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Kim DA, Ku DN. Material strengths of shear-induced platelet aggregation clots and coagulation clots. Sci Rep 2024; 14:11460. [PMID: 38769378 PMCID: PMC11106319 DOI: 10.1038/s41598-024-62165-1] [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: 09/18/2023] [Accepted: 05/14/2024] [Indexed: 05/22/2024] Open
Abstract
Arterial occlusion by thrombosis is the immediate cause of some strokes, heart attacks, and peripheral artery disease. Most prior studies assume that coagulation creates the thrombus. However, a contradiction arises as whole blood (WB) clots from coagulation are too weak to stop arterial blood pressures (> 150 mmHg). We measure the material mechanical properties of elasticity and ultimate strength for Shear-Induced Platelet Aggregation (SIPA) type clots, that form under stenotic arterial hemodynamics in comparison with coagulation clots. The ultimate strength of SIPA clots averaged 4.6 ± 1.3 kPa, while WB coagulation clots had a strength of 0.63 ± 0.3 kPa (p < 0.05). The elastic modulus of SIPA clots was 3.8 ± 1.5 kPa at 1 Hz and 0.5 mm displacement, or 2.8 times higher than WB coagulation clots (1.3 ± 1.2 kPa, p < 0.0001). This study shows that the SIPA thrombi, formed quickly under high shear hemodynamics, is seven-fold stronger and three-fold stiffer compared to WB coagulation clots. A force balance calculation shows a SIPA clot has the strength to resist arterial pressure with a short length of less than 2 mm, consistent with coronary pathology.
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Affiliation(s)
- Dongjune A Kim
- Georgia Institute of Technology, G.W. Woodruff School of Mechanical Engineering, 315 Ferst Drive NW, IBB 2307, Atlanta, GA, 30332, USA
| | - David N Ku
- Georgia Institute of Technology, G.W. Woodruff School of Mechanical Engineering, 315 Ferst Drive NW, IBB 2307, Atlanta, GA, 30332, USA.
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2
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Hao Y, Závodszky G, Tersteeg C, Barzegari M, Hoekstra AG. Image-based flow simulation of platelet aggregates under different shear rates. PLoS Comput Biol 2023; 19:e1010965. [PMID: 37428797 PMCID: PMC10358939 DOI: 10.1371/journal.pcbi.1010965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 06/10/2023] [Indexed: 07/12/2023] Open
Abstract
Hemodynamics is crucial for the activation and aggregation of platelets in response to flow-induced shear. In this paper, a novel image-based computational model simulating blood flow through and around platelet aggregates is presented. The microstructure of aggregates was captured by two different modalities of microscopy images of in vitro whole blood perfusion experiments in microfluidic chambers coated with collagen. One set of images captured the geometry of the aggregate outline, while the other employed platelet labelling to infer the internal density. The platelet aggregates were modelled as a porous medium, the permeability of which was calculated with the Kozeny-Carman equation. The computational model was subsequently applied to study hemodynamics inside and around the platelet aggregates. The blood flow velocity, shear stress and kinetic force exerted on the aggregates were investigated and compared under 800 s-1, 1600 s-1 and 4000 s-1 wall shear rates. The advection-diffusion balance of agonist transport inside the platelet aggregates was also evaluated by local Péclet number. The findings show that the transport of agonists is not only affected by the shear rate but also significantly influenced by the microstructure of the aggregates. Moreover, large kinetic forces were found at the transition zone from shell to core of the aggregates, which could contribute to identifying the boundary between the shell and the core. The shear rate and the rate of elongation flow were investigated as well. The results imply that the emerging shapes of aggregates are highly correlated to the shear rate and the rate of elongation. The framework provides a way to incorporate the internal microstructure of the aggregates into the computational model and yields a better understanding of the hemodynamics and physiology of platelet aggregates, hence laying the foundation for predicting aggregation and deformation under different flow conditions.
