from this value are measured and discussed in relation to the characteristic length scales of these F-actin networks and probes' properties, and also in connection with the different power-law exponents detected in the VAFs. Finally, we observed that the thin filament, composed of tropomyosin (Tm) and troponin (Tn) coupled to F-actin in the presence of Ca2+, shows exponent values less dispersed than that of F-actin alone, which we interpret as a micro-measurement of the filament stabilization.
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Affiliation(s)
- Pablo Domínguez-García
- Dep. Física Interdisciplinar, Universidad Nacional de Educación a Distancia (UNED), Madrid 28040, Spain.
| | - Jose R Pinto
- Department of Biomedical Sciences, Florida State University College of Medicine, Florida, USA
| | - Ana Akrap
- Department of Physics, University of Fribourg, Fribourg, Switzerland
| | - Sylvia Jeney
- Department of Physics, University of Fribourg, Fribourg, Switzerland
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3
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Alva E, George A, Brancaleon L, Marucho M. In vitro Preparation of Homogenous Actin Filaments for Dynamic and Electrophoretic Light Scattering Measurements. Bio Protoc 2022; 12:e4553. [PMID: 36561921 PMCID: PMC9729858 DOI: 10.21769/bioprotoc.4553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/24/2022] [Accepted: 09/12/2022] [Indexed: 11/19/2022] Open
Abstract
Actin filaments are essential for various biological activities in eukaryotic cellular processes. Available in vitro experimental data on these systems often lack details and information on sample preparation protocols and experimental techniques, leading to unreproducible results. Additionally, different experimental techniques and polymerization buffers provide different, sometimes contradictory results on the properties of these systems, making it substantially difficult to gather meaningful data and conclusive information from them. This article presents a robust, accurate, detailed polymerization protocol to prepare high-quality actin filament samples for light scattering experiments. It has been shown to provide unicity and consistency in preparing stable, dispersed, aggregates-free, homogenous actin filament samples that could benefit many other scientific research groups currently working in the field. To develop the protocol, we used conventional actin buffers in physiological conditions. However, it can easily be adapted to prepare samples using other buffers and biological fluids. This protocol yielded reproducible results on essential actin filament parameters such as the translational diffusion coefficient and electrophoretic mobility. Overall, suitable modifications of the proposed experimental method could generate accurate, reproducible light scattering results on other highly charged anionic filaments commonly found in biological cells (e.g., microtubules, DNAs, RNAs, or filamentous viruses). This protocol was validated in: Polymers (2022), DOI: 10.3390/polym14122438 Graphical abstract.
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Affiliation(s)
- Ernesto Alva
- Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, USA
| | - Annitta George
- Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, USA
| | - Lorenzo Brancaleon
- Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, USA
| | - Marcelo Marucho
- Department of Physics and Astronomy, The University of Texas at San Antonio, San Antonio, USA
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4
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Mao Y, Nielsen P, Ali J. Passive and Active Microrheology for Biomedical Systems. Front Bioeng Biotechnol 2022; 10:916354. [PMID: 35866030 PMCID: PMC9294381 DOI: 10.3389/fbioe.2022.916354] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 06/08/2022] [Indexed: 12/12/2022] Open
Abstract
Microrheology encompasses a range of methods to measure the mechanical properties of soft materials. By characterizing the motion of embedded microscopic particles, microrheology extends the probing length scale and frequency range of conventional bulk rheology. Microrheology can be characterized into either passive or active methods based on the driving force exerted on probe particles. Tracer particles are driven by thermal energy in passive methods, applying minimal deformation to the assessed medium. In active techniques, particles are manipulated by an external force, most commonly produced through optical and magnetic fields. Small-scale rheology holds significant advantages over conventional bulk rheology, such as eliminating the need for large sample sizes, the ability to probe fragile materials non-destructively, and a wider probing frequency range. More importantly, some microrheological techniques can obtain spatiotemporal information of local microenvironments and accurately describe the heterogeneity of structurally complex fluids. Recently, there has been significant growth in using these minimally invasive techniques to investigate a wide range of biomedical systems both in vitro and in vivo. Here, we review the latest applications and advancements of microrheology in mammalian cells, tissues, and biofluids and discuss the current challenges and potential future advances on the horizon.
