M E T H O D S I N M O L E C U L A R B I O L O G Y

Series EditorJohn M. Walker

School of Life SciencesUniversity of Hertfordshire

Hat fi eld, Hertfordshire, AL10 9AB, UK

For further volumes: http://www.springer.com/series/7651

Cardiac Tissue Engineering

Methods and Protocols

Edited by

Milica RadisicInstitute of Biomaterials and Biomedical Engineering, Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada;

Toronto General Research Institute, University Health Network, Toronto, ON, Canada

Lauren D. Black IIIDepartment of Biomedical Engineering, Tufts University, Medford, MA, USA;

Cellular, Molecular and Developmental Biology Program, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA

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ISSN 1064-3745 ISSN 1940-6029 (electronic)ISBN 978-1-4939-1046-5 ISBN 978-1-4939-1047-2 (eBook) DOI 10.1007/978-1-4939-1047-2 Springer New York Heidelberg Dordrecht London

Library of Congress Control Number: 2014940960

© Springer Science+Business Media New York 2014 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifi cally the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfi lms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. Exempted from this legal reservation are brief excerpts in connection with reviews or scholarly analysis or material supplied specifi cally for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’s location, in its current version, and permission for use must always be obtained from Springer. Permissions for use may be obtained through RightsLink at the Copyright Clearance Center. Violations are liable to prosecution under the respective Copyright Law. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specifi c statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.

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Humana Press is a brand of SpringerSpringer is part of Springer Science+Business Media (www.springer.com)

Editors Milica Radisic Institute of Biomaterials

and Biomedical Engineering Department of Chemical Engineering

and Applied ChemistryUniversity of Toronto Toronto , ON , Canada

Toronto General Research InstituteUniversity Health NetworkToronto, ON, Canada

Lauren D. Black III Department of Biomedical Engineering Tufts University Medford , MA , USA

Cellular, Molecular and Developmental Biology Program, Sackler School of Graduate Biomedical Sciences

Tufts University School of MedicineBoston, MA, USA

v

Human hearts have a limited regenerative potential, motivating the development of the alternative treatment options for the conditions that result in the loss of beating cardio-myocytes. An example is myocardial infarction that results in a death of tens of millions of ventricular cardiomyocytes that cannot be replaced by the body. It is estimated that fi ve to seven million patients live with myocardial infarction in North America alone. A majority of these patients do not need a surgical intervention, and medical management provides satisfac-tory results. However, over a period of 5 years, one-half of the patients who experience a myocardial infarction will develop heart failure, ultimately requiring heart transplantation.

The long-term goal of cardiac tissue engineering is to provide a living, beating, ideally autologous, and non-immunogenic myocardial patch that can restore the contractile function of the failing heart. The engineered tissues could also be used for preclinical drug testing to discover new targets for cardiac therapy and eliminate drugs, cardiac and noncardiac, with serious side effects. It generally involves a combination of suitable cell types, human or non-human cardiomyocytes and supporting cells, with an appropriate biomaterial made out of either synthetic or natural components and cultivation in an environment that reproduces some of the complexity of the native cardiac environment (e.g., electrical, mechanical stimula-tion, passive tension, or topographical cues).

This fi eld is still young. The term cardiac tissue engineering usually refers to engineering of myocardial wall in vitro using living and beating cardiomyocytes. The pioneering papers appeared in the late 1990s, and they all utilized either neonatal rat cardiomyocytes or embryonic chick cardiomyocytes as a cell source. Since then, the fi eld has matured signifi -cantly to include a range of approaches that all give cardiac tissues in vitro that are capable of developing contractile force and propagating electrical impulses. Advances in human embryonic stem cell research and induced pluripotent stem cell technology now provide the possibility of generating millions of bona fi de human cardiomyocytes. When research in cardiac tissue engineering started some 25 years ago, the issue of a human cell source appeared insurmountable; however the researchers continued to make way, and there are many reports now on the use of human pluripotent stem cells as a source of cardiomyocytes for cardiac tissue engineering. Although early researchers thought that having purifi ed car-diomyocytes in three-dimensional structures would be benefi cial, based on analogies with monolayer studies where fi broblasts overgrow cardiomyocytes, there is a consensus in the fi eld now that a mixed cell population is optimal for maintenance of cardiac phenotype and survival of cardiomyocytes in engineered tissues both in vitro and in vivo. The mixed popu-lation usually contains cardiomyocytes, endothelial cells, and a stromal cell type such as fi broblasts or mesenchymal stem cells. Also, there is a consensus that a form of physical stimulation, either mechanical or electrical, or passive tension is required for cardiomyo-cytes to achieve and maintain a differentiated phenotype and in vivo-like functional proper-ties during in vitro cultivation.

