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Okhovatian S, Shakeri A, Huyer LD, Radisic M. Elastomeric Polyesters in Cardiovascular Tissue Engineering and Organs-on-a-Chip. Biomacromolecules 2023; 24:4511-4531. [PMID: 37639715 PMCID: PMC10915885 DOI: 10.1021/acs.biomac.3c00387] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Cardiovascular tissue constructs provide unique design requirements due to their functional responses to substrate mechanical properties and cyclic stretching behavior of cardiac tissue that requires the use of durable elastic materials. Given the diversity of polyester synthesis approaches, an opportunity exists to develop a new class of biocompatible, elastic, and immunomodulatory cardiovascular polymers. Furthermore, elastomeric polyester materials have the capability to provide tailored biomechanical synergy with native tissue and hence reduce inflammatory response in vivo and better support tissue maturation in vitro. In this review, we highlight underlying chemistry and design strategies of polyester elastomers optimized for cardiac tissue scaffolds. The major advantages of these materials such as their tunable elasticity, desirable biodegradation, and potential for incorporation of bioactive compounds are further expanded. Unique fabrication methods using polyester materials such as micromolding, 3D stamping, electrospinning, laser ablation, and 3D printing are discussed. Moreover, applications of these biomaterials in cardiovascular organ-on-a-chip devices and patches are analyzed. Finally, we outline unaddressed challenges in the field that need further study to enable the impactful translation of soft polyesters to clinical applications.
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Affiliation(s)
- Sargol Okhovatian
- Institute of Biomaterials Engineering; University of Toronto; Toronto; Ontario, M5S 3G9; Canada
- Toronto General Research Institute, Toronto; Ontario, M5G 2C4; Canada
| | - Amid Shakeri
- Institute of Biomaterials Engineering; University of Toronto; Toronto; Ontario, M5S 3G9; Canada
- Toronto General Research Institute, Toronto; Ontario, M5G 2C4; Canada
| | - Locke Davenport Huyer
- Department of Applied Oral Sciences, Faculty of Dentistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
- School of Biomedical Engineering, Faculties of Medicine and Engineering, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
- Department of Microbiology & Immunology, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Milica Radisic
- Institute of Biomaterials Engineering; University of Toronto; Toronto; Ontario, M5S 3G9; Canada
- Toronto General Research Institute, Toronto; Ontario, M5G 2C4; Canada
- Department of Chemical Engineering and Applied Chemistry; University of Toronto; Toronto; Ontario, M5S 3E5; Canada
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2
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Hwang GW, Lee HJ, Kim DW, Yang T, Pang C. Soft Microdenticles on Artificial Octopus Sucker Enable Extraordinary Adaptability and Wet Adhesion on Diverse Nonflat Surfaces. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2202978. [PMID: 35975453 PMCID: PMC9631055 DOI: 10.1002/advs.202202978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/24/2022] [Indexed: 06/15/2023]
Abstract
Bioinspired soft devices, which possess high adaptability to targeted objects, provide promising solutions for a variety of industrial and medical applications. However, achieving stable and switchable attachment to objects with curved, rough, and irregular surfaces remains difficult, particularly in dry and underwater environments. Here, a highly adaptive soft microstructured switchable adhesion device is presented, which is inspired by the geometric and material characteristics of the tiny denticles on the surface of an octopus sucker. The contact interface of the artificial octopus sucker (AOS) is imprinted with soft, microscale denticles that interact adaptably with highly rough or curved surfaces. Robust and controllable attachment of the AOS with soft microdenticles (AOS-sm) to dry and wet surfaces with diverse morphologies is achieved, allowing conformal attachment on curved and soft objects with high roughness. In addition, AOS-sms assembled with an octopus-arm-inspired soft actuator demonstrate reliable grasping and the transport of complex polyhedrons, rough objects, and soft, delicate, slippery biological samples.
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Affiliation(s)
- Gui Won Hwang
- School of Chemical EngineeringSungkyunkwan University (SKKU)2066 Seobu‐ro, Jangan‐guSuwonGyeonggi‐do16419Republic of Korea
| | - Heon Joon Lee
- School of Chemical EngineeringSungkyunkwan University (SKKU)2066 Seobu‐ro, Jangan‐guSuwonGyeonggi‐do16419Republic of Korea
| | - Da Wan Kim
- School of Chemical EngineeringSungkyunkwan University (SKKU)2066 Seobu‐ro, Jangan‐guSuwonGyeonggi‐do16419Republic of Korea
- School of Electronic and Electrical EngineeringSungkyunkwan University (SKKU)2066 Seobu‐ro, Jangan‐guSuwonGyeonggi‐do16419Republic of Korea
| | - Tae‐Heon Yang
- Department of Electronic EngineeringKorea National University of TransportationChungju‐siChungbuk27469Republic of Korea
| | - Changhyun Pang
- School of Chemical EngineeringSungkyunkwan University (SKKU)2066 Seobu‐ro, Jangan‐guSuwonGyeonggi‐do16419Republic of Korea
- Samsung Advanced Institute for Health Sciences and Technology (SAIHST)Sungkyunkwan University (SKKU)2066 Seobu‐ro, Jangan‐guSuwonGyeonggi‐do16419Republic of Korea
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Okhovatian S, Mohammadi MH, Rafatian N, Radisic M. Engineering Models of the Heart Left Ventricle. ACS Biomater Sci Eng 2022; 8:2144-2160. [PMID: 35523206 DOI: 10.1021/acsbiomaterials.1c00636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Despite capturing the imagination of scientists for decades, the goal of creating an artificial heart for transplantation proved to be significantly more challenging than initially anticipated. Toward this goal, recent ground-breaking studies demonstrate the development of functional left ventricular (LV) models. LV models are artificially constructed 3D chambers that are capable of containing liquid within the engineered cavity and exhibit the functionality of native LV including contraction, ejection of fluid, and electrical impulse propagation. Various hydrogels and polymers have been used in manufacturing of LV models, relying on techniques such as electrospinning, bioprinting, casting, and molding. Most studies scaled down the models based on the dimensions of the human or rat ventricle. Initially, neonatal rat cardiomyocytes were the cell type of choice for construction the LV models. Yet, as the stem cell biology field advanced, recent studies focused on the use of cardiomyocytes derived from human induced pluripotent stem cells. In this review, we first describe the physiological characteristics of the human heart, to establish the parameter space for modeling. We then elaborate on current advances in the field and compare recently developed LV models among themselves and with the native human left ventricle. Fabrication methods, cell types, biomaterials, functional properties, and disease modeling capability are some of the major parameters that have distinguished these models. We also highlight some of the current challenges in this field, such as vascularization, cell composition and fidelity, and discuss potential solutions to overcome them.
