1
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Kanade PP, Oyunbaatar NE, Kim J, Lee BK, Kim ES, Lee DW. Cardiotoxicity Assessment through a Polymer-Based Cantilever Platform: An Integrated Electro-Mechanical Screening Approach. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2311274. [PMID: 38511575 DOI: 10.1002/smll.202311274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/08/2024] [Indexed: 03/22/2024]
Abstract
Preclinical drug screening for cardiac toxicity has traditionally relied on observing changes in cardiomyocytes' electrical activity, primarily through invasive patch clamp techniques or non-invasive microelectrode arrays (MEA). However, relying solely on field potential duration (FPD) measurements for electrophysiological assessment can miss the full spectrum of drug-induced toxicity, as different drugs affect cardiomyocytes through various mechanisms. A more comprehensive approach, combining field potential and contractility measurements, is essential for accurate toxicity profiling, particularly for drugs targeting contractile proteins without affecting electrophysiology. However, previously proposed platform has significant limitations in terms of simultaneous measurement. The novel platform addresses these issues, offering enhanced, non-invasive evaluation of drug-induced cardiotoxicity. It features eight cantilevers with patterned strain sensors and MEA, enabling real-time monitoring of both cardiomyocyte contraction force and field potential. This system can detect minimum cardiac contraction force of ≈2 µN and field potential signals with 50 µm MEA diameter, using the same cardiomyocytes in measurements of two parameters. Testing with six drugs of varied mechanisms of action, the platform successfully identifies these mechanisms and accurately assesses toxicity profiles, including drugs not inhibiting potassium channels. This innovative approach presents a comprehensive, non-invasive method for cardiac function assessment, poised to revolutionize preclinical cardiotoxicity screening.
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Affiliation(s)
- Pooja P Kanade
- School of Mechanical Engineering, Chonnam National University, Gwangju, 61186, South Korea
- Advanced Medical Device Research Center for Cardiovascular Disease, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Nomin-Erdene Oyunbaatar
- School of Mechanical Engineering, Chonnam National University, Gwangju, 61186, South Korea
- Advanced Medical Device Research Center for Cardiovascular Disease, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Jongyun Kim
- School of Mechanical Engineering, Chonnam National University, Gwangju, 61186, South Korea
- Advanced Medical Device Research Center for Cardiovascular Disease, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Bong-Kee Lee
- School of Mechanical Engineering, Chonnam National University, Gwangju, 61186, South Korea
| | - Eung-Sam Kim
- Department of Biological Sciences, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Dong-Weon Lee
- School of Mechanical Engineering, Chonnam National University, Gwangju, 61186, South Korea
- Advanced Medical Device Research Center for Cardiovascular Disease, Chonnam National University, Gwangju, 61186, Republic of Korea
- Center for Next-Generation Sensor Research and Development, Chonnam National University, Gwangju, 61186, Republic of Korea
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2
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Strohm EM, Callaghan NI, Ding Y, Latifi N, Rafatian N, Funakoshi S, Fernandes I, Reitz CJ, Di Paola M, Gramolini AO, Radisic M, Keller G, Kolios MC, Simmons CA. Noninvasive Quantification of Contractile Dynamics in Cardiac Cells, Spheroids, and Organs-on-a-Chip Using High-Frequency Ultrasound. ACS NANO 2024; 18:314-327. [PMID: 38147684 DOI: 10.1021/acsnano.3c06325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Cell-based models that mimic in vivo heart physiology are poised to make significant advances in cardiac disease modeling and drug discovery. In these systems, cardiomyocyte (CM) contractility is an important functional metric, but current measurement methods are inaccurate and low-throughput or require complex setups. To address this need, we developed a standalone noninvasive, label-free ultrasound technique operating at 40-200 MHz to measure the contractile kinetics of cardiac models, ranging from single adult CMs to 3D microtissue constructs in standard cell culture formats. The high temporal resolution of 1000 fps resolved the beat profile of single mouse CMs paced at up to 9 Hz, revealing limitations of lower speed optical based measurements to resolve beat kinetics or characterize aberrant beats. Coupling of ultrasound with traction force microscopy enabled the measurement of the CM longitudinal modulus and facile estimation of adult mouse CM contractile forces of 2.34 ± 1.40 μN, comparable to more complex measurement techniques. Similarly, the beat rate, rhythm, and drug responses of CM spheroid and microtissue models were measured, including in configurations without optical access. In conclusion, ultrasound can be used for the rapid characterization of CM contractile function in a wide range of commonly studied configurations ranging from single cells to 3D tissue constructs using standard well plates and custom microdevices, with applications in cardiac drug discovery and cardiotoxicity evaluation.