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Affiliation(s)
- Yue Hao
- Computational Science Lab, Informatics Institute, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
| | - Gábor Závodszky
- Computational Science Lab, Informatics Institute, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
- Department of Hydrodynamic Systems, Budapest University of Technology and Economics, Budapest, Hungary
| | - Claudia Tersteeg
- Laboratory for Thrombosis Research, IRF Life Sciences, KU Leuven Campus Kulak Kortrijk, Kortrijk, Belgium
| | - Mojtaba Barzegari
- Biomechanics Section, Department of Mechanical Engineering, KU Leuven, Leuven, Belgium
| | - Alfons G Hoekstra
- Computational Science Lab, Informatics Institute, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands
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3
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Tan ZQ, Ooi EH, Chiew YS, Foo JJ, Ng EYK, Ooi ET. A computational framework for the multiphysics simulation of microbubble-mediated sonothrombolysis using a forward-viewing intravascular transducer. ULTRASONICS 2023; 131:106961. [PMID: 36812819 DOI: 10.1016/j.ultras.2023.106961] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/08/2023] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Sonothrombolysis is a technique that utilises ultrasound waves to excite microbubbles surrounding a clot. Clot lysis is achieved through mechanical damage induced by acoustic cavitation and through local clot displacement induced by acoustic radiation force (ARF). Despite the potential of microbubble-mediated sonothrombolysis, the selection of the optimal ultrasound and microbubble parameters remains a challenge. Existing experimental studies are not able to provide a complete picture of how ultrasound and microbubble characteristics influence the outcome of sonothrombolysis. Likewise, computational studies have not been applied in detail in the context of sonothrombolysis. Hence, the effect of interaction between the bubble dynamics and acoustic propagation on the acoustic streaming and clot deformation remains unclear. In the present study, we report for the first time the computational framework that couples the bubble dynamic phenomena with the acoustic propagation in a bubbly medium to simulate microbubble-mediated sonothrombolysis using a forward-viewing transducer. The computational framework was used to investigate the effects of ultrasound properties (pressure and frequency) and microbubble characteristics (radius and concentration) on the outcome of sonothrombolysis. Four major findings were obtained from the simulation results: (i) ultrasound pressure plays the most dominant role over all the other parameters in affecting the bubble dynamics, acoustic attenuation, ARF, acoustic streaming, and clot displacement, (ii) smaller microbubbles could contribute to a more violent oscillation and improve the ARF simultaneously when they are stimulated at higher ultrasound pressure, (iii) higher microbubbles concentration increases the ARF, and (iv) the effect of ultrasound frequency on acoustic attenuation is dependent on the ultrasound pressure. These results may provide fundamental insight that is crucial in bringing sonothrombolysis closer to clinical implementation.
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Affiliation(s)
- Zhi Q Tan
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Ean H Ooi
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia; Advanced Engineering Platform, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia.
| | - Yeong S Chiew
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Ji J Foo
- Mechanical Engineering Discipline, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, 47500 Bandar Sunway, Selangor, Malaysia
| | - Eddie Y K Ng
- School of Mechanical and Aerospace Engineering, College of Engineering, Nanyang Technological University, 50 Nanyang Avenue 639798, Singapore
| | - Ean T Ooi
- School of Engineering and Information Technology, Faculty of Science and Technology, Federation University, VIC 3350, Australia
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Arevalo SE, Ebenstein DM, Pruitt LA. A methodological framework for nanomechanical characterization of soft biomaterials and polymers. J Mech Behav Biomed Mater 2022; 134:105384. [DOI: 10.1016/j.jmbbm.2022.105384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/08/2022] [Accepted: 07/15/2022] [Indexed: 11/24/2022]
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5
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Wysocki MA, Doyle S. Enhancing biomedical data validity with standardized segmentation finite element analysis. Sci Rep 2022; 12:9860. [PMID: 35701504 PMCID: PMC9198234 DOI: 10.1038/s41598-022-13961-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/31/2022] [Indexed: 11/09/2022] Open
Abstract
Finite element analysis is a powerful computational technique for augmenting biomedical research, prosthetics design, and preoperative surgical assessment. However, the validity of biomechanical data obtained from finite element analysis is dependent on the quality of the preceding data processing. Until now, little information was available about the effect of the segmentation process on finite element models and biomechanical data. The current investigation applied 4 segmentation approaches to 129 femur specimens, yielding a total of 516 finite element models. Biomechanical data including average displacement, pressure, stress, and strain were collected from experimental groups based on the different segmentation approaches. The results indicate that only a 5.0% variation in the segmentation process leads to statistically significant differences in all 4 biomechanical measurements. These results suggest that it is crucial for consistent segmentation procedures to be applied to all specimens within a study. This methodological advancement will help to ensure that finite element data will be more accurate and that research conclusions will have greater validity.
