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Hamada T, Mizuno S, Kitahata H. Shear-Induced Nonequilibrium Patterns in Lipid Bilayer Membranes Exhibiting Phase Separation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:8843-8850. [PMID: 38634601 DOI: 10.1021/acs.langmuir.3c03970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2024]
Abstract
The nonequilibrium dynamics of a fluid lipid membrane under external stimuli is an important issue that spans disciplines such as soft matter, biophysical chemistry, and interface science. This study investigated the dynamic response of lipid vesicles with order-disorder phase separation, which mimics a plasma membrane heterogeneity, to shear flow. Lipid vesicles were immobilized in a microfluidic chamber, and shear-induced nonequilibrium patterns on the membrane surface were observed by an optical microscope. We found that phase-separated membranes exhibit a dissipative structure of stripe patterns along the vortex flow on the membrane surface, and the number of stripes increased with the flow rate. At a high flow rate, the membrane exhibited a stripe-to-wave transition, where striped domains often migrated and the replacement of two different phases happened at vortex centers with time. We obtained a dynamic phase diagram of the shear-induced wave pattern by changing the flow rate, membrane components, and temperature. These findings could provide insight into the dissipative structures of lipid membranes out of equilibrium and flow-mediated mechanotransduction of biological membranes.
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Affiliation(s)
- Tsutomu Hamada
- School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi City, Ishikawa 923-1292, Japan
| | - Shino Mizuno
- School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi City, Ishikawa 923-1292, Japan
| | - Hiroyuki Kitahata
- Department of Physics, Graduate School of Science, Chiba University, Chiba 263-8522, Japan
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2
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Schlotterose L, Beldjilali-Labro M, Hagel M, Yadid M, Flaxer C, Flaxer E, Barnea AR, Hattermann K, Shohami E, Leichtmann-Bardoogo Y, Maoz BM. Inducing Mechanical Stimuli to Tissues Grown on a Magnetic Gel Allows Deconvoluting the Forces Leading to Traumatic Brain Injury. Neurotrauma Rep 2023; 4:560-572. [PMID: 37636339 PMCID: PMC10457614 DOI: 10.1089/neur.2023.0026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2023] Open
Abstract
Traumatic brain injury (TBI), which is characterized by damage to the brain resulting from a sudden traumatic event, is a major cause of death and disability worldwide. It has short- and long-term effects, including neuroinflammation, cognitive deficits, and depression. TBI consists of multiple steps that may sometimes have opposing effects or mechanisms, making it challenging to investigate and translate new knowledge into effective therapies. In order to better understand and address the underlying mechanisms of TBI, we have developed an in vitro platform that allows dynamic simulation of TBI conditions by applying external magnetic forces to induce acceleration and deceleration injury, which is often observed in human TBI. Endothelial and neuron-like cells were successfully grown on magnetic gels and applied to the platform. Both cell types showed an instant response to the TBI model, but the endothelial cells were able to recover quickly-in contrast to the neuron-like cells. In conclusion, the presented in vitro model mimics the mechanical processes of acceleration/deceleration injury involved in TBI and will be a valuable resource for further research on brain injury.
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Affiliation(s)
- Luise Schlotterose
- Institute of Anatomy, Kiel University, Kiel, Germany
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | | | - Mario Hagel
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Moran Yadid
- The Azrieli Faculty of Medicine, Bar Ilan University, Safed, Israel
| | - Carina Flaxer
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | - Eli Flaxer
- AFEKA–Tel-Aviv Academic College of Engineering, Tel-Aviv, Israel
| | - A. Ronny Barnea
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
| | | | - Esther Shohami
- Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
| | | | - Ben M. Maoz
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel
- Institute for Drug Research, The Hebrew University of Jerusalem, Jerusalem, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv, Israel
- Sagol Center for Regenerative Medicine, Tel Aviv University, Tel Aviv, Israel
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3
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Gimondi S, Ferreira H, Reis RL, Neves NM. Size-Dependent Polymeric Nanoparticle Distribution in a Static versus Dynamic Microfluidic Blood Vessel Model: Implications for Nanoparticle-Based Drug Delivery. ACS APPLIED NANO MATERIALS 2023; 6:7364-7374. [PMID: 37207132 PMCID: PMC10189782 DOI: 10.1021/acsanm.3c00481] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 04/06/2023] [Indexed: 05/21/2023]
Abstract
Nanoparticles (NPs) have been widely investigated in the nanomedicine field. One of the main challenges is to accurately predict the NP distribution and fate after administration. Microfluidic platforms acquired huge importance as tools to model the in vivo environment. In this study, we leveraged a microfluidic platform to produce FITC-labeled poly(lactide-co-glycolide)-block-poly(ethylene glycol) (PLGA-PEG) NPs with defined sizes of 30, 50, and 70 nm. The study aimed to compare the ability of NPs with differences of 20 nm in size to cross an endothelial barrier using static (Transwell inserts) and dynamic (microfluidic perfusion device) in vitro models. Our results evidence a size-dependent NP crossing in both models (30 > 50 > 70 nm) and highlight the bias deriving from the static model, which does not involve shear stresses. The permeation of each NP size was significantly higher in the static system than in the dynamic model at the earliest stages. However, it gradually decreased to levels comparable with those of the dynamic model. Overall, this work highlights clear differences in NP distribution over time in static versus dynamic conditions and distinct size-dependent patterns. These findings reinforce the need for accurate in vitro screening models that allow for more accurate predictions of in vivo performance.
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Affiliation(s)
- Sara Gimondi
- 3B’s
Research Group, I3Bs−Research Institute on Biomaterials, Biodegradables
and Biomimetics, University of Minho, Headquarters
of the European Institute of Excellence on Tissue Engineering and
Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da
Gandra, 4805-017 Barco, Guimarães, Portugal
- ICVS/3B’s−PT
Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Helena Ferreira
- 3B’s
Research Group, I3Bs−Research Institute on Biomaterials, Biodegradables
and Biomimetics, University of Minho, Headquarters
of the European Institute of Excellence on Tissue Engineering and
Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da
Gandra, 4805-017 Barco, Guimarães, Portugal
- ICVS/3B’s−PT
Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Rui L. Reis
- 3B’s
Research Group, I3Bs−Research Institute on Biomaterials, Biodegradables
and Biomimetics, University of Minho, Headquarters
of the European Institute of Excellence on Tissue Engineering and
Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da
Gandra, 4805-017 Barco, Guimarães, Portugal
- ICVS/3B’s−PT
Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Nuno M. Neves
- 3B’s
Research Group, I3Bs−Research Institute on Biomaterials, Biodegradables
and Biomimetics, University of Minho, Headquarters
of the European Institute of Excellence on Tissue Engineering and
Regenerative Medicine, AvePark, Parque de Ciência e Tecnologia, Zona Industrial da
Gandra, 4805-017 Barco, Guimarães, Portugal
- ICVS/3B’s−PT
Government Associate Laboratory, Braga/Guimarães, Portugal
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4
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Hamada T, Mizuno S, Kitahata H. Domain dynamics of phase-separated lipid membranes under shear flow. SOFT MATTER 2022; 18:9069-9075. [PMID: 36420806 DOI: 10.1039/d2sm00825d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The dynamical behaviour of lateral domains on phase-separated lipid vesicles under external flow is reported. A microfluidic chamber was used for the immobilization of vesicles and the application of shear. Microscopic observation revealed that domains tended to be localized at the vortex center and to exhibit a stripe morphology as the flow speed increased. We clarified the dependency of domain behaviors on the flow speed and lipid mixing fraction. The cholesterol ratio in the membrane affected these domain behaviors. Next, we investigated the growth of domains under flow. We discuss the mechanism of these trends by considering the free energy of phase separation, and reproduce the experimental results by numerical simulations. These findings may lead to a better understanding of the dynamical properties of the membrane under nonequilibrium situations and the biophysical mechanism of cellular mechanotransduction.