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Affiliation(s)
- Eric M Strohm
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, M5S 3G8, Canada
- Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, M5G 1M1, Canada
| | - Neal I Callaghan
- Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, M5G 1M1, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, M5S 3G9, Canada
| | - Yu Ding
- Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, M5G 1M1, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, M5S 3G9, Canada
| | - Neda Latifi
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, M5S 3G8, Canada
- Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, M5G 1M1, Canada
| | - Naimeh Rafatian
- Toronto General Hospital Research Institute, Toronto, M5G 2C4, Canada
| | - Shunsuke Funakoshi
- McEwen Stem Cell Institute, University Health Network, Toronto, M5G 1L7, Canada
| | - Ian Fernandes
- McEwen Stem Cell Institute, University Health Network, Toronto, M5G 1L7, Canada
| | - Cristine J Reitz
- Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, M5G 1M1, Canada
- Department of Physiology, University of Toronto, Toronto, M5S 1A8, Canada
| | - Michelle Di Paola
- Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, M5G 1M1, Canada
- Department of Physiology, University of Toronto, Toronto, M5S 1A8, Canada
| | - Anthony O Gramolini
- Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, M5G 1M1, Canada
- Department of Physiology, University of Toronto, Toronto, M5S 1A8, Canada
| | - Milica Radisic
- Institute of Biomedical Engineering, University of Toronto, Toronto, M5S 3G9, Canada
- Toronto General Hospital Research Institute, Toronto, M5G 2C4, Canada
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, M5S 3E5, Canada
| | - Gordon Keller
- McEwen Stem Cell Institute, University Health Network, Toronto, M5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, M5G 1L7, Canada
| | - Michael C Kolios
- Department of Physics, Toronto Metropolitan University, Toronto, M5B 2K3, Canada
| | - Craig A Simmons
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, M5S 3G8, Canada
- Translational Biology and Engineering Program, Ted Rogers Center for Heart Research, Toronto, M5G 1M1, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, M5S 3G9, Canada
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3
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English EJ, Samolyk BL, Gaudette GR, Pins GD. Micropatterned fibrin scaffolds increase cardiomyocyte alignment and contractility for the fabrication of engineered myocardial tissue. J Biomed Mater Res A 2023; 111:1309-1321. [PMID: 36932841 PMCID: PMC11128133 DOI: 10.1002/jbm.a.37530] [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] [Received: 10/04/2022] [Revised: 02/09/2023] [Accepted: 03/01/2023] [Indexed: 03/19/2023]
Abstract
Cardiovascular disease is the leading cause of death in the United States, which can result in blockage of a coronary artery, triggering a myocardial infarction (MI), scar tissue formation in the myocardium, and ultimately heart failure. Currently, the gold-standard solution for total heart failure is a heart transplantation. An alternative to total-organ transplantation is surgically remodeling the ventricle with the implantation of a cardiac patch. Acellular cardiac patches have previously been investigated using synthetic or decellularized native materials to improve cardiac function. However, a limitation of this strategy is that acellular cardiac patches only reshape the ventricle and do not increase cardiac contractile function. Toward the development of a cardiac patch, our laboratory previously developed a cell-populated composite fibrin scaffold and aligned microthreads to recapitulate the mechanical properties of native myocardium. In this study, we explore micropatterning the surfaces of fibrin gels to mimic anisotropic native tissue architecture and promote cellular alignment of human induced pluripotent stem cell cardiomyocytes (hiPS-CM), which is crucial for increasing scaffold contractile properties. hiPS-CMs seeded on micropatterned surfaces exhibit cellular elongation, distinct sarcomere alignment, and circumferential connexin-43 staining at 14 days of culture, which are necessary for mature contractile properties. Constructs were also subject to electrical stimulation during culture to promote increased contractile properties. After 7 days of stimulation, contractile strains of micropatterned constructs were significantly higher than unpatterned controls. These results suggest that the use of micropatterned topographic cues on fibrin scaffolds may be a promising strategy for creating engineered cardiac tissue.
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Affiliation(s)
- Elizabeth J. English
- Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
- Tessera Therapeutics, Somerville, Massachusetts, USA
| | - Bryanna L. Samolyk
- Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Glenn R. Gaudette
- Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
- Department of Engineering, Boston College, Newton, Massachusetts, USA
| | - George D. Pins
- Biomedical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
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4
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Liu W, Han JL, Tomek J, Bub G, Entcheva E. Simultaneous Widefield Voltage and Dye-Free Optical Mapping Quantifies Electromechanical Waves in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes. ACS PHOTONICS 2023; 10:1070-1083. [PMID: 37096210 PMCID: PMC10119986 DOI: 10.1021/acsphotonics.2c01644] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Indexed: 05/03/2023]
Abstract
Coupled electromechanical waves define a heart's function in health and diseases. Optical mapping of electrical waves using fluorescent labels offers mechanistic insights into cardiac conduction abnormalities. Dye-free/label-free mapping of mechanical waves presents an attractive non-invasive alternative. In this study, we developed a simultaneous widefield voltage and interferometric dye-free optical imaging methodology that was used as follows: (1) to validate dye-free optical mapping for quantification of cardiac wave properties in human iPSC-cardiomyocytes (CMs); (2) to demonstrate low-cost optical mapping of electromechanical waves in hiPSC-CMs using recent near-infrared (NIR) voltage sensors and orders of magnitude cheaper miniature industrial CMOS cameras; (3) to uncover previously underexplored frequency- and space-varying parameters of cardiac electromechanical waves in hiPSC-CMs. We find similarity in the frequency-dependent responses of electrical (NIR fluorescence-imaged) and mechanical (dye-free-imaged) waves, with the latter being more sensitive to faster rates and showing steeper restitution and earlier appearance of wavefront tortuosity. During regular pacing, the dye-free-imaged conduction velocity and electrical wave velocity are correlated; both modalities are sensitive to pharmacological uncoupling and dependent on gap-junctional protein (connexins) determinants of wave propagation. We uncover the strong frequency dependence of the electromechanical delay (EMD) locally and globally in hiPSC-CMs on a rigid substrate. The presented framework and results offer new means to track the functional responses of hiPSC-CMs inexpensively and non-invasively for counteracting heart disease and aiding cardiotoxicity testing and drug development.
