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Scavone M, Bozzi S, Mencarini T, Podda G, Cattaneo M, Redaelli A. Platelet Adhesion and Thrombus Formation in Microchannels: The Effect of Assay-Dependent Variables. Int J Mol Sci 2020; 21:E750. [PMID: 31979370 DOI: 10.3390/ijms21030750] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/13/2020] [Accepted: 01/21/2020] [Indexed: 12/12/2022] Open
Abstract
Microfluidic flow chambers (MFCs) allow the study of platelet adhesion and thrombus formation under flow, which may be influenced by several variables. We developed a new MFC, with which we tested the effects of different variables on the results of platelet deposition and thrombus formation on a collagen-coated surface. Methods: Whole blood was perfused in the MFC over collagen Type I for 4 min at different wall shear rates (WSR) and different concentrations of collagen-coating solutions, keeping blood samples at room temperature or 37 °C before starting the experiments. In addition, we tested the effects of the antiplatelet agent acetylsalicylic acid (ASA) (antagonist of cyclooxygenase-1, 100 µM) and cangrelor (antagonist of P2Y12, 1 µM). Results: Platelet deposition on collagen (I) was not affected by the storage temperature of the blood before perfusion (room temperature vs. 37 °C); (II) was dependent on a shear rate in the range between 300/s and 1700/s; and (III) was influenced by the collagen concentration used to coat the microchannels up to a value of 10 µg/mL. ASA and cangrelor did not cause statistically significant inhibition of platelet accumulation, except for ASA at low collagen concentrations. Conclusions: Platelet deposition on collagen-coated surfaces is a shear-dependent process, not influenced by the collagen concentration beyond a value of 10 µg/mL. However, the inhibitory effect of antiplatelet drugs is better observed using low concentrations of collagen.
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2
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Albers HJ, Passier R, van den Berg A, van der Meer AD. Automated Analysis of Platelet Aggregation on Cultured Endothelium in a Microfluidic Chip Perfused with Human Whole Blood. Micromachines (Basel) 2019; 10:E781. [PMID: 31739604 PMCID: PMC6915557 DOI: 10.3390/mi10110781] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 11/04/2019] [Accepted: 11/13/2019] [Indexed: 12/17/2022]
Abstract
Organ-on-a-chip models with incorporated vasculature are becoming more popular to study platelet biology. A large variety of image analysis techniques are currently used to determine platelet coverage, ranging from manually setting thresholds to scoring platelet aggregates. In this communication, an automated methodology is introduced, which corrects misalignment of a microfluidic channel, automatically defines regions of interest and utilizes a triangle threshold to determine platelet coverages and platelet aggregate size distributions. A comparison between the automated methodology and manual identification of platelet aggregates shows a high accuracy of the triangle methodology. Furthermore, the image analysis methodology can determine platelet coverages and platelet size distributions in microfluidic channels lined with either untreated or activated endothelium used for whole blood perfusion, proving the robustness of the method.
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Affiliation(s)
- Hugo J. Albers
- BIOS Lab-on-a-Chip Group, University of Twente, 7522 NH Enschede, The Netherlands
- Applied Stem Cell Technologies Group, University of Twente, 7522 NB Enschede, The Netherlands
| | - Robert Passier
- Applied Stem Cell Technologies Group, University of Twente, 7522 NB Enschede, The Netherlands
| | - Albert van den Berg
- BIOS Lab-on-a-Chip Group, University of Twente, 7522 NH Enschede, The Netherlands
| | - Andries D. van der Meer
- Applied Stem Cell Technologies Group, University of Twente, 7522 NB Enschede, The Netherlands
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3
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Abstract
The vasculature is a dynamic environment in which blood platelets constantly survey the endothelium for sites of vessel damage. The formation of a mechanically coherent hemostatic plug to prevent blood loss relies on a coordinated series of ligand-receptor interactions governing the recruitment, activation, and aggregation of platelets. The physical biology of each step is distinct in that the recruitment of platelets depends on the mechanosensing of the platelet receptor glycoprotein Ib for the adhesive protein von Willebrand factor, whereas platelet activation and aggregation are responsive to the mechanical forces sensed at adhesive junctions between platelets and at the platelet-matrix interface. Herein we take a biophysical perspective to discuss the current understanding of platelet mechanotransduction as well as the measurement techniques used to quantify the physical biology of platelets in the context of thrombus formation under flow.
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Affiliation(s)
- Caroline E Hansen
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Yongzhi Qiu
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
| | - Owen J T McCarty
- Department of Cell, Developmental, and Cancer Biology, Oregon Health & Science University, Portland, Oregon 97239, USA.,Division of Hematology and Medical Oncology and Department of Biomedical Engineering, School of Medicine, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Wilbur A Lam
- Aflac Cancer and Blood Disorders Center, Department of Pediatrics, Children's Healthcare of Atlanta/Emory University School of Medicine, Atlanta, Georgia 30332, USA; .,Wallace H. Coulter Department of Biomedical Engineering and Institute for Electronics and Nanotechnology, Georgia Institute of Technology and Emory University, Atlanta, Georgia 30332, USA
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4
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Chen Z, Lu J, Zhang C, Hsia I, Yu X, Marecki L, Marecki E, Asmani M, Jain S, Neelamegham S, Zhao R. Microclot array elastometry for integrated measurement of thrombus formation and clot biomechanics under fluid shear. Nat Commun 2019; 10:2051. [PMID: 31053712 DOI: 10.1038/s41467-019-10067-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 04/15/2019] [Indexed: 11/08/2022] Open
Abstract
Blood clotting at the vascular injury site is a complex process that involves platelet adhesion and clot stiffening/contraction in the milieu of fluid flow. An integrated understanding of the hemodynamics and tissue mechanics regulating this process is currently lacking due to the absence of an experimental system that can simultaneously model clot formation and measure clot mechanics under shear flow. Here we develop a microfluidic-integrated microclot-array-elastometry system (clotMAT) that recapitulates dynamic changes in clot mechanics under physiological shear. Treatments with procoagulants and platelet antagonists and studies with diseased patient plasma demonstrate the ability of the system to assay clot biomechanics associated with common antiplatelet treatments and bleeding disorders. The changes of clot mechanics under biochemical treatments and shear flow demonstrate independent yet equally strong effects of these two stimulants on clot stiffening. This microtissue force sensing system may have future research and diagnostic potential for various bleeding disorders.