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Affiliation(s)
- Tsutomu Hamada
- School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi City, Ishikawa 923-1292, Japan.
| | - Shino Mizuno
- School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi City, Ishikawa 923-1292, Japan.
| | - Hiroyuki Kitahata
- Department of Physics, Graduate School of Science, Chiba University, Chiba 263-8522, Japan
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5
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Kotlyarov S, Kotlyarova A. The Importance of the Plasma Membrane in Atherogenesis. MEMBRANES 2022; 12:1036. [PMID: 36363591 PMCID: PMC9698587 DOI: 10.3390/membranes12111036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
Atherosclerotic cardiovascular diseases are an important medical problem due to their high prevalence, impact on quality of life and prognosis. The pathogenesis of atherosclerosis is an urgent medical and social problem, the solution of which may improve the quality of diagnosis and treatment of patients. Atherosclerosis is a complex chain of events, which proceeds over many years and in which many cells in the bloodstream and the vascular wall are involved. A growing body of evidence suggests that there are complex, closely linked molecular mechanisms that occur in the plasma membranes of cells involved in atherogenesis. Lipid transport, innate immune system receptor function, and hemodynamic regulation are linked to plasma membranes and their biophysical properties. A better understanding of these interrelationships will improve diagnostic quality and treatment efficacy.
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Affiliation(s)
- Stanislav Kotlyarov
- Department of Nursing, Ryazan State Medical University, 390026 Ryazan, Russia
| | - Anna Kotlyarova
- Department of Pharmacy Management and Economics, Ryazan State Medical University, 390026 Ryazan, Russia
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6
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Kotlyarov S. Diversity of Lipid Function in Atherogenesis: A Focus on Endothelial Mechanobiology. Int J Mol Sci 2021; 22:11545. [PMID: 34768974 PMCID: PMC8584259 DOI: 10.3390/ijms222111545] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/12/2021] [Accepted: 10/21/2021] [Indexed: 12/12/2022] Open
Abstract
Atherosclerosis is one of the most important problems in modern medicine. Its high prevalence and social significance determine the need for a better understanding of the mechanisms of the disease's development and progression. Lipid metabolism and its disorders are one of the key links in the pathogenesis of atherosclerosis. Lipids are involved in many processes, including those related to the mechanoreception of endothelial cells. The multifaceted role of lipids in endothelial mechanobiology and mechanisms of atherogenesis are discussed in this review. Endothelium is involved in ensuring adequate vascular hemodynamics, and changes in blood flow characteristics are detected by endothelial cells and affect their structure and function.
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Affiliation(s)
- Stanislav Kotlyarov
- Department of Nursing, Ryazan State Medical University, 390026 Ryazan, Russia
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7
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Páez-Pérez M, López-Duarte I, Vyšniauskas A, Brooks NJ, Kuimova MK. Imaging non-classical mechanical responses of lipid membranes using molecular rotors. Chem Sci 2020; 12:2604-2613. [PMID: 34164028 PMCID: PMC8179291 DOI: 10.1039/d0sc05874b] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Lipid packing in cellular membranes has a direct effect on membrane tension and microviscosity, and plays a central role in cellular adaptation, homeostasis and disease. According to conventional mechanical descriptions, viscosity and tension are directly interconnected, with increased tension leading to decreased membrane microviscosity. However, the intricate molecular interactions that combine to build the structure and function of a cell membrane suggest a more complex relationship between these parameters. In this work, a viscosity-sensitive fluorophore (‘molecular rotor’) is used to map changes in microviscosity in model membranes under conditions of osmotic stress. Our results suggest that the relationship between membrane tension and microviscosity is strongly influenced by the bilayer's lipid composition. In particular, we show that the effects of increasing tension are minimised for membranes that exhibit liquid disordered (Ld) – liquid ordered (Lo) phase coexistence; while, surprisingly, membranes in pure gel and Lo phases exhibit a negative compressibility behaviour, i.e. they soften upon compression. Viscosity-sensitive molecular rotors demonstrate that the non-classical mechanical behaviour of model lipid membranes is able to buffer external stress.![]()
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Affiliation(s)
- Miguel Páez-Pérez
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
| | - Ismael López-Duarte
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK .,Departamento de Química Orgánica, Universidad Autónoma de Madrid Cantoblanco 28049 Madrid Spain
| | - Aurimas Vyšniauskas
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK .,Center of Physical Sciences and Technology Saulėtekio av. 3 Vilnius Lithuania
| | - Nicholas J Brooks
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
| | - Marina K Kuimova
- MSRH, Department of Chemistry, Imperial College London Wood Lane London W12 0BZ UK
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8
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Shear stress activates mitochondrial oxidative phosphorylation by reducing plasma membrane cholesterol in vascular endothelial cells. Proc Natl Acad Sci U S A 2020; 117:33660-33667. [PMID: 33318210 PMCID: PMC7776821 DOI: 10.1073/pnas.2014029117] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The mechanotransduction of shear stress in vascular endothelial cells is still not completely understood. We show a pathway of shear stress signal transduction mediated by plasma membrane cholesterol-dependent mitochondrial oxidative phosphorylation. The latest imaging technology using domain 4 mutant-derived cholesterol biosensors and a fluorescence resonance energy transfer-based adenosine triphosphate (ATP) biosensor revealed that shear stress rapidly decreases cholesterol levels in the plasma membrane via both efflux and internalization, and reduction in plasma membrane cholesterol was linked to the activation of mitochondrial ATP production. The addition of cholesterol blocked these shear stress effects. Increased mitochondrial ATP production led to ATP release from the endothelial cells, thereby activating purinoceptors in the plasma membrane and leading to purinergic Ca2+ signaling in response to shear stress. Vascular endothelial cells (ECs) sense and respond to hemodynamic shear stress, which is critical for circulatory homeostasis and the pathophysiology of vascular diseases. The mechanisms of shear stress mechanotransduction, however, remain elusive. We previously demonstrated a direct role of mitochondria in the purinergic signaling of shear stress: shear stress increases mitochondrial adenosine triphosphate (ATP) production, triggering ATP release and Ca2+ signaling via EC purinoceptors. Here, we showed that shear stress rapidly decreases cholesterol in the plasma membrane, thereby activating mitochondrial ATP production. Imaging using domain 4 mutant-derived cholesterol biosensors showed that the application of shear stress to cultured ECs markedly decreased cholesterol levels in both the outer and inner plasma membrane bilayers. Flow cytometry showed that the cholesterol levels in the outer bilayer decreased rapidly after the onset of shear stress, reached a minimum (around 60% of the control level) at 10 min, and plateaued thereafter. After the shear stress ceased, the decreased cholesterol levels returned to those seen in the control. A biochemical analysis showed that shear stress caused both the efflux and the internalization of plasma membrane cholesterol. ATP biosensor imaging demonstrated that shear stress significantly increased mitochondrial ATP production. Similarly, the treatment of cells with methyl-β-cyclodextrin (MβCD), a membrane cholesterol-depleting agent, increased mitochondrial ATP production. The addition of cholesterol to cells inhibited the increasing effects of both shear stress and MβCD on mitochondrial ATP production in a dose-dependent manner. These findings indicate that plasma membrane cholesterol dynamics are closely coupled to mitochondrial oxidative phosphorylation in ECs.
