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Akbarishandiz S, Khani S, Maia J. Adhesion dynamics of Janus nanocarriers to endothelial cells: A dissipative particle dynamics study. Phys Rev E 2024; 109:064408. [PMID: 39020963 DOI: 10.1103/physreve.109.064408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 03/28/2024] [Indexed: 07/20/2024]
Abstract
Janus nanocarriers (NCs) provide promising features in interfacial applications such as targeted drug delivery. Herein, we use dissipative particle dynamics simulations to study the adhesion dynamics of NCs with Janus ligand compositions to the endothelial cell as a function of a series of effects, such as the initial orientation, ligand density, shape, and size of Janus NCs. The Janus NCs, with its long axis parallel to the endothelial glycocalyx (EG) layer, has the best penetration depth due to its lower potential energy and the lowest shell entropy loss. Among different shapes of Janus NCs, both the potential energy and the EG entropy loss control the penetration. In fact, at the parallel orientations, Janus shapes with a robust mechanical strength and larger surface area at the EG/water interface can rotate and penetrate more efficiently. An increase in the ligand density of Janus NCs increases entropy losses of both the hydrophilic and the hydrophobic ligands and decreases the potential energy. Thus, for a specific Janus NCs, functionalizing with an appropriate ligand density would help driving forces prevail over barriers of penetration into the EG layer. For a particular ligand density, once the radius of the Janus NCs exceeds the appropriate size, barriers such as hydrophobic ligands and shell entropy losses are also reinforced significantly and surpass driving forces. Our observations reveal that entropy losses for hydrophobic ligands of Janus NCs and for the shell of NCs are decisive for the adhesion and penetration of Janus NCs to endothelial cells.
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2
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Qiao Y, He Q, Huang HH, Mastropietro D, Jiang Z, Zhou H, Liu Y, Tirrell MV, Chen W. Stretching of immersed polyelectrolyte brushes in shear flow. NANOSCALE 2023; 15:19282-19291. [PMID: 37997161 DOI: 10.1039/d3nr04187e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
The way that polymer brushes respond to shear flow has important implications in various applications, including antifouling, corrosion protection, and stimuli-responsive materials. However, there is still much to learn about the behaviours and mechanisms that govern these responses. To address this gap in knowledge, our study uses in situ X-ray reflectivity to investigate how poly(styrene sulfonate) (PSS) brushes stretch and change in different environments, such as isopropanol (a poor solvent), water (a good solvent), and aqueous solutions containing various cations (Cs+, Ba2+, La3+, and Y3+). We have designed a custom apparatus that exposes the PSS brushes to both tangential shear forces from the primary flow and upward drag forces from a secondary flow. Our experimental findings clearly show that shear forces have a significant impact on how the chains in PSS brushes are arranged. At low shear rates, the tangential shear force causes the chains to tilt, leading to brush contraction. In contrast, higher shear rates generate an upward shear force that stretches and expands the chains. By analysing electron density profiles obtained from X-ray reflectivity, we gain valuable insights into how the PSS brushes respond structurally, especially the role of the diffuse layer in this dynamic behaviour. Our results highlight the importance of the initial chain configuration, which is influenced by the solvent and cations present, in shaping how polymer brushes respond to shear flow. The strength of the salt bridge network also plays a crucial role in determining how easily the brushes can stretch, with stronger networks offering more resistance to stretching. Ultimately, our study aims to enhance our understanding of polymer physics at interfaces, with a particular focus on practical applications involving polymer brushes.
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Affiliation(s)
- Yijun Qiao
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
| | - Qiming He
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
| | - Hsin-Hsiang Huang
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
| | - Dean Mastropietro
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
| | - Zhang Jiang
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Hua Zhou
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Yuhong Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
| | - Matthew V Tirrell
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
| | - Wei Chen
- Materials Science Division and Centre for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA.
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
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3
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Akbarishandiz S, Khani S, Maia J. Adhesion dynamics of functionalized nanocarriers to endothelial cells: a dissipative particle dynamics study. SOFT MATTER 2023; 19:9254-9268. [PMID: 38009071 DOI: 10.1039/d3sm00865g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2023]
Abstract
Targeted drug delivery to endothelial cells utilizing functionalized nanocarriers (NCs) is an essential procedure in therapeutic and diagnosis therapies. Using dissipative particle dynamics simulation, NCs have been designed and combined with an endothelial environment, such as the endothelial glycocalyx (EG) layer, receptors, water, and cell wall. Furthermore, the energy landscapes of the functionalized NC with the endothelial cell have been analyzed as a function of properties such as the shape, size, initial orientation, and ligand density of NCs. Our results show that an appropriate higher ligand density for each particular NC provides more driving forces than barriers for the penetration of the NCs. Herein we report the importance of shell entropy loss for the NC shape effect on the adhesion and penetration into the EG layer. Moreover, the rotation of the disc shape NC as a wheel during the penetration is an extra driving force for its further inclusion. By increasing the NCs' size larger than the appropriate size for each particular ligand density, due to an increase in the NCs' shell entropy loss, the barriers surpass the driving forces for NC penetration. Furthermore, the parallel orientation provides the NCs with the best penetration capabilities. However, the rotation of the disc shape NCs enhances their diffusion in the perpendicular orientation too. Overall, our findings highlight the crucial role of the shell entropy loss in governing the penetration of NCs. Besides, studying NCs with a homogeneous ligand composition enabled us to cross barriers and probe energetics after the complete inclusion of the NCs.
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Affiliation(s)
- Saeed Akbarishandiz
- Department of Macromolecular Science and Engineering, Case Western Reserve University, USA.
| | - Shaghayegh Khani
- Department of Macromolecular Science and Engineering, Case Western Reserve University, USA.
| | - Joao Maia
- Department of Macromolecular Science and Engineering, Case Western Reserve University, USA.
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4
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Kabedev A, Lobaskin V. Endothelial glycocalyx permeability for nanoscale solutes. Nanomedicine (Lond) 2022; 17:979-996. [PMID: 35815713 DOI: 10.2217/nnm-2021-0367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Glycocalyx has a great impact on the accessibility of the endothelial cell membranes. Although the specific interactions play a crucial role in cross-membrane solute transport, nonspecific interactions cannot be neglected. In this work, we used computational modeling to quantify the nonspecific interactions that control the distribution of nanosized solutes across the endothelial glycocalyx. We evaluated the probabilities of various nanoparticles' passage through the luminal layer to the membrane. The calculations demonstrate that excluded volume and electrostatic interactions are decisive for the solute transport as compared with van der Waals and hydrodynamic interactions. Damaged glycocalyx models showed a relatively weak efficiency in sieving plasma solutes. We estimated the energy barriers and corresponding mean first passage times for nanoscale solute transport through the model glycocalyx.
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Affiliation(s)
- Aleksei Kabedev
- School of Physics, University College Dublin, Dublin 4, Ireland.,Department of Pharmacy, Uppsala University, Husargatan 3, Uppsala, 75 123, Sweden
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5
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Molecular dynamics simulation: A new way to understand the functionality of the endothelial glycocalyx. Curr Opin Struct Biol 2022; 73:102330. [DOI: 10.1016/j.sbi.2022.102330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 12/02/2021] [Accepted: 12/30/2021] [Indexed: 11/22/2022]
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6
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Santo KP, Neimark AV. Dissipative particle dynamics simulations in colloid and Interface science: a review. Adv Colloid Interface Sci 2021; 298:102545. [PMID: 34757286 DOI: 10.1016/j.cis.2021.102545] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/07/2021] [Accepted: 10/08/2021] [Indexed: 12/31/2022]
Abstract
Dissipative particle dynamics (DPD) is one of the most efficient mesoscale coarse-grained methodologies for modeling soft matter systems. Here, we comprehensively review the progress in theoretical formulations, parametrization strategies, and applications of DPD over the last two decades. DPD bridges the gap between the microscopic atomistic and macroscopic continuum length and time scales. Numerous efforts have been performed to improve the computational efficiency and to develop advanced versions and modifications of the original DPD framework. The progress in the parametrization techniques that can reproduce the engineering properties of experimental systems attracted a lot of interest from the industrial community longing to use DPD to characterize, help design and optimize the practical products. While there are still areas for improvements, DPD has been efficiently applied to numerous colloidal and interfacial phenomena involving phase separations, self-assembly, and transport in polymeric, surfactant, nanoparticle, and biomolecules systems.