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5
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Jain A, van der Meer AD, Papa AL, Barrile R, Lai A, Schlechter BL, Otieno MA, Louden CS, Hamilton GA, Michelson AD, Frelinger AL, Ingber DE. Assessment of whole blood thrombosis in a microfluidic device lined by fixed human endothelium. Biomed Microdevices 2017; 18:73. [PMID: 27464497 PMCID: PMC4963439 DOI: 10.1007/s10544-016-0095-6] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The vascular endothelium and shear stress are critical determinants of physiological hemostasis and platelet function in vivo, yet current diagnostic and monitoring devices do not fully incorporate endothelial function under flow in their assessment and, therefore, they can be unreliable and inaccurate. It is challenging to include the endothelium in assays for clinical laboratories or point-of-care settings because living cell cultures are not sufficiently robust. Here, we describe a microfluidic device that is lined by a human endothelium that is chemically fixed, but still retains its ability to modulate hemostasis under continuous flow in vitro even after few days of storage. This device lined with a fixed endothelium supports formation of platelet-rich thrombi in the presence of physiological shear, similar to a living arterial vessel. We demonstrate the potential clinical value of this device by showing that thrombus formation and platelet function can be measured within minutes using a small volume (0.5 mL) of whole blood taken from subjects receiving antiplatelet medications. The inclusion of a fixed endothelial microvessel will lead to biomimetic analytical devices that can potentially be used for diagnostics and point-of-care applications.
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Affiliation(s)
- Abhishek Jain
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 3 Blackfan Circle, CLSB 5, Boston, MA, 02115, USA.,Division of Hemostasis and Thrombosis, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.,Vascular Biology Program and Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Andries D van der Meer
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 3 Blackfan Circle, CLSB 5, Boston, MA, 02115, USA.,MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Anne-Laure Papa
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 3 Blackfan Circle, CLSB 5, Boston, MA, 02115, USA
| | - Riccardo Barrile
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 3 Blackfan Circle, CLSB 5, Boston, MA, 02115, USA.,Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Angela Lai
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Benjamin L Schlechter
- Division of Hematology and Oncology, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Monicah A Otieno
- Janssen Pharmaceutical Research and Development, Pre-Clinical Development and Safety, Spring House, PA, USA
| | - Calvert S Louden
- Janssen Pharmaceutical Research and Development, Pre-Clinical Development and Safety, Spring House, PA, USA
| | - Geraldine A Hamilton
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 3 Blackfan Circle, CLSB 5, Boston, MA, 02115, USA.,Emulate Inc., 210 Broadway St., Cambridge, MA, USA
| | - Alan D Michelson
- Center for Platelet Research Studies, Division of Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Andrew L Frelinger
- Center for Platelet Research Studies, Division of Hematology/Oncology, Boston Children's Hospital, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - Donald E Ingber
- Wyss Institute for Biologically Inspired Engineering, Harvard University, 3 Blackfan Circle, CLSB 5, Boston, MA, 02115, USA. .,Vascular Biology Program and Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA. .,Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, MA, USA.
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6
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Jain A, Barrile R, van der Meer AD, Mammoto A, Mammoto T, De Ceunynck K, Aisiku O, Otieno MA, Louden CS, Hamilton GA, Flaumenhaft R, Ingber DE. Primary Human Lung Alveolus-on-a-chip Model of Intravascular Thrombosis for Assessment of Therapeutics. Clin Pharmacol Ther 2017; 103:332-340. [PMID: 28516446 DOI: 10.1002/cpt.742] [Citation(s) in RCA: 191] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 04/26/2017] [Accepted: 05/08/2017] [Indexed: 12/26/2022]
Abstract
Pulmonary thrombosis is a significant cause of patient mortality; however, there are no effective in vitro models of thrombi formation in human lung microvessels that could also assess therapeutics and toxicology of antithrombotic drugs. Here, we show that a microfluidic lung alveolus-on-a-chip lined by human primary alveolar epithelium interfaced with endothelium and cultured under flowing whole blood can be used to perform quantitative analysis of organ-level contributions to inflammation-induced thrombosis. This microfluidic chip recapitulates in vivo responses, including platelet-endothelial dynamics and revealed that lipopolysaccharide (LPS) endotoxin indirectly stimulates intravascular thrombosis by activating the alveolar epithelium, rather than acting directly on endothelium. This model is also used to analyze inhibition of endothelial activation and thrombosis due to a protease activated receptor-1 (PAR-1) antagonist, demonstrating its ability to dissect complex responses and identify antithrombotic therapeutics. Thus, this methodology offers a new approach to study human pathophysiology of pulmonary thrombosis and advance drug development.