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Affiliation(s)
- Wei Liu
- Department
of Biomedical Engineering, George Washington
University, Washington, D.C. 20052, United States
| | - Julie L. Han
- Department
of Biomedical Engineering, George Washington
University, Washington, D.C. 20052, United States
| | - Jakub Tomek
- Department
of Pharmacology, University of California−Davis, Davis, California 95616, United States
| | - Gil Bub
- Department
of Physiology, McGill University, Montréal, Québec H3G 1Y6, Canada
| | - Emilia Entcheva
- Department
of Biomedical Engineering, George Washington
University, Washington, D.C. 20052, United States
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5
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Dou W, Daoud A, Chen X, Wang T, Malhi M, Gong Z, Mirshafiei F, Zhu M, Shan G, Huang X, Maynes JT, Sun Y. Ultrathin and Flexible Bioelectronic Arrays for Functional Measurement of iPSC-Cardiomyocytes under Cardiotropic Drug Administration and Controlled Microenvironments. NANO LETTERS 2023; 23:2321-2331. [PMID: 36893018 DOI: 10.1021/acs.nanolett.3c00017] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Emerging heart-on-a-chip technology is a promising tool to establish in vitro cardiac models for therapeutic testing and disease modeling. However, due to the technical complexity of integrating cell culture chambers, biosensors, and bioreactors into a single entity, a microphysiological system capable of reproducing controlled microenvironmental cues to regulate cell phenotypes, promote iPS-cardiomyocyte maturity, and simultaneously measure the dynamic changes of cardiomyocyte function in situ is not available. This paper reports an ultrathin and flexible bioelectronic array platform in 24-well format for higher-throughput contractility measurement under candidate drug administration or defined microenvironmental conditions. In the array, carbon black (CB)-PDMS flexible strain sensors were embedded for detecting iPSC-CM contractility signals. Carbon fiber electrodes and pneumatic air channels were integrated to provide electrical and mechanical stimulation to improve iPSC-CM maturation. Performed experiments validate that the bioelectronic array accurately reveals the effects of cardiotropic drugs and identifies mechanical/electrical stimulation strategies for promoting iPSC-CM maturation.
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Affiliation(s)
- Wenkun Dou
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Abdelkader Daoud
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Xin Chen
- Program in Developmental and Stem Cell Biology and Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Tiancong Wang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Manpreet Malhi
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Zheyuan Gong
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Fatemeh Mirshafiei
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Min Zhu
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Guanqiao Shan
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
| | - Xi Huang
- Program in Developmental and Stem Cell Biology and Arthur and Sonia Labatt Brain Tumour Research Centre, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Jason T Maynes
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 3G9, Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 3G4, Canada
- Department of Computer Science, University of Toronto, Toronto, Ontario M5T 3A1, Canada
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6
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Dou W, Malhi M, Zhao Q, Wang L, Huang Z, Law J, Liu N, Simmons CA, Maynes JT, Sun Y. Microengineered platforms for characterizing the contractile function of in vitro cardiac models. MICROSYSTEMS & NANOENGINEERING 2022; 8:26. [PMID: 35299653 PMCID: PMC8882466 DOI: 10.1038/s41378-021-00344-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 11/12/2021] [Accepted: 12/03/2021] [Indexed: 05/08/2023]
Abstract
Emerging heart-on-a-chip platforms are promising approaches to establish cardiac cell/tissue models in vitro for research on cardiac physiology, disease modeling and drug cardiotoxicity as well as for therapeutic discovery. Challenges still exist in obtaining the complete capability of in situ sensing to fully evaluate the complex functional properties of cardiac cell/tissue models. Changes to contractile strength (contractility) and beating regularity (rhythm) are particularly important to generate accurate, predictive models. Developing new platforms and technologies to assess the contractile functions of in vitro cardiac models is essential to provide information on cell/tissue physiologies, drug-induced inotropic responses, and the mechanisms of cardiac diseases. In this review, we discuss recent advances in biosensing platforms for the measurement of contractile functions of in vitro cardiac models, including single cardiomyocytes, 2D monolayers of cardiomyocytes, and 3D cardiac tissues. The characteristics and performance of current platforms are reviewed in terms of sensing principles, measured parameters, performance, cell sources, cell/tissue model configurations, advantages, and limitations. In addition, we highlight applications of these platforms and relevant discoveries in fundamental investigations, drug testing, and disease modeling. Furthermore, challenges and future outlooks of heart-on-a-chip platforms for in vitro measurement of cardiac functional properties are discussed.