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Affiliation(s)
- Matthew A Wysocki
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, 14203, USA.
| | - Scott Doyle
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, 14203, USA
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Hossack M, Fisher R, Torella F, Madine J, Field M, Akhtar R. Micromechanical and Ultrastructural Properties of Abdominal Aortic Aneurysms. Artery Res 2022. [DOI: 10.1007/s44200-022-00011-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
AbstractAbdominal aortic aneurysms are a common condition of uncertain pathogenesis that can rupture if left untreated. Current recommended thresholds for planned repair are empirical and based entirely on diameter. It has been observed that some aneurysms rupture before reaching the threshold for repair whilst other larger aneurysms do not rupture. It is likely that geometry is not the only factor influencing rupture risk. Biomechanical indices aiming to improve and personalise rupture risk prediction require, amongst other things, knowledge of the material properties of the tissue and realistic constitutive models. These depend on the composition and organisation of the vessel wall which has been shown to undergo drastic changes with aneurysmal degeneration, with loss of elastin, smooth muscle cells, and an accumulation of isotropically arranged collagen. Most aneurysms are lined with intraluminal thrombus, which has an uncertain effect on the underlying vessel wall, with some authors demonstrating a reduction in wall stress and others a reduction in wall strength. The majority of studies investigating biomechanical properties of ex vivo abdominal aortic aneurysm tissues have used low-resolution techniques, such as tensile testing, able to measure the global material properties at the macroscale. High-resolution engineering techniques such as nanoindentation and atomic force microscopy have been modified for use in soft biological tissues and applied to vascular tissues with promising results. These techniques have the potential to advance the understanding and improve the management of abdominal aortic aneurysmal disease.
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Wortmann N, Andersek T, Guerreiro H, Kyselyova AA, Frölich AM, Fiehler J, Krause D. Development of synthetic thrombus models to simulate stroke treatment in a physical neurointerventional training model. ALL LIFE 2022. [DOI: 10.1080/26895293.2022.2046181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Nadine Wortmann
- Institute of Product Development and Mechanical Engineering Design, Hamburg University of Technology, Hamburg, Germany
| | - Thomas Andersek
- WEINMANN Emergency Medical Technology GmbH + Co. KG, Hamburg, Germany
| | - Helena Guerreiro
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Anna A. Kyselyova
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Jens Fiehler
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Dieter Krause
- Institute of Product Development and Mechanical Engineering Design, Hamburg University of Technology, Hamburg, Germany
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8
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Fereidoonnezhad B, Moerman KM, Johnson S, McCarthy R, McGarry PJ. A new compressible hyperelastic model for the multi-axial deformation of blood clot occlusions in vessels. Biomech Model Mechanobiol 2021; 20:1317-1335. [PMID: 33818678 DOI: 10.1007/s10237-021-01446-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 03/06/2021] [Indexed: 10/21/2022]
Abstract
Mechanical thrombectomy can be significantly affected by the mechanical properties of the occluding thrombus. In this study, we provide the first characterisation of the volumetric behaviour of blood clots. We propose a new hyperelastic model for the volumetric and isochoric deformation of clot. We demonstrate that the proposed model provides significant improvements over established models in terms of accurate prediction of nonlinear stress-strain and volumetric behaviours of clots with low and high red blood cell compositions. We perform a rigorous investigation of the factors that govern clot occlusion of a tapered vessel. The motivation for such an analysis is twofold: (i) the role of clot composition on the in vivo occlusion location is an open clinical question that has significant implications for thrombectomy procedures; (ii) in vitro measurement of occlusion location in an engineered tapered tube can be used as a quick and simple methodology to assess the mechanical properties/compositions of clots. Simulations demonstrate that both isochoric and volumetric behaviours of clots are key determinants of clot lodgement location, in addition to clot-vessel friction. The proposed formulation is shown to provide accurate predictions of in vitro measurement of clot occlusion location in a silicone tapered vessel, in addition to accurately predicting the deformed shape of the clot.
