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Machin DR, Trott DW, Gogulamudi VR, Islam MT, Bloom SI, Vink H, Lesniewski LA, Donato AJ. Glycocalyx-targeted therapy ameliorates age-related arterial dysfunction. GeroScience 2023; 45:2351-2365. [PMID: 36787090 PMCID: PMC10651573 DOI: 10.1007/s11357-023-00745-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 01/26/2023] [Indexed: 02/15/2023] Open
Abstract
Advanced age is accompanied by arterial dysfunction, as well as a diminished glycocalyx, which may be linked to reduced high molecular weight-hyaluronan (HMW-HA) synthesis. However, the impact of glycocalyx deterioration in age-related arterial dysfunction is unknown. We sought to determine if manipulations in glycocalyx properties would alter arterial function. Tamoxifen-induced hyaluronan synthase 2 (Has2) reduction was used to decrease glycocalyx properties. Three weeks post-tamoxifen treatment, glycocalyx thickness was lower in Has2 knockout compared to wild-type mice (P<0.05). Has2 reduction induced arterial dysfunction, demonstrated by impaired endothelium-dependent dilation (EDD) and elevated aortic stiffness (P<0.05). To augment glycocalyx properties, old mice received 10 weeks of a glycocalyx-targeted therapy via Endocalyx™ (old+ECX), which contains HMW-HA and other glycocalyx components. Compared to old control mice, glycocalyx properties and EDD were augmented, and aortic stiffness decreased in old+ECX mice (P<0.05). Old+ECX mice had a more youthful aortic phenotype, demonstrated by lower collagen content and higher elastin content than old control mice (P<0.05). Functional outcomes were repeated in old mice that underwent a diet supplemented solely with HMW-HA (old+HA). Compared to old controls, glycocalyx properties and EDD were augmented, and aortic stiffness was lower in old+HA mice (P<0.05). We did not observe any differences between old+HA and old+ECX mice (P>0.05). Has2 reduction phenocopies age-related arterial dysfunction, while 10 weeks of glycocalyx-targeted therapy that restores the glycocalyx also ameliorates age-related arterial dysfunction. These findings suggest that the glycocalyx may be a viable therapeutic target to ameliorate age-related arterial dysfunction.
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Affiliation(s)
- Daniel R Machin
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA.
- Department of Nutrition and Integrative Physiology, Florida State University, Tallahassee, FL, 32306, USA.
| | - Daniel W Trott
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
| | | | - Md Torikul Islam
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - Samuel I Bloom
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - Hans Vink
- Department of Physiology, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands
- MicroVascular Health Solutions LLC, Alpine, UT, USA
| | - Lisa A Lesniewski
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- VA Salt Lake City, GRECC, Salt Lake City, UT, USA
| | - Anthony J Donato
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
- VA Salt Lake City, GRECC, Salt Lake City, UT, USA
- Department of Biochemistry, University of Utah, Salt Lake City, UT, USA
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The Endothelial Glycocalyx and Retinal Hemodynamics. PATHOPHYSIOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY FOR PATHOPHYSIOLOGY 2022; 29:663-677. [PMID: 36548208 PMCID: PMC9785437 DOI: 10.3390/pathophysiology29040052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/20/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
PURPOSE Previous studies suggest that the endothelial glycocalyx adds to vascular resistance, inhibits thrombosis, and is critical for regulating homogeneous blood flow and ensuring uniform red blood cell (RBC) distribution. However, these functions and consequences of the glycocalyx have not been examined in the retina. We hypothesize that the endothelial glycocalyx is a critical regulator of retinal hemodynamics and perfusion and decreases the propensity for retinal thrombus formation. METHODS Hyaluronidase and heparinase, which are endothelial glycocalyx-degrading enzymes, were infused into mice. Fluorescein isothiocyanate-dextran (2000 kDa) was injected to measure lumen diameter, while RBC velocity and distribution were measured using fluorescently labeled RBCs. The diameters and velocities were used to calculate retinal blood flow and shear rates. Mean circulation time was calculated by measuring the difference between arteriolar and venular mean transit times. Rose Bengal dye was infused, followed by illumination with a green light to induce thrombosis. RESULTS The acute infusion of hyaluronidase and heparinase led to significant increases in both arteriolar (7%) and venular (16%) diameters in the retina, with a tendency towards increased arteriolar velocity. In addition, the degradation caused a significant decrease in the venular shear rate (14%). The enzyme infusion resulted in substantial increases in total retinal blood flow (26%) and retinal microhematocrit but no changes in the mean circulation time through the retina. We also observed an enhanced propensity for retinal thrombus formation with the removal of the glycocalyx. CONCLUSIONS Our data suggest that acute degradation of the glycocalyx can cause significant changes in retinal hemodynamics, with increases in vessel diameter, blood flow, microhematocrit, pro-thrombotic conditions, and decreases in venular shear rate.