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Affiliation(s)
- Wenkun Dou
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8 Canada
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON M5G 1X8 Canada
| | - Manpreet Malhi
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON M5G 1X8 Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8 Canada
| | - Qili Zhao
- Institute of Robotics and Automatic Information System and the Tianjin Key Laboratory of Intelligent Robotics, Nankai University, Tianjin, 300350 China
| | - Li Wang
- School of Mechanical & Automotive Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353 China
| | - Zongjie Huang
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8 Canada
| | - Junhui Law
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8 Canada
| | - Na Liu
- School of Mechatronics Engineering and Automation, Shanghai University, Shanghai, 200444 China
| | - Craig A. Simmons
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8 Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9 Canada
- Translational Biology & Engineering Program, Ted Rogers Centre for Heart Research, Toronto, ON M5G 1M1 Canada
| | - Jason T. Maynes
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON M5G 1X8 Canada
- Department of Biochemistry, University of Toronto, Toronto, ON M5S 1A8 Canada
- Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, ON M5S 1A8 Canada
- Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, Toronto, ON M5G 1X8 Canada
| | - Yu Sun
- Department of Mechanical and Industrial Engineering, University of Toronto, Toronto, ON M5S 3G8 Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9 Canada
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON M5S 3G4 Canada
- Department of Computer Science, University of Toronto, Toronto, ON M5T 3A1 Canada
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7
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Kim J, Shanmugasundaram A, Lee DW. Enhancement of cardiac contractility using gold-coated SU-8 cantilevers and their application to drug-induced cardiac toxicity tests. Analyst 2021; 146:6768-6779. [PMID: 34642716 DOI: 10.1039/d1an01337h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, we propose an array of gold (Au)-coated SU-8 cantilevers with microgrooves for improved maturation of cardiomyocytes and describe its applications to drug-induced cardiac toxicity tests. Firstly, we evaluated the effect of cell culture substrates such as polydimethylsiloxane (PDMS), polyimide (PI), and SU-8 on the cardiomyocyte's maturation. Among these, the SU-8 with microgroove structures exhibits improved cardiomyocyte maturation. Further, thin layers of graphene and Au are coated on SU-8 substrates and the effects of these materials on cardiomyocyte maturation are evaluated by analyzing the expression of proteins such as alpha-actinin, Connexin 43 (Cx43), and Vinculin. While both conductive materials enhanced protein expression when compared to bare SU-8, the Au-coated SU-8 substrates demonstrated superior cardiomyocyte maturation. The cantilever structure is constructed using microgroove patterned SU-8 with and without an Au coating. The Au-coated SU-8 cantilever showed maximum displacement of 17.6 ± 0.3 μm on day 21 compared to bare SU-8 (14.2 ± 0.4 μm) owing to improved cardiomyocytes maturation. Verapamil and quinidine are used to characterize drug-induced changes in the contraction characteristics of cardiomyocytes on bare and Au-coated SU-8 cantilevers. The relative contraction forces and beat rates changed according to the calcium and sodium channel related drugs. Matured cardiomyocytes are less influenced by the drugs compared to immature cardiomyocytes and showed reliable IC50 values. These results indicate that the proposed Au-coated SU-8 cantilever array could help improve the accuracy of toxicity screening results by allowing for the use of cardiomyocytes that have been matured on the drug screening platform.
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Affiliation(s)
- Jongyun Kim
- Graduate School of Mechanical Engineering, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Arunkumar Shanmugasundaram
- MEMS and Nanotechnology Laboratory, School of Mechanical Engineering, Chonnam National University, Gwangju 61186, Republic of Korea.
| | - Dong-Weon Lee
- MEMS and Nanotechnology Laboratory, School of Mechanical Engineering, Chonnam National University, Gwangju 61186, Republic of Korea. .,Center for Next-Generation Sensor Research and Development, Chonnam National University, Gwangju 61186, Republic of Korea.,Advanced Medical Device Research Center for Cardiovascular Disease, Chonnam National University, Gwangju 61186, Republic of Korea
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8
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Robbins ER, Pins GD, Laflamme MA, Gaudette GR. Creation of a contractile biomaterial from a decellularized spinach leaf without ECM protein coating: An in vitro study. J Biomed Mater Res A 2020; 108:2123-2132. [PMID: 32323417 PMCID: PMC7725356 DOI: 10.1002/jbm.a.36971] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 03/24/2020] [Accepted: 03/28/2020] [Indexed: 01/08/2023]
Abstract
Myocardial infarction (MI) results in the death of cardiac tissue, decreases regional contraction, and can lead to heart failure. Tissue engineered cardiac patches containing human induced pluripotent stem cell-derived cardiomyocytes (hiPS-CMs) can restore contractile function. However, cells within thick patches require vasculature for blood flow. Recently, we demonstrated fibronectin coated decellularized leaves provide a suitable scaffold for hiPS-CMs. Yet, the necessity of this additional coating step is unclear. Therefore, we compared hiPS-CM behavior on decellularized leaves coated with collagen IV or fibronectin extracellular matrix (ECM) proteins to noncoated leaves for up to 21 days. Successful coating was verified by immunofluorescence. Similar numbers of hiPS-CMs adhered to coated and noncoated decellularized leaves for 21 days. At Day 14, collagen IV coated leaves contracted more than noncoated leaves (3.25 ± 0.39% vs. 1.54 ± 0.60%; p < .05). However, no differences in contraction were found between coated leaves, coated tissue culture plastic (TCP), noncoated leaves, or noncoated TCP at other time points. No significant differences were observed in hiPS-CM spreading or sarcomere lengths on leaves with or without coating. This study demonstrates that cardiac scaffolds can be created from decellularized leaves without ECM coatings. Noncoated decellularized leaf surfaces facilitate robust cell attachment for an engineered tissue patch.