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Affiliation(s)
- Kolattukudy P Santo
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States
| | - Alexander V Neimark
- Department of Chemical and Biochemical Engineering, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, United States.
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7
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Biagi S, Rovigatti L, Abbasi M, Bureau L, Sciortino F, Misbah C. Hydrodynamic instability and flow reduction in polymer brush coated channels. SOFT MATTER 2021; 17:9235-9245. [PMID: 34596648 DOI: 10.1039/d1sm00638j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A polymer brush is a passive medium. At equilibrium the knowledge of its chemical composition and thickness is enough for a full system characterization. However, when the brush is exposed to fluid flow it reveals a much more intriguing nature, in which filamentous protrusions and the way they interact among themselves and with the surrounding fluid are of outmost importance. Here we investigate such a rich behavior via numerical simulations. We focus on the brush hydrodynamic response at low Reynolds numbers, observing a significant fluid flow reduction inside a polymer-brush coated channel. We find that the reduction of the flow inside the channel is significantly larger than what would happen if the brush effect consisted only in reducing the effective channel width. This amplified reduction is understood as being due to the morphological instability of the brush-liquid interface which is shown to have an elastic origin: the mechanical stress acting on the brush due to the imposed flow is partially released by the interface modulation. In turn, this modulation dissipates more energy than a flat interface in the surrounding fluid, causing a reduction of flow velocity. Our results and interpretations provide an explanation for recent experimental measurements.
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Affiliation(s)
- Sofia Biagi
- Université Grenoble Alpes/CNRS, LIPhy UMR 5588, Grenoble, F-38401, France.
- Dipartimento di Fisica, Sapienza-Universitá di Roma, Piazzale A. Moro 5, 00185 Roma, Italy
| | - Lorenzo Rovigatti
- Dipartimento di Fisica, Sapienza-Universitá di Roma, Piazzale A. Moro 5, 00185 Roma, Italy
| | - Mehdi Abbasi
- Université Grenoble Alpes/CNRS, LIPhy UMR 5588, Grenoble, F-38401, France.
| | - Lionel Bureau
- Université Grenoble Alpes/CNRS, LIPhy UMR 5588, Grenoble, F-38401, France.
| | - Francesco Sciortino
- Dipartimento di Fisica, Sapienza-Universitá di Roma, Piazzale A. Moro 5, 00185 Roma, Italy
- Istituto Sistemi Complessi (ISC), Via dei Taurini 19, 00185 Roma, Italy
| | - Chaouqi Misbah
- Université Grenoble Alpes/CNRS, LIPhy UMR 5588, Grenoble, F-38401, France.
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8
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Jiang XZ, Luo KH, Ventikos Y. Understanding the Role of Endothelial Glycocalyx in Mechanotransduction via Computational Simulation: A Mini Review. Front Cell Dev Biol 2021; 9:732815. [PMID: 34485313 PMCID: PMC8415899 DOI: 10.3389/fcell.2021.732815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 07/27/2021] [Indexed: 11/25/2022] Open
Abstract
Endothelial glycocalyx (EG) is a forest-like structure, covering the lumen side of blood vessel walls. EG is exposed to the mechanical forces of blood flow, mainly shear, and closely associated with vascular regulation, health, diseases, and therapies. One hallmark function of the EG is mechanotransduction, which means the EG senses the mechanical signals from the blood flow and then transmits the signals into the cells. Using numerical modelling methods or in silico experiments to investigate EG-related topics has gained increasing momentum in recent years, thanks to tremendous progress in supercomputing. Numerical modelling and simulation allows certain very specific or even extreme conditions to be fulfilled, which provides new insights and complements experimental observations. This mini review examines the application of numerical methods in EG-related studies, focusing on how computer simulation contributes to the understanding of EG as a mechanotransducer. The numerical methods covered in this review include macroscopic (i.e., continuum-based), mesoscopic [e.g., lattice Boltzmann method (LBM) and dissipative particle dynamics (DPD)] and microscopic [e.g., molecular dynamics (MD) and Monte Carlo (MC) methods]. Accounting for the emerging trends in artificial intelligence and the advent of exascale computing, the future of numerical simulation for EG-related problems is also contemplated.
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Affiliation(s)
- Xi Zhuo Jiang
- School of Mechanical Engineering and Automation, Northeastern University, Shenyang, China
| | - Kai H Luo
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Yiannis Ventikos
- Department of Mechanical Engineering, University College London, London, United Kingdom
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9
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Barry E, Burns R, Chen W, De Hoe GX, De Oca JMM, de Pablo JJ, Dombrowski J, Elam JW, Felts AM, Galli G, Hack J, He Q, He X, Hoenig E, Iscen A, Kash B, Kung HH, Lewis NHC, Liu C, Ma X, Mane A, Martinson ABF, Mulfort KL, Murphy J, Mølhave K, Nealey P, Qiao Y, Rozyyev V, Schatz GC, Sibener SJ, Talapin D, Tiede DM, Tirrell MV, Tokmakoff A, Voth GA, Wang Z, Ye Z, Yesibolati M, Zaluzec NJ, Darling SB. Advanced Materials for Energy-Water Systems: The Central Role of Water/Solid Interfaces in Adsorption, Reactivity, and Transport. Chem Rev 2021; 121:9450-9501. [PMID: 34213328 DOI: 10.1021/acs.chemrev.1c00069] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The structure, chemistry, and charge of interfaces between materials and aqueous fluids play a central role in determining properties and performance of numerous water systems. Sensors, membranes, sorbents, and heterogeneous catalysts almost uniformly rely on specific interactions between their surfaces and components dissolved or suspended in the water-and often the water molecules themselves-to detect and mitigate contaminants. Deleterious processes in these systems such as fouling, scaling (inorganic deposits), and corrosion are also governed by interfacial phenomena. Despite the importance of these interfaces, much remains to be learned about their multiscale interactions. Developing a deeper understanding of the molecular- and mesoscale phenomena at water/solid interfaces will be essential to driving innovation to address grand challenges in supplying sufficient fit-for-purpose water in the future. In this Review, we examine the current state of knowledge surrounding adsorption, reactivity, and transport in several key classes of water/solid interfaces, drawing on a synergistic combination of theory, simulation, and experiments, and provide an outlook for prioritizing strategic research directions.