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Affiliation(s)
- Sargol Okhovatian
- Institute of Biomaterials Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Mohammad Hossein Mohammadi
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada
| | - Naimeh Rafatian
- Institute of Biomaterials Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
| | - Milica Radisic
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario M5S 3E5, Canada.,Institute of Biomaterials Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada.,Toronto General Research Institute, Toronto, Ontario M5G 2C4, Canada
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4
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Dhahri W, Sadikov Valdman T, Wilkinson D, Pereira E, Ceylan E, Andharia N, Qiang B, Masoudpour H, Wulkan F, Quesnel E, Jiang W, Funakoshi S, Mazine A, Gomez-Garcia MJ, Latifi N, Jiang Y, Huszti E, Simmons CA, Keller G, Laflamme MA. In Vitro Matured Human Pluripotent Stem Cell-derived Cardiomyocytes Form Grafts With Enhanced Structure and Function in Injured Hearts. Circulation 2022; 145:1412-1426. [PMID: 35089805 DOI: 10.1161/circulationaha.121.053563] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have tremendous promise for application in cardiac regeneration, but their translational potential is limited by an immature phenotype. We hypothesized that large-scale manufacturing of mature hPSC-CMs could be achieved via culture on polydimethylsiloxane (PDMS) lined roller bottles and that the transplantation of these cells would mediate better structural and functional outcomes than with conventional immature hPSC-CM populations. METHODS We comprehensively phenotyped hPSC-CMs after in vitro maturation for 20 and 40 days on either PDMS or standard tissue culture plastic (TCP) substrates. All hPSC-CMs were generated using a transgenic hPSC line that stably expressed a voltage-sensitive fluorescent reporter to facilitate in vitro and in vivo electrophysiological studies, and cardiomyocyte populations were also analyzed in vitro by immunocytochemistry, ultrastructure and fluorescent calcium imaging, as well as bulk and single-cell transcriptomics. We next compared outcomes after the transplantation of these populations into a guinea pig model of myocardial infarction (MI) using endpoints including histology, optical mapping of graft- and host-derived action potentials, echocardiography, and telemetric electrocardiographic (ECG) monitoring. RESULTS We demonstrated the economic generation of >1x108 mature hPSC-CMs per PDMS-lined roller bottle. Compared to their counterparts generated on TCP substrates, PDMS-matured hPSC-CMs exhibited increased cardiac gene expression and more mature structural and functional properties in vitro. More importantly, intra-cardiac grafts formed with PDMS-matured myocytes showed greatly enhanced structure and alignment, better host-graft electromechanical integration, less pro-arrhythmic behavior, and greater beneficial effects on contractile function. CONCLUSIONS In summary, we describe practical methods for the scaled generation of mature hPSC-CMs and provide the first evidence that the transplantation of more mature cardiomyocytes yields better outcomes in vivo.
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Affiliation(s)
- Wahiba Dhahri
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | | | | | | | - Eylül Ceylan
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - Naaz Andharia
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - Beiping Qiang
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - Hassan Masoudpour
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - Fanny Wulkan
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - Elya Quesnel
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - Wenlei Jiang
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - Shunsuke Funakoshi
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - Amine Mazine
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada
| | - M Juliana Gomez-Garcia
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Neda Latifi
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Yidi Jiang
- Biostatistics Research Unit, University Health Network, Toronto, ON, Canada
| | - Ella Huszti
- Biostatistics Research Unit, University Health Network, Toronto, ON, Canada
| | - Craig A Simmons
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada; Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON, Canada
| | - Gordon Keller
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada
| | - Michael A Laflamme
- McEwen Stem Cell Institute, University Health Network, Toronto, ON, Canada; Peter Munk Cardiac Centre, University Health Network, Toronto, ON, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada
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5
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Siami M, Jahani K, Rezaee M. Identifying the parameters of viscoelastic model for a gel-type material as representative of cardiac muscle in dynamic tests. Proc Inst Mech Eng H 2021; 235:1205-1216. [PMID: 34137313 DOI: 10.1177/09544119211025868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
In this paper, mechanical parameters of a calf heart muscle are identified and a gel-type material as the representative of the cardiac muscle in dynamic tests is introduced. The motivation of this study is to introduce a replacement material of the heart muscle to use in experimental studies of the leadless pacemaker. A particular test setup is developed to capture the experimental data based on the stress relaxation test method where its outputs are time histories of the force and displacement. The standard linear solid model is used for mathematical modeling of the heart muscle sample and a gel-type material specimen namely α-gel. Five tests with different strain history (13.6%,17.1%,20.6%22.4%and,23.8%) are performed by regarding and disregarding the influence of the initial ramp of the loading. The mechanical parameters of the standard linear solid model were identified with precise curve fitting. Consideration of the initial ramp significantly influences the consequences and they are so close to their experimental counterparts. The identified parameters of the standard linear solid model by regarding the influence of the initial ramp for the gel-type material are within an acceptable range for the viscoelastic properties of the calf heart tissue. These results show that the gel-type material has the potential to represent the cardiac muscle in the leadless pacemaker experimental studies. Dynamic mechanical analysis is used to characterize the dynamic viscoelastic properties for the gel by utilizing the identified parameters with taking into account the initial ramp in the frequency domain. Results show that Storage modulus, Loss modulus, and Loss tangent are strongly frequency-dependent especially at low-frequency around the heartbeat frequency range (0-2 Hz).
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Affiliation(s)
- Majid Siami
- Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran
| | - Kamal Jahani
- Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran
| | - Mousa Rezaee
- Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran
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Lu K, Seidel T, Cao-Ehlker X, Dorn T, Batcha AMN, Schneider CM, Semmler M, Volk T, Moretti A, Dendorfer A, Tomasi R. Progressive stretch enhances growth and maturation of 3D stem-cell-derived myocardium. Am J Cancer Res 2021; 11:6138-6153. [PMID: 33995650 PMCID: PMC8120210 DOI: 10.7150/thno.54999] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 03/23/2021] [Indexed: 12/22/2022] Open
Abstract
Bio-engineered myocardium has great potential to substitute damaged myocardium and for studies of myocardial physiology and disease, but structural and functional immaturity still implies limitations. Current protocols of engineered heart tissue (EHT) generation fall short of simulating the conditions of postnatal myocardial growth, which are characterized by tissue expansion and increased mechanical load. To investigate whether these two parameters can improve EHT maturation, we developed a new approach for the generation of cardiac tissues based on biomimetic stimulation under application of continuously increasing stretch. Methods: EHTs were generated by assembling cardiomyocytes derived from human induced pluripotent stem cells (hiPSC-CM) at high cell density in a low collagen hydrogel. Maturation and growth of the EHTs were induced in a custom-made biomimetic tissue culture system that provided continuous electrical stimulation and medium agitation along with progressive stretch at four different increments. Tissues were characterized after a three week conditioning period. Results: The highest rate of stretch (S3 = 0.32 mm/day) increased force development by 5.1-fold compared to tissue with a fixed length, reaching contractility of 11.28 mN/mm². Importantly, intensely stretched EHTs developed physiological length-dependencies of active and passive forces (systolic/diastolic ratio = 9.47 ± 0.84), and a positive force-frequency relationship (1.25-fold contractility at 180 min-1). Functional markers of stretch-dependent maturation included enhanced and more rapid Ca2+ transients, higher amplitude and upstroke velocity of action potentials, and pronounced adrenergic responses. Stretch conditioned hiPSC-CMs displayed structural improvements in cellular volume, linear alignment, and sarcomere length (2.19 ± 0.1 µm), and an overall upregulation of genes that are specifically expressed in adult cardiomyocytes. Conclusions: With the intention to simulate postnatal heart development, we have established techniques of tissue assembly and biomimetic culture that avoid tissue shrinkage and yield muscle fibers with contractility and compliance approaching the properties of adult myocardium. This study demonstrates that cultivation under progressive stretch is a feasible way to induce growth and maturation of stem cell-derived myocardium. The novel tissue-engineering approach fulfills important requirements of disease modelling and therapeutic tissue replacement.