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Affiliation(s)
- A Jain
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts, USA.,Vascular Biology Program and Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA.,Division of Hemostasis and Thrombosis, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.,Department of Biomedical Engineering, Dwight Look College of Engineering, Texas A&M University, College Station, Texas, USA
| | - R Barrile
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts, USA.,Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - A D van der Meer
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts, USA.,MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - A Mammoto
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - T Mammoto
- Vascular Biology Program and Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - K De Ceunynck
- Division of Hemostasis and Thrombosis, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - O Aisiku
- Division of Hemostasis and Thrombosis, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - M A Otieno
- Janssen Pharmaceutical Research and Development, Pre-Clinical Development and Safety, Spring House, Pennsylvania, USA
| | - C S Louden
- Janssen Pharmaceutical Research and Development, Pre-Clinical Development and Safety, Spring House, Pennsylvania, USA
| | | | - R Flaumenhaft
- Division of Hemostasis and Thrombosis, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - D E Ingber
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts, USA.,Vascular Biology Program and Department of Surgery, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, USA.,Harvard John A. Paulson School of Engineering and Applied Sciences, Cambridge, Massachusetts, USA
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7
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Zhu S, Herbig BA, Li R, Colace TV, Muthard RW, Neeves KB, Diamond SL. In microfluidico: Recreating in vivo hemodynamics using miniaturized devices. Biorheology 2016; 52:303-18. [PMID: 26600269 DOI: 10.3233/bir-15065] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Microfluidic devices create precisely controlled reactive blood flows and typically involve: (i) validated anticoagulation/pharmacology protocols, (ii) defined reactive surfaces, (iii) defined flow-transport regimes, and (iv) optical imaging. An 8-channel device can be run at constant flow rate or constant pressure drop for blood perfusion over a patterned collagen, collagen/kaolin, or collagen/tissue factor (TF) to measure platelet, thrombin, and fibrin dynamics during clot growth. A membrane-flow device delivers a constant flux of platelet agonists or coagulation enzymes into flowing blood. A trifurcated device sheaths a central blood flow on both sides with buffer, an ideal approach for on-chip recalcification of citrated blood or drug delivery. A side-view device allows clotting on a porous collagen/TF plug at constant pressure differential across the developing clot. The core-shell architecture of clots made in mouse models can be replicated in this device using human blood. For pathological flows, a stenosis device achieves shear rates of >100,000 s(-1) to drive plasma von Willebrand factor (VWF) to form thick long fibers on collagen. Similarly, a micropost-impingement device creates extreme elongational and shear flows for VWF fiber formation without collagen. Overall, microfluidics are ideal for studies of clotting, bleeding, fibrin polymerization/fibrinolysis, cell/clot mechanics, adhesion, mechanobiology, and reaction-transport dynamics.
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Affiliation(s)
- Shu Zhu
- Institute for Medicine and Engineering, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Bradley A Herbig
- Institute for Medicine and Engineering, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Ruizhi Li
- Institute for Medicine and Engineering, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas V Colace
- Institute for Medicine and Engineering, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Ryan W Muthard
- Institute for Medicine and Engineering, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Keith B Neeves
- Department of Chemical and Biomolecular Engineering, Colorado School of Mines, Golden, CO, USA
| | - Scott L Diamond
- Institute for Medicine and Engineering, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA, USA
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8
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Affiliation(s)
- Alinaghi Salari
- Department of Chemical Engineering; University of Toronto; 200 College Street Toronto Ontario M5S 3E5 Canada
| | - Eugenia Kumacheva
- Department of Chemical Engineering; University of Toronto; 200 College Street Toronto Ontario M5S 3E5 Canada
- Department of Chemistry; University of Toronto; 80 Saint George Street Toronto Ontario M5S 3H6 Canada
- Institute of Biomaterials and Biomedical Engineering; University of Toronto; 164 College Street Toronto Ontario M5S 3G9 Canada
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9
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Shi X, Yang J, Huang J, Long Z, Ruan Z, Xiao B, Xi X. Effects of different shear rates on the attachment and detachment of platelet thrombi. Mol Med Rep 2016; 13:2447-56. [PMID: 26847168 PMCID: PMC4768970 DOI: 10.3892/mmr.2016.4825] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 01/15/2016] [Indexed: 11/06/2022] Open
Abstract
Thrombosis and hemostasis take place in flowing blood, which generates shear forces. The effect of different shear rates, particularly pathological forces, on platelet thrombus formation remains to be fully elucidated. The present study observed the morphological characteristics and hierarchical structure of thrombi on the collagen surface at a wide range of wall shear rates (WSRs) and examined the underlying mechanisms. Calcein AM‑labeled whole blood was perfused over a collagen‑coated surface at different shear rates set by a Bioflux 200 microfluidic device and the thrombi formed were assessed for area coverage, the height and the hierarchical structure defined by the extent of platelet activation and packing density. The factors that affect thrombus formation were also investigated. Platelet thrombus formation varied under different WSRs, for example, dispersed platelet adhesion mixed with erythrocytes was observed at 125‑250 s(‑1), extensive and thin platelet thrombi were observed at 500‑1,500 s(‑1), and sporadic, thick thrombi were observed at pathological WSRs of 2,500‑5,000 s(‑1), which showed a tendency to be shed. With increasing WSRs, the height of the thrombi showed an increasing linear trend, whereas the total fluorescence intensity and area of the thrombi exhibited a parabolic curve‑like change, with a turning point at a WSR of 2,500 s(‑1). The number of thrombi, the average fluorescence intensity and the area per thrombus showed similar trends, with an initial upwards incline followed by a decline. The thrombi formed at higher WSRs had a thicker shell, which led to a more densely packed core. Platelet thrombus formation under shear‑flow was regulated by the adhesive strength, which was mediated by receptor‑ligand interaction, the platelet deposition induced by shear rates and the detachment by the dynamic force of flow. This resulted in a balance between thrombus attachment, including adhesion and aggregation, and detachment. Collectively, compared with physiological low WSRs, pathological high WSRs caused thicker and more easily shed thrombi with more condensed cores, which was regulated by an attachment‑detachment balance. These results provide novel insights into the properties of thrombus formation on collagen at different WSRs, and offers possible explanations for certain clinical physiopathological phenomena, including physical hemostasis and pathological thrombosis.