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Affiliation(s)
- Edward Barry
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Applied Materials Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Center for Molecular Engineering, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - Raelyn Burns
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Applied Materials Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - Wei Chen
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Center for Molecular Engineering, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Guilhem X De Hoe
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Center for Molecular Engineering, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Joan Manuel Montes De Oca
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Juan J de Pablo
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - James Dombrowski
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 United States
| | - Jeffrey W Elam
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Applied Materials Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Center for Molecular Engineering, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - Alanna M Felts
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 United States
| | - Giulia Galli
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - John Hack
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Qiming He
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Center for Molecular Engineering, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Xiang He
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - Eli Hoenig
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Aysenur Iscen
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 United States
| | - Benjamin Kash
- Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Harold H Kung
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemical and Biological Engineering, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 United States
| | - Nicholas H C Lewis
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Chong Liu
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Xinyou Ma
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Anil Mane
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Applied Materials Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - Alex B F Martinson
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Center for Molecular Engineering, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - Karen L Mulfort
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - Julia Murphy
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Kristian Mølhave
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Technical University of Denmark, Anker Engelunds Vej 1 Bygning 101A, Kgs. Lyngby, Lyngby, Hovedstaden 2800, DK Denmark
| | - Paul Nealey
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Yijun Qiao
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Center for Molecular Engineering, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - Vepa Rozyyev
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Applied Materials Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - George C Schatz
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 United States
| | - Steven J Sibener
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Dmitri Talapin
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - David M Tiede
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - Matthew V Tirrell
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Center for Molecular Engineering, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Andrei Tokmakoff
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Gregory A Voth
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Department of Chemistry, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Zhongyang Wang
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Zifan Ye
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
| | - Murat Yesibolati
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Technical University of Denmark, Anker Engelunds Vej 1 Bygning 101A, Kgs. Lyngby, Lyngby, Hovedstaden 2800, DK Denmark
| | - Nestor J Zaluzec
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Photon Sciences Directorate, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States
| | - Seth B Darling
- Advanced Materials for Energy-Water Systems (AMEWS) Energy Frontier Research Center (EFRC), Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Center for Molecular Engineering, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Chemical Sciences and Engineering Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439 United States.,Pritzker School of Molecular Engineering, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 United States
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10
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Grzelka M, Antoniuk I, Drockenmuller É, Chennevière A, Léger L, Restagno F. Slip and Friction Mechanisms at Polymer Semi-Dilute Solutions/Solid Interfaces. Macromolecules 2021. [DOI: 10.1021/acs.macromol.0c02804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marion Grzelka
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - Iurii Antoniuk
- Univ Lyon, Université Lyon 1, CNRS, Ingénierie des Matériaux Polymères, UMR 5223, F-69003 Lyon, France
| | - Éric Drockenmuller
- Univ Lyon, Université Lyon 1, CNRS, Ingénierie des Matériaux Polymères, UMR 5223, F-69003 Lyon, France
| | | | - Liliane Léger
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
| | - Frédéric Restagno
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405 Orsay, France
- Laboratoire Léon Brillouin, CEA Saclay, 91191 Gif-sur-Yvette, France
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11
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Pastorino C, Müller M. Liquid and Droplet Transport in Brush-Coated Cylindrical Nanochannels: Brush-Assisted Droplet Formation. J Phys Chem B 2021; 125:442-449. [PMID: 33400523 DOI: 10.1021/acs.jpcb.0c09189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We study, by coarse-grained molecular dynamics simulations, equilibrium and flow properties of a liquid in cylindrical nanochannels, coated with polymer brushes. The parameters of the interaction potential model confer a chemical incompatibility between brush monomers and liquid particles. First, we study cylindrical channels whose radii are larger than the brush height and a continuous column of liquid forms at the center of the channel. These results are contrasted to the limiting case in which the radius of the cylinder is comparable to the brush height. In this second case, the grafted polymers interact across the channel and "close" it. We observe a train of droplets as the stable liquid morphology. The droplet size is comparable to the cylinder radius. By applying a constant body force onto the liquid, we induce a Poiseuille-like flow and investigate the morphology and flow rate as a function of driving force. Upon increasing the driving force, we encounter a nonequilibrium transition from a closed channel with slowly moving droplets to a flowing liquid thread at the center. The switching between these two states is reversible.
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Affiliation(s)
- C Pastorino
- Departamento de Física de la Materia Condensada, Centro Atómico Constituyentes, CNEA, Av.Gral. Paz 1499, B1650 San Martín, Pcia. de Buenos Aires, Argentina.,Instituto de Nanociencia y Nanotecnología CONICET-CNEA, B1650 Buenos Aires, Argentina
| | - M Müller
- Institut für Theoretische Physik, Friedrich-Hund-Platz 1, 37077 Göttingen, Germany
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12
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Ramesh P, Xu WL, Sorci M, Trant C, Lee S, Kilduff J, Yu M, Belfort G. Organic solvent filtration by brush membranes: Permeability, selectivity and fouling correlate with degree of SET-LRP grafting. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2020.118699] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Xiao L, Zhang K, Zhao J, Chen S, Liu Y. Viscosity measurement and simulation of microbubble wetting on flat surfaces with many-body dissipative particle dynamics model. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2020.125559] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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Choudhury A, Dey M, Dixit HN, Feng JJ. Tear-film breakup: The role of membrane-associated mucin polymers. Phys Rev E 2021; 103:013108. [PMID: 33601537 DOI: 10.1103/physreve.103.013108] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 01/03/2021] [Indexed: 12/21/2022]
Abstract
Mucin polymers in the tear film protect the corneal surface from pathogens and modulate the tear-film flow characteristics. Recent studies have suggested a relationship between the loss of membrane-associated mucins and premature rupture of the tear film in various eye diseases. This work aims to elucidate the hydrodynamic mechanisms by which loss of membrane-associated mucins causes premature tear-film rupture. We model the bulk of the tear film as a Newtonian fluid in a two-dimensional periodic domain, and the lipid layer at the air-tear interface as insoluble surfactants. Gradual loss of membrane-associated mucins produces growing areas of exposed cornea in direct contact with the tear fluid. We represent the hydrodynamic consequences of this morphological change through two mechanisms: an increased van der Waals attraction due to loss of wettability on the exposed area, and a change of boundary condition from an effective negative slip on the mucin-covered areas to the no-slip condition on exposed cornea. Finite-element computations, with an arbitrary Lagrangian-Eulerian scheme to handle the moving interface, demonstrate a strong effect of the elevated van der Waals attraction on precipitating tear-film breakup. The change in boundary condition on the cornea has a relatively minor role. Using realistic parameters, our heterogeneous mucin model is able to predict quantitatively the shortening of tear-film breakup time observed in diseased eyes.
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Affiliation(s)
- Anjishnu Choudhury
- Department of Mechanical and Aerospace Engineering, Indian Institute of Technology Hyderabad, Telangana 502285, India and Department of Mathematics, University of British Columbia, Vancouver, British Columbia V6T 1Z2, Canada
| | - Mohar Dey
- Department of Mathematics, University of British Columbia, Vancouver, British Columbia V6T 1Z2, Canada
| | - Harish N Dixit
- Department of Mechanical and Aerospace Engineering, Indian Institute of Technology Hyderabad, Telangana 502285, India
| | - James J Feng
- Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada and Department of Mathematics, University of British Columbia, Vancouver, British Columbia V6T 1Z2, Canada
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15
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Qiao Y, Zhou H, Jiang Z, He Q, Gan S, Wang H, Wen S, de Pablo J, Liu Y, Tirrell MV, Chen W. An in situ shearing x-ray measurement system for exploring structures and dynamics at the solid-liquid interface. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:013908. [PMID: 32012592 DOI: 10.1063/1.5129819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Accepted: 01/05/2020] [Indexed: 06/10/2023]
Abstract
Revealing interfacial structure and dynamics has been one of the essential thematic topics in material science and condensed matter physics. Synchrotron-based x-ray scattering techniques can deliver unique and insightful probing of interfacial structures and dynamics, in particular, in reflection geometries with higher surface and interfacial sensitivity than transmission geometries. We demonstrate the design and implementation of an in situ shearing x-ray measurement system, equipped with both inline parallel-plate and cone-and-plate shearing setups and operated at the advanced photon source at Argonne National Laboratory, to investigate the structures and dynamics of end-tethered polymers at the solid-liquid interface. With a precise lifting motor, a micrometer-scale gap can be produced by aligning two surfaces of a rotating upper shaft and a lower sample substrate. A torsional shear flow forms in the gap and applies tangential shear forces on the sample surface. The technical combination with nanoscale rheology and the utilization of in situ x-ray scattering allow us to gain fundamental insights into the complex dynamics in soft interfaces under shearing. In this work, we demonstrate the technical scope and experimental capability of the in situ shearing x-ray system through the measurements of charged polymers at both flat and curved interfaces upon shearing. Through the in situ shearing x-ray scattering experiments integrated with theoretical simulations, we aim to develop a detailed understanding of the short-range molecular structure and mesoscale ionic aggregate morphology, as well as ion transport and dynamics in soft interfaces, thereby providing fundamental insight into a long-standing challenge in ionic polymer brushes with a significant technological impact.