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7
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Choi JS, Lee HJ, Rajaraman S, Kim DH. Recent advances in three-dimensional microelectrode array technologies for in vitro and in vivo cardiac and neuronal interfaces. Biosens Bioelectron 2021; 171:112687. [PMID: 33059168 PMCID: PMC7665982 DOI: 10.1016/j.bios.2020.112687] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 08/24/2020] [Accepted: 10/03/2020] [Indexed: 12/13/2022]
Abstract
Three-dimensional microelectrode arrays (3D MEAs) have emerged as promising tools to detect electrical activities of tissues or organs in vitro and in vivo, but challenges in achieving fast, accurate, and versatile monitoring have consistently hampered further advances in analyzing cell or tissue behaviors. In this review, we discuss emerging 3D MEA technologies for in vitro recording of cardiac and neural cellular electrophysiology, as well as in vivo applications for heart and brain health diagnosis and therapeutics. We first review various forms of recent 3D MEAs for in vitro studies in context of their geometry, materials, and fabrication processes as well as recent demonstrations of 3D MEAs to monitor electromechanical behaviors of cardiomyocytes and neurons. We then present recent advances in 3D MEAs for in vivo applications to the heart and the brain for monitoring of health conditions and stimulation for therapy. A brief overview of the current challenges and future directions of 3D MEAs are provided to conclude the review.
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Affiliation(s)
- Jong Seob Choi
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, United States
| | - Heon Joon Lee
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, United States
| | - Swaminathan Rajaraman
- NanoScience Technology Center (NSTC), University of Central Florida, Orlando, FL, 32826-0120, United States; Department of Electrical & Computer Engineering, University of Central Florida, Orlando, FL, 32816, United States; Department of Materials Science & Engineering, University of Central Florida, Orlando, FL, 32816, United States
| | - Deok-Ho Kim
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, United States; Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, United States.
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Krishnamoorthi MK, Sarig U, Baruch L, Ting S, Reuveny S, Oh S, Goldfracht I, Gepstein L, Venkatraman SS, Tan LP, Machluf M. Robust Fabrication of Composite 3D Scaffolds with Tissue-Specific Bioactivity: A Proof-of-Concept Study. ACS APPLIED BIO MATERIALS 2020; 3:4974-4986. [PMID: 35021675 DOI: 10.1021/acsabm.0c00310] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The basic requirement of any engineered scaffold is to mimic the native tissue extracellular matrix (ECM). Despite substantial strides in understanding the ECM, scaffold fabrication processes of sufficient product robustness and bioactivity require further investigation, owing to the complexity of the natural ECM. A promising bioacive platform for cardiac tissue engineering is that of decellularized porcine cardiac ECM (pcECM, used here as a soft tissue representative model). However, this platform's complexity and batch-to-batch variability serve as processing limitations in attaining a robust and tunable cardiac tissue-specific bioactive scaffold. To address these issues, we fabricated 3D composite scaffolds (3DCSs) that demonstrate comparable physical and biochemical properties to the natural pcECM using wet electrospinning and functionalization with a pcECM hydrogel. The fabricated 3DCSs are non-immunogenic in vitro and support human mesenchymal stem cells' proliferation. Most importantly, the 3DCSs demonstrate tissue-specific bioactivity in inducing spontaneous cardiac lineage differentiation in human induced pluripotent stem cells (hiPSC) and further support the viability, functionality, and maturation of hiPSC-derived cardiomyocytes. Overall, this work illustrates the technology to fabricate robust yet tunable 3D scaffolds of tissue-specific bioactivity (with a proof of concept provided for cardiac tissues) as a platform for basic materials science studies and possible future R&D application in regenerative medicine.
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Affiliation(s)
- Muthu Kumar Krishnamoorthi
- School of Materials Science & Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, 639798 Singapore.,Faculty of Biotechnology & Food Engineering, Technion-Israel Institute of Technology (IIT), Haifa 32000, Israel
| | - Udi Sarig
- School of Materials Science & Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, 639798 Singapore.,Faculty of Biotechnology & Food Engineering, Technion-Israel Institute of Technology (IIT), Haifa 32000, Israel.,Biotechnology & Food Engineering, Technion-Israel Institute of Technology (IIT), Guangdong-Technion Israel Institute of Technology (GTIIT), Shantou, Guangdong Province, 515063 P.R. China
| | - Limor Baruch
- Faculty of Biotechnology & Food Engineering, Technion-Israel Institute of Technology (IIT), Haifa 32000, Israel
| | - Sherwin Ting
- Bioprocessing Technology Institute, A*STAR, 20 Biopolis Way, 138668 Singapore
| | - Shaul Reuveny
- Bioprocessing Technology Institute, A*STAR, 20 Biopolis Way, 138668 Singapore
| | - Steve Oh
- Bioprocessing Technology Institute, A*STAR, 20 Biopolis Way, 138668 Singapore
| | - Idit Goldfracht
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Efron St 1, Haifa 31096, Israel
| | - Lior Gepstein
- The Ruth and Bruce Rappaport Faculty of Medicine, Technion, Efron St 1, Haifa 31096, Israel
| | - Subramanian S Venkatraman
- School of Materials Science & Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, 639798 Singapore
| | - Lay Poh Tan
- School of Materials Science & Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, 639798 Singapore
| | - Marcelle Machluf
- Faculty of Biotechnology & Food Engineering, Technion-Israel Institute of Technology (IIT), Haifa 32000, Israel
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Korn L, Lyra S, Rüschen D, Telyshev D, Leonhardt S, Walter M. In Silico and in Vitro Conductivity Models of the Left Heart Ventricle. JOURNAL OF ELECTRICAL BIOIMPEDANCE 2020; 11:62-71. [PMID: 33584905 PMCID: PMC7531104 DOI: 10.2478/joeb-2020-0010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/25/2020] [Indexed: 06/12/2023]
Abstract
Ventricular Assist Devices (VADs) are used to treat patients with cardiogenic shock. As the heart is unable to supply the organs with sufficient oxygenated blood and nutrients, a VAD maintains the circulation to keep the patient alive. The observation of the patient's hemodynamics is crucial for an individual treatment; therefore, sensors to measure quantifiable hemodynmaic parameters are desirable. In addition to pressure measurement, the volume of the left ventricle and the progress of muscle recovery seem to be promising parameters. Ongoing research aims to estimate ventricular volume and changes in electrical properties of cardiac muscle tissue by applying bioimpedance measurement. In the case where ventricular insufficiency is treated by a catheter-based VAD, this very catheter could be used to conduct bioimpedance measurement inside the assisted heart. However, the simultaneous measurement of bioimpedance and VAD support has not yet been realized, although this would allow the determination of various loading conditions of the ventricle. For this purpose, it is necessary to develop models to validate and quantify bioimpedance measurement during VAD support. In this study, we present an in silico and an in vitro conductivity model of a left ventricle to study the application of bioimpedance measurement in the context of VAD therapy. The in vitro model is developed from casting two anatomical silicone phantoms: One phantom of pure silicone, and one phantom enriched with carbon, to obtain a conductive behavior close to the properties of heart muscle tissue. Additionally, a measurement device to record the impedance inside the ventricle is presented. Equivalent to the in vitro model, the in silico model was designed. This finite element model offers changes in material properties for myocardium and the blood cavity. The measurements in the in vitro models show a strong correlation with the results of the simulation of the in silico model. The measurements and the simulation demonstrate a decrease in impedance, when conductive muscle properties are applied and higher impedances correspond to smaller ventricle cross sections. The in silico and in vitro models are used to further investigate the application of bioimpedance measurement inside the left heart ventricle during VAD support. We are confident that the models presented will allow for future evaluation of hemodynamic monitoring during VAD therapy at an early stage of research and development.