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Affiliation(s)
- Yating Mao
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, United States
- National High Magnetic Field Laboratory, Tallahassee, FL, United States
| | - Paige Nielsen
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, United States
- National High Magnetic Field Laboratory, Tallahassee, FL, United States
| | - Jamel Ali
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, FL, United States
- National High Magnetic Field Laboratory, Tallahassee, FL, United States
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5
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Alva E, George A, Brancaleon L, Marucho M. Hydrodynamic and Polyelectrolyte Properties of Actin Filaments: Theory and Experiments. Polymers (Basel) 2022; 14:polym14122438. [PMID: 35746014 PMCID: PMC9230757 DOI: 10.3390/polym14122438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/07/2022] [Accepted: 06/14/2022] [Indexed: 11/17/2022] Open
Abstract
Actin filament’s polyelectrolyte and hydrodynamic properties, their interactions with the biological environment, and external force fields play an essential role in their biological activities in eukaryotic cellular processes. In this article, we introduce a unique approach that combines dynamics and electrophoresis light-scattering experiments, an extended semiflexible worm-like chain model, and an asymmetric polymer length distribution theory to characterize the polyelectrolyte and hydrodynamic properties of actin filaments in aqueous electrolyte solutions. A fitting approach was used to optimize the theories and filament models for hydrodynamic conditions. We used the same sample and experimental conditions and considered several g-actin and polymerization buffers to elucidate the impact of their chemical composition, reducing agents, pH values, and ionic strengths on the filament translational diffusion coefficient, electrophoretic mobility, structure factor, asymmetric length distribution, effective filament diameter, electric charge, zeta potential, and semiflexibility. Compared to those values obtained from molecular structure models, our results revealed a lower value of the effective G-actin charge and a more significant value of the effective filament diameter due to the formation of the double layer of the electrolyte surrounding the filaments. Contrary to the data usually reported from electron micrographs, the lower values of our results for the persistence length and average contour filament length agree with the significant difference in the association rates at the filament ends that shift to sub-micro lengths, which is the maximum of the length distribution.
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Paul S, Kundu A, Banerjee A. Single-shot phase-sensitive wideband active microrheology of viscoelastic fluids using pulse-scanned optical tweezers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:504001. [PMID: 31315094 DOI: 10.1088/1361-648x/ab32f3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We present a fast phase sensitive active microrheology technique exploring the phase response of a microscopic probe particle trapped in a linear viscoelastic fluid using optical tweezers under an external perturbation. Thus, we experimentally determine the cumulative response of the probe to an entire repertoire of sinusoidal excitations simultaneously by applying a spatial square pulse as an excitation to the trapped probe. The square pulse naturally contains the fundamental sinusoidal frequency component and higher odd harmonics, so that we measure the phase response of the probe over a wide frequency band in a single shot, with the band being tunable over the spectrum by choosing suitable experimental parameters. We then determine the responses to individual harmonics using a lock-in algorithm, and compare the phase shifts to those obtained theoretically by solving the equation of motion of the probe particle confined in a harmonic potential in the fluid in the presence of a sinusoidal perturbation. We go on to relate the phase response of the probe to the complex shear modulus [Formula: see text], and proceed to verify our technique in a mixture of polyacrylamide and water, which we compare with known values in literature and obtain very good agreement. Our method increases the robustness of active microrheology in general and ensures that any drifts in time are almost entirely ruled out from the data, with the added advantage of high speed and ease of use.