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Affiliation(s)
- Yijun Qiao
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Hua Zhou
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Zhang Jiang
- X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Qiming He
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Shenglong Gan
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Hongdong Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Shizhu Wen
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Juan de Pablo
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Yuhong Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Matthew V Tirrell
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Wei Chen
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
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16
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Wang H, Pemberton JE. Direct Nanoscopic Measurement of Laminar Slip Flow Penetration of Deformable Polymer Brush Surfaces: Synergistic Effect of Grafting Density and Solvent Quality. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13646-13655. [PMID: 31558025 DOI: 10.1021/acs.langmuir.9b02357] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A detailed quantitative nanoscopic description of soft surfaces under dynamic flow is lacking, despite its importance. To better understand the role of surface texture in nanoscopic mass transport in complex media, we used Förster resonance energy transfer in combination with total internal reflectance fluorescence microscopy (FRET-TIRFM) to directly measure laminar slip flow penetration depth (slip length) on poly(N-isopropylacrylamide) (pNIPAM) thin films (50-110 nm) of different grafting densities (0.60, 0.38, and 0.27 chain/nm2) in solvents of different qualities created via cononsolvency in situ. Nontrivial synergistic interplay of grafting density and solvent quality on slip length was observed. Slip lengths are typically tens of nm (40-100 nm), increasing and then reaching a plateau with applied linear flow velocity (192-2,952 μm/s) regardless of experimental system. Slip length was systematically larger for lower density films, but the effect of grafting density was more significant in a good solvent than a poor solvent. Interestingly, however, the stagnant film thickness (polymer swollen thickness minus the slip length) collapsed to almost a singular value for a given grafting density regardless of solvent quality, likely suggesting a large gradient of segmental mobility at nonequilibrium. Moreover, we found that slip flow penetrates into soft pNIPAM surfaces more deeply in a good solvent than in a poor solvent and that this behavior was general and independent of grafting density. This behavior is counter to the notion that less interaction between a fluid (probe) and a solid surface promotes slip.
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Affiliation(s)
- Huan Wang
- Department of Chemistry and Biochemistry University of Arizona , Tucson , Arizona 85721 , United States
| | - Jeanne E Pemberton
- Department of Chemistry and Biochemistry University of Arizona , Tucson , Arizona 85721 , United States
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17
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Sáez P, Gallo D, Morbiducci U. Mechanotransmission of haemodynamic forces by the endothelial glycocalyx in a full-scale arterial model. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190607. [PMID: 31312506 PMCID: PMC6599767 DOI: 10.1098/rsos.190607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 05/14/2019] [Indexed: 06/10/2023]
Abstract
The glycocalyx has been identified as a key mechano-sensor of the shear forces exerted by streaming blood onto the vascular endothelial lining. Although the biochemical reaction to the blood flow has been extensively studied, the mechanism of transmission of the haemodynamic shear forces to the endothelial transmembrane anchoring structures and, consequently, to the subcellular elements in the cytoskeleton, is still not fully understood. Here we apply a multiscale approach to elucidate how haemodynamic shear forces are transmitted to the transmembrane anchors of endothelial cells. Wall shear stress time histories, as obtained from image-based computational haemodynamics models of a carotid bifurcation, are used as a load and a continuum model is applied to obtain the mechanical response of the glycocalyx all along the cardiac cycle. The main findings of this in silico study are that: (1) the forces transmitted to the transmembrane anchors are in the range of 1-10 pN, which is in the order of magnitude reported for the different conformational states of transmembrane mechanotranductors; (2) locally, the forces transmitted to the anchors of the glycocalyx structure can be markedly different from the near-wall haemodynamic shear forces both in amplitude and frequency content. The findings of this in silico approach warrant future studies focusing on the actual forces transmitted to the transmembrane mechanotransductors, which might outperform haemodynamic descriptors of disturbed shear as localizing factors of vascular disease.
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Affiliation(s)
- P. Sáez
- Laboratori de Càlcul Numèric (LàCaN), Universitat Politècnica de Catalunya, Barcelona, Spain
- Barcelona Graduate School of Mathematics (BGSMath), Barcelona, Spain
| | - D. Gallo
- PoliTo Med Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy
| | - U. Morbiducci
- PoliTo Med Lab, Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Torino, Italy
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18
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The role of solvent quality, inhomogeneous polymer brush composition, grafting density and number of free chains on the viscosity, friction between surfaces, and their scaling laws. Chem Phys Lett 2019. [DOI: 10.1016/j.cplett.2019.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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19
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Wang Y, Li Z, Xu J, Yang C, Karniadakis GE. Concurrent coupling of atomistic simulation and mesoscopic hydrodynamics for flows over soft multi-functional surfaces. SOFT MATTER 2019; 15:1747-1757. [PMID: 30672954 PMCID: PMC6414210 DOI: 10.1039/c8sm02170h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We develop an efficient parallel multiscale method that bridges the atomistic and mesoscale regimes, from nanometers to microns and beyond, via concurrent coupling of atomistic simulation and mesoscopic dynamics. In particular, we combine an all-atom molecular dynamics (MD) description for specific atomistic details in the vicinity of the functional surface with a dissipative particle dynamics (DPD) approach that captures mesoscopic hydrodynamics in the domain away from the functional surface. In order to achieve a seamless transition in dynamic properties we endow the MD simulation with a DPD thermostat, which is validated against experimental results by modeling water at different temperatures. We then validate the MD-DPD coupling method for transient Couette and Poiseuille flows, demonstrating that the concurrent MD-DPD coupling can resolve accurately the continuum-based analytical solutions. Subsequently, we simulate shear flows over grafted polydimethylsiloxane (PDMS) surfaces (polymer brushes) for various grafting densities, and investigate the slip flow as a function of the shear stress. We verify that a "universal" power law exists for the slip length, in agreement with published results. Having validated the MD-DPD coupling method, we simulate time-dependent flows past an endothelial glycocalyx layer (EGL) in a microchannel. Coupled simulation results elucidate the dynamics of the EGL changing from an equilibrium state to a compressed state under shear by aligning the molecular structures along the shear direction. MD-DPD simulation results agree well with results of a single MD simulation, but with the former more than two orders of magnitude faster than the latter for system sizes above one micron.