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Affiliation(s)
- Leonie Korn
- Medical Information Technology, RWTH Aachen University, Aachen, Germany
| | - Simon Lyra
- Medical Information Technology, RWTH Aachen University, Aachen, Germany
| | - Daniel Rüschen
- Medical Information Technology, RWTH Aachen University, Aachen, Germany
| | - Dmitry Telyshev
- Institute for Biomedical Systems, National Research University of Electronic Technology, Moscow, Russian Federation
- Institute for Bionic Technologies and Engineering, I. M. Sechenov First MSMU, Moscow, Russian Federation
| | - Steffen Leonhardt
- Medical Information Technology, RWTH Aachen University, Aachen, Germany
| | - Marian Walter
- Medical Information Technology, RWTH Aachen University, Aachen, Germany
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10
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Zargar SM, Mehdikhani M, Rafienia M. Reduced graphene oxide–reinforced gellan gum thermoresponsive hydrogels as a myocardial tissue engineering scaffold. J BIOACT COMPAT POL 2019. [DOI: 10.1177/0883911519876080] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Myocardial infarction is one of the most prevalent diseases around the world. Cardiac tissue engineering is a new approach to repair and revive the structure and functionality of cardiac damaged tissue. In this study, gellan gum/reduced graphene oxide composite hydrogels were fabricated, characterized, and evaluated. The hydrogels were prepared using the solvent casting method and characterized via scanning electron microscopy and Fourier-transform infrared spectroscopy. Compressive mechanical analysis, injectability as well as electrical conductivity test were run. Furthermore, water swelling and degradation analyses were conducted. MTT assay was performed using rat myoblasts (H9C2) to determine the cytotoxicity of our samples. Results showed that reduced graphene oxide fillers dispersed acceptably and enhanced the compressive modulus and electrical conductivity of gellan gum hydrogels. However, in this regard, compressive strength and ductility were not significantly boosted with reduced graphene oxide addition. The water-swelling ratio (%) rised in the presence of reduced graphene oxide, whereas the degradation rate was not significantly affected by them. Meanwhile, synthesized hydrogels showed suitable injectability. MTT assay results revealed that gellan gum hydrogels containing 1% and 2% reduced graphene oxide were not cytotoxic. According to the findings, gellan gum/2% reduced graphene oxide composite hydrogel can be a promising candidate for repairing and healing infarcted myocardial tissue.
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Affiliation(s)
- Seyed Mohammad Zargar
- Department of Biomedical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, Iran
| | - Mehdi Mehdikhani
- Department of Biomedical Engineering, Faculty of Engineering, University of Isfahan, Isfahan, Iran
| | - Mohammad Rafienia
- Biosensor Research Center (BRC), Department of Biomaterials, Nanotechnology and Tissue Engineering, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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11
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Baik S, Lee HJ, Kim DW, Min H, Pang C. Capillarity-Enhanced Organ-Attachable Adhesive with Highly Drainable Wrinkled Octopus-Inspired Architectures. ACS APPLIED MATERIALS & INTERFACES 2019; 11:25674-25681. [PMID: 31251017 DOI: 10.1021/acsami.9b05511] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Mimicking the attachment of octopus suction cups has become appealing for the development of skin/organ adhesive patches capable of strong, reversible adhesion in dry and wet conditions. However, achieving high conformity against the three-dimensionally (3D) rough and curved surfaces of the human body remains an enduring challenge for further medical applications of wound protection, diagnosis, or therapeutics. Here, an adhesive patch inspired by the soft wrinkles of miniaturized 3D octopus suction cups is presented for high drainability and robust attachment against dry and wet human organs. Investigating the structural aspects of the wrinkles, a simple model is developed to maximize capillary interactions of the wrinkles against wet substrates. A layer of soft siloxane derivative is then transferred onto the wrinkles to enhance fixation against dry and sweaty skin as well as various wet organ surfaces. Our bioinspired patch offers opportunities for enhancing the versatility of adhesives for developing skin- and/or organ-attachable devices.
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12
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Bejleri D, Davis ME. Decellularized Extracellular Matrix Materials for Cardiac Repair and Regeneration. Adv Healthc Mater 2019; 8:e1801217. [PMID: 30714354 PMCID: PMC7654553 DOI: 10.1002/adhm.201801217] [Citation(s) in RCA: 99] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/20/2018] [Indexed: 12/20/2022]
Abstract
Decellularized extracellular matrix (dECM) is a promising biomaterial for repairing cardiovascular tissue, as dECM most effectively captures the complex array of proteins, glycosaminoglycans, proteoglycans, and many other matrix components that are found in native tissue, providing ideal cues for regeneration and repair of damaged myocardium. dECM can be used in a variety of forms, such as solid scaffolds that maintain native matrix structure, or as soluble materials that can form injectable hydrogels for tissue repair. dECM has found recent success in many regeneration and repair therapies, such as for musculoskeletal, neural, and liver tissues. This review focuses on dECM in the context of cardiovascular applications, with variations in tissue and species sourcing, and specifically discusses advances in solid and soluble dECM development, in vitro studies, in vivo implementation, and clinical translation.
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Affiliation(s)
- Donald Bejleri
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Dr., Atlanta, GA, 30322, USA
| | - Michael E Davis
- Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 1760 Haygood Dr., Atlanta, GA, 30322, USA
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13
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Ramadan S, Paul N, Naguib HE. Development and characterization of a synthetic PVC/DEHP myocardial tissue analogue material for CT imaging applications. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2018; 29:582-598. [DOI: 10.1080/09205063.2018.1433421] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Sherif Ramadan
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
| | - Narinder Paul
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
- Joint Department of Medical Imaging, Peter Munk Cardiac Centre, University Health Network, University of Toronto, Toronto, Canada
- Medical Imaging, Schulich School of Medicine & Dentistry, Western University, London Health Sciences Centre and St. Joseph’s Health Care London, University Hospital, London, Canada
| | - Hani E. Naguib
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada
- Department of Mechanical & Industrial Engineering, University of Toronto, Toronto, Canada
- Department of Materials Science & Engineering, University of Toronto, Toronto, Canada
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14
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Abilez OJ, Tzatzalos E, Yang H, Zhao MT, Jung G, Zöllner AM, Tiburcy M, Riegler J, Matsa E, Shukla P, Zhuge Y, Chour T, Chen VC, Burridge PW, Karakikes I, Kuhl E, Bernstein D, Couture LA, Gold JD, Zimmermann WH, Wu JC. Passive Stretch Induces Structural and Functional Maturation of Engineered Heart Muscle as Predicted by Computational Modeling. Stem Cells 2018; 36:265-277. [PMID: 29086457 PMCID: PMC5785460 DOI: 10.1002/stem.2732] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 10/18/2017] [Accepted: 10/23/2017] [Indexed: 12/16/2022]
Abstract
The ability to differentiate human pluripotent stem cells (hPSCs) into cardiomyocytes (CMs) makes them an attractive source for repairing injured myocardium, disease modeling, and drug testing. Although current differentiation protocols yield hPSC-CMs to >90% efficiency, hPSC-CMs exhibit immature characteristics. With the goal of overcoming this limitation, we tested the effects of varying passive stretch on engineered heart muscle (EHM) structural and functional maturation, guided by computational modeling. Human embryonic stem cells (hESCs, H7 line) or human induced pluripotent stem cells (IMR-90 line) were differentiated to hPSC-derived cardiomyocytes (hPSC-CMs) in vitro using a small molecule based protocol. hPSC-CMs were characterized by troponin+ flow cytometry as well as electrophysiological measurements. Afterwards, 1.2 × 106 hPSC-CMs were mixed with 0.4 × 106 human fibroblasts (IMR-90 line) (3:1 ratio) and type-I collagen. The blend was cast into custom-made 12-mm long polydimethylsiloxane reservoirs to vary nominal passive stretch of EHMs to 5, 7, or 9 mm. EHM characteristics were monitored for up to 50 days, with EHMs having a passive stretch of 7 mm giving the most consistent formation. Based on our initial macroscopic observations of EHM formation, we created a computational model that predicts the stress distribution throughout EHMs, which is a function of cellular composition, cellular ratio, and geometry. Based on this predictive modeling, we show cell alignment by immunohistochemistry and coordinated calcium waves by calcium imaging. Furthermore, coordinated calcium waves and mechanical contractions were apparent throughout entire EHMs. The stiffness and active forces of hPSC-derived EHMs are comparable with rat neonatal cardiomyocyte-derived EHMs. Three-dimensional EHMs display increased expression of mature cardiomyocyte genes including sarcomeric protein troponin-T, calcium and potassium ion channels, β-adrenergic receptors, and t-tubule protein caveolin-3. Passive stretch affects the structural and functional maturation of EHMs. Based on our predictive computational modeling, we show how to optimize cell alignment and calcium dynamics within EHMs. These findings provide a basis for the rational design of EHMs, which enables future scale-up productions for clinical use in cardiovascular tissue engineering. Stem Cells 2018;36:265-277.