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Affiliation(s)
- Xiaofeng Shi
- Department of Hematology, Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Sino‑French Research Center for Life Sciences and Genomics, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, P.R. China
| | - Jichun Yang
- Department of Hematology, Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Sino‑French Research Center for Life Sciences and Genomics, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, P.R. China
| | - Jiansong Huang
- Department of Hematology, Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Sino‑French Research Center for Life Sciences and Genomics, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, P.R. China
| | - Zhangbiao Long
- Department of Hematology, Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Sino‑French Research Center for Life Sciences and Genomics, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, P.R. China
| | - Zheng Ruan
- Department of Hematology, Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Sino‑French Research Center for Life Sciences and Genomics, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, P.R. China
| | - Bing Xiao
- Department of Hematology, Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Sino‑French Research Center for Life Sciences and Genomics, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, P.R. China
| | - Xiaodong Xi
- Department of Hematology, Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, Collaborative Innovation Center of Hematology, Sino‑French Research Center for Life Sciences and Genomics, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200025, P.R. China
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10
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Zhu S, Diamond SL. Contact activation of blood coagulation on a defined kaolin/collagen surface in a microfluidic assay. Thromb Res 2014; 134:1335-43. [PMID: 25303860 DOI: 10.1016/j.thromres.2014.09.030] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 09/01/2014] [Accepted: 09/24/2014] [Indexed: 11/22/2022]
Abstract
Generation of active Factor XII (FXIIa) triggers blood clotting on artificial surfaces and may also enhance intravascular thrombosis. We developed a patterned kaolin (0 to 0.3 pg/μm(2))/type 1 collagen fibril surface for controlled microfluidic clotting assays. Perfusion of whole blood (treated only with a low level of 4 μg/mL of the XIIa inhibitor, corn trypsin inhibitor) drove platelet deposition followed by fibrin formation. At venous wall shear rate (100 s(-1)), kaolin accelerated onset of fibrin formation by ~100 sec when compared to collagen alone (250 sec vs. 350 sec), with little effect on platelet deposition. Even with kaolin present, arterial wall shear rate (1000 s(-1)) delayed and suppressed fibrin formation compared to venous wall shear rate. A comparison of surfaces for extrinsic activation (tissue factor TF/collagen) versus contact activation (kaolin/collagen) that each generated equal platelet deposition at 100 s(-1) revealed: (1) TF surfaces promoted much faster fibrin onset (at 100 sec) and more endpoint fibrin at 600 sec at either 100 s(-1) or 1000 s(-1), and (2) kaolin and TF surfaces had a similar sensitivity for reduced fibrin deposition at 1000 s(-1) (compared to fibrin formed at 100 s(-1)) despite differing coagulation triggers. Anti-platelet drugs inhibiting P2Y1, P2Y12, cyclooxygenase-1 or activating IP-receptor or guanylate cyclase reduced platelet and fibrin deposition on kaolin/collagen. Since FXIIa or FXIa inhibition may offer safe antithrombotic therapy, especially for biomaterial thrombosis, these defined collagen/kaolin surfaces may prove useful in drug screening tests or in clinical diagnostic assays of blood under flow conditions.
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11
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Li X, Chen W, Li Z, Li L, Gu H, Fu J. Emerging microengineered tools for functional analysis and phenotyping of blood cells. Trends Biotechnol 2014; 32:586-594. [PMID: 25283971 DOI: 10.1016/j.tibtech.2014.09.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 09/09/2014] [Accepted: 09/09/2014] [Indexed: 01/09/2023]
Abstract
The available techniques for assessing blood cell functions are limited considering the various types of blood cell and their diverse functions. In the past decade, rapid advances in microengineering have enabled an array of blood cell functional measurements that are difficult or impossible to achieve using conventional bulk platforms. Such miniaturized blood cell assay platforms also provide the attractive capabilities of reducing chemical consumption, cost, and assay time, as well as exciting opportunities for device integration, automation, and assay standardization. This review summarizes these contemporary microengineered tools and discusses their promising potential for constructing accurate in vitro models and rapid clinical diagnosis using minimal amounts of whole-blood samples.