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9
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Targeting Caveolin-1 and Claudin-5 with AY9944, Improve Blood-Brain Barrier Permeability; Computational Simulation and Experimental Study. Cell Mol Neurobiol 2020; 42:1125-1139. [PMID: 33222099 DOI: 10.1007/s10571-020-01004-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 11/11/2020] [Indexed: 10/22/2022]
Abstract
The current study aimed to determine the protective effect of AY9944 related to Caveolin-1 and Claudin-5 role in lipid raft, which can rescue the blood-brain barrier from enhanced permeability. Therefore, in vivo analyses were performed following ischemia in normal, ischemic, and AY9944-treated animal groups. The results revealed that AY9944 reduced the infarct size, edema, and brain water content. The extravasation of Alb-Alexa 594 and biocytin-TMR was minimum in the AY9944-treated animals. The results showed a significant decrease in the expression level of Caveolin-1 over 8 h and 48 h and a remarkable increase in the level of Claudin-5 over 48 h following ischemia in AY9944-treated animals. Molecular docking simulation demonstrated that AY9944 exerts a possible protective role via attenuating the interaction of the Caveolin-1 and cholesterol in lipid raft. These findings point out that AY9944 plays a protective role in stroke by means of blood-brain barrier preservation. Proper neural function essentially needs a constant homeostatic brain environment which is provided by the blood-brain barrier. Rescuing blood-brain barrier from enhanced permeability via inducing the protective effect of AY9944 related to caveolin-1 and claudin-5 role in lipid raft was the aim of the current study.
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10
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Butler PJ. Mechanobiology of dynamic enzyme systems. APL Bioeng 2020; 4:010907. [PMID: 32161834 PMCID: PMC7054122 DOI: 10.1063/1.5133645] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Accepted: 01/28/2020] [Indexed: 12/29/2022] Open
Abstract
This Perspective paper advances a hypothesis of mechanosensation by endothelial cells in which the cell is a dynamic crowded system, driven by continuous enzyme activity, that can be shifted from one non-equilibrium state to another by external force. The nature of the shift will depend on the direction, rate of change, and magnitude of the force. Whether force induces a pathophysiological or physiological change in cell biology will be determined by whether the dynamics of a cellular system can accommodate the dynamics and magnitude of the force application. The complex interplay of non-static cytoskeletal structures governs internal cellular rheology, dynamic spatial reorganization, and chemical kinetics of proteins such as integrins, and a flaccid membrane that is dynamically supported; each may constitute the necessary dynamic properties able to sense external fluid shear stress and reorganize in two and three dimensions. The resulting reorganization of enzyme systems in the cell membrane and cytoplasm may drive the cell to a new physiological state. This review focuses on endothelial cell mechanotransduction of shear stress, but may lead to new avenues of investigation of mechanobiology in general requiring new tools for interrogation of mechanobiological systems, tools that will enable the synthesis of large amounts of spatial and temporal data at the molecular, cellular, and system levels.
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Affiliation(s)
- Peter J. Butler
- Department of Biomedical Engineering The Pennsylvania State University University Park, Pennsylvania 16802, USA
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11
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Lubart Q, Hannestad JK, Pace H, Fjällborg D, Westerlund F, Esbjörner EK, Bally M. Lipid vesicle composition influences the incorporation and fluorescence properties of the lipophilic sulphonated carbocyanine dye SP-DiO. Phys Chem Chem Phys 2020; 22:8781-8790. [DOI: 10.1039/c9cp04158c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lipid membrane composition influences insertion efficiency and photophysical properties of lipophilic membrane-inserting dyes.
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Affiliation(s)
- Quentin Lubart
- Division of Biological Physics
- Department of Physics
- Chalmers University of Technology
- 41296 Gothenburg
- Sweden
| | - Jonas K. Hannestad
- Division of Biological Physics
- Department of Physics
- Chalmers University of Technology
- 41296 Gothenburg
- Sweden
| | - Hudson Pace
- Department of Integrative Medical Biology
- Umeå University
- 90185 Umeå
- Sweden
| | - Daniel Fjällborg
- Division of Biological Physics
- Department of Physics
- Chalmers University of Technology
- 41296 Gothenburg
- Sweden
| | - Fredrik Westerlund
- Division of Chemical Biology
- Department of Biology and Biological Engineering
- Chalmers University of Technology
- 41296 Gothenburg
- Sweden
| | - Elin K. Esbjörner
- Division of Chemical Biology
- Department of Biology and Biological Engineering
- Chalmers University of Technology
- 41296 Gothenburg
- Sweden
| | - Marta Bally
- Department of Clinical Microbiology & Wallenberg Centre for Molecular Medicine
- Umeå University
- 90185 Umeå
- Sweden
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12
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Le Roux AL, Quiroga X, Walani N, Arroyo M, Roca-Cusachs P. The plasma membrane as a mechanochemical transducer. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180221. [PMID: 31431176 PMCID: PMC6627014 DOI: 10.1098/rstb.2018.0221] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2019] [Indexed: 12/20/2022] Open
Abstract
Cells are constantly submitted to external mechanical stresses, which they must withstand and respond to. By forming a physical boundary between cells and their environment that is also a biochemical platform, the plasma membrane (PM) is a key interface mediating both cellular response to mechanical stimuli, and subsequent biochemical responses. Here, we review the role of the PM as a mechanosensing structure. We first analyse how the PM responds to mechanical stresses, and then discuss how this mechanical response triggers downstream biochemical responses. The molecular players involved in PM mechanochemical transduction include sensors of membrane unfolding, membrane tension, membrane curvature or membrane domain rearrangement. These sensors trigger signalling cascades fundamental both in healthy scenarios and in diseases such as cancer, which cells harness to maintain integrity, keep or restore homeostasis and adapt to their external environment. This article is part of a discussion meeting issue 'Forces in cancer: interdisciplinary approaches in tumour mechanobiology'.