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Affiliation(s)
- Emily R. Robbins
- Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts
| | - George D. Pins
- Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts
| | - Michael A. Laflamme
- McEwen Stem Cell Institute, University Health Network, Toronto, Ontario, Canada
| | - Glenn R. Gaudette
- Biomedical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts
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9
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Pölönen RP, Swan H, Aalto-Setälä K. Mutation-specific differences in arrhythmias and drug responses in CPVT patients: simultaneous patch clamp and video imaging of iPSC derived cardiomyocytes. Mol Biol Rep 2019; 47:1067-1077. [PMID: 31786768 DOI: 10.1007/s11033-019-05201-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 11/21/2019] [Indexed: 12/26/2022]
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited cardiac disease characterized by arrhythmias under adrenergic stress. Mutations in the cardiac ryanodine receptor (RYR2) are the leading cause for CPVT. We characterized electrophysiological properties of CPVT patient-specific induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) carrying different mutations in RYR2 and evaluated effects of carvedilol and flecainide on action potential (AP) and contractile properties of hiPSC-CMs. iPSC-CMs were generated from skin biopsies of CPVT patients carrying exon 3 deletion (E3D) and L4115F mutation in RYR2. APs and contractile movement were recorded simultaneously from the same hiPSC-CMs. Differences in AP properties of ventricular like CMs were seen in CPVT and control CMs: APD90 of both E3D (n = 20) and L4115F (n = 25) CPVT CMs was shorter than in control CMs (n = 15). E3D-CPVT CMs had shortest AP duration, lowest AP amplitude, upstroke velocity and more depolarized diastolic potential than controls. Adrenaline had positive and carvedilol and flecainide negative chronotropic effect in all hiPSC CMs. CPVT CMs had increased amount of delayed after depolarizations (DADs) and early after depolarizations (EADs) after adrenaline exposure. E3D CPVT CMs had the most DADs, EADs, and tachyarrhythmia. Discordant negatively coupled alternans was seen in L4115F CPVT CMs. Carvedilol cured almost all arrhythmias in L4115F CPVT CMs. Both drugs decreased contraction amplitude in all hiPSC CMs. E3D CPVT CMs have electrophysiological properties, which render them more prone to arrhythmias. iPSC-CMs provide a unique platform for disease modeling and drug screening for CPVT. Combining electrophysiological measurements, we can gain deeper insight into mechanisms of arrhythmias.
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Affiliation(s)
- R P Pölönen
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Arvo2 D441, 33520, Tampere, Finland.
| | - H Swan
- Helsinki University Hospital and Helsinki University, PO Box 340, 00029, Helsinki, Finland
| | - K Aalto-Setälä
- Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Arvo2 D441, 33520, Tampere, Finland
- Heart Center, Tampere University Hospital, Arvo Ylpön katu 34, Arvo2 D437, 33520, Tampere, Finland
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10
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Pires RH, Shree N, Manu E, Guzniczak E, Otto O. Cardiomyocyte mechanodynamics under conditions of actin remodelling. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190081. [PMID: 31587648 PMCID: PMC6792454 DOI: 10.1098/rstb.2019.0081] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2019] [Indexed: 01/26/2023] Open
Abstract
The mechanical performance of cardiomyocytes (CMs) is an important indicator of their maturation state and of primary importance for the development of therapies based on cardiac stem cells. As the mechanical analysis of adherent cells at high-throughput remains challenging, we explore the applicability of real-time deformability cytometry (RT-DC) to probe cardiomyocytes in suspension. RT-DC is a microfluidic technology allowing for real-time mechanical analysis of thousands of cells with a throughput exceeding 1000 cells per second. For CMs derived from human-induced pluripotent stem cells, we determined a Young's modulus of 1.25 ± 0.08 kPa which is in close range to previous reports. Upon challenging the cytoskeleton with cytochalasin D (CytoD) to induce filamentous actin depolymerization, we distinguish three different regimes in cellular elasticity. Transitions are observed below 10 nM and above 103 nM and are characterized by a decrease in Young's modulus. These regimes can be linked to cytoskeletal and sarcomeric actin contributions by CM contractility measurements at varying CytoD concentrations, where we observe a significant reduction in pulse duration only above 103 nM while no change is found for compound exposure at lower concentrations. Comparing our results to mechanical cell measurements using atomic force microscopy, we demonstrate for the first time to our knowledge, the feasibility of using a microfluidic technique to measure mechanical properties of large samples of adherent cells while linking our results to the composition of the cytoskeletal network. This article is part of a discussion meeting issue 'Single cell ecology'.