This book gathers for the fi rst time a collection of protocols on cardiac tissue engineering from pioneering and leading researchers around the globe. Protocols related to cell prepa-ration, biomaterial preparation, cell seeding, and cultivation in various systems are provided.

Pref ace

vi

Our goal is to enable adoption of these protocols in laboratories that are interested in enter-ing the fi eld as well as enable transfer of knowledge between laboratories that are already in this fi eld. We hope that these efforts will lead to standardization, defi nition of best practices in cardiac tissue cultivation, and direct comparison of various production protocols using controlled in vivo studies that would ultimately lead to translational efforts. Although bio-material patches alone and hydrogels have been investigated in clinical studies focused on myocardial regeneration, a cardiac patch based on living, beating human cardiomyocytes has not yet been tested in humans. Only patches based on non-cardiomyocytes have been tested in humans with mixed results. Bringing a new therapy to the clinic is an overwhelm-ing task, one that we must approach in a collaborative rather than competitive spirit. We hope that sharing of the best protocols in cardiac tissue engineering will enable this goal.

Toronto, ON, Canada Milica Radisic Medford, MA, USA Lauren D. Black III, Ph.D.

Preface

vii

Contents

Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v Contributors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

1 Second Generation Codon Optimized Minicircle (CoMiC) for Nonviral Reprogramming of Human Adult Fibroblasts . . . . . . . . . . . . . . . 1 Sebastian Diecke, Leszek Lisowski, Nigel G. Kooreman, and Joseph C. Wu

2 Scalable Cardiac Differentiation of Human Pluripotent Stem Cells as Microwell-Generated, Size Controlled Three- Dimensional Aggregates . . . . 15 Celine L. Bauwens and Mark D. Ungrin

3 Preparation and Characterization of Circulating Angiogenic Cells for Tissue Engineering Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Aleksandra Ostojic, Suzanne Crowe, Brian McNeill, Marc Ruel, and Erik J. Suuronen

4 Isolation and Expansion of C-Kit-Positive Cardiac Progenitor Cells by Magnetic Cell Sorting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Kristin M. French and Michael E. Davis

5 Synthesis of Aliphatic Polyester Hydrogel for Cardiac Tissue Engineering . . . . 51 Sanjiv Dhingra, Richard D. Weisel, and Ren-Ke Li

6 Fabrication of PEGylated Fibrinogen: A Versatile Injectable Hydrogel Biomaterial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Iris Mironi-Harpaz, Alexandra Berdichevski, and Dror Seliktar

7 Natural Cardiac Extracellular Matrix Hydrogels for Cultivation of Human Stem Cell-Derived Cardiomyocytes . . . . . . . . . . . . . . . . . . . . . . . . 69 Donald O. Freytes, John D. O’Neill, Yi Duan-Arnold, Emily A. Wrona, and Gordana Vunjak-Novakovic

8 Magnetically Actuated Alginate Scaffold: A Novel Platform for Promoting Tissue Organization and Vascularization. . . . . . . . . . . . . . . . . . 83 Yulia Sapir, Emil Ruvinov, Boris Polyak, and Smadar Cohen

9 Shrink-Induced Biomimetic Wrinkled Substrates for Functional Cardiac Cell Alignment and Culture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 Nicole Mendoza, Roger Tu, Aaron Chen, Eugene Lee, and Michelle Khine

10 Injectable ECM Scaffolds for Cardiac Repair . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Todd D. Johnson, Rebecca L. Braden, and Karen L. Christman