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Affiliation(s)
| | - Kevin M Moerman
- Biomedical Engineering, National University of Ireland Galway, Galway, Ireland
| | - Sarah Johnson
- Cerenovus Galway Neuro-Technology Centre, Johnson & Johnson, Galway, Ireland
| | - Ray McCarthy
- Cerenovus Galway Neuro-Technology Centre, Johnson & Johnson, Galway, Ireland
| | - Patrick J McGarry
- Biomedical Engineering, National University of Ireland Galway, Galway, Ireland.
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9
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Investigating the Mechanical Behavior of Clot Analogues Through Experimental and Computational Analysis. Ann Biomed Eng 2020; 49:420-431. [PMID: 32691265 DOI: 10.1007/s10439-020-02570-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Accepted: 07/11/2020] [Indexed: 10/23/2022]
Abstract
With mechanical thrombectomy emerging as the new standard of care for stroke treatment, clot analogues provide an extremely useful tool in the testing and design of these treatment devices. The aim of this study is to characterise the mechanical behavior of thrombus analogues as a function of composition. Platelet-contracted clot analogues were prepared from blood mixtures of various hematocrits. Mechanical testing was performed whereby clots were subjected to unconfined compression between two rigid plates. Two loading protocols were imposed: cyclic compression for 10 cycles at a constant strain-rate magnitude; stress-relaxation at a constant applied compressive strain. A hyper-viscoelastic constitutive law was identified and calibrated based on the experimental mechanical test data. Scanning electron microscopy (SEM) investigated the clot microstructure at various time-points. Clot analogue composition was found to strongly affect the observed mechanical behavior. The SEM found that the microstructure of the clot analogues was affected by the storage solution and age of the clot. The proposed hyper-viscoelastic constitutive model was found to successfully capture the material test data. The results presented in this study are of key importance to the evaluation and future development mechanical thrombectomy devices and procedures.
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10
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Chernysh IN, Spiewak R, Cambor CL, Purohit PK, Weisel JW. Structure, mechanical properties, and modeling of cyclically compressed pulmonary emboli. J Mech Behav Biomed Mater 2020; 105:103699. [PMID: 32279846 DOI: 10.1016/j.jmbbm.2020.103699] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 02/11/2020] [Accepted: 02/13/2020] [Indexed: 12/15/2022]
Abstract
Pulmonary embolism occurs when blood flow to a part of the lungs is blocked by a venous thrombus that has traveled from the lower limbs. Little is known about the mechanical behavior of emboli under compressive forces from the surrounding musculature and blood pressure. We measured the stress-strain responses of human pulmonary emboli under cyclic compression, and showed that emboli exhibit a hysteretic stress-strain curve. The fibrin fibers and red blood cells (RBCs) are damaged during the compression process, causing irreversible changes in the structure of the emboli. We showed using electron and confocal microscopy that bundling of fibrin fibers occurs due to compression, and damage is accumulated as more cycles are applied. The stress-strain curves depend on embolus structure, such that variations in composition give quantitatively different responses. Emboli with a high fibrin component demonstrate higher normal stress compared to emboli that have a high RBC component. We compared the compression response of emboli to that of whole blood clots containing various volume fractions of RBCs, and found that RBCs rupture at a certain critical stress. We describe the hysteretic response characteristic of foams, using a model of phase transitions in which the compressed foam is segregated into coexisting rarefied and densified phases whose fractions change during compression. Our model takes account of the rupture of RBCs in the compressed emboli and stresses due to fluid flow through their small pores. Our results can help in classifying emboli as rich in fibrin or rich in red blood cells, and can help in understanding what responses to expect when stresses are applied to thrombi in vivo.