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Introini V, Govendir MA, Rayner JC, Cicuta P, Bernabeu M. Biophysical Tools and Concepts Enable Understanding of Asexual Blood Stage Malaria. Front Cell Infect Microbiol 2022; 12:908241. [PMID: 35711656 PMCID: PMC9192966 DOI: 10.3389/fcimb.2022.908241] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 04/27/2022] [Indexed: 12/02/2022] Open
Abstract
Forces and mechanical properties of cells and tissues set constraints on biological functions, and are key determinants of human physiology. Changes in cell mechanics may arise from disease, or directly contribute to pathogenesis. Malaria gives many striking examples. Plasmodium parasites, the causative agents of malaria, are single-celled organisms that cannot survive outside their hosts; thus, thost-pathogen interactions are fundamental for parasite’s biological success and to the host response to infection. These interactions are often combinations of biochemical and mechanical factors, but most research focuses on the molecular side. However, Plasmodium infection of human red blood cells leads to changes in their mechanical properties, which has a crucial impact on disease pathogenesis because of the interaction of infected red blood cells with other human tissues through various adhesion mechanisms, which can be probed and modelled with biophysical techniques. Recently, natural polymorphisms affecting red blood cell biomechanics have also been shown to protect human populations, highlighting the potential of understanding biomechanical factors to inform future vaccines and drug development. Here we review biophysical techniques that have revealed new aspects of Plasmodium falciparum invasion of red blood cells and cytoadhesion of infected cells to the host vasculature. These mechanisms occur differently across Plasmodium species and are linked to malaria pathogenesis. We highlight promising techniques from the fields of bioengineering, immunomechanics, and soft matter physics that could be beneficial for studying malaria. Some approaches might also be applied to other phases of the malaria lifecycle and to apicomplexan infections with complex host-pathogen interactions.
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Affiliation(s)
- Viola Introini
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
- *Correspondence: Viola Introini,
| | - Matt A. Govendir
- European Molecular Biology Laboratory (EMBL) Barcelona, Barcelona, Spain
| | - Julian C. Rayner
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Pietro Cicuta
- Cavendish Laboratory, University of Cambridge, Cambridge, United Kingdom
| | - Maria Bernabeu
- European Molecular Biology Laboratory (EMBL) Barcelona, Barcelona, Spain
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4
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Preziosi V, Barra M, Tomaiuolo G, D'Angelo P, Marasso SL, Verna A, Cocuzza M, Cassinese A, Guido S. Organic electrochemical transistors as novel biosensing platforms to study the electrical response of whole blood and plasma. J Mater Chem B 2021; 10:87-95. [PMID: 34870646 DOI: 10.1039/d1tb01584b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In this paper, for the first time to the best of our knowledge, organic electrochemical transistors are employed to investigate the electrical response of human blood, plasma and alternative buffer solutions that inhibit red blood cell (RBC) aggregation. Our focus is on selecting a suitable electrolytic platform and the related operating conditions, where the RBC effect on the OECT response can be observed separately from the strong ionic environment of plasma in whole blood. The transient response of whole blood to pulse experiments is characterized by two time constants, which can be related to blood viscosity and to the capacitive coupling between the ionic and electronic components of the overall system. The role of capacitive effects, likely due to enhanced double-layer formation by negatively charged RBCs, is also confirmed by the increase of transconductance which was found in RBC suspensions as compared to the suspending buffer. Overall, the complex behavior found in these experiments provides new insights for the development of innovative blood-based sensing devices for biomedical applications.
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Affiliation(s)
- Valentina Preziosi
- Department of Chemical, Materials and Production Engineering - University Federico II, P.le Tecchio 80, I-80125 Naples, Italy.
| | - Mario Barra
- CNR-SPIN, c/o Department of Physics "Ettore Pancini", P.le Tecchio, 80, I-80125 Napoli, Italy.
| | - Giovanna Tomaiuolo
- Department of Chemical, Materials and Production Engineering - University Federico II, P.le Tecchio 80, I-80125 Naples, Italy.
| | | | - Simone Luigi Marasso
- IMEM-CNR, Parco Area delle Scienze 37/A, I-43124 Parma, Italy.,Chi-Lab, Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Alessio Verna
- Chi-Lab, Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Matteo Cocuzza
- IMEM-CNR, Parco Area delle Scienze 37/A, I-43124 Parma, Italy.,Chi-Lab, Department of Applied Science and Technology, Politecnico di Torino, C.so Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Antonio Cassinese
- CNR-SPIN, c/o Department of Physics "Ettore Pancini", P.le Tecchio, 80, I-80125 Napoli, Italy. .,Department of Physics "Ettore Pancini", University Federico II, P.le Tecchio 80, I-80125 Naples, Italy
| | - Stefano Guido
- Department of Chemical, Materials and Production Engineering - University Federico II, P.le Tecchio 80, I-80125 Naples, Italy. .,National Interuniversity Consortium for Materials Science and Technology (INSTM), 50121 Firenze, Italy.,CEINGE, Advanced Biotechnologies, 80145 Napoli, Italy
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5
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Haymet AB, Bartnikowski N, Wood ES, Vallely MP, McBride A, Yacoub S, Biering SB, Harris E, Suen JY, Fraser JF. Studying the Endothelial Glycocalyx in vitro: What Is Missing? Front Cardiovasc Med 2021; 8:647086. [PMID: 33937360 PMCID: PMC8079726 DOI: 10.3389/fcvm.2021.647086] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/19/2021] [Indexed: 12/16/2022] Open
Abstract
All human cells are coated by a surface layer of proteoglycans, glycosaminoglycans (GAGs) and plasma proteins, called the glycocalyx. The glycocalyx transmits shear stress to the cytoskeleton of endothelial cells, maintains a selective permeability barrier, and modulates adhesion of blood leukocytes and platelets. Major components of the glycocalyx, including syndecans, heparan sulfate, and hyaluronan, are shed from the endothelial surface layer during conditions including ischaemia and hypoxia, sepsis, atherosclerosis, diabetes, renal disease, and some viral infections. Studying mechanisms of glycocalyx damage in vivo can be challenging due to the complexity of immuno-inflammatory responses which are inextricably involved. Previously, both static as well as perfused in vitro models have studied the glycocalyx, and have reported either imaging data, assessment of barrier function, or interactions of blood components with the endothelial monolayer. To date, no model has simultaneously incorporated all these features at once, however such a model would arguably enhance the study of vasculopathic processes. This review compiles a series of current in vitro models described in the literature that have targeted the glycocalyx layer, their limitations, and potential opportunities for further developments in this field.