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Affiliation(s)
- Yuying Wang
- CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
- Division of Applied Mathematics, Brown University, Providence, RI 02912, USA
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhen Li
- Division of Applied Mathematics, Brown University, Providence, RI 02912, USA
| | - Junbo Xu
- CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Chao Yang
- CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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20
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Speyer K, Pastorino C. Pressure responsive gating in nanochannels coated by semiflexible polymer brushes. SOFT MATTER 2019; 15:937-946. [PMID: 30644495 DOI: 10.1039/c8sm02388c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We study by coarse-grained molecular-dynamics simulations the liquid flow in a slit channel with the inner walls coated by semiflexible polymer brushes. The distance between walls is close enough such that polymers grafted to opposing walls interact among each other and form bundles across the channel in poor solvent conditions. The solvent is simulated explicitly, including particles that fill the interior of the channel. The system is studied in equilibrium and under flow, by applying a constant body force on each particle of the system. A non-linear relation between external force and flow rate is observed, for a particular set of parameters. This non-linear response is linked to a morphological change of the polymer brushes. For large enough forces, the bundle structures formed across the channel break as the chains lean in the direction of the flow, and clear the middle of the channel. This morphological alteration of the polymer configurations translates in a sudden increase in the flow rate, acting as a pressure-responsive gate. The relation between flow and external force is investigated for various parameters, such as grafting density, quality of the solvent and polymer bending rigidity. We observe a non-monotonic dependence of the flow as a function of the polymer rigidity, and find an optimum value for the persistence length. We also find that the force threshold at which the morphological changes happen in the polymer brush, depends linearly on the grafting density. These findings can lead to new flow control techniques in micro and nano-fluidic devices.
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Affiliation(s)
- K Speyer
- Departamento de Física de la Materia Condensada, Centro Atómico Constituyentes, CNEA, Av. Gral. Paz 1499, 1650 Pcia. de Buenos Aires, Argentina.
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21
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Jiang XZ, Gong H, Luo KH, Ventikos Y. Large-scale molecular dynamics simulation of coupled dynamics of flow and glycocalyx: towards understanding atomic events on an endothelial cell surface. J R Soc Interface 2018; 14:rsif.2017.0780. [PMID: 29212760 PMCID: PMC5746579 DOI: 10.1098/rsif.2017.0780] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 11/10/2017] [Indexed: 12/11/2022] Open
Abstract
The glycocalyx has a prominent role in orchestrating multiple biological processes occurring at the plasma membrane. In this paper, an all-atom flow/glycocalyx system is constructed with the bulk flow velocity in the physiologically relevant ranges for the first time. The system is simulated by molecular dynamics using 5.8 million atoms. Flow dynamics and statistics in the presence of the glycocalyx are presented and discussed. Complex dynamic behaviours of the glycocalyx, particularly the sugar chains, are observed in response to blood flow. In turn, the motion of the glycocalyx, including swing and swirling, disturbs the flow by altering the velocity profiles and modifying the vorticity distributions. As a result, the initially one-dimensional forcing is spread to all directions in the region near the endothelial cell surface. Furthermore, the coupled dynamics exist not only between the flow and the glycocalyx but also within the glycocalyx molecular constituents. Shear stress distributions between one-dimer and three-dimer cases are also conducted. Finally, potential force transmission pathways are discussed based on the dynamics of the glycocalyx constituents, which provides new insight into the mechanism of mechanotransduction of the glycocalyx. These findings have relevance in the pathologies of glycocalyx-related diseases, for example in renal or cardiovascular conditions.
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Affiliation(s)
- Xi Zhuo Jiang
- Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Haipeng Gong
- MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - Kai Hong Luo
- Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | - Yiannis Ventikos
- Department of Mechanical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
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22
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Davies HS, Débarre D, El Amri N, Verdier C, Richter RP, Bureau L. Elastohydrodynamic Lift at a Soft Wall. PHYSICAL REVIEW LETTERS 2018; 120:198001. [PMID: 29799224 DOI: 10.1103/physrevlett.120.198001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 03/02/2018] [Indexed: 06/08/2023]
Abstract
We study experimentally the motion of nondeformable microbeads in a linear shear flow close to a wall bearing a thin and soft polymer layer. Combining microfluidics and 3D optical tracking, we demonstrate that the steady-state bead-to-surface distance increases with the flow strength. Moreover, such lift is shown to result from flow-induced deformations of the layer, in quantitative agreement with theoretical predictions from elastohydrodynamics. This study thus provides the first experimental evidence of "soft lubrication" at play at small scale, in a system relevant, for example, to the physics of blood microcirculation.
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Affiliation(s)
| | | | - Nouha El Amri
- Université Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
| | - Claude Verdier
- Université Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
| | - Ralf P Richter
- School of Biomedical Sciences, Faculty of Biological Sciences, School of Physics and Astronomy, Faculty of Mathematics and Physical Sciences, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
- CIC biomaGUNE, Paseo Miramon 182, 20014 San Sebastian, Spain
| | - Lionel Bureau
- Université Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France
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23
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Regimes of Flow over Complex Structures of Endothelial Glycocalyx: A Molecular Dynamics Simulation Study. Sci Rep 2018; 8:5732. [PMID: 29636511 PMCID: PMC5893603 DOI: 10.1038/s41598-018-24041-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 03/26/2018] [Indexed: 01/20/2023] Open
Abstract
Flow patterns on surfaces grafted with complex structures play a pivotal role in many engineering and biomedical applications. In this research, large-scale molecular dynamics (MD) simulations are conducted to study the flow over complex surface structures of an endothelial glycocalyx layer. A detailed structure of glycocalyx has been adopted and the flow/glycocalyx system comprises about 5,800,000 atoms. Four cases involving varying external forces and modified glycocalyx configurations are constructed to reveal intricate fluid behaviour. Flow profiles including temporal evolutions and spatial distributions of velocity are illustrated. Moreover, streamline length and vorticity distributions under the four scenarios are compared and discussed to elucidate the effects of external forces and glycocalyx configurations on flow patterns. Results show that sugar chain configurations affect streamline length distributions but their impact on vorticity distributions is statistically insignificant, whilst the influence of the external forces on both streamline length and vorticity distributions are trivial. Finally, a regime diagram for flow over complex surface structures is proposed to categorise flow patterns.
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24
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Structure and elasticity of bush and brush-like models of the endothelial glycocalyx. Sci Rep 2018; 8:240. [PMID: 29321567 PMCID: PMC5762753 DOI: 10.1038/s41598-017-18577-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/14/2017] [Indexed: 12/12/2022] Open
Abstract
The endothelial glycocalyx (EG), a sugar-rich layer that lines the luminal surface of blood vessels, is an important constituent of the vascular system. Although the chemical composition of the EG is fairly well known, there is no consensus regarding its ultrastructure. While previous experiments probed the properties of the layer at the continuum level, they did not provide sufficient insight into its molecular organisation. In this work, we investigate the EG mechanics using two simple brush and bush-like simulation models, and use these models to describe its molecular structure and elastic response to indentation. We analyse the relationship between the mechanical properties of the EG layer and several molecular parameters, including the filament bending rigidity, grafting density, and the type of ultrastructure . We show that variations in the glycan density determine the elasticity of the EG for small deformations, and that the normal stress may be effectively dampened by the EG layer, preventing the stress from being transferred to the cell membrane. Furthermore, our bush-like model allows us to evaluate the forces and energies required to overcome the mechanical resistance of the EG.
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25
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Mirbod P, Wu Z, Ahmadi G. Laminar flow drag reduction on soft porous media. Sci Rep 2017; 7:17263. [PMID: 29222460 PMCID: PMC5722956 DOI: 10.1038/s41598-017-17141-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 11/22/2017] [Indexed: 11/10/2022] Open
Abstract
While researches have focused on drag reduction of various coated surfaces such as superhydrophobic structures and polymer brushes, the insights tso understand the fundamental physics of the laminar skin friction coefficient and the related drag reduction due to the formation of finite velocity at porous surfaces is still relatively unknown. Herein, we quantitatively investigated the flow over a porous medium by developing a framework to model flow of a Newtonian fluid in a channel where the lower surface was replaced by various porous media. We showed that the flow drag reduction induced by the presence of the porous media depends on the values of the permeability parameter α = L/(MK)1/2 and the height ratio δ = H/L, where L is the half thickness of the free flow region, H is the thickness and K is the permeability of the fiber layer, and M is the ratio of the fluid effective dynamic viscosity μe in porous media to its dynamic viscosity μ. We also examined the velocity and shear stress profiles for flow over the permeable layer for the limiting cases of α → 0 and α → ∞. The model predictions were compared with the experimental data for specific porous media and good agreement was found.