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Affiliation(s)
- Irina N Chernysh
- Department of Cell Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Russell Spiewak
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Carolyn L Cambor
- Department of Pathology and Laboratory of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Prashant K Purohit
- Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - John W Weisel
- Department of Cell Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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11
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Kadri OE, Chandran VD, Surblyte M, Voronov RS. In vivo measurement of blood clot mechanics from computational fluid dynamics based on intravital microscopy images. Comput Biol Med 2019; 106:1-11. [PMID: 30660757 PMCID: PMC6390965 DOI: 10.1016/j.compbiomed.2019.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 01/04/2019] [Accepted: 01/04/2019] [Indexed: 12/31/2022]
Abstract
Ischemia which leads to heart attacks and strokes is one of the major causes of death in the world. Whether an occlusion occurs or not depends on the ability of a growing thrombus to resist flow forces exerted on its structure. This manuscript provides the first known in vivo measurement of how much stress a clot can withstand, before yielding to the surrounding blood flow. Namely, Lattice-Boltzmann Method flow simulations are performed based on 3D clot geometries, which are estimated from intravital microscopy images of laser-induced injuries in cremaster microvasculature of live mice. In addition to reporting the blood clot yield stresses, we also show that the thrombus "core" does not experience significant deformation, while its "shell" does. This indicates that the shell is more prone to embolization. Therefore, drugs should be designed to target the shell selectively, while leaving the core intact to minimize excessive bleeding. Finally, we laid down a foundation for a nondimensionalization procedure which unraveled a relationship between clot mechanics and biology. Hence, the proposed framework could ultimately lead to a unified theory of thrombogenesis, capable of explaining all clotting events. Thus, the findings presented herein will be beneficial to the understanding and treatment of heart attacks, strokes and hemophilia.
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Affiliation(s)
- Olufemi Emmanuel Kadri
- Otto H. York Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Vishnu Deep Chandran
- Otto H. York Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Migle Surblyte
- Ying Wu College of Computing Sciences, Department of Computer Science, New Jersey Institute of Technology, Newark, NJ, 07102, USA
| | - Roman S Voronov
- Otto H. York Department of Chemical and Materials Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA.
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Weafer FM, Duffy S, Machado I, Gunning G, Mordasini P, Roche E, McHugh PE, Gilvarry M. Characterization of strut indentation during mechanical thrombectomy in acute ischemic stroke clot analogs. J Neurointerv Surg 2019; 11:891-897. [DOI: 10.1136/neurintsurg-2018-014601] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 12/22/2018] [Accepted: 12/28/2018] [Indexed: 11/04/2022]
Abstract
BackgroundAlthough it is common practice to wait for an ‘embedding time’ during mechanical thrombectomy (MT) to allow strut integration of a stentriever device into an occluding thromboembolic clot, there is a scarcity of evidence demonstrating the value or optimal timing for the wide range of thrombus compositions. This work characterizes the behavior of clot analogs of varying fibrin and cellular compositions subject to indentation forces and embedding times representative of those imparted by a stentriever during MT. The purpose of this study is to quantify the effect of thrombus composition on device strut embedding, and to examine the precise nature of clot integration into a stentriever device at a microstructural level.MethodClot analogs with 0% (varying densities), 5%, 40%, and 80% red blood cell (RBC) content were created using ovine blood. Clot indentation behavior during an initial load application (loading phase) followed by a 5-min embedding time (creep phase) was analyzed using a mechanical tester under physiologically relevant conditions. The mechanism of strut integration was examined using micro-computed tomography (µCT) with an EmboTrap MT device (Cerenovus, Galway, Ireland) deployed in each clot type. Microstructural clot characteristics were identified using scanning electron microscopy (SEM).ResultsCompressive clot stiffness measured during the initial loading phase was shown to be lowest in RBC-rich clots, with a corresponding greatest maximum indentation depth. Meanwhile, additional depth achieved during the simulated embedding time was most pronounced in fibrin-rich clots. SEM imaging identified variations in microstructural mechanisms (fibrin stretching vs rupturing) which was dependent on fibrin:cellular content, while µCT analysis demonstrated the mechanism of strut integration was predominantly the formation of surface undulations rather than clot penetration.ConclusionsDisparities in indentation behavior between clot analogs were attributed to varying microstructural features induced by the cellular:fibrin content. Greater indentation was identified in clots with higher RBC content, but with an increased level of fibrin rupture, suggesting an increased propensity for fragmentation. Additional embedding time improves strut integration, especially in fibrin-rich clots, through the mechanism of fibrin stretching with the majority of additional integration occurring after 3 mins. The level of thrombus incorporation into the EmboTrap MT device (Cerenovus, Galway, Ireland) was primarily influenced by the stentriever design, with increased integration in regions of open architecture.