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Affiliation(s)
- Andrew B Haymet
- Critical Care Research Group, The Prince Charles Hospital, Chermside, QLD, Australia.,Faculty of Medicine, University of Queensland, St Lucia, QLD, Australia
| | - Nicole Bartnikowski
- Critical Care Research Group, The Prince Charles Hospital, Chermside, QLD, Australia.,Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD, Australia
| | - Emily S Wood
- Critical Care Research Group, The Prince Charles Hospital, Chermside, QLD, Australia.,Faculty of Medicine, University of Queensland, St Lucia, QLD, Australia
| | - Michael P Vallely
- Division of Cardiac Surgery, The Ohio State University Wexner Medical Center, Columbus, OH, United States
| | - Angela McBride
- Department of Global Health and Infection, Brighton and Sussex Medical School, Brighton, United Kingdom.,Oxford University Clinical Research Unit, Wellcome Trust Africa Asia Programme, Ho Chi Minh City, Vietnam
| | - Sophie Yacoub
- Oxford University Clinical Research Unit, Wellcome Trust Africa Asia Programme, Ho Chi Minh City, Vietnam.,Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom
| | - Scott B Biering
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA, United States
| | - Eva Harris
- Division of Infectious Diseases and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA, United States
| | - Jacky Y Suen
- Critical Care Research Group, The Prince Charles Hospital, Chermside, QLD, Australia.,Faculty of Medicine, University of Queensland, St Lucia, QLD, Australia
| | - John F Fraser
- Critical Care Research Group, The Prince Charles Hospital, Chermside, QLD, Australia.,Faculty of Medicine, University of Queensland, St Lucia, QLD, Australia
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6
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Fenech M, Girod V, Claveria V, Meance S, Abkarian M, Charlot B. Microfluidic blood vasculature replicas using backside lithography. LAB ON A CHIP 2019; 19:2096-2106. [PMID: 31086935 DOI: 10.1039/c9lc00254e] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Blood vessels in living tissues are an organized and hierarchical network of arteries, arterioles, capillaries, veinules and veins. Their sizes, lengths, shapes and connectivity are set up for an optimum perfusion of the tissues in which they deploy. In order to study the hemodynamics and hemophysics of blood flows and also to investigate artificial vasculature for organs on a chip, it is essential to reproduce most of these geometric features. Common microfluidic techniques produce channels with a uniform height and a rectangular cross section that do not capture the size hierarchy observed in vivo. This paper presents a new single-mask photolithography process using an optical diffuser to produce a backside exposure leading to microchannels with both a rounded cross section and a direct proportionality between local height and local width, allowing a one-step design of intrinsically hierarchical networks.
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Affiliation(s)
- Marianne Fenech
- Department of Mechanical Engineering, University of Ottawa, Ottawa, Canada
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7
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Machin DR, Phuong TT, Donato AJ. The role of the endothelial glycocalyx in advanced age and cardiovascular disease. Curr Opin Pharmacol 2019; 45:66-71. [PMID: 31112922 DOI: 10.1016/j.coph.2019.04.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Accepted: 04/15/2019] [Indexed: 12/24/2022]
Abstract
The endothelial glycocalyx is a gel-like structure that is bound to the luminal surface of the vascular endothelium. At the interface between flowing blood and endothelial cells, the glycocalyx has several functions that are critical for the maintenance of a healthy vasculature, particularly in regard to the vascular endothelium. Within the vasculature, the glycocalyx modulates vascular resistance to maintain blood flow homogeneity in the microcirculation, mechanotransduces fluid shear stress to the endothelium, and buffers endothelial cells from plasma oxidants, cytokines, and circulating immune cells. In advanced age and cardiovascular disease (CVD), the glycocalyx is deteriorated. Moreover, glycocalyx deterioration may precede traditional measurements of age-related vascular dysfunction, such as impaired endothelium-dependent dilation and large artery stiffness, suggesting that a deteriorated glycocalyx could initiate age-related CVD pathology.
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Affiliation(s)
- Daniel R Machin
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, UT, United States
| | - Tam Tt Phuong
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, UT, United States
| | - Anthony J Donato
- University of Utah, Department of Internal Medicine, Division of Geriatrics, Salt Lake City, UT, United States; Veterans Affairs Medical Center-Salt Lake City, Geriatrics Research Education and Clinical Center, Salt Lake City, UT, United States.
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8
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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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9
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Introini V, Carciati A, Tomaiuolo G, Cicuta P, Guido S. Endothelial glycocalyx regulates cytoadherence in Plasmodium falciparum malaria. J R Soc Interface 2018; 15:20180773. [PMID: 30958233 PMCID: PMC6303788 DOI: 10.1098/rsif.2018.0773] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 11/20/2018] [Indexed: 12/31/2022] Open
Abstract
Malaria is associated with significant microcirculation disorders, especially when the infection reaches its severe stage. This can lead to a range of fatal conditions, from cerebral malaria to multiple organ failure, of not fully understood pathogenesis. It has recently been proposed that a breakdown of the glycocalyx, the carbohydrate-rich layer lining the vascular endothelium, plays a key role in severe malaria, but direct evidence supporting this hypothesis is still lacking. Here, the interactions between Plasmodium falciparum infected red blood cells ( PfRBCs) and endothelial glycocalyx are investigated by developing an in vitro, physiologically relevant model of human microcirculation based on microfluidics. Impairment of the glycocalyx is obtained by enzymatic removal of sialic acid residues, which, due to their terminal location and net negative charge, are implicated in the initial interactions with contacting cells. We show a more than twofold increase of PfRBC adhesion to endothelial cells upon enzymatic treatment, relative to untreated endothelial cells. As a control, no effect of enzymatic treatment on healthy red blood cell adhesion is found. The increased adhesion of PfRBCs is also associated with cell flipping and reduced velocity as compared to the untreated endothelium. Altogether, these results provide a compelling evidence of the increased cytoadherence of PfRBCs to glycocalyx-impaired vascular endothelium, thus supporting the advocated role of glycocalyx disruption in the pathogenesis of this disease.