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Affiliation(s)
- Shuvojit Paul
- Indian Institute of Science Education and Research, Kolkata, India
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8
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Nabavizadeh A, Bayat M, Kumar V, Gregory A, Webb J, Alizad A, Fatemi M. Viscoelastic biomarker for differentiation of benign and malignant breast lesion in ultra- low frequency range. Sci Rep 2019; 9:5737. [PMID: 30952880 PMCID: PMC6450913 DOI: 10.1038/s41598-019-41885-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 03/15/2019] [Indexed: 02/06/2023] Open
Abstract
Benign and malignant tumors differ in the viscoelastic properties of their cellular microenvironments and in their spatiotemporal response to very low frequency stimuli. These differences can introduce a unique viscoelastic biomarker in differentiation of benign and malignant tumors. This biomarker may reduce the number of unnecessary biopsies in breast patients. Although different methods have been developed so far for this purpose, none of them have focused on in vivo and in situ assessment of local viscoelastic properties in the ultra-low (sub-Hertz) frequency range. Here we introduce a new, noninvasive model-free method called Loss Angle Mapping (LAM). We assessed the performance results on 156 breast patients. The method was further improved by detection of out-of-plane motion using motion compensation cross correlation method (MCCC). 45 patients met this MCCC criterion and were considered for data analysis. Among this population, we found 77.8% sensitivity and 96.3% specificity (p < 0.0001) in discriminating between benign and malignant tumors using logistic regression method regarding the pre known information about the BIRADS number and size. The accuracy and area under the ROC curve, AUC, was 88.9% and 0.94, respectively. This method opens new avenues to investigate the mechanobiology behavior of different tissues in a frequency range that has not yet been explored in any in vivo patient studies.
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Affiliation(s)
- Alireza Nabavizadeh
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
- Biomedical Informatics and Computational Biology, University of Minnesota Rochester, Rochester, Minnesota, USA
| | - Mahdi Bayat
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Viksit Kumar
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Adriana Gregory
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Jeremy Webb
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Azra Alizad
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
| | - Mostafa Fatemi
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
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9
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Okada Y, Goto Y, Tanaka R, Katashima T, Jiang X, Terao K, Sato T, Inoue T. Viscoelastic Properties of Tightly Entangled Semiflexible Polymer Solutions. Macromolecules 2018. [DOI: 10.1021/acs.macromol.8b01582] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Yuki Okada
- Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Yuka Goto
- Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Reina Tanaka
- Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Takuya Katashima
- Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Xinyue Jiang
- Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Ken Terao
- Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Takahiro Sato
- Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Tadashi Inoue
- Graduate School of Science, Osaka University, 1-1, Machikaneyama, Toyonaka, Osaka 560-0043, Japan
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10
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Tassieri M. Dynamics of Semiflexible Polymer Solutions in the Tightly Entangled Concentration Regime. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01024] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Manlio Tassieri
- Division of Biomedical Engineering,
School of Engineering, University of Glasgow, Glasgow G12 8LT, U.K
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11
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Waigh TA. Advances in the microrheology of complex fluids. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2016; 79:074601. [PMID: 27245584 DOI: 10.1088/0034-4885/79/7/074601] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
New developments in the microrheology of complex fluids are considered. Firstly the requirements for a simple modern particle tracking microrheology experiment are introduced, the error analysis methods associated with it and the mathematical techniques required to calculate the linear viscoelasticity. Progress in microrheology instrumentation is then described with respect to detectors, light sources, colloidal probes, magnetic tweezers, optical tweezers, diffusing wave spectroscopy, optical coherence tomography, fluorescence correlation spectroscopy, elastic- and quasi-elastic scattering techniques, 3D tracking, single molecule methods, modern microscopy methods and microfluidics. New theoretical techniques are also reviewed such as Bayesian analysis, oversampling, inversion techniques, alternative statistical tools for tracks (angular correlations, first passage probabilities, the kurtosis, motor protein step segmentation etc), issues in micro/macro rheological agreement and two particle methodologies. Applications where microrheology has begun to make some impact are also considered including semi-flexible polymers, gels, microorganism biofilms, intracellular methods, high frequency viscoelasticity, comb polymers, active motile fluids, blood clots, colloids, granular materials, polymers, liquid crystals and foods. Two large emergent areas of microrheology, non-linear microrheology and surface microrheology are also discussed.