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Affiliation(s)
- Oscar J. Abilez
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
- Bio-X Program, Stanford University, Stanford, California, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University, Stanford, California, USA
| | - Evangeline Tzatzalos
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Huaxiao Yang
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Ming-Tao Zhao
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Gwanghyun Jung
- Stanford Cardiovascular Institute, Stanford, California, USA
- Department of Pediatrics, Division of Cardiology, Stanford University, Stanford, California, USA
| | - Alexander M. Zöllner
- Department of Mechanical Engineering, Stanford University, Stanford, California, USA
| | - Malte Tiburcy
- Institute of Pharmacology and Toxicology, Heart Research Center, University Medical Center, Georg-August-University, Gӧttingen, Germany
- DZHK (German Center for Cardiovascular Research) Partner Site, Gӧttingen, Germany
| | - Johannes Riegler
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Elena Matsa
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Praveen Shukla
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Yan Zhuge
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Tony Chour
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Vincent C. Chen
- Center for Biomedicine and Genetics, City of Hope, Duarte, California, USA
| | - Paul W. Burridge
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Ioannis Karakikes
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Ellen Kuhl
- Stanford Cardiovascular Institute, Stanford, California, USA
- Bio-X Program, Stanford University, Stanford, California, USA
- Department of Mechanical Engineering, Stanford University, Stanford, California, USA
| | - Daniel Bernstein
- Stanford Cardiovascular Institute, Stanford, California, USA
- Department of Pediatrics, Division of Cardiology, Stanford University, Stanford, California, USA
| | - Larry A. Couture
- Center for Biomedicine and Genetics, City of Hope, Duarte, California, USA
- Center for Applied Technology Development, City of Hope, Duarte, California, USA
| | - Joseph D. Gold
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
| | - Wolfram H. Zimmermann
- Institute of Pharmacology and Toxicology, Heart Research Center, University Medical Center, Georg-August-University, Gӧttingen, Germany
- DZHK (German Center for Cardiovascular Research) Partner Site, Gӧttingen, Germany
| | - Joseph C. Wu
- Stanford Cardiovascular Institute, Stanford, California, USA
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California, USA
- Bio-X Program, Stanford University, Stanford, California, USA
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University, Stanford, California, USA
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15
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Cohrs NH, Petrou A, Loepfe M, Yliruka M, Schumacher CM, Kohll AX, Starck CT, Schmid Daners M, Meboldt M, Falk V, Stark WJ. A Soft Total Artificial Heart-First Concept Evaluation on a Hybrid Mock Circulation. Artif Organs 2017; 41:948-958. [DOI: 10.1111/aor.12956] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 11/27/2022]
Affiliation(s)
- Nicholas H. Cohrs
- Institute for Chemical and Bioengineering; ETH Zurich; Zurich Switzerland
| | - Anastasios Petrou
- Product Development Group Zurich, Department of Mechanical and Process Engineering; ETH Zurich; Zurich Switzerland
| | - Michael Loepfe
- Institute for Chemical and Bioengineering; ETH Zurich; Zurich Switzerland
| | - Maria Yliruka
- Institute for Chemical and Bioengineering; ETH Zurich; Zurich Switzerland
| | | | - A. Xavier Kohll
- Institute for Chemical and Bioengineering; ETH Zurich; Zurich Switzerland
| | - Christoph T. Starck
- Department for Cardiothoracic and Vascular Surgery; Deutsches Herzzentrum Berlin; Berlin Germany
| | - Marianne Schmid Daners
- Product Development Group Zurich, Department of Mechanical and Process Engineering; ETH Zurich; Zurich Switzerland
| | - Mirko Meboldt
- Product Development Group Zurich, Department of Mechanical and Process Engineering; ETH Zurich; Zurich Switzerland
| | - Volkmar Falk
- Department for Cardiothoracic and Vascular Surgery; Deutsches Herzzentrum Berlin; Berlin Germany
| | - Wendelin J. Stark
- Institute for Chemical and Bioengineering; ETH Zurich; Zurich Switzerland
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16
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Tzatzalos E, Abilez OJ, Shukla P, Wu JC. Engineered heart tissues and induced pluripotent stem cells: Macro- and microstructures for disease modeling, drug screening, and translational studies. Adv Drug Deliv Rev 2016; 96:234-244. [PMID: 26428619 DOI: 10.1016/j.addr.2015.09.010] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/16/2015] [Accepted: 09/23/2015] [Indexed: 01/01/2023]
Abstract
Engineered heart tissue has emerged as a personalized platform for drug screening. With the advent of induced pluripotent stem cell (iPSC) technology, patient-specific stem cells can be developed and expanded into an indefinite source of cells. Subsequent developments in cardiovascular biology have led to efficient differentiation of cardiomyocytes, the force-producing cells of the heart. iPSC-derived cardiomyocytes (iPSC-CMs) have provided potentially limitless quantities of well-characterized, healthy, and disease-specific CMs, which in turn has enabled and driven the generation and scale-up of human physiological and disease-relevant engineered heart tissues. The combined technologies of engineered heart tissue and iPSC-CMs are being used to study diseases and to test drugs, and in the process, have advanced the field of cardiovascular tissue engineering into the field of precision medicine. In this review, we will discuss current developments in engineered heart tissue, including iPSC-CMs as a novel cell source. We examine new research directions that have improved the function of engineered heart tissue by using mechanical or electrical conditioning or the incorporation of non-cardiomyocyte stromal cells. Finally, we discuss how engineered heart tissue can evolve into a powerful tool for therapeutic drug testing.