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Affiliation(s)
- Ricardo H. Pires
- Zentrum für Innovationskompetenz: Humorale Immunreaktionen bei kardiovaskulären Erkrankungen, Universität Greifswald, Fleischmannstrasse 42, 17489 Greifswald, Germany
| | - Nithya Shree
- Zentrum für Innovationskompetenz: Humorale Immunreaktionen bei kardiovaskulären Erkrankungen, Universität Greifswald, Fleischmannstrasse 42, 17489 Greifswald, Germany
| | - Emmanuel Manu
- Zentrum für Innovationskompetenz: Humorale Immunreaktionen bei kardiovaskulären Erkrankungen, Universität Greifswald, Fleischmannstrasse 42, 17489 Greifswald, Germany
| | - Ewa Guzniczak
- Heriot-Watt University School of Engineering and Physical Science, Institute of Biological Chemistry, Biophysics and Bioengineering, Edinburgh Campus, Edinburgh EH14 4AS, UK
| | - Oliver Otto
- Zentrum für Innovationskompetenz: Humorale Immunreaktionen bei kardiovaskulären Erkrankungen, Universität Greifswald, Fleischmannstrasse 42, 17489 Greifswald, Germany
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11
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Guth BD, Engwall M, Eldridge S, Foley CM, Guo L, Gintant G, Koerner J, Parish ST, Pierson JB, Ribeiro AJS, Zabka T, Chaudhary KW, Kanda Y, Berridge B. Considerations for an In Vitro, Cell-Based Testing Platform for Detection of Adverse Drug-Induced Inotropic Effects in Early Drug Development. Part 1: General Considerations for Development of Novel Testing Platforms. Front Pharmacol 2019; 10:884. [PMID: 31447679 PMCID: PMC6697071 DOI: 10.3389/fphar.2019.00884] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 07/15/2019] [Indexed: 01/10/2023] Open
Abstract
Drug-induced effects on cardiac contractility can be assessed through the measurement of the maximal rate of pressure increase in the left ventricle (LVdP/dtmax) in conscious animals, and such studies are often conducted at the late stage of preclinical drug development. Detection of such effects earlier in drug research using simpler, in vitro test systems would be a valuable addition to our strategies for identifying the best possible drug development candidates. Thus, testing platforms with reasonably high throughput, and affordable costs would be helpful for early screening purposes. There may also be utility for testing platforms that provide mechanistic information about how a given drug affects cardiac contractility. Finally, there could be in vitro testing platforms that could ultimately contribute to the regulatory safety package of a new drug. The characteristics needed for a successful cell or tissue-based testing platform for cardiac contractility will be dictated by its intended use. In this article, general considerations are presented with the intent of guiding the development of new testing platforms that will find utility in drug research and development. In the following article (part 2), specific aspects of using human-induced stem cell-derived cardiomyocytes for this purpose are addressed.
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Affiliation(s)
- Brian D Guth
- Department of Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co KG, Biberach an der Riss, Germany.,PreClinical Drug Development Platform (PCDDP), North-West University, Potchefstroom, South Africa
| | - Michael Engwall
- Safety Pharmacology and Animal Research Center, Amgen Research, Thousand Oaks, CA, United States
| | - Sandy Eldridge
- Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institutes of Health, Bethesda, MD, United States
| | - C Michael Foley
- Department of Integrative Pharmacology, Integrated Sciences and Technology, AbbVie, North Chicago, IL, United States
| | - Liang Guo
- Laboratory of Investigative Toxicology, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD, United States
| | - Gary Gintant
- Department of Integrative Pharmacology, Integrated Sciences and Technology, AbbVie, North Chicago, IL, United States
| | - John Koerner
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, United States
| | - Stanley T Parish
- Health and Environmental Sciences Institute, Washington, DC, United States
| | - Jennifer B Pierson
- Health and Environmental Sciences Institute, Washington, DC, United States
| | - Alexandre J S Ribeiro
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Office of Translation Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, United States
| | - Tanja Zabka
- Department of Safety Assessment, Genentech, South San Francisco, CA, United States
| | - Khuram W Chaudhary
- Global Safety Pharmacology, GlaxoSmithKline plc, Collegeville, PA, United States
| | - Yasunari Kanda
- Division of Pharmacology, National Institute of Health Sciences, Kanagawa, Japan
| | - Brian Berridge
- National Toxicology Program, National Institute of Environmental Health Sciences, Durham, NC, United States
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12
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Yoshida S, Sumomozawa K, Nagamine K, Nishizawa M. Hydrogel Microchambers Integrated with Organic Electrodes for Efficient Electrical Stimulation of Human iPSC-Derived Cardiomyocytes. Macromol Biosci 2019; 19:e1900060. [PMID: 31038841 DOI: 10.1002/mabi.201900060] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 03/30/2019] [Indexed: 12/20/2022]
Abstract