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13
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Artificial Stroke Clots: How Wide is the Gap to the Real World? World Neurosurg 2018; 110:e90-e99. [DOI: 10.1016/j.wneu.2017.10.090] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/17/2017] [Indexed: 12/15/2022]
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14
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Review of Mechanical Testing and Modelling of Thrombus Material for Vascular Implant and Device Design. Ann Biomed Eng 2017; 45:2494-2508. [DOI: 10.1007/s10439-017-1906-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 08/16/2017] [Indexed: 10/19/2022]
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15
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Gunning GM, McArdle K, Mirza M, Duffy S, Gilvarry M, Brouwer PA. Clot friction variation with fibrin content; implications for resistance to thrombectomy. J Neurointerv Surg 2017; 10:34-38. [PMID: 28044009 DOI: 10.1136/neurintsurg-2016-012721] [Citation(s) in RCA: 173] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 12/01/2016] [Accepted: 12/12/2016] [Indexed: 11/03/2022]
Abstract
BACKGROUND Despite significant advancements in the procedural efficacy of mechanical thrombectomy in patients with ischemic stroke in recent years, there still remains a portion of the population that does not achieve good recanalization. The reasons for this may be varied. We hypothesized that static friction between the clot and the vessel, or catheter wall might contribute to the difficulty in removing the clot. OBJECTIVE To determine if there is a relationship between clot composition and the resistance to sliding (friction) which might contribute to resistance to clot removal. METHODS As clot composition can vary significantly, we investigated five different types of clot in order to measure their respective frictional properties. To do this, a custom-made testing apparatus was created, consisting of various replaceable low-friction surfaces on which the clots could be placed. The surface was then gradually tilted until the clots began to slide; the angle at which this occurred is related to the coefficient of friction of the clots. The experiment was repeated on a bovine aortic surface in order to confirm the results. RESULTS We found that fibrin-rich clots (<20% red blood cell content) have a significantly higher coefficient of friction than clots with a red blood cell content >20%. This result was confirmed by repeating the experiment on a bovine aortic surface as a representation of the interaction between clots and the arterial wall. CONCLUSIONS The friction properties of clots were found to be related to the content ratio of fibrin to red blood cells. Future imaging techniques that could show fibrin and red blood cell content might help us to predict the 'stickiness' of a clot.
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Affiliation(s)
| | | | | | - Sharon Duffy
- Neuravi Ltd, Galway, Ireland
- Department of Mechanical and Industrial Engineering, Galway-Mayo Technologies Centre, Galway-Mayo Institute of Technology, Galway, Ireland
| | | | - Patrick A Brouwer
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
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Brass LF, Diamond SL. Transport physics and biorheology in the setting of hemostasis and thrombosis. J Thromb Haemost 2016; 14:906-17. [PMID: 26848552 PMCID: PMC4870125 DOI: 10.1111/jth.13280] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 01/20/2016] [Accepted: 01/26/2016] [Indexed: 02/02/2023]
Abstract
The biophysics of blood flow can dictate the function of molecules and cells in the vasculature with consequent effects on hemostasis, thrombosis, embolism, and fibrinolysis. Flow and transport dynamics are distinct for (i) hemostasis vs. thrombosis and (ii) venous vs. arterial episodes. Intraclot transport changes dramatically the moment hemostasis is achieved or the moment a thrombus becomes fully occlusive. With platelet concentrations that are 50- to 200-fold greater than platelet-rich plasma, clots formed under flow have a different composition and structure compared with blood clotted statically in a tube. The platelet-rich, core/shell architecture is a prominent feature of self-limiting hemostatic clots formed under flow. Importantly, a critical threshold concentration of surface tissue factor is required for fibrin generation under flow. Once initiated by wall-derived tissue factor, thrombin generation and its spatial propagation within a clot can be modulated by γ'-fibrinogen incorporated into fibrin, engageability of activated factor (FIXa)/activated FVIIIa tenase within the clot, platelet-derived polyphosphate, transclot permeation, and reduction of porosity via platelet retraction. Fibrin imparts tremendous strength to a thrombus to resist embolism up to wall shear stresses of 2400 dyne cm(-2) . Extreme flows, as found in severe vessel stenosis or in mechanical assist devices, can cause von Willebrand factor self-association into massive fibers along with shear-induced platelet activation. Pathological von Willebrand factor fibers are A Disintegrin And Metalloprotease with ThromboSpondin-1 domain 13 resistant but are a substrate for fibrin generation due to FXIIa capture. Recently, microfluidic technologies have enhanced the ability to interrogate blood in the context of stenotic flows, acquired von Willebrand disease, hemophilia, traumatic bleeding, and drug action.