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Affiliation(s)
- Evangeline Tzatzalos
- Stanford Cardiovascular Institute
- Institute for Stem Cell Biology and Regenerative Medicine
| | - Oscar J Abilez
- Stanford Cardiovascular Institute
- Institute for Stem Cell Biology and Regenerative Medicine
- Bio-X Program
- Department of Medicine, Division of Cardiovascular Medicine
| | - Praveen Shukla
- Stanford Cardiovascular Institute
- Institute for Stem Cell Biology and Regenerative Medicine
| | - Joseph C Wu
- Stanford Cardiovascular Institute
- Institute for Stem Cell Biology and Regenerative Medicine
- Bio-X Program
- Department of Medicine, Division of Cardiovascular Medicine
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17
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Gao H, Li WG, Cai L, Berry C, Luo XY. Parameter estimation in a Holzapfel-Ogden law for healthy myocardium. JOURNAL OF ENGINEERING MATHEMATICS 2015; 95:231-248. [PMID: 26663931 PMCID: PMC4662962 DOI: 10.1007/s10665-014-9740-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 08/10/2014] [Indexed: 05/26/2023]
Abstract
A central problem in biomechanical studies of personalized human left ventricular (LV) modelling is to estimate material properties from in vivo clinical measurements. In this work we evaluate the passive myocardial mechanical properties inversely from the in vivo LV chamber pressure-volume and strain data. The LV myocardium is described using a structure-based orthotropic Holzapfel-Ogden constitutive law with eight parameters. In the first part of the paper we demonstrate how to use a multi-step non-linear least-squares optimization procedure to inversely estimate the parameters from the pressure-volume and strain data obtained from a synthetic LV model in diastole. In the second part, we show that to apply this procedure to clinical situations with limited in vivo data, additional constraints are required in the optimization procedure. Our study, based on three different healthy volunteers, demonstrates that the parameters of the Holzapfel-Ogden law could be extracted from pressure-volume and strain data with a suitable multi-step optimization procedure. Although the uniqueness of the solution cannot be addressed using our approaches, the material response is shown to be robustly determined.
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Affiliation(s)
- H. Gao
- School of Mathematics and Statistics, University of Glasgow, Glasgow, UK
| | - W. G. Li
- School of Mathematics and Statistics, University of Glasgow, Glasgow, UK
| | - L. Cai
- School of Science, Northwestern Polytechnical University Xi’an, Xi’an, 710072 Shaanxi People’s Republic of China
| | - C. Berry
- Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - X. Y. Luo
- School of Mathematics and Statistics, University of Glasgow, Glasgow, UK
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18
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Characterization of aging-associated cardiac diastolic dysfunction. PLoS One 2014; 9:e97455. [PMID: 24869961 PMCID: PMC4037178 DOI: 10.1371/journal.pone.0097455] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 04/20/2014] [Indexed: 01/28/2023] Open
Abstract
AIMS Diastolic dysfunction is common in geriatric heart failure. A reliable parameter to predict myocardium stiffness and relaxation under similar end-diastolic pressure is being developed. We propose a material and mathematical model for calculating myocardium stiffness based on the concept of linear correlation between [Formula: see text] and wedge pressure. METHODS AND RESULTS We enrolled 919 patients (male: [Formula: see text][Formula: see text]). Compared with the younger population of controls (mean age: [Formula: see text] years; [Formula: see text]; male: [Formula: see text] [Formula: see text]), the elderly (mean age: [Formula: see text]; [Formula: see text]; male: [Formula: see text] [Formula: see text]) had a greater prevalence of hypertension, diabetes mellitus, and coronary artery disease (all [Formula: see text]). We collected their M-mode and 2-D echocardiographic volumetric parameters, intraventricular filling pressure, and speckle tracking images to establish a mathematical model. The feasibility of this model was validated. The average early diastolic velocity of the mitral annulus assessed using tissue Doppler imaging was significantly attenuated in the elderly ([Formula: see text]: [Formula: see text] vs. [Formula: see text]; [Formula: see text]) and corresponded to the higher estimated wedge ([Formula: see text]) pressure ([Formula: see text] vs. [Formula: see text]; [Formula: see text]) in that cohort. E (Young's modulus) was calculated to describe the tensile elasticity of the myocardium. With the same intraventricular filling pressure, E was significantly higher in the elderly, especially those with [Formula: see text] values [Formula: see text]. Compared with diastolic dysfunction parameters, E also presented sentinel characteristics more sensitive for detecting early myocardial relaxation impairment, which indicates stiffer myocardium in aging hearts. CONCLUSION Our material and geometric mathematical model successfully described the stiffer myocardium in aging hearts with higher intraventricular pressure. Additional studies that compare individual differences, especially in health status, are needed to validate its application for detecting diastolic heart failure.
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19
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Palchesko RN, Zhang L, Sun Y, Feinberg AW. Development of polydimethylsiloxane substrates with tunable elastic modulus to study cell mechanobiology in muscle and nerve. PLoS One 2012; 7:e51499. [PMID: 23240031 PMCID: PMC3519875 DOI: 10.1371/journal.pone.0051499] [Citation(s) in RCA: 323] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 11/02/2012] [Indexed: 11/18/2022] Open
Abstract
Mechanics is an important component in the regulation of cell shape, proliferation, migration and differentiation during normal homeostasis and disease states. Biomaterials that match the elastic modulus of soft tissues have been effective for studying this cell mechanobiology, but improvements are needed in order to investigate a wider range of physicochemical properties in a controlled manner. We hypothesized that polydimethylsiloxane (PDMS) blends could be used as the basis of a tunable system where the elastic modulus could be adjusted to match most types of soft tissue. To test this we formulated blends of two commercially available PDMS types, Sylgard 527 and Sylgard 184, which enabled us to fabricate substrates with an elastic modulus anywhere from 5 kPa up to 1.72 MPa. This is a three order-of-magnitude range of tunability, exceeding what is possible with other hydrogel and PDMS systems. Uniquely, the elastic modulus can be controlled independently of other materials properties including surface roughness, surface energy and the ability to functionalize the surface by protein adsorption and microcontact printing. For biological validation, PC12 (neuronal inducible-pheochromocytoma cell line) and C2C12 (muscle cell line) were used to demonstrate that these PDMS formulations support cell attachment and growth and that these substrates can be used to probe the mechanosensitivity of various cellular processes including neurite extension and muscle differentiation.
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Affiliation(s)
- Rachelle N. Palchesko
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- Department of Ophthalmology, Louis J. Fox Center for Vision Restoration, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Ling Zhang
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Yan Sun
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Adam W. Feinberg
- Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
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20
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Kim HN, Kang DH, Kim MS, Jiao A, Kim DH, Suh KY. Patterning methods for polymers in cell and tissue engineering. Ann Biomed Eng 2012; 40:1339-55. [PMID: 22258887 PMCID: PMC5439960 DOI: 10.1007/s10439-012-0510-y] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Accepted: 01/04/2012] [Indexed: 12/23/2022]
Abstract
Polymers provide a versatile platform for mimicking various aspects of physiological extracellular matrix properties such as chemical composition, rigidity, and topography for use in cell and tissue engineering applications. In this review, we provide a brief overview of patterning methods of various polymers with a particular focus on biocompatibility and processability. The materials highlighted here are widely used polymers including thermally curable polydimethyl siloxane, ultraviolet-curable polyurethane acrylate and polyethylene glycol, thermo-sensitive poly(N-isopropylacrylamide) and thermoplastic and conductive polymers. We also discuss how micro- and nanofabricated polymeric substrates of tunable elastic modulus can be used to engineer cell and tissue structure and function. Such synergistic effect of topography and rigidity of polymers may be able to contribute to constructing more physiologically relevant microenvironment.