11 Generation of Strip-Format Fibrin-Based Engineered Heart Tissue (EHT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Sebastian Schaaf, Alexandra Eder, Ingra Vollert, Andrea Stöhr, Arne Hansen, and Thomas Eschenhagen

viii

12 Cell Tri-Culture for Cardiac Vascularization . . . . . . . . . . . . . . . . . . . . . . . . . . 131 Ayelet Lesman, Lior Gepstein, and Shulamit Levenberg

13 Cell Sheet Technology for Cardiac Tissue Engineering . . . . . . . . . . . . . . . . . . 139 Yuji Haraguchi, Tatsuya Shimizu, Katsuhisa Matsuura, Hidekazu Sekine, Nobuyuki Tanaka, Kenjiro Tadakuma, Masayuki Yamato, Makoto Kaneko, and Teruo Okano

14 Design and Fabrication of Biological Wires . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 Jason W. Miklas, Sara S. Nunes, Boyang Zhang, and Milica Radisic

15 Collagen-Based Engineered Heart Muscle. . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 Malte Tiburcy, Tim Meyer, Poh Loong Soong, and Wolfram-Hubertus Zimmermann

16 Creation of a Bioreactor for the Application of Variable Amplitude Mechanical Stimulation of Fibrin Gel-Based Engineered Cardiac Tissue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Kathy Y. Morgan and Lauren D. Black III

17 Preparation of Acellular Myocardial Scaffolds with Well- Preserved Cardiomyocyte Lacunae, and Method for Applying Mechanical and Electrical Simulation to Tissue Construct . . . . . . . . . . . . . . . . . . . . . . . . . 189 Bo Wang, Lakiesha N. Williams, Amy L. de Jongh Curry, and Jun Liao

18 Patch-Clamp Technique in ESC-Derived Cardiomyocytes . . . . . . . . . . . . . . . . 203 Jie Liu and Peter H. Backx

19 Optogenetic Control of Cardiomyocytes via Viral Delivery . . . . . . . . . . . . . . . 215 Christina M. Ambrosi and Emilia Entcheva

20 Methods for Assessing the Electromechanical Integration of Human Pluripotent Stem Cell-Derived Cardiomyocyte Grafts . . . . . . . . . . . 229 Wei-Zhong Zhu, Dominic Filice, Nathan J. Palpant, and Michael A. Laflamme

21 Quantifying Electrical Interactions Between Cardiomyocytes and Other Cells in Micropatterned Cell Pairs. . . . . . . . . . . . . . . . . . . . . . . . . . 249 Hung Nguyen, Nima Badie, Luke McSpadden, Dawn Pedrotty, and Nenad Bursac

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263

Contents

ix

CHRISTINA M. AMBROSI, PH.D. • Department of Biomedical Engineering, Institute for Molecular Cardiology , Stony Brook University , Stony Brook , NY , USA

PETER H. BACKX • Department of Physiology and Medicine , University of Toronto , Toronto , ON , Canada ; The Heart and Stroke/Richard Lewar Centre of Excellence , Toronto , ON , Canada ; Division of Cardiology , University Health Network , Toronto , ON , Canada

NIMA BADIE • Department of Biomedical Engineering , Duke University , Durham , NC , USA CELINE L. BAUWENS • Centre for Commercialization of Regenerative Medicine , Toronto ,

ON , Canada ALEXANDRA BERDICHEVSKI • Faculty of Biomedical Engineering , Technion—Israel Institute

of Technology , Haifa , Israel LAUREN D. BLACK III, PH.D. • Department of Biomedical Engineering , Tufts University ,

Medford , MA , USA ; Cellular, Molecular and Developmental Biology Program, Sackler School of Graduate Biomedical Sciences , Tufts University School of Medicine , Boston , MA , USA

REBECCA L. BRADEN, M.S. • Department of Bioengineering , University of California San Diego , La Jolla , CA , USA ; Sanford Consortium for Regenerative Medicine , La Jolla , CA , USA

NENAD BURSAC, PH.D. • Department of Biomedical Engineering , Duke University , Durham , NC , USA

AARON CHEN • Department of Chemical Engineering and Materials Science , University of California , Irvine , CA , USA

KAREN L. CHRISTMAN, PH.D. • Department of Bioengineering , University of California San Diego , La Jolla , CA , USA ; Sanford Consortium for Regenerative Medicine , La Jolla , CA , USA