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Affiliation(s)
- Anabel-Lise Le Roux
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
| | - Xarxa Quiroga
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
| | - Nikhil Walani
- LaCàN, Universitat Politècnica de Catalunya-BarcelonaTech, Spain
| | - Marino Arroyo
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
- LaCàN, Universitat Politècnica de Catalunya-BarcelonaTech, Spain
| | - Pere Roca-Cusachs
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute for Science and Technology (BIST), Barcelona 08028, Spain
- Department of Biomedical Sciences, Universitat de Barcelona, Barcelona 08036, Spain
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13
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Abbandonato G, Polli D, Viola D, Cerullo G, Storti B, Cardarelli F, Salomone F, Nifosì R, Signore G, Bizzarri R. Simultaneous Detection of Local Polarizability and Viscosity by a Single Fluorescent Probe in Cells. Biophys J 2019; 114:2212-2220. [PMID: 29742414 DOI: 10.1016/j.bpj.2018.02.032] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 02/14/2018] [Accepted: 02/14/2018] [Indexed: 11/29/2022] Open
Abstract
Many intracellular reactions are dependent on the dielectric ("polarity") and viscosity properties of their milieu. Fluorescence imaging offers a convenient strategy to report on such environmental properties. Yet, concomitant and independent monitoring of polarity and viscosity in cells at submicron scale is currently hampered by the lack of fluorescence probes characterized by unmixed responses to both parameters. Here, the peculiar photophysics of a green fluorescent protein chromophore analog is exploited for quantifying and imaging polarity and viscosity independently in living cells. We show that the polarity and viscosity profile around a novel hybrid drug-delivery peptide changes dramatically upon cell internalization via endosomes, shedding light on the spatiotemporal features of the release mechanism. Accordingly, our fluorescent probe opens the way to monitor the environmental effects on several processes relevant to cell biochemistry and nanomedicine.
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Affiliation(s)
| | - Dario Polli
- IFN-CNR and Dipartimento di Fisica, Politecnico di Milano, Milano, Italy; Center for Nano Science and Technology at Polimi, Istituto Italiano di Tecnologia, Milano, Italy
| | - Daniele Viola
- IFN-CNR and Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Giulio Cerullo
- IFN-CNR and Dipartimento di Fisica, Politecnico di Milano, Milano, Italy
| | - Barbara Storti
- NEST, Scuola Normale Superiore and NANO-CNR, Pisa, Italy
| | - Francesco Cardarelli
- NEST, Scuola Normale Superiore and NANO-CNR, Pisa, Italy; Center for Nanotechnology Innovation at NEST, Istituto Italiano di Tecnologia, Pisa, Italy
| | | | | | - Giovanni Signore
- NEST, Scuola Normale Superiore and NANO-CNR, Pisa, Italy; Center for Nanotechnology Innovation at NEST, Istituto Italiano di Tecnologia, Pisa, Italy.
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14
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FRET biosensor allows spatio-temporal observation of shear stress-induced polar RhoGDIα activation. Commun Biol 2018; 1:224. [PMID: 30564745 PMCID: PMC6288100 DOI: 10.1038/s42003-018-0232-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 11/14/2018] [Indexed: 12/25/2022] Open
Abstract
Rho GDP-dissociation inhibitor α (RhoGDIα) is a known negative regulator of the Rho family that shuts off GDP/GTP cycling and cytoplasm/membrane translocation to regulate cell migration. However, to our knowledge, no reports are available that focus on how the RhoGDIα-Rho GTPases complex is activated by laminar flow through exploring the activation of RhoGDIα itself. Here, we constructed a new biosensor using fluorescence resonance energy transfer (FRET) technology to measure the spatio-temporal activation of RhoGDIα in its binding with Rho GTPases in living HeLa cells. Using this biosensor, we find that the dissociation of the RhoGDIα-Rho GTPases complex is increased by shear stress, and its dissociation rate varies with subcellular location. Moreover, this process is mediated by membrane fluidity, cytoskeleton and Src activity, which indicates that the regulation of RhoGDIα activation under shear stress application represents a relatively separate pathway from the shear stress-induced Rho pathway. Shuai Shao, Xiaoling Liao et al. present a new FRET biosensor for measuring the spatio-temporal activation of RhoGDIα upon binding Rho GTPases. They find that dissociation of the RhoGDIα-Rho GTPase complex is increased by shear stress and varies with subcellular location.
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15
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Abstract
Vascular endothelial cells (ECs) maintain circulatory system homeostasis by changing their functions in response to changes in hemodynamic forces, including shear stress and stretching. However, it is unclear how ECs sense changes in shear stress and stretching and transduce these changes into intracellular biochemical signals. The plasma membranes of ECs have recently been shown to respond to shear stress and stretching differently by rapidly changing their lipid order, fluidity, and cholesterol content. Such changes in the membranes' physical properties trigger the activation of membrane receptors and cell responses specific to each type of force. Artificial lipid-bilayer membranes show similar changes in lipid order in response to shear stress and stretching, indicating that they are physical phenomena rather than biological reactions. These findings suggest that the plasma membranes of ECs act as mechanosensors; in response to mechanical forces, they first alter their physical properties, modifying the conformation and function of membrane proteins, which then activates downstream signaling pathways. This new appreciation of plasma membranes as mechanosensors could help to explain the distinctive features of mechanotransduction in ECs involving shear stress and stretching, which activate a variety of membrane proteins and multiple signal transduction pathways almost simultaneously.
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Affiliation(s)
- Kimiko Yamamoto
- Laboratory of System Physiology, Department of Biomedical Engineering, Graduate School of Medicine, The University of Tokyo
| | - Joji Ando
- Laboratory of Biomedical Engineering, School of Medicine, Dokkyo Medical University
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Osella S, Di Meo F, Murugan NA, Fabre G, Ameloot M, Trouillas P, Knippenberg S. Combining (Non)linear Optical and Fluorescence Analysis of DiD To Enhance Lipid Phase Recognition. J Chem Theory Comput 2018; 14:5350-5359. [DOI: 10.1021/acs.jctc.8b00553] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Silvio Osella
- Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097 Warsaw, Poland
- Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - Florent Di Meo
- Faculty of Pharmacy, UMR 1248 INSERM, Limoges University, 2 rue du Docteur Marcland, 87025 Limoges Cedex, France
| | - N. Arul Murugan
- Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology, SE-10691 Stockholm, Sweden
| | - Gabin Fabre
- LCSN-EA1069, Faculty of Pharmacy, Limoges University, 2, rue du Dr. Marcland, 87025 Limoges Cedex, France
| | - Marcel Ameloot
- Biomedical Research Institute, Hasselt University, B-3590, Diepenbeek, Belgium
| | - Patrick Trouillas
- Faculty of Pharmacy, UMR 1248 INSERM, Limoges University, 2 rue du Docteur Marcland, 87025 Limoges Cedex, France
- Centre of Advanced Technologies and Materials, Faculty of Science, Palacký University, tř. 17 listopadu 12, 771 46 Olomouc, Czech Republic
| | - Stefan Knippenberg
- Department of Theoretical Chemistry and Biology, School of Engineering Sciences in Chemistry, Biotechnology and Health, Royal Institute of Technology, SE-10691 Stockholm, Sweden
- Biomedical Research Institute, Hasselt University, B-3590, Diepenbeek, Belgium
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17
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The Role of Endothelial Surface Glycocalyx in Mechanosensing and Transduction. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1097:1-27. [PMID: 30315537 DOI: 10.1007/978-3-319-96445-4_1] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The endothelial cells (ECs) forming the inner wall of every blood vessel are constantly exposed to the mechanical forces generated by blood flow. The EC responses to these hemodynamic forces play a critical role in the homeostasis of the circulatory system. A variety of mechanosensors and transducers, locating on the EC surface, intra- and trans-EC membrane, and within the EC cytoskeleton, have thus been identified to ensure proper functions of ECs. Among them, the most recent candidate is the endothelial surface glycocalyx (ESG), which is a matrix-like thin layer covering the luminal surface of the EC. It consists of various proteoglycans, glycosaminoglycans, and plasma proteins and is close to other prominent EC mechanosensors and transducers. This chapter summarizes the ESG composition, thickness, and structure observed by different labeling and visualization techniques and in different types of vessels. It also presents the literature in determining the ESG mechanical properties by atomic force microscopy and optical tweezers. The molecular mechanisms by which the ESG plays the role in EC mechanosensing and transduction are described as well as the ESG remodeling by shear stress, the actin cytoskeleton, the membrane rafts, the angiogenic factors, and the sphingosine-1-phosphate.