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Affiliation(s)
- Lawrence F. Brass
- Departments of Medicine and Systems Pharmacology, University of Pennsylvania, Philadelphia, PA, USA
| | - Scott L. Diamond
- Departments of Medicine and Systems Pharmacology, University of Pennsylvania, Philadelphia, PA, USA
- Institute for Medicine and Engineering, Department of Chemical Engineering, University of Pennsylvania, Philadelphia, PA, USA
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Swieringa F, Baaten CCFMJ, Verdoold R, Mastenbroek TG, Rijnveld N, van der Laan KO, Breel EJ, Collins PW, Lancé MD, Henskens YMC, Cosemans JMEM, Heemskerk JWM, van der Meijden PEJ. Platelet Control of Fibrin Distribution and Microelasticity in Thrombus Formation Under Flow. Arterioscler Thromb Vasc Biol 2016; 36:692-9. [PMID: 26848157 DOI: 10.1161/atvbaha.115.306537] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 01/15/2016] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Platelet- and fibrin-dependent thrombus formation is regulated by blood flow and exposure of collagen and tissue factor. However, interactions between these blood-borne and vascular components are not well understood. APPROACH AND RESULTS Here, we developed a method to assess whole-blood thrombus formation on microspots with defined amounts of collagen and tissue factor, allowing determination of the mechanical properties and intrathrombus composition. Confining the collagen content resulted in diminished platelet deposition and fibrin formation at high shear flow conditions, but this effect was compensated by a larger thrombus size and increased accumulation of fibrin in the luminal regions of the thrombi at the expense of the base regions. These thrombi were more dependent on tissue factor-triggered thrombin generation. Microforce nanoindentation analysis revealed a significantly increased microelasticity of thrombi with luminal-oriented fibrin. At a low shear rate, fibrin fibers tended to luminally cover the thrombi, again resulting in a higher microelasticity. Studies with blood from patients with distinct hemostatic insufficiencies indicated an impairment in the formation of a platelet-fibrin thrombus in the cases of dilutional coagulopathy, thrombocytopenia, Scott syndrome, and hemophilia B. CONCLUSIONS Taken together, our data indicate that (1) thrombin increases the platelet thrombus volume; (2) tissue factor drives the formation of fibrin outside of the platelet thrombus; (3) limitation of platelet adhesion redirects fibrin from bottom to top of the thrombus; (4) a lower shear rate promotes thrombus coverage with fibrin; (5) the fibrin distribution pattern determines thrombus microelasticity; and (6) the thrombus-forming process is reduced in patients with diverse hemostatic defects.
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Affiliation(s)
- Frauke Swieringa
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Constance C F M J Baaten
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Remco Verdoold
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Tom G Mastenbroek
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Niek Rijnveld
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Koen O van der Laan
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Ernst J Breel
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Peter W Collins
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Marcus D Lancé
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Yvonne M C Henskens
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Judith M E M Cosemans
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Johan W M Heemskerk
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Paola E J van der Meijden
- From the Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands (F.S., C.C.F.M.J.B., R.V., T.G.M., J.M.E.M.C., J.W.M.H., P.E.J.v.d.M.); Research and Development, Optics11, Amsterdam, The Netherlands (N.R., K.O.v.d.L., E.J.B.); Arthur Bloom Haemophilia Centre, Cardiff Institute of Infection & Immunity, School of Medicine, Cardiff University, Cardiff, United Kingdom (P.W.C.); and Central Diagnostic Laboratory (Y.M.C.H.), Departments of Anaesthesiology (M.D.L.) and Internal Medicine (Y.M.C.H.), Maastricht University Medical Center, Maastricht, The Netherlands.