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Affiliation(s)
- Thomas Andrew Waigh
- Biological Physics Group, School of Physics and Astronomy, University of Manchester, Oxford Rd., Manchester, M13 9PL, UK. Photon Science Institute, University of Manchester, Oxford Rd., Manchester, M13 9PL, UK
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12
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Tassieri M. Linear microrheology with optical tweezers of living cells 'is not an option'! SOFT MATTER 2015; 11:5792-5798. [PMID: 26100967 DOI: 10.1039/c5sm01133g] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Optical tweezers have been successfully adopted as exceptionally sensitive transducers for microrheology studies of complex fluids. Despite the general trend, in this article I explain why a similar approach should not be adopted for microrheology studies of living cells. This conclusion is acheived on the basis of statistical mechanics principles that indicate the unsuitability of optical tweezers for such purpose.
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Affiliation(s)
- Manlio Tassieri
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, UK.
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13
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Owczarz M, Motta AC, Morbidelli M, Arosio P. A Colloidal Description of Intermolecular Interactions Driving Fibril-Fibril Aggregation of a Model Amphiphilic Peptide. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:7590-7600. [PMID: 26125620 DOI: 10.1021/acs.langmuir.5b01110] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We apply a kinetic analysis platform to study the intermolecular interactions underlying the colloidal stability of dispersions of charged amyloid fibrils consisting of a model amphiphilic peptide (RADA 16-I). In contrast to the aggregation mechanisms observed in the large majority of proteins and peptides, where several elementary reactions involving both monomers and fibrils are present simultaneously, the system selected in this work allows the specific investigation of the fibril-fibril aggregation process. We examine the intermolecular interactions driving the aggregation reaction at pH 2.0 by changing the buffer composition in terms of salt concentration, type of ion as well as type and concentration of organic solvent. The aggregation kinetics are followed by dynamic light scattering, and the experimental data are simulated by Smoluchowski population balance equations, which allow to estimate the energy barrier between two colliding fibrils in terms of the Fuchs stability ratio (W). When normalized on a dimensionless time weighted on the Fuchs stability ratio, the aggregation profiles under a broad range of conditions collapse on a single master curve, indicating that the buffer composition modifies the aggregation kinetics without affecting the aggregation mechanism. Our results show that the aggregation process does not occur under diffusion-limited conditions. Rather, the reaction rate is limited by the presence of an activation energy barrier that is largely dominated by electrostatic repulsive interactions. Such interactions could be reduced by increasing the concentration of salt, which induces charge screening, or the concentration of organic solvent, which affects the dielectric constant. It is remarkable that the dependence of the activation energy on the ionic strength can be described quantitatively in terms of charge screening effects in the frame of the DLVO theory, although specific anion and cation effects are also observed. While anion effects are mainly related to the binding to the positive groups of the fibril surface and to the resulting decrease of the surface charge, cation effects are more complex and involve additional solvation forces.
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Affiliation(s)
- Marta Owczarz
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
| | - Anna C Motta
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
| | - Massimo Morbidelli
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
| | - Paolo Arosio
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Zurich 8093, Switzerland
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14
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Tassieri M, Giudice FD, Robertson EJ, Jain N, Fries B, Wilson R, Glidle A, Greco F, Netti PA, Maffettone PL, Bicanic T, Cooper JM. Microrheology with optical tweezers: measuring the relative viscosity of solutions 'at a glance'. Sci Rep 2015; 5:8831. [PMID: 25743468 PMCID: PMC4894396 DOI: 10.1038/srep08831] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 02/05/2015] [Indexed: 11/08/2022] Open
Abstract
We present a straightforward method for measuring the relative viscosity of fluids via a simple graphical analysis of the normalised position autocorrelation function of an optically trapped bead, without the need of embarking on laborious calculations. The advantages of the proposed microrheology method are evident when it is adopted for measurements of materials whose availability is limited, such as those involved in biological studies. The method has been validated by direct comparison with conventional bulk rheology methods, and has been applied both to characterise synthetic linear polyelectrolytes solutions and to study biomedical samples.