A hydrogel-based microchamber with organic electrodes for efficient electrical stimulations of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) is described. The microchamber is made from molecularly permeable, optically transparent, and electrically conductive polyvinyl alcohol (PVA) hydrogel and highly capacitive carbon electrode modified with poly(3,4-ethylenedioxythiophene) (PEDOT). Spheroids of hiPSC-CMs are cultured in microchambers, and electrically stimulated by the electrode for maturation. The large interfacial capacitance of the electrodes enables several days of electrical stimulation without generation of cytotoxic bubbles even when the electrodes are placed near the spheroids. The spheroids can be cultivated in the closed microchambers because of the permeated nutrients through the hydrogel, thus the spheroids are stably addressable and the culture medium around the sealed microchambers can be simply exchanged. Synchronized beating of the spheroids can be optically analyzed in situ, which makes it possible to selectively collect electrically responsive cells for further use. As the hydrogel is electrically conductive, the amount of electrical charge needed for maturing the spheroids can be reduced by configuring electrodes on the top and the bottom of the microchamber. The bioreactor will be useful for efficient production of matured hiPSC-CMs for regenerative medicine and drug screening.
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Affiliation(s)
- Shotaro Yoshida
- Department of Finemechanics, Tohoku University, 6-6-1 Aramaki Aoba, Sendai, 980-8579, Japan
| | - Kensuke Sumomozawa
- Department of Finemechanics, Tohoku University, 6-6-1 Aramaki Aoba, Sendai, 980-8579, Japan
| | - Kuniaki Nagamine
- Department of Finemechanics, Tohoku University, 6-6-1 Aramaki Aoba, Sendai, 980-8579, Japan
| | - Matsuhiko Nishizawa
- Department of Finemechanics, Tohoku University, 6-6-1 Aramaki Aoba, Sendai, 980-8579, Japan
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13
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Callaghan NI, Hadipour-Lakmehsari S, Lee SH, Gramolini AO, Simmons CA. Modeling cardiac complexity: Advancements in myocardial models and analytical techniques for physiological investigation and therapeutic development in vitro. APL Bioeng 2019; 3:011501. [PMID: 31069331 PMCID: PMC6481739 DOI: 10.1063/1.5055873] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 12/31/2018] [Indexed: 02/06/2023] Open
Abstract
Cardiomyopathies, heart failure, and arrhythmias or conduction blockages impact millions of patients worldwide and are associated with marked increases in sudden cardiac death, decline in the quality of life, and the induction of secondary pathologies. These pathologies stem from dysfunction in the contractile or conductive properties of the cardiomyocyte, which as a result is a focus of fundamental investigation, drug discovery and therapeutic development, and tissue engineering. All of these foci require in vitro myocardial models and experimental techniques to probe the physiological functions of the cardiomyocyte. In this review, we provide a detailed exploration of different cell models, disease modeling strategies, and tissue constructs used from basic to translational research. Furthermore, we highlight recent advancements in imaging, electrophysiology, metabolic measurements, and mechanical and contractile characterization modalities that are advancing our understanding of cardiomyocyte physiology. With this review, we aim to both provide a biological framework for engineers contributing to the field and demonstrate the technical basis and limitations underlying physiological measurement modalities for biologists attempting to take advantage of these state-of-the-art techniques.
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Affiliation(s)
| | | | | | | | - Craig A. Simmons
- Author to whom correspondence should be addressed: . Present address: Ted Rogers Centre for Heart
Research, 661 University Avenue, 14th Floor Toronto, Ontario M5G 1M1, Canada. Tel.:
416-946-0548. Fax: 416-978-7753
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14
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Jiang Y, Zhou Y, Bao X, Chen C, Randolph LN, Du J, Lian XL. An Ultrasensitive Calcium Reporter System via CRISPR-Cas9-Mediated Genome Editing in Human Pluripotent Stem Cells. iScience 2018; 9:27-35. [PMID: 30368079 PMCID: PMC6203247 DOI: 10.1016/j.isci.2018.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 08/26/2018] [Accepted: 10/08/2018] [Indexed: 12/21/2022] Open
Abstract
Genetically encoded calcium indicator (GCaMP) proteins have been reported for imaging cardiac cell activity based on intracellular calcium transients. To bring human pluripotent stem cell (hPSC)-derived cardiomyocytes (CMs) to the clinic, it is critical to evaluate the functionality of CMs. Here, we show that GCaMP6s-expressing hPSCs can be generated and used for CM characterization. By leveraging CRISPR-Cas9 genome editing tools, we generated a knockin cell line that constitutively expresses GCaMP6s, an ultrasensitive calcium sensor protein. We further showed that this clone maintained pluripotency and cardiac differentiation potential. These knockin hPSC-derived CMs exhibited sensitive fluorescence fluctuation with spontaneous contraction. We then compared the fluorescence signal with mechanical contraction signal. The knockin hPSC-derived CMs also showed sensitive response to isoprenaline treatment in a concentration-dependent manner. Therefore, the GCaMP6s knockin hPSC line provides a non-invasive, sensitive, and economic approach to characterize the functionality of hPSC-derived CMs.