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Affiliation(s)
- Viola Introini
- Biological and Soft Systems, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK
| | - Antonio Carciati
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Napoli, Italy
| | - Giovanna Tomaiuolo
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Napoli, Italy
- CEINGE Biotecnologie avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy
| | - Pietro Cicuta
- Biological and Soft Systems, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK
| | - Stefano Guido
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Napoli, Italy
- CEINGE Biotecnologie avanzate, Via Gaetano Salvatore 486, 80145 Napoli, Italy
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10
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Xu Z, Yang Y, Zhu G, Chen P, Huang Z, Dai X, Hou C, Yan L. Simulating Transport of Soft Matter in Micro/Nano Channel Flows with Dissipative Particle Dynamics. ADVANCED THEORY AND SIMULATIONS 2018. [DOI: 10.1002/adts.201800160] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ziyang Xu
- State Key Laboratory of Chemical EngineeringDepartment of Chemical EngineeringTsinghua University Beijing 100084 China
| | - Ye Yang
- State Key Laboratory of Chemical EngineeringDepartment of Chemical EngineeringTsinghua University Beijing 100084 China
| | - Guolong Zhu
- State Key Laboratory of Chemical EngineeringDepartment of Chemical EngineeringTsinghua University Beijing 100084 China
| | - Pengyu Chen
- State Key Laboratory of Chemical EngineeringDepartment of Chemical EngineeringTsinghua University Beijing 100084 China
| | - Zihan Huang
- State Key Laboratory of Chemical EngineeringDepartment of Chemical EngineeringTsinghua University Beijing 100084 China
| | - Xiaobin Dai
- State Key Laboratory of Chemical EngineeringDepartment of Chemical EngineeringTsinghua University Beijing 100084 China
| | - Cuiling Hou
- State Key Laboratory of Chemical EngineeringDepartment of Chemical EngineeringTsinghua University Beijing 100084 China
| | - Li‐Tang Yan
- State Key Laboratory of Chemical EngineeringDepartment of Chemical EngineeringTsinghua University Beijing 100084 China
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11
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Gutierrez M, Ojeda LS, Eniola-Adefeso O. Vascular-targeted particle binding efficacy in the presence of rigid red blood cells: Implications for performance in diseased blood. BIOMICROFLUIDICS 2018; 12:042217. [PMID: 30018696 PMCID: PMC6027197 DOI: 10.1063/1.5027760] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 06/08/2018] [Indexed: 05/03/2023]
Abstract
The field of drug delivery has taken an interest in combating numerous blood and heart diseases via the use of injectable vascular-targeted carriers (VTCs). However, VTC technology has encountered limited efficacy due to a variety of challenges associated with the immense complexity of the in vivo blood flow environment, including the hemodynamic interactions of blood cells, which impact their margination and adhesion to the vascular wall. Red blood cell (RBC) physiology, i.e., size, shape, and deformability, drive cellular distribution in blood flow and has been shown to impact VTC margination to the vessel wall significantly. The RBC shape and deformability are known to be altered in certain human diseases, yet little experimental work has been conducted towards understanding the effect of these alterations, specifically RBC rigidity, on VTC dynamics in physiological blood flow. In this work, we investigate the impact of RBCs of varying stiffnesses on the adhesion efficacy of particles of various sizes, moduli, and shapes onto an inflamed endothelial layer in a human vasculature-inspired, in vitro blood flow model. The blood rigid RBC compositions and degrees of RBC stiffness evaluated are analogous to conditions in diseases such as sickle cell disease. We find that particles of different sizes, moduli, and shapes yield drastically different adhesion patterns in blood flow in the presence of rigid RBCs when compared to 100% healthy RBCs. Specifically, up to 50% reduction in the localization and adhesion of non-deformable 2 μm particles to the vessel wall was observed in the presence of rigid RBCs. Interestingly, deformable 2 μm particles showed enhanced vessel wall localization and adhesion, by up to 85%, depending on the rigidity of RBCs evaluated. Ultimately, this work experimentally clarifies the importance of considering RBC rigidity in the intelligent design of particle therapeutics and highlights possible implications for a wide range of diseases relating to RBC deformability.