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18
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β 1-Integrin-Mediated Adhesion Is Lipid-Bilayer Dependent. Biophys J 2017; 113:1080-1092. [PMID: 28877491 DOI: 10.1016/j.bpj.2017.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 06/19/2017] [Accepted: 07/13/2017] [Indexed: 11/21/2022] Open
Abstract
Integrin-mediated adhesion is a central feature of cellular adhesion, locomotion, and endothelial cell mechanobiology. Although integrins are known to be transmembrane proteins, little is known about the role of membrane biophysics and dynamics in integrin adhesion. We treated human aortic endothelial cells with exogenous amphiphiles, shown previously in model membranes, and computationally, to affect bilayer thickness and lipid phase separation, and subsequently measured single-integrin-molecule adhesion kinetics using an optical trap, and diffusion using fluorescence correlation spectroscopy. Benzyl alcohol (BA) partitions to liquid-disordered (Ld) domains, thins them, and causes the greatest increase in hydrophobic mismatch between liquid-ordered (Lo) and Ld domains among the three amphiphiles, leading to domain separation. In human aortic endothelial cells, BA increased β1-integrin-Arg-Gly-Asp-peptide affinity by 18% with a transition from single to double valency, consistent with a doubling of the molecular brightness of mCherry-tagged β1-integrins measured using fluorescence correlation spectroscopy. Accordingly, BA caused an increase in the size of focal-adhesion-kinase/paxillin-positive peripheral adhesions and reduced migration speeds as measured using wound-healing assays. Vitamin E, which thickens Lo domains and disperses them by lowering edge energy on domain boundaries, left integrin affinity unchanged but reduced binding probability, leading to smaller focal adhesions and equivalent migration speed relative to untreated cells. Vitamin E reversed the BA-induced decrease in migration speed. Triton X-100 also thickens Lo domains, but partitions to both lipid phases and left unchanged binding kinetics, focal adhesion sizes, and migration speed. These results demonstrate that only the amphiphile that thinned Ld lipid domains increased β1-integrin-Arg-Gly-Asp-peptide affinity and valency, thus implicating Ld domains in modulation of integrin adhesion, nascent adhesion formation, and cell migration.
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Arumugam S, Kaur A. The Lipids of the Early Endosomes: Making Multimodality Work. Chembiochem 2017; 18:1053-1060. [PMID: 28374483 DOI: 10.1002/cbic.201700046] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Indexed: 01/21/2023]
Abstract
Early endosomes are dynamic intracellular compartments that fuse with incoming endocytic carrier vesicles and associated cargoes from the plasma membrane. It has been long known that the chemical structures of lipids confer striking properties and rich biochemistry on bilayers. Although the organisational principles of the plasma membrane are relatively better understood, understanding endosomal membranes has been challenging. It has become increasingly apparent that endosomal membranes, because of their lipid compositions and interactions, use distinct lipid chemistries. We discuss the biochemical and biophysical phenomena in play at the early endosomal membrane. We focus on cholesterol, phosphoinositides, and phosphatidylserine and their clear roles in endosome functions. We discuss the various principles and mechanisms underpinning how these lipids are implicated at the functional level in the working of endosomes, and we summarise early endosomes as a multimodal organelle employing distinct lipid-specific mechanisms.
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Affiliation(s)
- Senthil Arumugam
- European Molecular Biology Laboratory Australia Node for Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, University of New South Wales, Sydney, 2052, New South Wales, Australia
| | - Amandeep Kaur
- European Molecular Biology Laboratory Australia Node for Single Molecule Science and ARC Centre of Excellence in Advanced Molecular Imaging, School of Medical Sciences, University of New South Wales, Sydney, 2052, New South Wales, Australia
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20
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Sturzenegger F, Robinson T, Hess D, Dittrich PS. Membranes under shear stress: visualization of non-equilibrium domain patterns and domain fusion in a microfluidic device. SOFT MATTER 2016; 12:5072-5076. [PMID: 27241894 DOI: 10.1039/c6sm00049e] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this study we investigate the effect of shear force on lipid membranes induced by external fluid flow. We use giant unilamellar vesicles (GUVs) as simple cell models and chose a ternary lipid mixture that exhibits liquid-ordered and liquid-disordered domains. These domains are stained with different dyes to allow visualization of changes within the membrane after the application of flow. A microfluidic device served as a valuable platform to immobilize the vesicles and apply shear forces of a defined strength. Moreover, integration of valves allowed us to stop the flow instantaneously and visualize the relaxing domain patterns by means of high-resolution fluorescence microscopy. We observed the formation of transient, non-deterministic patterns of the formerly round domains during application of flow. When the flow is stopped, round domains are formed again on a time scale of ms to s. At longer time scales of several seconds to minutes, the domains fuse into larger domains until they reach equilibrium. These processes are accelerated with increasing temperature and vesicles with budding domains do not fuse unless the temperature is elevated. Our results show the strong effect of the flow on the lipid membrane and we believe that this phenomenon plays a crucial role in the processes of mechanotransduction in living cells.
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21
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Kepczynski M, Róg T. Functionalized lipids and surfactants for specific applications. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2362-2379. [PMID: 26946243 DOI: 10.1016/j.bbamem.2016.02.038] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 02/23/2016] [Accepted: 02/25/2016] [Indexed: 12/17/2022]
Abstract
Synthetic lipids and surfactants that do not exist in biological systems have been used for the last few decades in both basic and applied science. The most notable applications for synthetic lipids and surfactants are drug delivery, gene transfection, as reporting molecules, and as support for structural lipid biology. In this review, we describe the potential of the synergistic combination of computational and experimental methodologies to study the behavior of synthetic lipids and surfactants embedded in lipid membranes and liposomes. We focused on select cases in which molecular dynamics simulations were used to complement experimental studies aiming to understand the structure and properties of new compounds at the atomistic level. We also describe cases in which molecular dynamics simulations were used to design new synthetic lipids and surfactants, as well as emerging fields for the application of these compounds. This article is part of a Special Issue entitled: Biosimulations edited by Ilpo Vattulainen and Tomasz Róg.