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Affiliation(s)
- Yuqian Jiang
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA; The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Yuxiao Zhou
- Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Xiaoping Bao
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA 94720, USA
| | - Chuanxin Chen
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA; College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China
| | - Lauren N Randolph
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA; The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jing Du
- Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - Xiaojun Lance Lian
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA; The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802, USA; Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA.
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15
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Park JS, Grijalva SI, Aziz MK, Chi T, Li S, Sayegh MN, Wang A, Cho HC, Wang H. Multi-parametric cell profiling with a CMOS quad-modality cellular interfacing array for label-free fully automated drug screening. LAB ON A CHIP 2018; 18:3037-3050. [PMID: 30168827 PMCID: PMC8513687 DOI: 10.1039/c8lc00156a] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Cells are complex systems with concurrent multi-physical responses, and cell physiological signals are often encoded with spatiotemporal dynamics and further coupled with multiple cellular activities. However, most existing electronic sensors are only single-modality and cannot capture multi-parametric cellular responses. In this paper, a 1024-pixel CMOS quad-modality cellular interfacing array that enables multi-parametric cell profiling for drug development is presented. The quad-modality CMOS array features cellular impedance characterization, optical detection, extracellular potential recording, and biphasic current stimulation. The fibroblast transparency and surface adhesion are jointly monitored by cellular impedance and optical sensing modalities for comprehensive cell growth evaluation. Simultaneous current stimulation and opto-mechanical monitoring based on cardiomyocytes are demonstrated without any stimulation/sensing dead-zone. Furthermore, drug dose-dependent multi-parametric feature extractions in cardiomyocytes from their extracellular potentials and opto-mechanical signals are presented. The CMOS array demonstrates great potential for fully automated drug screening and drug safety assessments, which may substantially reduce the drug screening time and cost in future new drug development.
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Affiliation(s)
- Jong Seok Park
- The School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30308, USA.
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16
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Hansen KJ, Laflamme MA, Gaudette GR. Development of a Contractile Cardiac Fiber From Pluripotent Stem Cell Derived Cardiomyocytes. Front Cardiovasc Med 2018; 5:52. [PMID: 29942806 PMCID: PMC6004416 DOI: 10.3389/fcvm.2018.00052] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 05/04/2018] [Indexed: 01/25/2023] Open
Abstract
Stem cell therapy has the potential to regenerate cardiac function after myocardial infarction. In this study, we sought to examine if fibrin microthread technology could be leveraged to develop a contractile fiber from human pluripotent stem cell derived cardiomyocytes (hPS-CM). hPS-CM seeded onto fibrin microthreads were able to adhere to the microthread and began to contract seven days after initial seeding. A digital speckle tracking algorithm was applied to high speed video data (>60 fps) to determine contraction behaviour including beat frequency, average and maximum contractile strain, and the principal angle of contraction of hPS-CM contracting on the microthreads over 21 days. At day 7, cells seeded on tissue culture plastic beat at 0.83 ± 0.25 beats/sec with an average contractile strain of 4.23±0.23%, which was significantly different from a beat frequency of 1.11 ± 0.45 beats/sec and an average contractile strain of 3.08±0.19% at day 21 (n = 18, p < 0.05). hPS-CM seeded on microthreads beat at 0.84 ± 0.15 beats/sec with an average contractile strain of 3.56±0.22%, which significantly increased to 1.03 ± 0.19 beats/sec and 4.47±0.29%, respectively, at 21 days (n = 18, p < 0.05). At day 7, 27% of the cells had a principle angle of contraction within 20 degrees of the microthread, whereas at day 21, 65% of hPS-CM were contracting within 20 degrees of the microthread (n = 17). Utilizing high speed calcium transient data (>300 fps) of Fluo-4AM loaded hPS-CM seeded microthreads, conduction velocities significantly increased from 3.69 ± 1.76 cm/s at day 7 to 24.26 ± 8.42 cm/s at day 21 (n = 5-6, p < 0.05). hPS-CM seeded microthreads exhibited positive expression for connexin 43, a gap junction protein, between cells. These data suggest that the fibrin microthread is a suitable scaffold for hPS-CM attachment and contraction. In addition, extended culture allows cells to contract in the direction of the thread, suggesting alignment of the cells in the microthread direction.
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Affiliation(s)
- Katrina J. Hansen
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States
| | - Michael A. Laflamme
- Toronto General Hospital Research Institute, McEwen Centre for Regenerative Medicine, University Health Network, Toronto, ON, Canada
| | - Glenn R. Gaudette
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA, United States
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