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Affiliation(s)
- Xiang Li
- Integrated Biosystems and Biomechanics Laboratory, University of Michigan, Ann Arbor, MI 48109, USA; Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Weiqiang Chen
- Integrated Biosystems and Biomechanics Laboratory, University of Michigan, Ann Arbor, MI 48109, USA; Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Zida Li
- Integrated Biosystems and Biomechanics Laboratory, University of Michigan, Ann Arbor, MI 48109, USA; Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ling Li
- Department of Precision Instruments, Tsinghua University, Beijing 100084, China
| | - Hongchen Gu
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Jianping Fu
- Integrated Biosystems and Biomechanics Laboratory, University of Michigan, Ann Arbor, MI 48109, USA; Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
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12
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Jamiolkowski MA, Woolley JR, Kameneva MV, Antaki JF, Wagner WR. Real time visualization and characterization of platelet deposition under flow onto clinically relevant opaque surfaces. J Biomed Mater Res A 2014; 103:1303-11. [PMID: 24753320 DOI: 10.1002/jbm.a.35202] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 03/31/2014] [Accepted: 04/18/2014] [Indexed: 11/07/2022]
Abstract
Although the thrombogenic nature of the surfaces of cardiovascular devices is an important aspect of blood biocompatibility, few studies have examined platelet deposition onto opaque materials used for these devices in real time. This is particularly true for the metallic surfaces used in current ventricular assist devices (VADs). Using hemoglobin depleted red blood cells (RBC ghosts) and long working distance optics to visualize platelet deposition, we sought to perform such an evaluation. Fluorescently labeled platelets mixed with human RBC ghosts were perfused across six opaque materials (a titanium alloy (Ti6Al4V), silicon carbide (SiC), alumina (Al2O3, 2-methacryloyloxyethyl phosphorylcholine polymer coated Ti6Al4V (MPC-Ti6Al4V), yttria partially stabilized zirconia (YZTP), and zirconia toughened alumina (ZTA)) for 5 min at wall shear rates of 400 and 1000 s(-1). Ti6Al4V had significantly increased platelet deposition relative to MPC-Ti6Al4V, Al2 O3 , YZTP, and ZTA at both wall shear rates (p < 0.01). For all test surfaces, increasing the wall shear rate produced a trend of decreased platelet adhesion. The described system can be a utilized as a tool for comparative analysis of candidate blood-contacting materials with acute blood contact.
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Affiliation(s)
- Megan A Jamiolkowski
- McGowan Institute for Regenerative Medicine, Pittsburgh, Pennsylvania; Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania
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13
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Abstract
Blood systems biology seeks to quantify outside-in signaling as platelets respond to numerous external stimuli, typically under flow conditions. Platelets can activate via GPVI collagen receptor and numerous G-protein coupled receptors (GPCRs) responsive to ADP, thromboxane, thrombin, and prostacyclin. A bottom-up ODE approach allowed prediction of platelet calcium and phosphoinositides following P2Y1 activation with ADP, either for a population average or single cell stochastic behavior. The homeostasis assumption (i.e., a resting platelet stays resting until activated) was particularly useful in finding global steady states for these large metabolic networks. Alternatively, a top-down approach involving Pairwise Agonist Scanning (PAS) allowed large data sets of measured calcium mobilization to predict an individual's platelet responses. The data was used to train neural network (NN) models of signaling to predict patient-specific responses to combinatorial stimulation. A kinetic description of platelet signaling then allows prediction of inside-out activation of platelets as they experience the complex biochemical milieu at the site of thrombosis. Multiscale lattice kinetic Monte Carlo (LKMC) utilizes these detailed descriptions of platelet signaling under flow conditions where released soluble species are solved by finite element method and the flow field around the growing thrombus is updated using computational fluid dynamics or lattice Boltzmann method. Since hemodynamic effects are included in a multiscale approach, thrombosis can then be predicted under arterial and venous thrombotic conditions for various anatomical geometries. Such systems biology approaches accommodate the effect of anti-platelet pharmacological intervention where COX1 pathways or ADP signaling are modulated in a patient-specific manner.
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Affiliation(s)
- Scott L Diamond
- Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, University of Pennsylvania Philadelphia, PA, USA
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14
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Abstract
ADAMTS-13, a plasma reprolysin-like metalloprotease, cleaves von Willebrand factor (VWF). Severe deficiency of plasma ADAMTS-13 activity results in thrombotic thrombocytopenic purpura (TTP), while mild to moderate deficiencies of plasma ADAMTS-13 activity are emerging risk factors for developing myocardial and cerebral infarction, pre-eclampsia, and malignant malaria. Moreover, Adamts13(-/-) mice develop more severe inflammatory responses, leading to increased ischemia/perfusion injury and formation of atherosclerosis. Structure-function studies demonstrate that the N-terminal portion of ADAMTS-13 (MDTCS) is necessary and sufficient for proteolytic cleavage of VWF under various conditions and attenuation of arterial/venous thrombosis after oxidative injury. The more distal portion of ADAMTS-13 (TSP1 2-8 repeats and CUB domains) may function as a disulfide bond reductase to prevent an elongation of ultra-large VWF strings on activated endothelial cells and inhibit platelet adhesion/aggregation on collagen surface under flow. Remarkably, the proteolytic cleavage of VWF by ADAMTS-13 is accelerated by FVIII and platelets under fluid shear stress. A disruption of the interactions between FVIII (or platelet glycoprotein 1bα) and VWF dramatically impairs ADAMTS-13-dependent proteolysis of VWF in vitro and in vivo. These results suggest that FVIII and platelets may be physiological cofactors regulating VWF proteolysis. Finally, the structure-function and autoantibody mapping studies allow us to identify an ADAMTS-13 variant with increased specific activity but reduced inhibition by autoantibodies in patients with acquired TTP. Together, these findings provide novel insight into the mechanism of VWF proteolysis and tools for the therapy of acquired TTP and perhaps other arterial thrombotic disorders.