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Affiliation(s)
- Mario Gutierrez
- Department of Chemical Engineering, University of
Michigan, Ann Arbor, Michigan 48109, USA
| | - Lauro Sebastian Ojeda
- Department of Chemical Engineering, University of
Michigan, Ann Arbor, Michigan 48109, USA
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12
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Guckenberger A, Kihm A, John T, Wagner C, Gekle S. Numerical-experimental observation of shape bistability of red blood cells flowing in a microchannel. SOFT MATTER 2018; 14:2032-2043. [PMID: 29473072 DOI: 10.1039/c7sm02272g] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Red blood cells flowing through capillaries assume a wide variety of different shapes owing to their high deformability. Predicting the realized shapes is a complex field as they are determined by the intricate interplay between the flow conditions and the membrane mechanics. In this work we construct the shape phase diagram of a single red blood cell with a physiological viscosity ratio flowing in a microchannel. We use both experimental in vitro measurements as well as 3D numerical simulations to complement the respective other one. Numerically, we have easy control over the initial starting configuration and natural access to the full 3D shape. With this information we obtain the phase diagram as a function of initial position, starting shape and cell velocity. Experimentally, we measure the occurrence frequency of the different shapes as a function of the cell velocity to construct the experimental diagram which is in good agreement with the numerical observations. Two different major shapes are found, namely croissants and slippers. Notably, both shapes show coexistence at low (<1 mm s-1) and high velocities (>3 mm s-1) while in-between only croissants are stable. This pronounced bistability indicates that RBC shapes are not only determined by system parameters such as flow velocity or channel size, but also strongly depend on the initial conditions.
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Affiliation(s)
- Achim Guckenberger
- Biofluid Simulation and Modeling, Theoretische Physik, Universität Bayreuth, Germany.
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13
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Pikoula M, Tessier MB, Woods RJ, Ventikos Y. Oligosaccharide model of the vascular endothelial glycocalyx in physiological flow. MICROFLUIDICS AND NANOFLUIDICS 2018; 22:21. [PMID: 29568255 PMCID: PMC5847235 DOI: 10.1007/s10404-018-2037-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 01/15/2018] [Indexed: 05/28/2023]
Abstract
Experiments have consistently revealed the pivotal role of the endothelial glycocalyx layer in vasoregulation and the layer's contribution to mechanotransduction pathways. However, the exact mechanism by which the glycocalyx mediates fluid shear stress remains elusive. This study employs atomic-scale molecular simulations with the aim of investigating the conformational and orientation properties of highly flexible oligosaccharide components of the glycocalyx and their suitability as transduction molecules under hydrodynamic loading. Fluid flow was shown to have nearly no effect on the conformation populations explored by the oligosaccharide, in comparison with static (diffusion) conditions. However, the glycan exhibited a significant orientation change, when compared to simple diffusion, aligning itself with the flow direction. It is the tethered end of the glycan, an asparagine amino acid, which experienced conformational changes as a result of this flow-induced bias. Our results suggest that shear flow through the layer can have an impact on the conformational properties of saccharide-decorated transmembrane proteins, thus acting as a mechanosensor.
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Affiliation(s)
- Maria Pikoula
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, OX1 3PJ UK
- Farr Institute, UCL Institute of Health Informatics, 222 Euston Road, London, NW1 2DA UK
| | - Matthew B. Tessier
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
- Department of Chemistry, University of Georgia, 140 Cedar St, Athens, GA 30602 USA
| | - Robert J. Woods
- Complex Carbohydrate Research Center, University of Georgia, 315 Riverbend Road, Athens, GA 30602 USA
| | - Yiannis Ventikos
- Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE UK
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14
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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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15
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Microvasculature on a chip: study of the Endothelial Surface Layer and the flow structure of Red Blood Cells. Sci Rep 2017; 7:45036. [PMID: 28338083 PMCID: PMC5364477 DOI: 10.1038/srep45036] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Accepted: 02/17/2017] [Indexed: 12/20/2022] Open
Abstract
Microvasculatures-on-a-chip, i.e. in vitro models that mimic important features of microvessel networks, have gained increasing interest in recent years. Such devices have allowed investigating pathophysiological situations involving abnormal biophysical interactions between blood cells and vessel walls. Still, a central question remains regarding the presence, in such biomimetic systems, of the endothelial glycocalyx. The latter is a glycosaminoglycans-rich surface layer exposed to blood flow, which plays a crucial role in regulating the interactions between circulating cells and the endothelium. Here, we use confocal microscopy to characterize the layer expressed by endothelial cells cultured in microfluidic channels. We show that, under our culture conditions, endothelial cells form a confluent layer on all the walls of the circuit and display a glycocalyx that fully lines the lumen of the microchannels. Moreover, the thickness of this surface layer is found to be on the order of 600 nm, which compares well with measurements performed ex or in vivo on microcapillaries. Furthermore, we investigate how the presence of endothelial cells in the microchannels affects their hydrodynamic resistance and the near-wall motion of red blood cells. Our study thus provides an important insight into the physiological relevance of in vitro microvasculatures.
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16
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Zoppe JO, Ataman NC, Mocny P, Wang J, Moraes J, Klok HA. Surface-Initiated Controlled Radical Polymerization: State-of-the-Art, Opportunities, and Challenges in Surface and Interface Engineering with Polymer Brushes. Chem Rev 2017; 117:1105-1318. [PMID: 28135076 DOI: 10.1021/acs.chemrev.6b00314] [Citation(s) in RCA: 587] [Impact Index Per Article: 83.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The generation of polymer brushes by surface-initiated controlled radical polymerization (SI-CRP) techniques has become a powerful approach to tailor the chemical and physical properties of interfaces and has given rise to great advances in surface and interface engineering. Polymer brushes are defined as thin polymer films in which the individual polymer chains are tethered by one chain end to a solid interface. Significant advances have been made over the past years in the field of polymer brushes. This includes novel developments in SI-CRP, as well as the emergence of novel applications such as catalysis, electronics, nanomaterial synthesis and biosensing. Additionally, polymer brushes prepared via SI-CRP have been utilized to modify the surface of novel substrates such as natural fibers, polymer nanofibers, mesoporous materials, graphene, viruses and protein nanoparticles. The last years have also seen exciting advances in the chemical and physical characterization of polymer brushes, as well as an ever increasing set of computational and simulation tools that allow understanding and predictions of these surface-grafted polymer architectures. The aim of this contribution is to provide a comprehensive review that critically assesses recent advances in the field and highlights the opportunities and challenges for future work.