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Affiliation(s)
- Hong Nam Kim
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea
| | - Do-Hyun Kang
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea
| | - Min Sung Kim
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea
| | - Alex Jiao
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Deok-Ho Kim
- Department of Bioengineering, University of Washington, Seattle, WA 98195, USA
| | - Kahp-Yang Suh
- School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742, Korea
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21
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Hunter RJ, Liu Y, Lu Y, Wang W, Schilling RJ. Left Atrial Wall Stress Distribution and Its Relationship to Electrophysiologic Remodeling in Persistent Atrial Fibrillation. Circ Arrhythm Electrophysiol 2012; 5:351-60. [DOI: 10.1161/circep.111.965541] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Atrial stretch causes remodeling that predisposes to atrial fibrillation. We tested the hypothesis that peaks in left atrial (LA) wall stress are associated with focal remodeling.
Methods and Results—
Nineteen patients underwent LA mapping before catheter ablation for persistent atrial fibrillation. Finite Element Analysis was used to predict wall stress distribution based on LA geometry from CT. The relationship was assessed between wall stress and (1) electrogram voltage and (2) complex fractionated atrial electrograms (CFAE), using CFAE mean (the mean interval between deflections). Wall stress varied widely within atria and between subjects (median, 36 kPa; interquartile range, 26–51 kP). Peaks in wall stress (≥90th percentile) were common at the pulmonary vein (PV) ostia (93%), the appendage ridge (100%), the high posterior wall (84%), and the anterior wall and septal regions (42–84%). Electrogram voltage showed an inverse relationship across quartiles for wall stress (19% difference across quartiles,
P
=0.016). There was no effect on CFAE mean across quartiles of wall stress. Receiver operating characteristic analysis showed high wall stress was associated with low voltage (ie, <0.5 mV) and electrical scar (ie, <0.05 mV; both
P
<0.0001) and with absence of CFAE (ie, CFAE mean <120 ms;
P
<0.0001). However, peaks in wall stress and CFAE were found at 88% of PV ostia.
Conclusions—
Peaks in wall stress were associated with areas of low voltage, suggestive of focal remodeling. Although peaks in wall stress were not associated with LA CFAE, the PV ostia may respond differently.
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Affiliation(s)
- Ross J. Hunter
- From the Cardiology Research Department, Barts and The London NHS Trust and QMUL, St Bartholomew's Hospital, London, United Kingdom (R.J.H., R.J.S.); and the School of Engineering and Materials Science, Queen Mary's University of London, London, United Kingdom (Y. Liu, Y. Lu, W.W.)
| | - Yankai Liu
- From the Cardiology Research Department, Barts and The London NHS Trust and QMUL, St Bartholomew's Hospital, London, United Kingdom (R.J.H., R.J.S.); and the School of Engineering and Materials Science, Queen Mary's University of London, London, United Kingdom (Y. Liu, Y. Lu, W.W.)
| | - Yiling Lu
- From the Cardiology Research Department, Barts and The London NHS Trust and QMUL, St Bartholomew's Hospital, London, United Kingdom (R.J.H., R.J.S.); and the School of Engineering and Materials Science, Queen Mary's University of London, London, United Kingdom (Y. Liu, Y. Lu, W.W.)
| | - Wen Wang
- From the Cardiology Research Department, Barts and The London NHS Trust and QMUL, St Bartholomew's Hospital, London, United Kingdom (R.J.H., R.J.S.); and the School of Engineering and Materials Science, Queen Mary's University of London, London, United Kingdom (Y. Liu, Y. Lu, W.W.)
| | - Richard J. Schilling
- From the Cardiology Research Department, Barts and The London NHS Trust and QMUL, St Bartholomew's Hospital, London, United Kingdom (R.J.H., R.J.S.); and the School of Engineering and Materials Science, Queen Mary's University of London, London, United Kingdom (Y. Liu, Y. Lu, W.W.)
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22
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GHISTA DHANJOON, ZHONG LIANG, LE THUTHAO, TAN RUSAN. CARDIAC CONTRACTILITY MEASURES OF LEFT VENTRICULAR SYSTOLIC FUNCTIONAL ASSESSMENT OF NORMAL AND DISEASED HEARTS. J MECH MED BIOL 2011. [DOI: 10.1142/s0219519409003139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Left ventricular (LV) contraction is the basis of LV systolic function, impairment of which underlies heart failure pathophysiology. Its accurate quantification in the form of LV contractility indices is imperative for diagnostic and follow-up assessment of LV systolic function in heart failure. Herein, we analyze LV contractile performance by focusing on LV contractility indices at different physiological organizational levels: from sarcomere dynamics to LV myocardial properties (such as elastic modulus and elastance), and from LV wall contractile stress development to the generation of intra-LV blood flow velocities and pressure distributions. Further, we present the development analyses of these indices and their medical applications. Using improved development of invasive and noninvasive techniques for measuring ventricular pressure, geometry, and volume, we show how these indices have become more amenable for clinical usage to obtain better patient assessment. The purpose of this paper is to present a comprehensive coverage of LV contraction physiology, indices to qualify LV contraction, formulation, and medical applications of some major intrinsic LV contractility indices, so as to provide the basis of functional assessment of normal versus diseased hearts.
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Affiliation(s)
| | - LIANG ZHONG
- Department of Cardiology, National Heart Centre, Mistri Wing, 17 Third Hospital Avenue, Singapore
- College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, P. R. China
| | - THU-THAO LE
- Research and Development Unit, National Heart Centre, Mistri Wing, 17 Third Hospital Avenue, Singapore
| | - RU-SAN TAN
- Department of Cardiology, National Heart Centre, Mistri Wing, 17 Third Hospital Avenue, Singapore
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23
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Zhong L, Ghista DN, Tan RS. Left ventricular wall stress compendium. Comput Methods Biomech Biomed Engin 2011; 15:1015-41. [PMID: 21547783 DOI: 10.1080/10255842.2011.569885] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Left ventricular (LV) wall stress has intrigued scientists and cardiologists since the time of Lame and Laplace in 1800s. The left ventricle is an intriguing organ structure, whose intrinsic design enables it to fill and contract. The development of wall stress is intriguing to cardiologists and biomedical engineers. The role of left ventricle wall stress in cardiac perfusion and pumping as well as in cardiac pathophysiology is a relatively unexplored phenomenon. But even for us to assess this role, we first need accurate determination of in vivo wall stress. However, at this point, 150 years after Lame estimated left ventricle wall stress using the elasticity theory, we are still in the exploratory stage of (i) developing left ventricle models that properly represent left ventricle anatomy and physiology and (ii) obtaining data on left ventricle dynamics. In this paper, we are responding to the need for a comprehensive survey of left ventricle wall stress models, their mechanics, stress computation and results. We have provided herein a compendium of major type of wall stress models: thin-wall models based on the Laplace law, thick-wall shell models, elasticity theory model, thick-wall large deformation models and finite element models. We have compared the mean stress values of these models as well as the variation of stress across the wall. All of the thin-wall and thick-wall shell models are based on idealised ellipsoidal and spherical geometries. However, the elasticity model's shape can vary through the cycle, to simulate the more ellipsoidal shape of the left ventricle in the systolic phase. The finite element models have more representative geometries, but are generally based on animal data, which limits their medical relevance. This paper can enable readers to obtain a comprehensive perspective of left ventricle wall stress models, of how to employ them to determine wall stresses, and be cognizant of the assumptions involved in the use of specific models.
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Affiliation(s)
- L Zhong
- Department of Cardiology, National Heart Centre Singapore, Mistri Wing 17 Third Hospital Avenue, Singapore 168752, Singapore.