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Affiliation(s)
- X L Zheng
- Department of Pathology and Laboratory Medicine, The Children's Hospital of Philadelphia, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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15
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Abstract
The study of blood ex vivo can occur in closed or open systems, with or without flow. Microfluidic devices, which constrain fluids to a small (typically submillimeter) scale, facilitate analysis of platelet function, coagulation biology, cellular biorheology, adhesion dynamics, and pharmacology and, as a result, can be an invaluable tool for clinical diagnostics. An experimental session can accommodate hundreds to thousands of unique clotting, or thrombotic, events. Using microfluidics, thrombotic events can be studied on defined surfaces of biopolymers, matrix proteins, and tissue factor, under constant flow rate or constant pressure drop conditions. Distinct shear rates can be generated on a device using a single perfusion pump. Microfluidics facilitated both the determination of intraluminal thrombus permeability and the discovery that platelet contractility can be activated by a sudden decrease in flow. Microfluidic devices are ideal for multicolor imaging of platelets, fibrin, and phosphatidylserine and provide a human blood analog to mouse injury models. Overall, microfluidic advances offer many opportunities for research, drug testing under relevant hemodynamic conditions, and clinical diagnostics.
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Affiliation(s)
- Thomas V Colace
- Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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16
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Voronov RS, Stalker TJ, Brass LF, Diamond SL. Simulation of intrathrombus fluid and solute transport using in vivo clot structures with single platelet resolution. Ann Biomed Eng 2013; 41:1297-307. [PMID: 23423707 DOI: 10.1007/s10439-013-0764-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 02/11/2013] [Indexed: 01/01/2023]
Abstract
The mouse laser injury thrombosis model provides up to 0.22 μm-resolved voxel information about the pore architecture of the dense inner core and loose outer shell regions of an in vivo arterial thrombus. Computational studies were conducted on this 3D structure to quantify transport within and around the clot: Lattice Boltzmann method defined vessel hemodynamics, while passive Lagrangian Scalar Tracking with Brownian motion contribution simulated diffusive-convective transport of various inert solutes (released from lumen or the injured wall). For an input average lumen blood velocity of 0.478 cm/s (measured by Doppler velocimetry), a 0.2 mm/s mean flow rate was obtained within the thrombus structure, most of which occurred in the 100-fold more permeable outer shell region (calculated permeability of the inner core was 10(-11) cm(2)). Average wall shear stresses were 80-100 dyne/cm(2) (peak values >200 dyne/cm(2)) on the outer rough surface of the thrombus. Within the thrombus, small molecule tracers (0.1 kDa) experienced ~70,000 collisions/s and penetrated/exited it in about 1 s, whereas proteins (~50 kDa) had ~9000 collisions/s and required about 10 s (tortuosity ~2-2.5). These simulations help define physical processes during thrombosis and constraints for drug delivery to the thrombus.
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17
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Neeves KB, Onasoga AA, Hansen RR, Lilly JJ, Venckunaite D, Sumner MB, Irish AT, Brodsky G, Manco-Johnson MJ, Di Paola JA. Sources of variability in platelet accumulation on type 1 fibrillar collagen in microfluidic flow assays. PLoS One 2013; 8:e54680. [PMID: 23355889 PMCID: PMC3552855 DOI: 10.1371/journal.pone.0054680] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 12/13/2012] [Indexed: 12/22/2022] Open
Abstract
Microfluidic flow assays (MFA) that measure shear dependent platelet function have potential clinical applications in the diagnosis and treatment of bleeding and thrombotic disorders. As a step towards clinical application, the objective of this study was to measure how phenotypic and genetic factors, as well as experimental conditions, affect the variability of platelet accumulation on type 1 collagen within a MFA. Whole blood was perfused over type 1 fibrillar collagen at wall shear rates of 150, 300, 750 and 1500 s−1 through four independent channels with a height of 50 µm and a width of 500 µm. The accumulation of platelets was characterized by the lag time to 1% platelet surface coverage (LagT), the rate of platelet accumulation (VPLT), and platelet surface coverage (SC). A cohort of normal donors was tested and the results were correlated to plasma von Willebrand factor (VWF) levels, platelet count, hematocrit, sex, and collagen receptors genotypes. VWF levels were the strongest determinant of platelet accumulation. VWF levels were positively correlated to VPLT and SC at all wall shear rates. A longer LagT for platelet accumulation at arterial shear rates compared to venous shear rates was attributed to the time required for plasma proteins to adsorb to collagen. There was no association between platelet accumulation and hematocrit or platelet count. Individuals with the AG genotype of the GP6 gene had lower platelet accumulation than individuals with the AA genotype at 150 s−1 and 300 s−1. Recalcified blood collected into sodium citrate and corn trypsin inhibitor (CTI) resulted in diminished platelet accumulation compared to CTI alone, suggesting that citrate irreversibly diminishes platelet function. This study the largest association study of MFA in healthy donors (n = 104) and will likely set up the basis for the determination of the normal range of platelet responses in this type of assay.