SMADAR COHEN, PH.D. • Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, The Center for Regenerative Medicine and Stem Cell (RMSC) Research , Ben-Gurion University of the Negev , Beer-Sheva , Israel ; The Ilse Katz Institute for Nanoscale Science and Technology , Ben-Gurion University of the Negev , Beer-Sheva , Israel

SUZANNE CROWE • Division of Cardiac Surgery , University of Ottawa Heart Institute , Ottawa , ON , Canada

MICHAEL E. DAVIS, PH.D. • Wallace H. Coulter Department of Biomedical Engineering , Emory University and Georgia Institute of Technology , Atlanta , GA , USA

AMY L. DE JONGH CURRY • Department of Biomedical Engineering , University of Memphis , Memphis , TN , USA

SANJIV DHINGRA • Regenerative Medicine Program, Institute of Cardiovascular Sciences, St. Boniface Research Centre , University of Manitoba , Winnipeg , MB , Canada

SEBASTIAN DIECKE • Lorry I. Lokey Stem Cell Research Building , Stanford University School of Medicine , Stanford , CA , USA

YI DUAN-ARNOLD • Department of Biomedical Engineering , Columbia University , New York , NY , USA

ALEXANDRA EDER • Department of Experimental Pharmacology and Toxicology , University Medical Center Hamburg-Eppendorf (UKE) , Hamburg , Germany ; DZHK (German Centre for Cardiovascular Research) , Hamburg , Germany

Contributors

x

EMILIA ENTCHEVA, PH.D. • Department of Biomedical Engineering, Institute for Molecular Cardiology , Stony Brook University , Stony Brook , NY , USA

THOMAS ESCHENHAGEN • Department of Experimental Pharmacology and Toxicology , University Medical CenterHamburg-Eppendorf (UKE) , Hamburg , Germany ; DZHK (German Centre for Cardiovascular Research) , Hamburg , Germany

DOMINIC FILICE • Department of Bioengineering, Institute for Stem Cells and Regenerative Medicine , University of Washington , Seattle , WA , USA

KRISTIN M. FRENCH • Wallace H. Coulter Department of Biomedical Engineering , Emory University and Georgia Institute of Technology , Atlanta , GA , USA

DONALD O. FREYTES • New York Stem Cell Foundation , New York , NY , USA LIOR GEPSTEIN • The Sohnis Family Research Laboratory for Cardiac Electrophysiology

and Regenerative medicine, the Bruce Rappaport Faculty of Medicine , Technion—Israel Institute of Technology , Haifa , Israel

ARNE HANSEN • Department of Experimental Pharmacology and Toxicology , University Medical CenterHamburg-Eppendorf (UKE) , Hamburg , Germany ; DZHK (German Centre for Cardiovascular Research) , Hamburg , Germany

YUJI HARAGUCHI • Institute of Advanced Biomedical Engineering and Science, TWIns , Tokyo Women’s Medical University , Shinjuku-ku , Tokyo , Japan

TODD D. JOHNSON, M.S. • Department of Bioengineering , University of California San Diego , La Jolla , CA , USA ; Sanford Consortium for Regenerative Medicine , La Jolla , CA , USA

MAKOTO KANEKO • Department of Mechanical Engineering, Graduate School of Engineering , Osaka University , Yamadaoka, Suita , Japan

MICHELLE KHINE, PH.D. • Department of Biomedical Engineering , University of California , Irvine , CA , USA ; Department of Chemical Engineering , University of California , Irvine , CA , USA

NIGEL G. KOOREMAN • Lorry I. Lokey Stem Cell Research Building , Stanford University School of Medicine , Stanford , CA , USA

MICHAEL A. LAFLAMME, M.D., PH.D. • Department of Pathology, Institute for Stem Cells and Regenerative Medicine , University of Washington , Seattle , WA , USA

EUGENE LEE • Department of Biomedical Engineering , University of California , Irvine , CA , USA

AYELET LESMAN • Department of Chemistry and Chemical Engineering , California Institute of Technology , Pasadena , CA , USA ; Department of Biomedical Engineering , Technion—Israel Institute of Technology , Haifa , Israel