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Affiliation(s)
- Parisa Mirbod
- Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York, United States.
| | - Zhenxing Wu
- Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York, United States
| | - Goodarz Ahmadi
- Department of Mechanical and Aeronautical Engineering, Clarkson University, Potsdam, New York, United States
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26
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Speyer K, Pastorino C. Droplet Transport in a Nanochannel Coated by Hydrophobic Semiflexible Polymer Brushes: The Effect of Chain Stiffness. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:10753-10763. [PMID: 28892398 DOI: 10.1021/acs.langmuir.7b02640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We study the influence of chain stiffness on droplet flow in a nanochannel, coated with semiflexible hydrophobic polymers by means of nonequilibrium molecular dynamics simulations. The studied system is then a moving droplet in the slit channel, coexisting with its vapor and subjected to periodic boundary conditions in the flow direction. The polymer chains, grafted by the terminal bead to the confining walls, are described by a coarse-grained model that accounts for chain connectivity, excluded volume interactions and local chain stiffness. The rheological, frictional and dynamical properties of the brush are explored over a wide range of persistence lengths. We find a rich behavior of polymer conformations and concomitant changes in the friction properties over the wide range of studied polymer stiffnesses. A rapid decrease in the droplet velocity was observed as the rigidity of the chains is increased for polymers whose persistence length is smaller than their contour length. We find a strong relation between the internal dynamics of the brush and the droplet transport properties, which could be used to tailor flow properties by surface functionalization. The monomers of the brush layer, under the droplet, present a collective "treadmill belt" like dynamics which can only be present due the existence of grafted chains. We describe its changes in spatial extension upon variations of polymer stiffness, with bidimensional velocity and density profiles. The deformation of the polymer brushes due to the presence of the droplet is analyzed in detail. Lastly, the droplet-gas interaction is studied by varying the liquid to gas ratio, observing a 16% speed increase for droplets that flow close to each other, compared to a train of droplets that present a large gap between consecutive droplets.
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Affiliation(s)
- K Speyer
- Departamento de Física de la Materia Condensada, Centro Atómico Constituyentes, CNEA , Av.Gral. Paz 1499, 1650 Pcia. de Buenos Aires, Argentina
- CONICET , Godoy Cruz 2290 (C1425FQB) Buenos Aires, Argentina
| | - C Pastorino
- Departamento de Física de la Materia Condensada, Centro Atómico Constituyentes, CNEA , Av.Gral. Paz 1499, 1650 Pcia. de Buenos Aires, Argentina
- CONICET , Godoy Cruz 2290 (C1425FQB) Buenos Aires, Argentina
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Hernández Velázquez J, Mejía-Rosales S, Gama Goicochea A. Nanorheology of poly - and monodispersed polymer brushes under oscillatory flow as models of epithelial cancerous and healthy cell brushes. POLYMER 2017. [DOI: 10.1016/j.polymer.2017.09.046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Qi S, Klushin LI, Skvortsov AM, Schmid F. Polydisperse Polymer Brushes: Internal Structure, Critical Behavior, and Interaction with Flow. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b02026] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Shuanhu Qi
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7, D-55099 Mainz, Germany
| | - Leonid I. Klushin
- Department of Physics, American University of Beirut, P.O. Box 11-0236, Beirut 1107 2020, Lebanon
| | | | - Friederike Schmid
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg
7, D-55099 Mainz, Germany
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Keating JJ, Imbrogno J, Belfort G. Polymer Brushes for Membrane Separations: A Review. ACS APPLIED MATERIALS & INTERFACES 2016; 8:28383-28399. [PMID: 27709877 DOI: 10.1021/acsami.6b09068] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The fundamentals and applications of polymer brush-modified membranes are reviewed. This new class of synthetic membranes is explored with an emphasis on tuning the membrane performance through polymer brush grafting. This work highlights the intriguing performance characteristics of polymer brush-modified membranes in a variety of separations. Polymer brushes are a versatile and effective means in designing membranes for applications in protein adsorption and purification, colloid stabilization, sensors, water purification, pervaporation of organic compounds, gas separations, and as stimuli responsive materials.
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Affiliation(s)
- John J Keating
- Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Joseph Imbrogno
- Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
| | - Georges Belfort
- Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
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Gama Goicochea A, López-Esparza R, Balderas Altamirano M, Rivera-Paz E, Waldo-Mendoza M, Pérez E. Friction coefficient and viscosity of polymer brushes with and without free polymers as slip agents. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.03.039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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31
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Yazdani A, Li X, Em Karniadakis G. Dynamic and rheological properties of soft biological cell suspensions. RHEOLOGICA ACTA 2016; 55:433-449. [PMID: 27540271 PMCID: PMC4987001 DOI: 10.1007/s00397-015-0869-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Quantifying dynamic and rheological properties of suspensions of soft biological particles such as vesicles, capsules, and red blood cells (RBCs) is fundamentally important in computational biology and biomedical engineering. In this review, recent studies on dynamic and rheological behavior of soft biological cell suspensions by computer simulations are presented, considering both unbounded and confined shear flow. Furthermore, the hemodynamic and hemorheological characteristics of RBCs in diseases such as malaria and sickle cell anemia are highlighted.
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Affiliation(s)
- Alireza Yazdani
- Division of Applied Mathematics, Brown University, Providence, Rhode Island 02912, USA
| | - Xuejin Li
- Division of Applied Mathematics, Brown University, Providence, Rhode Island 02912, USA
| | - George Em Karniadakis
- Division of Applied Mathematics, Brown University, Providence, Rhode Island 02912, USA
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Al-Khazraji BK, Jackson DN, Goldman D. A Microvascular Wall Shear Rate Function Derived From In Vivo Hemodynamic and Geometric Parameters in Continuously Branching Arterioles. Microcirculation 2016; 23:311-9. [PMID: 27018869 DOI: 10.1111/micc.12279] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 03/26/2016] [Indexed: 12/26/2022]
Abstract
OBJECTIVES Conventional approaches to WSR estimation in the microcirculation involve assumptions that may result in under-/over-estimation of WSR. Therefore, our objectives were: (i) calculate WSR from RBC velocity profiles for a wide range of arteriolar diameters, (ii) provide an experimentally derived and straightforward WSR estimation function, and (iii) compare calculated to conventional WSR estimations. METHODS We characterized RBC velocity profiles in arterioles (n = 39) of branching networks (21-115 μm) in the rat gluteus maximus muscle (n = 6). Measures included mean and maximum velocities, CFL thickness, and RBC column edge velocity, and an experiment-based WSR function was derived. RESULTS CFL thickness (1-4.3 μm) positively correlated with arteriolar diameter (r(2) = 0.64). Results from the WSR equation were similar to values from edge RBC velocities/CFL. Experimental WSRs (1317-4334/sec) were independent of arteriolar diameter, and were greater than pseudoshear rates (for VRatio of 1.6, 2, or diameter-dependent VRatio function) (p < 0.05). CONCLUSION A WSR equation was derived from experimental hemodynamic parameters, and is adaptable to other velocity measurement techniques in order to obtain WSR and stress (when plasma viscosity is known). These findings provide insight on the nature of conventional WSR calculation methods in underestimating microvascular WSR values.