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Affiliation(s)
- Keith B. Neeves
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado, United States of America
- Department of Pediatrics, Hemophilia and Thrombosis Center, University of Colorado Denver, Aurora, Colorado, United States of America
- * E-mail: (KBN); (JADP)
| | - Abimbola A. Onasoga
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado, United States of America
| | - Ryan R. Hansen
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado, United States of America
| | - Jessica J. Lilly
- Department of Pediatrics, Hemophilia and Thrombosis Center, University of Colorado Denver, Aurora, Colorado, United States of America
| | - Diana Venckunaite
- Department of Pediatrics, Hemophilia and Thrombosis Center, University of Colorado Denver, Aurora, Colorado, United States of America
| | - Meghan B. Sumner
- Department of Pediatrics, Hemophilia and Thrombosis Center, University of Colorado Denver, Aurora, Colorado, United States of America
| | - Andrew T. Irish
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, Colorado, United States of America
| | - Gary Brodsky
- Department of Pediatrics, Hemophilia and Thrombosis Center, University of Colorado Denver, Aurora, Colorado, United States of America
| | - Marilyn J. Manco-Johnson
- Department of Pediatrics, Hemophilia and Thrombosis Center, University of Colorado Denver, Aurora, Colorado, United States of America
| | - Jorge A. Di Paola
- Department of Pediatrics, Hemophilia and Thrombosis Center, University of Colorado Denver, Aurora, Colorado, United States of America
- * E-mail: (KBN); (JADP)
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18
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Fallah MA, Huck V, Niemeyer V, Desch A, Angerer JI, McKinnon TAJ, Wixforth A, Schneider SW, Schneider MF. Circulating but not immobilized N-deglycosylated von Willebrand factor increases platelet adhesion under flow conditions. Biomicrofluidics 2013; 7:44124. [PMID: 24404057 PMCID: PMC3772935 DOI: 10.1063/1.4819746] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Accepted: 08/13/2013] [Indexed: 05/10/2023]
Abstract
The role of von Willebrand factor (VWF) as a shear stress activated platelet adhesive has been related to a coiled-elongated shape conformation. The forces dominating this transition have been suggested to be controlled by the proteins polymeric architecture. However, the fact that 20% of VWF molecular weight originates from glycan moieties has so far been neglected in these calculations. In this study, we present a systematic experimental investigation on the role of N-glycosylation for VWF mediated platelet adhesion under flow. A microfluidic flow chamber with a stenotic compartment that allows one to mimic various physiological flow conditions was designed for the efficient analysis of the adhesion spectrum. Surprisingly, we found an increase in platelet adhesion with elevated shear rate, both qualitatively and quantitatively fully conserved when N-deglycosylated VWF (N-deg-VWF) instead of VWF was immobilized in the microfluidic channel. This has been demonstrated consistently over four orders of magnitude in shear rate. In contrast, when N-deg-VWF was added to the supernatant, an increase in adhesion rate by a factor of two was detected compared to the addition of wild-type VWF. It appears that once immobilized, the role of glycans is at least modified if not-as found here for the case of adhesion-negated. These findings strengthen the physical impact of the circulating polymer on shear dependent platelet adhesion events. At present, there is no theoretical explanation for an increase in platelet adhesion to VWF in the absence of its N-glycans. However, our data indicate that the effective solubility of the protein and hence its shape or conformation may be altered by the degree of glycosylation and is therefore a good candidate for modifying the forces required to uncoil this biopolymer.
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Affiliation(s)
- M A Fallah
- University of Augsburg, Chair of Experimental Physics I, 86159 Augsburg, Germany ; Department of Biophysical Chemistry, University of Konstanz, 78457 Konstanz, Germany
| | - V Huck
- Heidelberg University, Medical Faculty Mannheim, Experimental Dermatology, 68167 Mannheim, Germany
| | - V Niemeyer
- Heidelberg University, Medical Faculty Mannheim, Experimental Dermatology, 68167 Mannheim, Germany
| | - A Desch
- Heidelberg University, Medical Faculty Mannheim, Experimental Dermatology, 68167 Mannheim, Germany
| | - J I Angerer
- University of Augsburg, Chair of Experimental Physics I, 86159 Augsburg, Germany
| | - T A J McKinnon
- Imperial College London, Hammersmith Hospital Campus, Department of Medicine, London W12 0NN, United Kingdom
| | - A Wixforth
- University of Augsburg, Chair of Experimental Physics I, 86159 Augsburg, Germany
| | - S W Schneider
- Heidelberg University, Medical Faculty Mannheim, Experimental Dermatology, 68167 Mannheim, Germany
| | - M F Schneider
- Department of Mechanical Engineering, Boston University, Boston, Massachusetts 02215, USA
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19
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Flamm MH, Colace TV, Chatterjee MS, Jing H, Zhou S, Jaeger D, Brass LF, Sinno T, Diamond SL. Multiscale prediction of patient-specific platelet function under flow. Blood 2012; 120:190-8. [PMID: 22517902 DOI: 10.1182/blood-2011-10-388140] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
During thrombotic or hemostatic episodes, platelets bind collagen and release ADP and thromboxane A(2), recruiting additional platelets to a growing deposit that distorts the flow field. Prediction of clotting function under hemodynamic conditions for a patient's platelet phenotype remains a challenge. A platelet signaling phenotype was obtained for 3 healthy donors using pairwise agonist scanning, in which calcium dye-loaded platelets were exposed to pairwise combinations of ADP, U46619, and convulxin to activate the P2Y(1)/P2Y(12), TP, and GPVI receptors, respectively, with and without the prostacyclin receptor agonist iloprost. A neural network model was trained on each donor's pairwise agonist scanning experiment and then embedded into a multiscale Monte Carlo simulation of donor-specific platelet deposition under flow. The simulations were compared directly with microfluidic experiments of whole blood flowing over collagen at 200 and 1000/s wall shear rate. The simulations predicted the ranked order of drug sensitivity for indomethacin, aspirin, MRS-2179 (a P2Y(1) inhibitor), and iloprost. Consistent with measurement and simulation, one donor displayed larger clots and another presented with indomethacin resistance (revealing a novel heterozygote TP-V241G mutation). In silico representations of a subject's platelet phenotype allowed prediction of blood function under flow, essential for identifying patient-specific risks, drug responses, and novel genotypes.