SHULAMIT LEVENBERG • Department of Biomedical Engineering , Technion—Israel Institute of Technology , Haifa , Israel

REN-KE LI, M.D., PH.D. • Division of Cardiovascular Surgery, Toronto General Research Institute , University Health Network , Toronto , ON , Canada ; Division of Cardiac Surgery, Department of Surgery , University of Toronto , Toronto , ON , Canada

JUN LIAO, PH.D. • Tissue Bioengineering Laboratory, Department of Biological Engineering , Mississippi State University , Mississippi State , MS , USA

LESZEK LISOWSKI • Gene Transfer, Targeting and Therapeutics Facility , Salk Institute for Biological Studies , San Diego , CA , USA

JIE LIU • Department of Physiology and Medicine, University of Toronto , Toronto , ON , Canada ; Materials Science , University of California , Irvine , CA , USA

KATSUHISA MATSUURA • Institute of Advanced Biomedical Engineering and Science , TWIns , Tokyo Women’s Medical University , Shinjuku-ku , Tokyo , Japan

BRIAN MCNEILL • Division of Cardiac Surgery , University of Ottawa Heart Institute , Ottawa , ON , Canada

Contributors

xi

LUKE MCSPADDEN • Department of Biomedical Engineering , Duke University , Durham , NC , USA

NICOLE MENDOZA • Department of Biomedical Engineering , University of California , Irvine , CA , USA

TIM MEYER • Institute of Pharmacology, Heart Research Center Göttingen (HRCG) , University Medical Center Göttingen , Göttingen , Germany ; DZHK (German Center for Cardiovascular Research), partner site Göttingen , Göttingen , Germany

JASON W. MIKLAS • Institute of Biomaterials and Biomedical Engineering , University of Toronto , Toronto , ON , Canada

IRIS MIRONI-HARPAZ • Faculty of Biomedical Engineering , Technion—Israel Institute of Technology , Haifa , Israel

KATHY Y. MORGAN • Department of Biomedical Engineering , Tufts University , Medford , MA , USA

HUNG NGUYEN • Department of Biomedical Engineering , Duke University , Durham , NC , USA

SARA S. NUNES • Institute of Biomaterials and Biomedical Engineering , University of Toronto , Toronto , ON , Canada ; Toronto General Research Institute , University Health Network , Toronto , ON , Canada

TERUO OKANO • Institute of Advanced Biomedical Engineering and Science, TWIns , Tokyo Women’s Medical University , Shinjuku-ku , Tokyo , Japan

JOHN D. O’NEILL • Department of Biomedical Engineering , Columbia University , New York , NY , USA

ALEKSANDRA OSTOJIC • Division of Cardiac Surgery , University of Ottawa Heart Institute , Ottawa , ON , Canada

NATHAN J. PALPANT • Department of Pathology, Institute for Stem Cells and Regenerative Medicine , University of Washington , Seattle , WA , USA

DAWN PEDROTTY • Department of Biomedical Engineering , Duke University , Durham , NC , USA

BORIS POLYAK, PH.D. • Department of Surgery , Drexel University College of Medicine , Philadelphia , PA , USA ; Department of Pharmacology and Physiology , Drexel University College of Medicine , Philadelphia , PA , USA

MILICA RADISIC • Institute of Biomaterials and Biomedical Engineering , Department of Chemical Engineering and Applied Chemistry, University of Toronto , Toronto , ON , Canada ; Toronto General Research Institute, University Health Network, Toronto, ON, Canada

MARC RUEL • Division of Cardiac Surgery , University of Ottawa Heart Institute , Ottawa , ON , Canada

EMIL RUVINOV, PH.D. • Avram and Stella Goldstein-Goren Department of Biotechnology Engineering , Ben-Gurion University of the Negev , Beer-Sheva , Israel

YULIA SAPIR, M.SC. • Avram and Stella Goldstein-Goren Department of Biotechnology Engineering , Ben-Gurion University of the Negev , Beer-Sheva , Israel

SEBASTIAN SCHAAF • Department of Experimental Pharmacology and Toxicology , University Medical CenterHamburg-Eppendorf (UKE) , Hamburg , Germany ; DZHK (German Centre for Cardiovascular Research) , Hamburg , Germany