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Affiliation(s)
- Mariusz Kepczynski
- Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
| | - Tomasz Róg
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101, Tampere, Finland; Department of Physics, Helsinki University, P.O. Box 64, FI 00014 Helsinki, Finland.
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22
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23
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Kyrychenko A. Using fluorescence for studies of biological membranes: a review. Methods Appl Fluoresc 2015; 3:042003. [DOI: 10.1088/2050-6120/3/4/042003] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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24
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Abstract
This review article focuses on the physiochemical mechanisms underlying nanoparticle uptake into cells. When nanoparticles are in close vicinity to a cell, the interactions between the nanoparticles and the cell membrane generate forces from different origins. This leads to the membrane wrapping of the nanoparticles followed by cellular uptake. This article discusses how the kinetics, energetics, and forces are related to these interactions and dependent on the size, shape, and stiffness of nanoparticles, the biomechanical properties of the cell membrane, as well as the local environment of the cells. The discussed fundamental principles of the physiochemical causes for nanoparticle-cell interaction may guide new studies of nanoparticle endocytosis and lead to better strategies to design nanoparticle-based approaches for biomedical applications.
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Affiliation(s)
- Sulin Zhang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Address correspondence to , ,
| | - Huajian Gao
- School of Engineering, Brown University, Providence, Rhode Island 02912, United States
- Address correspondence to , ,
| | - Gang Bao
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
- Address correspondence to , ,
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25
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Huang C, Ozdemir T, Xu LC, Butler PJ, Siedlecki CA, Brown JL, Zhang S. The role of substrate topography on the cellular uptake of nanoparticles. J Biomed Mater Res B Appl Biomater 2015; 104:488-95. [PMID: 25939598 DOI: 10.1002/jbm.b.33397] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Revised: 01/15/2015] [Accepted: 02/08/2015] [Indexed: 12/12/2022]
Abstract
Improving targeting efficacy has been a central focus of the studies on nanoparticle (NP)-based drug delivery nanocarriers over the past decades. As cells actively sense and respond to the local physical environments, not only the NP design (e.g., size, shape, ligand density, etc.) but also the cell mechanics (e.g., stiffness, spreading, expressed receptors, etc.) affect the cellular uptake efficiency. While much work has been done to elucidate the roles of NP design for cells seeded on a flat tissue culture surface, how the local physical environments of cells mediate uptake of NPs remains unexplored, despite the widely known effect of local physical environments on cellular responses in vitro and disease states in vivo. Here, we report the active responses of human osteosarcoma cells to fibrous substrate topographies and the subsequent changes in the cellular uptake of NPs. Our experiments demonstrate that surface topography modulates cellular uptake efficacy by mediating cell spreading and membrane mechanics. The findings provide a concrete example of the regulative role of the physical environments of cells on cellular uptake of NPs, therefore advancing the rational design of NPs for enhanced drug delivery in targeted cancer therapy.
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Affiliation(s)
- Changjin Huang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania, 16802
| | - Tugba Ozdemir
- Department of Bioengineering, The Pennsylvania State University, University Park, Pennsylvania, 16802
| | - Li-Chong Xu
- Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, 17033
| | - Peter J Butler
- Department of Bioengineering, The Pennsylvania State University, University Park, Pennsylvania, 16802
| | - Christopher A Siedlecki
- Department of Bioengineering, The Pennsylvania State University, University Park, Pennsylvania, 16802.,Department of Surgery, The Pennsylvania State University, College of Medicine, Hershey, Pennsylvania, 17033
| | - Justin L Brown
- Department of Bioengineering, The Pennsylvania State University, University Park, Pennsylvania, 16802
| | - Sulin Zhang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania, 16802.,Department of Bioengineering, The Pennsylvania State University, University Park, Pennsylvania, 16802
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26
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Lee IH, Saha S, Polley A, Huang H, Mayor S, Rao M, Groves JT. Live cell plasma membranes do not exhibit a miscibility phase transition over a wide range of temperatures. J Phys Chem B 2015; 119:4450-9. [PMID: 25747462 DOI: 10.1021/jp512839q] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Lipid/cholesterol mixtures derived from cell membranes as well as their synthetic reconstitutions exhibit well-defined miscibility phase transitions and critical phenomena near physiological temperatures. This suggests that lipid/cholesterol-mediated phase separation plays a role in the organization of live cell membranes. However, macroscopic lipid-phase separation is not generally observed in cell membranes, and the degree to which properties of isolated lipid mixtures are preserved in the cell membrane remain unknown. A fundamental property of phase transitions is that the variation of tagged particle diffusion with temperature exhibits an abrupt change as the system passes through the transition, even when the two phases are distributed in a nanometer-scale emulsion. We support this using a variety of Monte Carlo and atomistic simulations on model lipid membrane systems. However, temperature-dependent fluorescence correlation spectroscopy of labeled lipids and membrane-anchored proteins in live cell membranes shows a consistently smooth increase in the diffusion coefficient as a function of temperature. We find no evidence of a discrete miscibility phase transition throughout a wide range of temperatures: 14-37 °C. This contrasts the behavior of giant plasma membrane vesicles (GPMVs) blebbed from the same cells, which do exhibit phase transitions and macroscopic phase separation. Fluorescence lifetime analysis of a DiI probe in both cases reveals a significant environmental difference between the live cell and the GPMV. Taken together, these data suggest the live cell membrane may avoid the miscibility phase transition inherent to its lipid constituents by actively regulating physical parameters, such as tension, in the membrane.