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Affiliation(s)
- Justin O Zoppe
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Nariye Cavusoglu Ataman
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Piotr Mocny
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Jian Wang
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - John Moraes
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
| | - Harm-Anton Klok
- Institut des Matériaux and Institut des Sciences et Ingénierie Chimiques, Laboratoire des Polymères Bâtiment MXD, Ecole Polytechnique Fédérale de Lausanne (EPFL) , Station 12 CH-1015 Lausanne, Switzerland
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17
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Red blood cell phase separation in symmetric and asymmetric microchannel networks: effect of capillary dilation and inflow velocity. Sci Rep 2016; 6:36763. [PMID: 27857165 PMCID: PMC5114676 DOI: 10.1038/srep36763] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 10/20/2016] [Indexed: 12/31/2022] Open
Abstract
The non-uniform partitioning or phase separation of red blood cells (RBCs) at a diverging bifurcation of a microvascular network is responsible for RBC heterogeneity within the network. The mechanisms controlling RBC heterogeneity are not yet fully understood and there is a need to improve the basic understanding of the phase separation phenomenon. In this context, in vitro experiments can fill the gap between existing in vivo and in silico models as they provide better controllability than in vivo experiments without mathematical idealizations or simplifications inherent to in silico models. In this study, we fabricated simple models of symmetric/asymmetric microvascular networks; we provided quantitative data on the RBC velocity, line density and flux in the daughter branches. In general our results confirmed the tendency of RBCs to enter the daughter branch with higher flow rate (Zweifach-Fung effect); in some cases even inversion of the Zweifach-Fung effect was observed. We showed for the first time a reduction of the Zweifach-Fung effect with increasing flow rate. Moreover capillary dilation was shown to cause an increase of RBC line density and RBC residence time within the dilated capillary underlining the possible role of pericytes in regulating the oxygen supply.
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18
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Koutsiaris AG. Wall shear stress in the human eye microcirculation in vivo, segmental heterogeneity and performance of in vitro cerebrovascular models. Clin Hemorheol Microcirc 2016; 63:15-33. [DOI: 10.3233/ch-151976] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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19
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Roman S, Merlo A, Duru P, Risso F, Lorthois S. Going beyond 20 μm-sized channels for studying red blood cell phase separation in microfluidic bifurcations. BIOMICROFLUIDICS 2016; 10:034103. [PMID: 27190568 PMCID: PMC4866949 DOI: 10.1063/1.4948955] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 04/27/2016] [Indexed: 05/13/2023]
Abstract
Despite the development of microfluidics, experimental challenges are considerable for achieving a quantitative study of phase separation, i.e., the non-proportional distribution of Red Blood Cells (RBCs) and suspending fluid, in microfluidic bifurcations with channels smaller than 20 μm. Yet, a basic understanding of phase separation in such small vessels is needed for understanding the coupling between microvascular network architecture and dynamics at larger scale. Here, we present the experimental methodologies and measurement techniques developed for that purpose for RBC concentrations (tube hematocrits) ranging between 2% and 20%. The maximal RBC velocity profile is directly measured by a temporal cross-correlation technique which enables to capture the RBC slip velocity at walls with high resolution, highlighting two different regimes (flat and more blunted ones) as a function of RBC confinement. The tube hematocrit is independently measured by a photometric technique. The RBC and suspending fluid flow rates are then deduced assuming the velocity profile of a Newtonian fluid with no slip at walls for the latter. The accuracy of this combination of techniques is demonstrated by comparison with reference measurements and verification of RBC and suspending fluid mass conservation at individual bifurcations. The present methodologies are much more accurate, with less than 15% relative errors, than the ones used in previous in vivo experiments. Their potential for studying steady state phase separation is demonstrated, highlighting an unexpected decrease of phase separation with increasing hematocrit in symmetrical, but not asymmetrical, bifurcations and providing new reference data in regimes where in vitro results were previously lacking.
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20
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Kreer T. Polymer-brush lubrication: a review of recent theoretical advances. SOFT MATTER 2016; 12:3479-3501. [PMID: 27029521 DOI: 10.1039/c5sm02919h] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This review compiles recent theoretical advances to describe compressive and shear forces of polymer-brush bilayers, which consist of two opposing brushes in contact. Such model systems for polymer-brush lubrication are frequently used as a benchmark to gain insight into biological problems, e.g., synovial joint lubrication. Based on scaling theory, I derive conformational and collective properties of polymer-brush bilayers in equilibrium and out-of-equilibrium situations, such as shear forces in the linear and nonlinear response regimes of stationary shear and under non-stationary shear. Furthermore, I discuss the influence of macromolecular inclusions and electrostatic interactions on polymer-brush lubrication. Comparisons to alternative analytical approaches, experiments and numerical results are performed. Special emphasis is given to methods for simulating polymer-brush bilayers using molecular dynamics simulations.
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Affiliation(s)
- T Kreer
- Leibniz-Institut für Polymerforschung Dresden, Hohe Straße 6, 01069 Dresden, Germany.