HIDEKAZU SEKINE • Institute of Advanced Biomedical Engineering and Science, TWIns , Tokyo Women’s Medical University , Shinjuku-ku , Tokyo , Japan

DROR SELIKTAR • Faculty of Biomedical Engineering , Technion—Israel Institute of Technology , Haifa , Israel ; Nanoscience and Nanotechnology Initiative , National University of Singapore , Singapore , Singapore

Contributors

xii

TATSUYA SHIMIZU • Institute of Advanced Biomedical Engineering and Science, TWIns , Tokyo Women’s Medical University , Shinjuku-ku , Tokyo , Japan

POH LOONG SOONG • Institute of Pharmacology, Heart Research Center Göttingen (HRCG) , University Medical Center Göttingen , Göttingen , Germany ; DZHK (German Center for Cardiovascular Research), partner site Göttingen , Göttingen , Germany

ANDREA STÖHR • Department of Experimental Pharmacology and Toxicology , University Medical Center Hamburg-Eppendorf (UKE) , Hamburg , Germany ; DZHK (German Centre for Cardiovascular Research) , Hamburg , Germany

ERIK J. SUURONEN • Division of Cardiac Surgery , University of Ottawa Heart Institute , Ottawa , ON , Canada

KENJIRO TADAKUMA • Department of Mechanical Engineering, Graduate School of Engineering , Osaka University , Yamadaoka, Suita , Japan

NOBUYUKI TANAKA • Institute of Advanced Biomedical Engineering and Science, TWIns , Tokyo Women’s Medical University , Shinjuku-ku , Tokyo , Japan

MALTE TIBURCY • Institute of Pharmacology, Heart Research Center Göttingen (HRCG) , University Medical Center Göttingen , Göttingen , Germany ; DZHK (German Center for Cardiovascular Research), partner site Göttingen , Göttingen , Germany

ROGER TU • Department of Biological Sciences , University of California , Irvine , CA , USA MARK D. UNGRIN • Department of Comparative Biology and Experimental Medicine,

Faculty of Veterinary Medicine , University of Calgary , Calgary , AB , Canada INGRA VOLLERT • Department of Experimental Pharmacology and Toxicology , University

Medical Center Hamburg-Eppendorf (UKE) , Hamburg , Germany ; DZHK (German Centre for Cardiovascular Research) , Hamburg , Germany

GORDANA VUNJAK-NOVAKOVIC • Department of Biomedical Engineering , Columbia University , New York , NY , USA

BO WANG • Tissue Bioengineering Laboratory, Department of Biological Engineering , Mississippi State University , Mississippi State , MS , USA ; Department of Surgery, Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine , Northwestern University , Chicago , IL , USA

RICHARD D. WEISEL • Division of Cardiovascular Surgery, Toronto General Research Institute , University Health Network , Toronto , ON , Canada ; Department of Surgery, Division of Cardiac Surgery , University of Toronto , Toronto , ON , Canada

LAKIESHA N. WILLIAMS • Tissue Bioengineering Laboratory, Department of Biological Engineering , Mississippi State University , Mississippi State , MS , USA

EMILY A. WRONA • New York Stem Cell Foundation , New York , NY , USA JOSEPH C. WU, M.D., PH.D. • Lorry I. Lokey Stem Cell Research Building , Stanford

University School of Medicine , Stanford , CA , USA MASAYUKI YAMATO • Institute of Advanced Biomedical Engineering and Science, TWIns ,

Tokyo Women’s Medical University , Shinjuku-ku , Tokyo , Japan BOYANG ZHANG • Department of Chemical Engineering and Applied Chemistry , University

of Toronto , Toronto , ON , Canada ; Institute of Biomaterials and Biomedical Engineering , University of Toronto , Toronto , ON , Canada

WEI-ZHONG ZHU • Department of Pathology, Institute for Stem Cells and Regenerative Medicine , University of Washington , Seattle , WA , USA

WOLFRAM-HUBERTUS ZIMMERMANN, M.D. • Institute of Pharmacology, Heart Research Center Göttingen (HRCG) , University Medical Center Göttingen , Göttingen , Germany ; DZHK (German Center for Cardiovascular Research), partner site Göttingen , Göttingen , Germany

Contributors