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Affiliation(s)
- Il-Hyung Lee
- †Department of Chemistry, California Institute for Quantitative Biosciences (QB3), Howard Hughes Medical Institute, University of California, Berkeley, California 94720, United States
| | - Suvrajit Saha
- §National Centre for Biological Sciences (TIFR), Bellary Road, Bangalore 560065, India
| | - Anirban Polley
- ∥Raman Research Institute, C.V. Raman Avenue, Bangalore 560080, India
| | - Hector Huang
- †Department of Chemistry, California Institute for Quantitative Biosciences (QB3), Howard Hughes Medical Institute, University of California, Berkeley, California 94720, United States
| | - Satyajit Mayor
- §National Centre for Biological Sciences (TIFR), Bellary Road, Bangalore 560065, India
| | - Madan Rao
- §National Centre for Biological Sciences (TIFR), Bellary Road, Bangalore 560065, India.,∥Raman Research Institute, C.V. Raman Avenue, Bangalore 560080, India
| | - Jay T Groves
- †Department of Chemistry, California Institute for Quantitative Biosciences (QB3), Howard Hughes Medical Institute, University of California, Berkeley, California 94720, United States.,‡Materials Sciences Division, Physical Biosciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
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27
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Yen W, Cai B, Yang J, Zhang L, Zeng M, Tarbell JM, Fu BM. Endothelial surface glycocalyx can regulate flow-induced nitric oxide production in microvessels in vivo. PLoS One 2015; 10:e0117133. [PMID: 25575016 PMCID: PMC4289188 DOI: 10.1371/journal.pone.0117133] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 12/19/2014] [Indexed: 11/18/2022] Open
Abstract
Due to its unique location, the endothelial surface glycocalyx (ESG) at the luminal side of the microvessel wall may serve as a mechano-sensor and transducer of blood flow and thus regulate endothelial functions. To examine this role of the ESG, we used fluorescence microscopy to measure nitric oxide (NO) production in post-capillary venules and arterioles of rat mesentery under reduced (low) and normal (high) flow conditions, with and without enzyme pretreatment to remove heparan sulfate (HS) of the ESG and in the presence of an endothelial nitric oxide synthase (eNOS) inhibitor, NG-monomethyl-L-arginine (L-NMMA). Rats (SD, 250–300g) were anesthetized. The mesentery was gently taken out from the abdominal cavity and arranged on the surface of a glass coverslip for the measurement. An individual post-capillary venule or arteriole was cannulated and loaded for 45 min with 5 μM 4, 5-Diaminofluorescein diacetate, a membrane permeable fluorescent indictor for NO, then the NO production was measured for ~10 min under a low flow (~300 μm/s) and for ~60 min under a high flow (~1000 μm/s). In the 15 min after switching to the high flow, DAF-2-NO fluorescence intensity increased to 1.27-fold of its baseline, DAF-2-NO continuously increased under the high flow, to 1.53-fold of its baseline in 60 min. Inhibition of eNOS by 1 mM L-NMMA attenuated the flow-induced NO production to 1.13-fold in 15 min and 1.30-fold of its baseline in 60 min, respectively. In contrast, no significant increase in NO production was observed after switching to the high flow for 60 min when 1 h pretreatment with 50 mU/mL heparanase III to degrade the ESG was applied. Similar NO production was observed in arterioles under low and high flows and under eNOS inhibition. Our results suggest that ESG participates in endothelial cell mechanosensing and transduction through its heparan sulfate to activate eNOS.
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Affiliation(s)
- Wanyi Yen
- Department of Biomedical Engineering, The City College of the City University of New York, New York, New York, United States of America
| | - Bin Cai
- Department of Biomedical Engineering, The City College of the City University of New York, New York, New York, United States of America
| | - Jinlin Yang
- Department of Biomedical Engineering, The City College of the City University of New York, New York, New York, United States of America
| | - Lin Zhang
- Department of Biomedical Engineering, The City College of the City University of New York, New York, New York, United States of America
| | - Min Zeng
- Department of Biomedical Engineering, The City College of the City University of New York, New York, New York, United States of America
| | - John M. Tarbell
- Department of Biomedical Engineering, The City College of the City University of New York, New York, New York, United States of America
| | - Bingmei M. Fu
- Department of Biomedical Engineering, The City College of the City University of New York, New York, New York, United States of America
- * E-mail:
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28
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Huang C, Butler PJ, Tong S, Muddana HS, Bao G, Zhang S. Substrate stiffness regulates cellular uptake of nanoparticles. NANO LETTERS 2013; 13:1611-1615. [PMID: 23484640 DOI: 10.1021/nl400033h] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Nanoparticle (NP)-bioconjugates hold great promise for more sensitive disease diagnosis and more effective anticancer drug delivery compared with existing approaches. A critical aspect in both applications is cellular internalization of NPs, which is influenced by NP properties and cell surface mechanics. Despite considerable progress in optimization of the NP-bioconjugates for improved targeting, the role of substrate stiffness on cellular uptake has not been investigated. Using polyacrylamide (PA) hydrogels as model substrates with tunable stiffness, we quantified the relationship between substrate stiffness and cellular uptake of fluorescent NPs by bovine aortic endothelial cells (BAECs). We found that a stiffer substrate results in a higher total cellular uptake on a per cell basis, but a lower uptake per unit membrane area. To obtain a mechanistic understanding of the cellular uptake behavior, we developed a thermodynamic model that predicts that membrane spreading area and cell membrane tension are two key factors controlling cellular uptake of NPs, both of which are modulated by substrate stiffness. Our experimental and modeling results not only open up new avenues for engineering NP-based cancer cell targets for more effective in vivo delivery but also contribute an example of how the physical environment dictates cellular behavior and function.
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Affiliation(s)
- Changjin Huang
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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29
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Fu BM, Tarbell JM. Mechano-sensing and transduction by endothelial surface glycocalyx: composition, structure, and function. WILEY INTERDISCIPLINARY REVIEWS-SYSTEMS BIOLOGY AND MEDICINE 2013; 5:381-90. [PMID: 23401243 DOI: 10.1002/wsbm.1211] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The endothelial cells (ECs) lining every blood vessel wall are constantly exposed to the mechanical forces generated by blood flow. The EC responses to these hemodynamic forces play a critical role in the homeostasis of the circulatory system. To ensure proper EC mechano-sensing and transduction, there are a variety of mechano-sensors and transducers that have been identified on the EC surface, intra- and trans-EC membrane and within the EC cytoskeleton. Among them, the most recent candidate is the endothelial surface glycocalyx (ESG), which is a matrix-like thin layer covering the luminal surface of the EC. It consists of various proteoglycans, glycosaminoglycans, and plasma proteins, and is close to other prominent EC mechano-sensors and transducers. The ESG thickness was found to be in the order of 0.1-1 µm by different visualization techniques and in different types of vessels. Detailed analysis on the electron microscopy (EM) images of the microvascular ESG revealed a quasi-periodic substructure with the ESG fiber diameter of 10-12 and 20 nm spacing between adjacent fibers. Atomic force microscopy and optical tweezers were applied to investigate the mechanical properties of the ESG on the cultured EC monolayers and in solutions. Enzymatic degradation of specific ESG glycosaminoglycan components was used to directly elucidate the role of the ESG in EC mechano-sensing and transduction by measuring the shear-induced productions of nitric oxide and prostacyclin, two characteristic responses of the ECs to the flow. The unique location, composition, and structure of the ESG determine its role in EC mechano-sensing and transduction.
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Affiliation(s)
- Bingmei M Fu
- Department of Biomedical Engineering, The City College of the City University of New York, New York, NY, USA.