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Lunkenheimer PP, Lunkenheimer A, Stroh N, Köhler F, Welham K, Graham G, Kirk E, Sonnenblick E, Kröller J. Vergleich klassischer und neuer methodischer Zugänge zum intramyokardialen Kraftverteilungsmuster8. ACTA ACUST UNITED AC 2010. [DOI: 10.1111/j.1439-0442.1982.tb01817.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Bettendorff-Bakman DE, Schmid P, Lunkenheimer PP, Niederer P. Diastolic ventricular aspiration: a mechanism supporting the rapid filling phase of the human ventricles. J Theor Biol 2007; 250:581-92. [PMID: 18068727 DOI: 10.1016/j.jtbi.2007.10.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Revised: 09/23/2007] [Accepted: 10/27/2007] [Indexed: 11/19/2022]
Abstract
During the rapid filling phase of the heart cycle, the internal volumes of the two ventricular cavities approximately double, while the intraventricular pressures rise typically only by an amount of less than 1 kPa. Such a small pressure increase cannot be the sole driving mechanism for the large inflow of blood associated with ventricular expansion during this period. Instead, the rapid filling phase is to be interpreted as being mediated primarily by the heart recoiling elastically from its contracted state, causing blood to be aspirated rapidly into the ventricles. In order to study the role of this mechanism, elastic finite element (FE) simulations of ventricular expansion were performed, taking into account the large deformations occurring during this period and the effective compressibility of the myocardium due to intramural fluid flow. Thereby, a realistic three-dimensional geometry derived from magnetic resonance imaging (MRI) measurements of both human ventricles was used. To validate our FE analyses, the results were compared with published measurements relating to the rapid filling phase of the human left ventricle. Our study shows that, under normal physiological conditions, ventricular aspiration plays a key role in the ventricular filling process.
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Affiliation(s)
- D-E Bettendorff-Bakman
- Institute for Biomedical Engineering, University and ETH Zurich, Gloriastr. 35, 8092 Zürich, Switzerland
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Tani J, Yamamoto H, Honda H, Ootomo K, Koiwa Y, Takagi T, Kikuchi J, Hoshi N, Takishima T. Estimation of left ventricular myocardial elasticity and viscosity by a thick-walled spherical model. Med Biol Eng Comput 1993; 31:325-32. [PMID: 8231293 DOI: 10.1007/bf02446683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The authors measured the transfer function (TF) of the left ventricle (LV) in an isolated canine preparation. Here TF indicates the ratio of induced vibration in LV to input vibration when an external mechanical oscillation is applied. TF had a single peak the frequency of which changed from 40 Hz to 80 Hz when LV pressure (LVP) increased from 6 mm Hg to 96 mm Hg. A mathematical model was formulated to estimate the viscoelasticity of the spherical shell. This model was constructed of the material points, elastic components which connected all the material points, and viscous components placed in series with elastic components. Theoretical TF can be computed if the viscoelastic values are given. The value of viscoelasticity at which the theoretical TF best fitted the experimental TF was considered to be the viscoelasticity of the model. The validity of this approach was verified using a silicone spherical shell. The estimated myocardial elasticity was 40 kPa when LVP was 6 mm Hg, 160-170 kPa when LVP was 96 mm Hg and was approximately proportional to LVP, whereas viscosity showed small change. The inclination of elasticity was consistent with previous reports. These results proved that myocardial elasticity can be estimated by analysing the transfer function of the left ventricle.
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Affiliation(s)
- J Tani
- Institute of Fluid Science, Tohoku University, Sendai, Japan
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Subbaraj K, Ghista DN, Fallen EL. Intrinsic indices of the left ventricle as a blood pump in normal and infarcted left ventricles. JOURNAL OF BIOMEDICAL ENGINEERING 1987; 9:206-15. [PMID: 3613544 DOI: 10.1016/0141-5425(87)90004-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
To assess the left ventricle as a blood pump, data are collected from contrast angiograms and analysed by computer, using two-dimensional finite element analysis, to provide instantaneous distributions of intra-LV flow and differential pressure during the diastolic and ejection phases. Characteristic indices are derived for normal and infarcted LVs, and for cases before and after administration of nitroglycerin. These indices may be used to assess the degree and nature of dysfunction in coronary artery disease.
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Phillips CA, Petrofsky JS. Myocardial material mechanics: characteristic variation of the circumferential and longitudinal systolic moduli in left ventricular dysfunction. J Biomech 1984; 17:561-8. [PMID: 6490668 DOI: 10.1016/0021-9290(84)90087-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Active systolic moduli for the circumferential (E theta) and longitudinal (E phi) axes of the left ventricle were determined along with circumferential and longitudinal contractile filament stress (sigma theta and sigma phi) and circumferential and longitudinal fiber strain (epsilon theta and epsilon phi). These material property parameters were determined at four points during cardiac systole. Thirty-nine patients comprising five clinical groups were evaluated using pressure and volume data acquired from single-plane cineangiography. The results indicate that the active moduli exponentially decrease during cardiac systole. Characteristic variations from normal differentiated the various pathological groups. With compensated volume overload, E theta was significantly reduced during the latter half of systole (p less than 0.25). With decompensated volume overload, both E theta and E phi were not significantly different from the normal group throughout cardiac systole. With compensated pressure overload, both E theta and E phi were significantly lower than the normal group at end-systole (p less than 0.005; p less than 0.005). With congestive cardiomyopathy, both E theta and E phi were significantly greater during the latter half of systole compared to the normal group (p less than 0.05 and p less than or equal to 0.025).
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Ghista DN, Ray G, Sandler H. Cardiac assessment mechanics: 1. Left ventricular mechanomyocardiography, a new approach to the detection of diseased myocardial elements and states. Med Biol Eng Comput 1980; 18:271-80. [PMID: 7421307 DOI: 10.1007/bf02443379] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Yettram AL, Vinson CA, Gibson DG. Influence of the distribution of stiffness in the human left ventricular myocardium on shape change in diastole. Med Biol Eng Comput 1979; 17:553-62. [PMID: 316069 DOI: 10.1007/bf02440899] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Yettram AL, Vinson CA. Orthotropic elastic moduli for left ventricular mechanical behaviour. Med Biol Eng Comput 1979; 17:25-30. [PMID: 312382 DOI: 10.1007/bf02440950] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Ghista DN, Hamid MS. Finite element stress analysis of the human left ventricle whose irregular shape is developed from single plane cineangiocardiogram. COMPUTER PROGRAMS IN BIOMEDICINE 1977; 7:219-31. [PMID: 891161 DOI: 10.1016/0010-468x(77)90030-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The three-dimensional left ventricular chamber geometrical model is developed from single plane cineangiocardiogram. This left ventricular model is loaded by an internal pressure monitored by cardiac catheterization. The resulting stresses in the left ventricular model chamber's wall are determined by computerized finite element procedure. For the discretization of this left ventricular model structure, a 20-node, isoparametric finite element is employed. The analysis and formulation of the computerised procedure is presented in the paper, along with the detailed algorithms and computer programs. The procedure is applied to determine the stresses in a left ventricle at an instant, during systole. Next, a portion (represented by a finite element) of this left ventricular chamber is simulated as being infarcted by making its active-state modulus value equal to its passive-state value; the neighbouring elements are shown to relieve the "infarcted" element of stress by themselves taking on more stress.
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Deswysen BA. Parameter estimation of a simple model of the left ventricle and of the systemic vascular bed, with particular attention to the physical meaning of the left ventricular parameters. IEEE Trans Biomed Eng 1977; 24:29-38. [PMID: 832886 DOI: 10.1109/tbme.1977.326205] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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