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20
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Abstract
Blood clotting under hemodynamic conditions involves numerous multiscale interactions from the molecular scale to macroscopic vessel and systemic circulation scales. Transmission of shear forces to platelet receptors such as GPIbα, P-selectin, α(2)β(1), and α(2b)β(3) controls adhesion dynamics. These forces also drive membrane tether formation, cellular deformation, and mechanosignaling in blood cells. Blood flow results in red blood cell (RBC) drift towards the center of the vessel along with a near-wall plasma layer enriched with platelets. RBC motions also dramatically enhance platelet dispersion. Trajectories of individual platelets near a thrombotic deposit dictate capture-activation-arrest dynamics as these newly arriving platelets are exposed to chemical gradients of ADP, thromboxane, and thrombin within a micron-scale boundary layer formed around the deposit. If shear forces are sufficiently elevated (>50 dyne/cm(2)), the largest polymers of von Willebrand Factor may elongate with concomitant shear-induced platelet activation. Finally, thrombin generation enhances platelet recruitment and clot strength via fibrin polymerization. By combination of coarse-graining, continuum, and stochastic algorithms, the numerical simulation of the growth rate, composition, and occlusive/embolic potential of a thrombus now spans multiscale phenomena. These simulations accommodate particular flow geometries, blood phenotype, pharmacological regimen, and reactive surfaces to help predict disease risk or response to therapy.
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Affiliation(s)
- Mathew H Flamm
- Department of Chemical and Biomolecular Engineering, Institute for Medicine and Engineering, 1024 Vagelos Research Laboratory, University of Pennsylvania, Philadelphia, PA 19104, USA
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21
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Feghhi S, Sniadecki NJ. Mechanobiology of platelets: techniques to study the role of fluid flow and platelet retraction forces at the micro- and nano-scale. Int J Mol Sci 2011; 12:9009-30. [PMID: 22272117 PMCID: PMC3257114 DOI: 10.3390/ijms12129009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 11/24/2011] [Accepted: 11/28/2011] [Indexed: 12/29/2022] Open
Abstract
Coagulation involves a complex set of events that are important in maintaining hemostasis. Biochemical interactions are classically known to regulate the hemostatic process, but recent evidence has revealed that mechanical interactions between platelets and their surroundings can also play a substantial role. Investigations into platelet mechanobiology have been challenging however, due to the small dimensions of platelets and their glycoprotein receptors. Platelet researchers have recently turned to microfabricated devices to control these physical, nanometer-scale interactions with a higher degree of precision. These approaches have enabled exciting, new insights into the molecular and biomechanical factors that affect platelets in clot formation. In this review, we highlight the new tools used to understand platelet mechanobiology and the roles of adhesion, shear flow, and retraction forces in clot formation.
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Affiliation(s)
- Shirin Feghhi
- Department of Mechanical Engineering, University of Washington, Stevens Way, Box 352600, Seattle, WA 98195, USA; E-Mail:
| | - Nathan J. Sniadecki
- Department of Mechanical Engineering, University of Washington, Stevens Way, Box 352600, Seattle, WA 98195, USA; E-Mail:
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98105, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-206-685-6591; Fax: +1-206-685-8047
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22
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Corum LE, Eichinger CD, Hsiao TW, Hlady V. Using microcontact printing of fibrinogen to control surface-induced platelet adhesion and activation. Langmuir 2011; 27:8316-22. [PMID: 21657213 PMCID: PMC3261074 DOI: 10.1021/la201064d] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The ability to promote or inhibit specific platelet-surface interactions in well-controlled environments is crucial to studying fundamental adhesion and activation mechanisms. Here, microcontact printing was used to immobilize human fibrinogen covalently in the form of randomly placed, micrometer-sized islands at an overall surface coverage of 20, 50, or 85%. The nonprinted background region was blocked with covalently immobilized human albumin. Platelet adhesion and morphology on each substrate were assessed using combined differential interference and fluorescence microscopy. At 20% coverage, most of the fibrinogen surface features were small round islands, and platelet adhesion and spreading areas were limited by the position and the size of the islands. Platelet circularity, indicated the morphology was mostly rounded. At 50% coverage, some fibrinogen islands coalesced and platelet adhesion and spreading areas increased. Platelet morphology was controlled by the shape of underlying fibrinogen islands, leading to more irregular spreading. At 85% coverage, the fibrinogen pattern was completely interconnected and both platelet adhesion and the spreading area were significantly higher than at lower coverage. In addition, platelets also spread over the albumin regions, suggesting that after a critical surface density of fibrinogen ligands is reached, platelet spreading is no longer inhibited by albumin. Increasing the overall fibrinogen coverage resulted in higher activation levels defined by key morphological characteristics of the spreading platelet.
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