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Affiliation(s)
- Baraa K Al-Khazraji
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
| | - Dwayne N Jackson
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada.,Biomedical Engineering Graduate Program, The University of Western Ontario, London, Ontario, Canada
| | - Daniel Goldman
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada.,Biomedical Engineering Graduate Program, The University of Western Ontario, London, Ontario, Canada
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33
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Surface wave excitations and backflow effect over dense polymer brushes. Sci Rep 2016; 6:22257. [PMID: 26975329 PMCID: PMC4792148 DOI: 10.1038/srep22257] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 02/10/2016] [Indexed: 02/06/2023] Open
Abstract
Polymer brushes are being increasingly used to tailor surface physicochemistry for diverse applications such as wetting, adhesion of biological objects, implantable devices and much more. Here we perform Dissipative Particle Dynamics simulations to study the behaviour of dense polymer brushes under flow in a slit-pore channel. We discover that the system displays flow inversion at the brush interface for several disconnected ranges of the imposed flow. We associate such phenomenon to collective polymer dynamics: a wave propagating on the brush surface. The relation between the wavelength, the amplitude and the propagation speed of the flow-generated wave is consistent with the solution of the Stokes equations when an imposed traveling wave is assumed as the boundary condition (the famous Taylor’s swimmer).
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Charrault E, Lee T, Easton CD, Neto C. Boundary flow on end-grafted PEG brushes. SOFT MATTER 2016; 12:1906-1914. [PMID: 26700583 DOI: 10.1039/c5sm02546j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We investigated the boundary conditions for flow of a Newtonian liquid over soft interfaces by measuring hydrodynamic drainage forces with colloid probe atomic force microscopy in a viscous liquid. The investigated soft surfaces are end-grafted brushes of thiolated poly(ethylene glycol) (PEG), of molecular weight 1k and 30k, grafted-to gold. The conditions for brush preparation were optimized as to meet the stringent conditions required for surface force measurements, namely reproducible and uniform surface composition and roughness. The fit of a slip model to the experimental data returned a slip length of 16 nm on the PEG 1k brush and 25 nm on the PEG30k brush. The slip length can be interpreted as a penetration length, which accounts for flow within the top half of the brush for the PEG30k case, and within the brush and surface roughness for the PEG1k case. These findings confirm earlier simulation studies by our group on the flow of liquids within polymer brushes.
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Affiliation(s)
- Eric Charrault
- School of Chemistry F11, The University of Sydney, NSW 2006, Australia.
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Gompper G, Fedosov DA. Modeling microcirculatory blood flow: current state and future perspectives. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2015; 8:157-68. [PMID: 26695350 DOI: 10.1002/wsbm.1326] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 11/03/2015] [Accepted: 11/03/2015] [Indexed: 12/31/2022]
Abstract
Microvascular blood flow determines a number of important physiological processes of an organism in health and disease. Therefore, a detailed understanding of microvascular blood flow would significantly advance biophysical and biomedical research and its applications. Current developments in modeling of microcirculatory blood flow already allow to go beyond available experimental measurements and have a large potential to elucidate blood flow behavior in normal and diseased microvascular networks. There exist detailed models of blood flow on a single cell level as well as simplified models of the flow through microcirculatory networks, which are reviewed and discussed here. The combination of these models provides promising prospects for better understanding of blood flow behavior and transport properties locally as well as globally within large microvascular networks.
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Affiliation(s)
- Gerhard Gompper
- Theoretical Soft Matter and Biophysics, Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich, Germany
| | - Dmitry A Fedosov
- Theoretical Soft Matter and Biophysics, Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, Jülich, Germany
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36
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Speyer K, Pastorino C. Brushes of semiflexible polymers in equilibrium and under flow in a super-hydrophobic regime. SOFT MATTER 2015; 11:5473-5484. [PMID: 26061866 DOI: 10.1039/c5sm01075f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We performed molecular dynamics simulations to study the equilibrium and flow properties of a liquid in a nano-channel with confining surfaces coated with a layer of grafted semiflexible polymers. The coverage spans a wide range of grafting densities from essentially isolated chains to dense brushes. The end-grafted polymers were described by a bead spring model with a harmonic potential to include the bond stiffness of the chains. We varied the rigidity of the chains, from fully flexible polymers to rigid rods, in which the configurational entropy of the chains is negligible. The brush-liquid interaction was tuned to obtain a super-hydrophobic channel, in which the liquid did not penetrate the polymer brush, giving rise to a Cassie-Baxter state. Equilibrium properties such as brush height and bending energy were measured, varying the grafting density and the stiffness of the polymers. We also studied the characteristics of the brush-liquid interface and the morphology of the polymer chains supporting the liquid for different bending rigidities. Non-equilibrium simulations were performed, moving the walls of the channel in opposite directions at constant speed, obtaining a Couette velocity profile in the bulk liquid. The molecular degrees of freedom of the polymers were studied as a function of the Weissenberg number. Also, the violation of the no-slip boundary condition and the slip properties were analyzed as a function of the shear rate, grafting density and bending stiffness. At high grafting densities, a finite slip length independent of the shear rate or bending constant was found, while at low grafting densities a very interesting non-monotonic dependence on the bending constant is observed.
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Affiliation(s)
- K Speyer
- Departamento de Física de la Materia Condensada, Centro Atómico Constituyentes, CNEA, Av. Gral. Paz 1499, 1650 Pcia. de Buenos Aires, Argentina.
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Deng M, Grinberg L, Caswell B, Karniadakis GE. Effects of thermal noise on the transitional dynamics of an inextensible elastic filament in stagnation flow. SOFT MATTER 2015; 11:4962-72. [PMID: 26023834 PMCID: PMC4478604 DOI: 10.1039/c4sm02395a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We investigate the dynamics of a single inextensible elastic filament subject to anisotropic friction in a viscous stagnation-point flow, by employing both a continuum model represented by Langevin type stochastic partial differential equations (SPDEs) and a dissipative particle dynamics (DPD) method. Unlike previous works, the filament is free to rotate and the tension along the filament is determined by the local inextensible constraint. The kinematics of the filament is recorded and studied with normal modes analysis. The results show that the filament displays an instability induced by negative tension, which is analogous to Euler buckling of a beam. Symmetry breaking of normal modes dynamics and stretch-coil transitions are observed above the threshold of the buckling instability point. Furthermore, both temporal and spatial noise are amplified resulting from the interaction of thermal fluctuations and nonlinear filament dynamics. Specifically, the spatial noise is amplified with even normal modes being excited due to symmetry breaking, while the temporal noise is amplified with increasing time correlation length and variance.
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Affiliation(s)
- Mingge Deng
- Division of Applied Mathematics, Brown University, Providence, RI 02912, USA.