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Affiliation(s)
- Manlio Tassieri
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, UK
| | - Francesco Del Giudice
- Center for Advanced Biomaterials for Health Care @CRIB, IIT, P.le Tecchio 80, 80125 Naples, Italy
| | - Emma J. Robertson
- Department of Infection and Immunity, St George's University of London, London SW17 0RS, UK
| | - Neena Jain
- Department of Medicine, Albert Einstein College of Medicine, Bronx NY, USA
| | - Bettina Fries
- Department of Medicine, Albert Einstein College of Medicine, Bronx NY, USA
| | - Rab Wilson
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, UK
| | - Andrew Glidle
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, UK
| | - Francesco Greco
- Istituto di Ricerche sulla Combustione, IRC-CNR, P.le Tecchio 80, 80125 Naples, Italy
| | - Paolo Antonio Netti
- Center for Advanced Biomaterials for Health Care @CRIB, IIT, P.le Tecchio 80, 80125 Naples, Italy
| | - Pier Luca Maffettone
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, , Universitá di Napoli Federico II, P.le Tecchio 80, 80125 Naples, Italy
| | - Tihana Bicanic
- Department of Infection and Immunity, St George's University of London, London SW17 0RS, UK
| | - Jonathan M. Cooper
- Division of Biomedical Engineering, School of Engineering, University of Glasgow, Glasgow G12 8LT, UK
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15
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Owczarz M, Bolisetty S, Mezzenga R, Arosio P. Sol–gel transition of charged fibrils composed of a model amphiphilic peptide. J Colloid Interface Sci 2015; 437:244-251. [DOI: 10.1016/j.jcis.2014.09.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 09/09/2014] [Accepted: 09/10/2014] [Indexed: 10/24/2022]
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16
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Arosio P, Owczarz M, Wu H, Butté A, Morbidelli M. End-to-end self-assembly of RADA 16-I nanofibrils in aqueous solutions. Biophys J 2012; 102:1617-26. [PMID: 22500762 DOI: 10.1016/j.bpj.2012.03.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 02/23/2012] [Accepted: 03/02/2012] [Indexed: 10/28/2022] Open
Abstract
RADARADARADARADA (RADA 16-I) is a synthetic amphiphilic peptide designed to self-assemble in a controlled way into fibrils and higher ordered structures depending on pH. In this work, we use various techniques to investigate the state of the peptide dispersed in water under dilute conditions at different pH and in the presence of trifluoroacetic acid or hydrochloric acid. We have identified stable RADA 16-I fibrils at pH 2.0-4.5, which have a length of ∼200-400 nm and diameter of 10 nm. The fibrils have the characteristic antiparallel β-sheet structure of amyloid fibrils, as measured by circular dichroism and Fourier transform infrared spectrometry. During incubation at pH 2.0-4.5, the fibrils elongate very slowly via an end-to-end fibril-fibril aggregation mechanism, without changing their diameter, and the kinetics of such aggregation depends on pH and anion type. At pH 2.0, we also observed a substantial amount of monomers in the system, which do not participate in the fibril elongation and degrade to fragments. The fibril-fibril elongation kinetics has been simulated using the Smoluchowski kinetic model, population balance equations, and the simulation results are in good agreement with the experimental data. It is also found that the aggregation process is not limited by diffusion but rather is an activated process with energy barrier in the order of 20 kcal/mol.