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21
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D'Apolito R, Taraballi F, Minardi S, Liu X, Caserta S, Cevenini A, Tasciotti E, Tomaiuolo G, Guido S. Microfluidic interactions between red blood cells and drug carriers by image analysis techniques. Med Eng Phys 2016; 38:17-23. [DOI: 10.1016/j.medengphy.2015.10.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 10/01/2015] [Accepted: 10/13/2015] [Indexed: 01/01/2023]
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22
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Ciasca G, Papi M, Di Claudio S, Chiarpotto M, Palmieri V, Maulucci G, Nocca G, Rossi C, De Spirito M. Mapping viscoelastic properties of healthy and pathological red blood cells at the nanoscale level. NANOSCALE 2015; 7:17030-17037. [PMID: 26415744 DOI: 10.1039/c5nr03145a] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In order to pass through the microcirculation, red blood cells (RBCs) need to undergo extensive deformations and to recover the original shape. This extreme deformability is altered by various pathological conditions. On the other hand, an altered RBC deformability can have major effects on blood flow and can lead to pathological implications. The study of the viscoelastic response of red blood cells to mechanical stimuli is crucial to fully understand deformability changes under pathological conditions. However, the typical erythrocyte biconcave shape hints to a complex and intrinsically heterogeneous mechanical response that must be investigated by using probes at the nanoscale level. In this work, the local viscoelastic behaviour of healthy and pathological red blood cells was probed by Atomic Force Microscopy (AFM). Our results clearly show that the RBC stiffness is not spatially homogeneous, suggesting a strong correlation with the erythrocyte biconcave shape. Moreover, our nanoscale mapping highlights the key role played by viscous forces, demonstrating that RBCs do not behave as pure elastic bodies. The fundamental role played by viscous forces is further strengthened by the comparison between healthy and pathological (diabetes mellitus) RBCs. It is well known that pathological RBCs are usually stiffer than the healthy ones. Our measures unveil a more complex scenario according to which the difference between normal and pathological red blood cells does not merely lie in their stiffness but also in a different dynamical response to external stimuli that is governed by viscous forces.
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Affiliation(s)
- G Ciasca
- Instituto di Fisica, Università Cattolica del Sacro Cuore, Largo F. Vito 1, 00168, Roma, Italy.
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23
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D'Apolito R, Tomaiuolo G, Taraballi F, Minardi S, Kirui D, Liu X, Cevenini A, Palomba R, Ferrari M, Salvatore F, Tasciotti E, Guido S. Red blood cells affect the margination of microparticles in synthetic microcapillaries and intravital microcirculation as a function of their size and shape. J Control Release 2015; 217:263-72. [PMID: 26381900 DOI: 10.1016/j.jconrel.2015.09.013] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 09/05/2015] [Accepted: 09/09/2015] [Indexed: 12/29/2022]
Abstract
A key step in particle-based drug delivery throughmicrocirculation is particlemigration from blood flow to vesselwalls, also known as “margination”,which promotes particle contact and adhesion to the vesselwall. Margination and adhesion should be independently addressed as two distinct phenomena, considering that the former is a fundamental prerequisite to achieve particle adhesion and subsequent extravasation. Although margination has beenmodeled by numerical simulations and investigated inmodel systems in vitro, experimental studies including red blood cells (RBCs) are lacking. Here, we evaluate the effect of RBCs on margination through microfluidic studies in vitro and by intravital microscopy in vivo.We showthatmargination,which is almost absent when particles are suspended in a cell-free medium, is drastically enhanced by RBCs. This effect is size- and shape-dependent, larger spherical/discoid particles being more effectively marginated both in vitro and in vivo. Our findings can be explained by the collision of particles with RBCs that induces the drifting of the particles towards the vessel walls where they become trapped in the cell-free layer. These results are relevant for the design of drug delivery strategies based on systemically administered carriers.
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Affiliation(s)
- Rosa D'Apolito
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Italy; CEINGE Biotecnologie avanzate, Napoli, Italy
| | - Giovanna Tomaiuolo
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Italy; CEINGE Biotecnologie avanzate, Napoli, Italy.
| | - Francesca Taraballi
- Department of NanoMedicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Silvia Minardi
- Department of NanoMedicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Dickson Kirui
- Department of NanoMedicine, Houston Methodist Research Institute, Houston, TX, USA; Naval Medical Research Unit, San Antonio, TX, USA
| | - Xuewu Liu
- Department of NanoMedicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Armando Cevenini
- Department of Molecular Medicine and Medical Biotechnology, Università di Napoli Federico II, Italy
| | - Roberto Palomba
- Department of NanoMedicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Mauro Ferrari
- Department of NanoMedicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Francesco Salvatore
- Department of Molecular Medicine and Medical Biotechnology, Università di Napoli Federico II, Italy; CEINGE Biotecnologie avanzate, Napoli, Italy
| | - Ennio Tasciotti
- Department of NanoMedicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Stefano Guido
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II, Italy; CEINGE Biotecnologie avanzate, Napoli, Italy
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24
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Marki A, Esko JD, Pries AR, Ley K. Role of the endothelial surface layer in neutrophil recruitment. J Leukoc Biol 2015; 98:503-15. [PMID: 25979432 DOI: 10.1189/jlb.3mr0115-011r] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 03/25/2015] [Indexed: 12/15/2022] Open
Abstract
Neutrophil recruitment in most tissues is limited to postcapillary venules, where E- and P-selectins are inducibly expressed by venular endothelial cells. These molecules support neutrophil rolling via binding of PSGL-1 and other ligands on neutrophils. Selectins extend ≤ 38 nm above the endothelial plasma membrane, and PSGL-1 extends to 50 nm above the neutrophil plasma membrane. However, endothelial cells are covered with an ESL composed of glycosaminoglycans that is ≥ 500 nm thick and has measurable resistance against compression. The neutrophil surface is also covered with a surface layer. These surface layers would be expected to completely shield adhesion molecules; thus, neutrophils should not be able to roll and adhere. However, in the cremaster muscle and in many other models investigated using intravital microscopy, neutrophils clearly roll, and their rolling is easily and quickly induced. This conundrum was thought to be resolved by the observation that the induction of selectins is accompanied by ESL shedding; however, ESL shedding only partially reduces the ESL thickness (to 200 nm) and thus is insufficient to expose adhesion molecules. In addition to its antiadhesive functions, the ESL also presents neutrophil arrest-inducing chemokines. ESL heparan sulfate can also bind L-selectin expressed by the neutrophils, which contributes to rolling and arrest. We conclude that ESL has both proadhesive and antiadhesive functions. However, most previous studies considered either only the proadhesive or only the antiadhesive effects of the ESL. An integrated model for the role of the ESL in neutrophil rolling, arrest, and transmigration is needed.