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38
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Neratova IV, Kreer T, Sommer JU. Translocation of Molecules with Different Architectures through a Brush-Covered Microchannel. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b00042] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Irina V. Neratova
- Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, D-01069 Dresden, Germany
- Institut
für Theoretische Physik, Technische Universität Dresden, Zellescher Weg 17, D-01069 Dresden, Germany
| | - Torsten Kreer
- Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, D-01069 Dresden, Germany
| | - Jens-Uwe Sommer
- Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straße 6, D-01069 Dresden, Germany
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Cruz-Chu ER, Malafeev A, Pajarskas T, Pivkin IV, Koumoutsakos P. Structure and response to flow of the glycocalyx layer. Biophys J 2014; 106:232-43. [PMID: 24411255 DOI: 10.1016/j.bpj.2013.09.060] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2013] [Revised: 09/03/2013] [Accepted: 09/30/2013] [Indexed: 12/31/2022] Open
Abstract
The glycocalyx is a sugar-rich layer located at the luminal part of the endothelial cells. It is involved in key metabolic processes and its malfunction is related to several diseases. To understand the function of the glycocalyx, a molecular level characterization is necessary. In this article, we present large-scale molecular-dynamics simulations that provide a comprehensive description of the structure and dynamics of the glycocalyx. We introduce the most detailed, to-date, all-atom glycocalyx model, composed of lipid bilayer, proteoglycan dimers, and heparan sulfate chains with realistic sequences. Our results reveal the folding of proteoglycan ectodomain and the extended conformation of heparan sulfate chains. Furthermore, we study the glycocalyx response under shear flow and its role as a flypaper for binding fibroblast growth factors (FGFs), which are involved in diverse functions related to cellular differentiation, including angiogenesis, morphogenesis, and wound healing. The simulations show that the glycocalyx increases the effective concentration of FGFs, leading to FGF oligomerization, and acts as a lever to transfer mechanical stimulus into the cytoplasmic side of endothelial cells.
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Affiliation(s)
- Eduardo R Cruz-Chu
- Computational Science and Engineering Laboratory, ETH, Zurich, Switzerland
| | - Alexander Malafeev
- Scientific Computing Group, Institute of Computational Science, University of Lugano, Lugano, Switzerland
| | | | - Igor V Pivkin
- Scientific Computing Group, Institute of Computational Science, University of Lugano, Lugano, Switzerland
| | - Petros Koumoutsakos
- Computational Science and Engineering Laboratory, ETH, Zurich, Switzerland; Scientific Computing Group, Institute of Computational Science, University of Lugano, Lugano, Switzerland.
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Lee T, Charrault E, Neto C. Interfacial slip on rough, patterned and soft surfaces: a review of experiments and simulations. Adv Colloid Interface Sci 2014; 210:21-38. [PMID: 24630344 DOI: 10.1016/j.cis.2014.02.015] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Revised: 02/14/2014] [Accepted: 02/15/2014] [Indexed: 11/26/2022]
Abstract
Advancements in the fabrication of microfluidic and nanofluidic devices and the study of liquids in confined geometries rely on understanding the boundary conditions for the flow of liquids at solid surfaces. Over the past ten years, a large number of research groups have turned to investigating flow boundary conditions, and the occurrence of interfacial slip has become increasingly well-accepted and understood. While the dependence of slip on surface wettability is fairly well understood, the effect of other surface modifications that affect surface roughness, structure and compliance, on interfacial slip is still under intense investigation. In this paper we review investigations published in the past ten years on boundary conditions for flow on complex surfaces, by which we mean rough and structured surfaces, surfaces decorated with chemical patterns, grafted with polymer layers, with adsorbed nanobubbles, and superhydrophobic surfaces. The review is divided in two interconnected parts, the first dedicated to physical experiments and the second to computational experiments on interfacial slip of simple (Newtonian) liquids on these complex surfaces. Our work is intended as an entry-level review for researchers moving into the field of interfacial slip, and as an indication of outstanding problems that need to be addressed for the field to reach full maturity.
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Suo T, Whitmore MD. Doubly self-consistent field theory of grafted polymers under simple shear in steady state. J Chem Phys 2014; 140:114901. [DOI: 10.1063/1.4867998] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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42
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Pastorino C, Müller M. Mixed brush of chemically and physically adsorbed polymers under shear: Inverse transport of the physisorbed species. J Chem Phys 2014; 140:014901. [DOI: 10.1063/1.4851195] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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43
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Goicochea AG, Mayoral E, Klapp J, Pastorino C. Nanotribology of biopolymer brushes in aqueous solution using dissipative particle dynamics simulations: an application to PEG covered liposomes in a theta solvent. SOFT MATTER 2014; 10:166-174. [PMID: 24652222 DOI: 10.1039/c3sm52486h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We undertake the investigation of sheared polymer chains grafted onto flat surfaces to model liposomes covered with polyethylene glycol brushes as a case study for the mechanisms of efficient drug delivery in biologically relevant situations, for example, as carriers for topical treatments of illnesses in the human vasculature. For these applications, specific rheological properties are required, such as low viscosity at high shear rates, to improve the transport of the liposomes. Therefore, extensive non-equilibrium, coarse-grained dissipative particle dynamics simulations of polymer brushes of various lengths and shear rates are performed to obtain the average viscosity and the friction coefficient of the system as functions of the shear rate and polymerization degree under theta-solvent conditions, and we find that the brushes experience considerable shear thinning at large shear rates. The viscosity (η) and the friction coefficient (μ) are shown to obey the scaling laws η ∼ γ dot above (-0.31) and μ ∼ γ dot above (0.69) at high shear rates (γ dot above) in a theta solvent, irrespective of the degree of polymerization of brushes. These results confirm recent scaling predictions and reproduce very well trends in measurements of the viscosity at a high shear rate (γ dot above) of red blood cells in a liposome containing medium.
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Affiliation(s)
- A Gama Goicochea
- Instituto Nacional de Investigaciones Nucleares, Carretera México-Toluca s/n, La Marquesa Ocoyoacac, Estado de México 52750, Mexico.
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Lanotte L, Tomaiuolo G, Misbah C, Bureau L, Guido S. Red blood cell dynamics in polymer brush-coated microcapillaries: A model of endothelial glycocalyx in vitro. BIOMICROFLUIDICS 2014; 8:014104. [PMID: 24753725 PMCID: PMC3977877 DOI: 10.1063/1.4863723] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 01/19/2014] [Indexed: 05/19/2023]
Abstract
The confined flow of red blood cells (RBCs) in microvasculature is essential for oxygen delivery to body tissues and has been extensively investigated in the literature, both in vivo and in vitro. One of the main problems still open in microcirculation is that flow resistance in microcapillaries in vivo is higher than that in vitro. This discrepancy has been attributed to the glycocalyx, a macromolecular layer lining the inner walls of vessels in vivo, but no direct experimental evidence of this hypothesis has been provided so far. Here, we investigate the flow behavior of RBCs in glass microcapillaries coated with a polymer brush (referred to as "hairy" microcapillaries as opposed to "bare" ones with no coating), an experimental model system of the glycocalyx. By high-speed microscopy imaging and image analysis, a velocity reduction of RBCs flowing in hairy microcapillaries as compared to bare ones is indeed found at the same pressure drop. Interestingly, such slowing down is larger than expected from lumen reduction due to the polymer brush and displays an on-off trend with a threshold around 70 nm of polymer brush dry thickness. Above this threshold, the presence of the polymer brush is associated with an increased RBC deformation, and RBC velocity is independent on polymer brush thickness (at the same pressure drop). In conclusion, this work provides direct support to the hypothesis that the glycocalyx is the main factor responsible of the higher flow resistance found in microcapillaries in vivo.
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Affiliation(s)
- Luca Lanotte
- Dipartimento di Ingegneria chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy ; Univ. Grenoble 1/CNRS, LIPhy UMR 5588, BP 87, 38041 Grenoble, France
| | - Giovanna Tomaiuolo
- Dipartimento di Ingegneria chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy ; CEINGE, Advanced Biotechnologies, via G. Salvatore 486, 80145 Napoli, Italy
| | - Chaouqi Misbah
- Univ. Grenoble 1/CNRS, LIPhy UMR 5588, BP 87, 38041 Grenoble, France
| | - Lionel Bureau
- Univ. Grenoble 1/CNRS, LIPhy UMR 5588, BP 87, 38041 Grenoble, France
| | - Stefano Guido
- Dipartimento di Ingegneria chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli, Italy ; CEINGE, Advanced Biotechnologies, via G. Salvatore 486, 80145 Napoli, Italy
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