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Affiliation(s)
- Paolo Arosio
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, Zurich, Switzerland
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Vikhorev PG, Vikhoreva NN, Cammarato A, Sparrow JC. In vitro motility of native thin filaments from Drosophila indirect flight muscles reveals that the held-up 2 TnI mutation affects calcium activation. J Muscle Res Cell Motil 2010; 31:171-9. [PMID: 20658179 DOI: 10.1007/s10974-010-9221-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 07/13/2010] [Indexed: 11/26/2022]
Abstract
A procedure for the isolation of regulated native thin filaments from the indirect flight muscles (IFM) of Drosophila melanogaster is described. These are the first striated invertebrate thin filaments to show Ca-regulated in vitro motility. Regulated native thin filaments from wild type and a troponin I mutant, held-up-2, were compared by in vitro motility assays that showed that the mutant troponin I caused activation of motility at pCa values higher than wild type. The held-up2 mutation, in the sole troponin I gene (wupA) in the Drosophila genome, is known to cause hypercontraction of the IFM and other muscles in vivo leading to their eventual destruction. The mutation causes substitution of alanine by valine at a homologous and completely conserved troponin I residue (A25) in the vertebrate skeletal muscle TnI isoform. The effects of the held-up 2 mutation on calcium activation of thin filament in vitro motility are discussed with respect to its effects on hypercontraction and dysfunction. Previous electron microscopy and 3-dimensional reconstruction studies showed that the tropomyosin of held-up 2 thin filaments occupies positions associated with the so-called 'closed' state, but independently of calcium concentration. This is discussed with respect to calcium dependent regulation of held-up-2 thin filaments in in vitro motility.
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Affiliation(s)
- P G Vikhorev
- Department of Biology, University of York, York YO10 5DD, UK
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Lai SK, Wang YY, Wirtz D, Hanes J. Micro- and macrorheology of mucus. Adv Drug Deliv Rev 2009; 61:86-100. [PMID: 19166889 PMCID: PMC2736374 DOI: 10.1016/j.addr.2008.09.012] [Citation(s) in RCA: 711] [Impact Index Per Article: 47.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2007] [Accepted: 09/22/2008] [Indexed: 11/30/2022]
Abstract
Mucus is a complex biological material that lubricates and protects the human lungs, gastrointestinal (GI) tract, vagina, eyes, and other moist mucosal surfaces. Mucus serves as a physical barrier against foreign particles, including toxins, pathogens, and environmental ultrafine particles, while allowing rapid passage of selected gases, ions, nutrients, and many proteins. Its selective barrier properties are precisely regulated at the biochemical level across vastly different length scales. At the macroscale, mucus behaves as a non-Newtonian gel, distinguished from classical solids and liquids by its response to shear rate and shear stress, while, at the nanoscale, it behaves as a low viscosity fluid. Advances in the rheological characterization of mucus from the macroscopic to nanoscopic levels have contributed critical understanding to mucus physiology, disease pathology, and the development of drug delivery systems designed for use at mucosal surfaces. This article reviews the biochemistry that governs mucus rheology, the macro- and microrheology of human and laboratory animal mucus, rheological techniques applied to mucus, and the importance of an improved understanding of the physical properties of mucus to advancing the field of drug and gene delivery.
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Affiliation(s)
- Samuel K. Lai
- Department of Chemical & Biomolecular Engineering (JH Primary Appointment), Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218
| | - Ying-Ying Wang
- Department of Biomedical Engineering, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Denis Wirtz
- Department of Chemical & Biomolecular Engineering (JH Primary Appointment), Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218
- Institute for NanoBioTechnology, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218
| | - Justin Hanes
- Department of Chemical & Biomolecular Engineering (JH Primary Appointment), Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218
- Institute for NanoBioTechnology, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218
- Department of Biomedical Engineering, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21205
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD 21205
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