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Affiliation(s)
- Alex Marki
- *Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California, USA; and Department of Physiology and Center for Cardiovascular Research, Charite, Berlin, Germany
| | - Jeffrey D Esko
- *Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California, USA; and Department of Physiology and Center for Cardiovascular Research, Charite, Berlin, Germany
| | - Axel R Pries
- *Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California, USA; and Department of Physiology and Center for Cardiovascular Research, Charite, Berlin, Germany
| | - Klaus Ley
- *Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, California, USA; and Department of Physiology and Center for Cardiovascular Research, Charite, Berlin, Germany
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25
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Lázaro GR, Hernández-Machado A, Pagonabarraga I. Rheology of red blood cells under flow in highly confined microchannels: I. effect of elasticity. SOFT MATTER 2014; 10:7195-206. [PMID: 25105872 DOI: 10.1039/c4sm00894d] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
We analyze the rheology of dilute red blood cell suspensions in pressure driven flows at low Reynolds number, in terms of the morphologies and elasticity of the cells. We focus on narrow channels of width similar to the cell diameter, when the interactions with the walls dominate the cell dynamics. The suspension presents a shear-thinning behaviour, with a Newtonian-behaviour at low shear rates, an intermediate region of strong decay of the suspension viscosity, and an asymptotic regime at high shear rates in which the effective viscosity converges to that of the solvent. We identify the relevant aspects of cell elasticity that contribute to the rheological response of blood at high confinement. In a second paper, we will explore the focusing of red blood cells while flowing at high shear rates and how this effect is controlled by the geometry of the channel.
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Affiliation(s)
- Guillermo R Lázaro
- Departament d'Estructura i Constituents de la Materia, Universitat de Barcelona, Av. Diagonal 647, E08028 Barcelona, Spain.
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26
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Alterations in red blood cell deformability during storage: a microfluidic approach. BIOMED RESEARCH INTERNATIONAL 2014; 2014:764268. [PMID: 25295273 PMCID: PMC4176636 DOI: 10.1155/2014/764268] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 08/15/2014] [Indexed: 12/11/2022]
Abstract
Red blood cells (RBCs) undergo extensive deformation when travelling through the microcapillaries. Deformability, the combined result of properties of the membrane-cytoskeleton complex, the surface area-to-volume ratio, and the hemoglobin content, is a critical determinant of capillary blood flow. During blood bank storage and in many pathophysiological conditions, RBC morphology changes, which has been suggested to be associated with decreased deformability and removal of RBC. While various techniques provide information on the rheological properties of stored RBCs, their clinical significance is controversial. We developed a microfluidic approach for evaluating RBC deformability in a physiologically meaningful and clinically significant manner. Unlike other techniques, our method enables a high-throughput determination of changes in deformation capacity to provide statistically significant data, while providing morphological information at the single-cell level. Our data show that, under conditions that closely mimic capillary dimensions and flow, the capacity to deform and the capacity to relax are not affected during storage in the blood bank. Our data also show that altered cell morphology by itself does not necessarily affect deformability.
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27
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Tomaiuolo G. Biomechanical properties of red blood cells in health and disease towards microfluidics. BIOMICROFLUIDICS 2014; 8:051501. [PMID: 25332724 PMCID: PMC4189537 DOI: 10.1063/1.4895755] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 09/03/2014] [Indexed: 05/04/2023]
Abstract
Red blood cells (RBCs) possess a unique capacity for undergoing cellular deformation to navigate across various human microcirculation vessels, enabling them to pass through capillaries that are smaller than their diameter and to carry out their role as gas carriers between blood and tissues. Since there is growing evidence that red blood cell deformability is impaired in some pathological conditions, measurement of RBC deformability has been the focus of numerous studies over the past decades. Nevertheless, reports on healthy and pathological RBCs are currently limited and, in many cases, are not expressed in terms of well-defined cell membrane parameters such as elasticity and viscosity. Hence, it is often difficult to integrate these results into the basic understanding of RBC behaviour, as well as into clinical applications. The aim of this review is to summarize currently available reports on RBC deformability and to highlight its association with various human diseases such as hereditary disorders (e.g., spherocytosis, elliptocytosis, ovalocytosis, and stomatocytosis), metabolic disorders (e.g., diabetes, hypercholesterolemia, obesity), adenosine triphosphate-induced membrane changes, oxidative stress, and paroxysmal nocturnal hemoglobinuria. Microfluidic techniques have been identified as the key to develop state-of-the-art dynamic experimental models for elucidating the significance of RBC membrane alterations in pathological conditions and the role that such alterations play in the microvasculature flow dynamics.
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Affiliation(s)
- Giovanna Tomaiuolo
- Dipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale, Università di Napoli Federico II , Piazzale Tecchio 80, Napoli 80125, Italy and CEINGE Biotecnologie Avanzate , Via Gaetano Salvatore 486, Napoli 80145, Italy
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