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Buffinton CM, Tong KJ, Blaho RA, Buffinton EM, Ebenstein DM. Comparison of mechanical testing methods for biomaterials: Pipette aspiration, nanoindentation, and macroscale testing. J Mech Behav Biomed Mater 2015; 51:367-79. [DOI: 10.1016/j.jmbbm.2015.07.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Revised: 07/17/2015] [Accepted: 07/22/2015] [Indexed: 10/23/2022]
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McGann ME, Bonitsky CM, Ovaert TC, Wagner DR. The effect of collagen crosslinking on the biphasic poroviscoelastic cartilage properties determined from a semi-automated microindentation protocol for stress relaxation. J Mech Behav Biomed Mater 2014; 34:264-72. [PMID: 24631625 DOI: 10.1016/j.jmbbm.2014.02.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Revised: 01/28/2014] [Accepted: 02/05/2014] [Indexed: 10/25/2022]
Abstract
Given the important role of the collagenous structure in cartilage mechanics, there is considerable interest in the relationship between collagen crosslinking and the mechanical behavior of the cartilage matrix. While crosslink-induced alterations to the elastic modulus of cartilage have been described, changes to time-dependent behavior have not yet been determined. The objective of the study was to quantify changes to cartilage material properties, including viscoelastic coefficients, with crosslinking via indentation. To accomplish this, a semi-autonomous microindentation stress relaxation protocol was first developed, validated and then applied to cartilage specimens before and after crosslinking. The change in mechanical properties with crosslinking was analyzed both in the unloading portions of the test via the Oliver-Pharr method and in the holding portion with an inverse iterative finite element model that represented cartilage as a biphasic poroviscoelastic material. Although both techniques suggested a similar increase in equilibrium modulus in the crosslinked specimens as compared to the controls, distinct differences in the control specimens were apparent, suggesting that the two different techniques may be capturing different aspects of the material behavior. No differences in time-dependent properties were observed between the crosslinked and the control specimens. These results give further insight into the effects of crosslinking in cartilage mechanical behavior. Additionally, the microindentation stress relaxation protocol may enable increased automation for high-throughput testing.
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Affiliation(s)
- Megan E McGann
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Craig M Bonitsky
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Timothy C Ovaert
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Diane R Wagner
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, IN 46556, USA.
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Eliminating adhesion errors in nanoindentation of compliant polymers and hydrogels. J Mech Behav Biomed Mater 2013; 20:316-26. [PMID: 23517775 DOI: 10.1016/j.jmbbm.2013.02.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 01/29/2013] [Accepted: 02/04/2013] [Indexed: 11/22/2022]
Abstract
Nanoindentation is a valuable tool for characterization of biomaterials due to its ability to measure local properties in heterogeneous, small or irregularly shaped samples. However, applying nanoindentation to compliant, hydrated biomaterials leads to many challenges including adhesion between the nanoindenter tip and the sample. Although adhesion leads to overestimation of the modulus of compliant samples when analyzing nanoindentation data using traditional analysis techniques, most studies of biomaterials have ignored its effects. This paper demonstrates two methods for managing adhesion in nanoindentation analysis, the nano-JKR force curve method and the surfactant method, through application to two biomedically-relevant compliant materials, poly(dimethyl siloxane) (PDMS) elastomers and poly(ethylene glycol) (PEG) hydrogels. The nano-JKR force curve method accounts for adhesion during data analysis using equations based on the Johnson-Kendall-Roberts (JKR) adhesion model, while the surfactant method eliminates adhesion during data collection, allowing data analysis using traditional techniques. In this study, indents performed in air or water resulted in adhesion between the tip and the sample, while testing the same materials submerged in Optifree Express(®) contact lens solution eliminated tip-sample adhesion in most samples. Modulus values from the two methods were within 7% of each other, despite different hydration conditions and evidence of adhesion. Using surfactant also did not significantly alter the properties of the tested material, allowed accurate modulus measurements using commercial software, and facilitated nanoindentation testing in fluids. This technique shows promise for more accurate and faster determination of modulus values from nanoindentation of compliant, hydrated biological samples.
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