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30
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Reddy AS, Warshaviak DT, Chachisvilis M. Effect of membrane tension on the physical properties of DOPC lipid bilayer membrane. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2271-81. [PMID: 22588133 DOI: 10.1016/j.bbamem.2012.05.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 05/03/2012] [Accepted: 05/07/2012] [Indexed: 01/15/2023]
Abstract
Molecular dynamics simulations of a dioleoylphosphocholine (DOPC) lipid bilayer were performed to explore its mechanosensitivity. Variations in the bilayer properties, such as area per lipid, volume, thickness, hydration depth (HD), hydration thickness (HT), lateral diffusion coefficient, and changes in lipid structural order were computed in the membrane tension range 0 to 15dyn/cm. We determined that an increase in membrane tension results in a decrease in the bilayer thickness and HD of ~5% and ~5.7% respectively, whereas area per lipid, volume, and HT/HD increased by 6.8%, 2.4%, and 5% respectively. The changes in lipid conformation and orientation were characterized using orientational (S(2)) and deuterium (S(CD)) order parameters. Upon increase of membrane tension both order parameters indicated an increase in lipid disorder by 10-20%, mostly in the tail end region of the hydrophobic chains. The effect of membrane tension on lipid lateral diffusion in the DOPC bilayer was analyzed on three different time scales corresponding to inertial motion, anomalous diffusion and normal diffusion. The results showed that lateral diffusion of lipid molecules is anomalous in nature due to the non-exponential distribution of waiting times. The anomalous and normal diffusion coefficients increased by 20% and 52% when the membrane tension changed from 0 to 15dyn/cm, respectively. In conclusion, our studies showed that membrane tension causes relatively significant changes in the area per lipid, volume, polarity, membrane thickness, and fluidity of the membrane suggesting multiple mechanisms by which mechanical perturbation of the membrane could trigger mechanosensitive response in cells.
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Wurm M, Zeng AP. Mechanical disruption of mammalian cells in a microfluidic system and its numerical analysis based on computational fluid dynamics. LAB ON A CHIP 2012; 12:1071-1077. [PMID: 22311121 DOI: 10.1039/c2lc20918g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The lysis of mammalian cells is an essential part of different lab-on-a-chip sample preparation methods, which aim at the release, separation, and subsequent analysis of DNA, proteins, or metabolites. Particularly for the analysis of compartmented in vivo metabolism of mammalian cells, such a method must be very fast compared to the metabolic turnover-rates, it should not affect the native metabolite concentrations, and should ideally leave cell organelles undamaged. So far, no such a method is available. We have developed a microfluidic system for the effective rapid mechanical cell disruption and established a mathematical model to describe the efficiency of the system. Chinese hamster ovary (CHO) cells were disrupted with high efficiency by passing through two consecutive micronozzle arrays. Simultaneous cell compression and shearing led to a disruption rate of ≥90% at a sample flow rate of Q = 120 μL min(-1) per nozzle passage, which corresponds to a mean fluid velocity of 13.3 m s(-1) and a mean Reynolds number of 22.6 in the nozzle gap. We discussed the problem of channel clogging by cellular debris and the resulting flow instability at the micronozzle arrays. The experimental results were compared to predictions from Computational Fluid Dynamics (CFD) simulations and the critical energy dissipation rate for the disruption of the CHO cell population with known size distribution was determined to be 4.7 × 10(8) W m(-3). Our model for the calculation of cell disruption on the basis of CFD-data could be applied to other microgeometries to predict intended disruption or undesired cell damage.
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Affiliation(s)
- Matthias Wurm
- Hamburg University of Technology, Institute of Bioprocess and Biosystems Engineering, Hamburg, Germany
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Fuentes DE, Butler PJ. Coordinated Mechanosensitivity of Membrane Rafts and Focal Adhesions. Cell Mol Bioeng 2012; 5:143-154. [PMID: 23487555 DOI: 10.1007/s12195-012-0225-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Endothelial cells sense mechanical forces of blood flow through mechanisms that involve focal adhesions (FAs). The mechanosensitive pathways that originate from FA-associated integrin activation may involve membrane rafts, small cholesterol- and sphigolipid-rich domains that are either immobilized, by virtue of their attachment to the cytoskeleton, or highly mobile in the plane of the plasma membrane. In this study, we fluorescently labeled non-mobile and mobile populations of GM1, a ganglioside associated with lipid rafts, and transfected cells with the red fluorescent protein-(RFP-) talin, an indicator of integrin activation at FAs, in order to determine the kinetics and sequential order of raft and talin mechanosensitivity. Cells were imaged under confocal microscopy during mechanical manipulation of a FA induced by a fibronectin (FN)-functionalized nanoelectrode with feedback control of position. First, FA deformation led to long range deformation of immobile rafts followed by active recoil of a subpopulation of displaced rafts. Second, initial adhesion between the FN-probe and the cell induced rapid accumulation of GM1 at the probe site with a time constant of 1.7 s. Talin accumulated approximately 20 s later with a time constant of 0.6 s. Third, a 1 μm deformation of the FA lead to immediate (0.3 s) increase in GM1 fluorescence and a later (6 s) increase in talin. Fourth, long term deformation of FAs led to continual GM1 accumulation at the probe site that was reversed upon removal of the deformation. These results demonstrate that rafts are directly mechanosensitive and that raft mobility may enable the earliest events related to FA mechanosensing and reinforcement upon force application.
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Affiliation(s)
- Daniela E Fuentes
- Department of Bioengineering, The Pennsylvania State University, 205 Hallowell Building, University Park, PA 16802, USA
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Muddana HS, Chiang HH, Butler PJ. Tuning membrane phase separation using nonlipid amphiphiles. Biophys J 2012; 102:489-97. [PMID: 22325271 DOI: 10.1016/j.bpj.2011.12.033] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Revised: 12/14/2011] [Accepted: 12/19/2011] [Indexed: 01/25/2023] Open
Abstract
Lipid phase separation may be a mechanism by which lipids participate in sorting membrane proteins and facilitate membrane-mediated biochemical signaling in cells. To provide new tools for membrane lipid phase manipulation that avoid direct effects on protein activity and lipid composition, we studied phase separation in binary and ternary lipid mixtures under the influence of three nonlipid amphiphiles, vitamin E (VE), Triton-X (TX)-100, and benzyl alcohol (BA). Mechanisms of additive-induced phase separation were elucidated using coarse-grained molecular dynamics simulations of these additives in a liquid bilayer made from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dilinoleoyl-sn-glycero-3-phosphocholine [corrected]. From simulations, the additive's partitioning preference, changes in membrane thickness, and alterations in lipid order were quantified. Simulations showed that VE favored the DPPC phase but partitioned predominantly to the domain boundaries and lowered the tendency for domain formation, and therefore acted as a linactant. This simulated behavior was consistent with experimental observations in which VE promoted lipid mixing and dispersed domains in both gel/liquid and liquid-ordered/liquid-disordered systems. From simulation, BA partitioned predominantly to the DUPC phase, decreased lipid order there, and thinned the membrane. These actions explain why, experimentally, BA promoted phase separation in both binary and ternary lipid mixtures. In contrast, TX, a popular detergent used to isolate raft membranes in cells, exhibited equal preference for both phases, as demonstrated by simulations, but nonetheless, was a strong domain promoter in all lipid mixtures. Further analysis showed that TX increased membrane thickness of the DPPC phase to a greater extent than the DUPC phase and thus increased hydrophobic mismatch, which may explain experimental observation of phase separation in the presence of TX. In summary, these nonlipid amphiphiles provide new tools to tune domain formation in model vesicle systems and could provide the means to form or disperse membrane lipid domains in cells, in addition to the well-known methods involving cholesterol enrichment and sequestration.
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Affiliation(s)
- Hari S Muddana
- Department of Bioengineering, The Pennsylvania State University, University Park, Pennsylvania, USA
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