PMID- 33995650 OWN - NLM STAT- MEDLINE DCOM- 20210728 LR - 20210728 IS - 1838-7640 (Electronic) IS - 1838-7640 (Linking) VI - 11 IP - 13 DP - 2021 TI - Progressive stretch enhances growth and maturation of 3D stem-cell-derived myocardium. PG - 6138-6153 LID - 10.7150/thno.54999 [doi] AB - 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/mm(2). 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 Ca(2+) 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 microm), 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. CI - (c) The author(s). FAU - Lu, Kun AU - Lu K AD - Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-University Munchen, Munich, Germany. FAU - Seidel, Thomas AU - Seidel T AD - Institute of Cellular and Molecular Physiology, Friedrich-Alexander University Erlangen-Nurnberg, Erlangen, Germany. FAU - Cao-Ehlker, Xiaochun AU - Cao-Ehlker X AD - Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-University Munchen, Munich, Germany. FAU - Dorn, Tatjana AU - Dorn T AD - First Department of Medicine, Cardiology, Klinikum rechts der Isar, Technical University Munchen, Munich, Germany. FAU - Batcha, Aarif Mohamed Nazeer AU - Batcha AMN AD - Institute for Medical Information Processing Biometry and Epidemiology, Ludwig-Maximilians-University Munchen, Munich, Germany. AD - DIFUTURE (Data Integration for Future Medicine), Ludwig-Maximilians-University Munchen, Munich, Germany. FAU - Schneider, Christine Maria AU - Schneider CM AD - First Department of Medicine, Cardiology, Klinikum rechts der Isar, Technical University Munchen, Munich, Germany. FAU - Semmler, Marie AU - Semmler M AD - Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-University Munchen, Munich, Germany. FAU - Volk, Tilmann AU - Volk T AD - Institute of Cellular and Molecular Physiology, Friedrich-Alexander University Erlangen-Nurnberg, Erlangen, Germany. FAU - Moretti, Alessandra AU - Moretti A AD - First Department of Medicine, Cardiology, Klinikum rechts der Isar, Technical University Munchen, Munich, Germany. AD - DZHK (German Center for Cardiovascular Research), Partner site Munich Heart Alliance, Munich, Germany. FAU - Dendorfer, Andreas AU - Dendorfer A AD - Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-University Munchen, Munich, Germany. AD - DZHK (German Center for Cardiovascular Research), Partner site Munich Heart Alliance, Munich, Germany. FAU - Tomasi, Roland AU - Tomasi R AD - Walter-Brendel-Centre of Experimental Medicine, University Hospital, Ludwig-Maximilians-University Munchen, Munich, Germany. AD - Clinic of Anaesthesiology, University Hospital, Ludwig-Maximilians-University Munchen, Munich, Germany. LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20210415 PL - Australia TA - Theranostics JT - Theranostics JID - 101552395 RN - 0 (Hydrogels) RN - 0 (RNA, Messenger) SB - IM MH - Biomimetic Materials MH - Bioreactors MH - Cell Size MH - Diastole MH - Electric Stimulation MH - Excitation Contraction Coupling MH - Humans MH - Hydrogels MH - Induced Pluripotent Stem Cells/*cytology MH - Muscle Spindles MH - *Myocardium MH - Myocytes, Cardiac/*cytology MH - Myofibrils/physiology/ultrastructure MH - Organoids MH - RNA, Messenger/biosynthesis/genetics MH - *Stress, Mechanical MH - Systole MH - *Tissue Culture Techniques/instrumentation/methods MH - *Tissue Engineering PMC - PMC8120210 OTO - NOTNLM OT - biomechanics OT - engineered heart tissue OT - maturation OT - progressive stretch OT - stem-cell-derived myocardium COIS- Competing Interests: AD and TS are shareholders of InVitroSys GmbH. Other authors declare no conflict of interest. EDAT- 2021/05/18 06:00 MHDA- 2021/07/29 06:00 PMCR- 2021/01/01 CRDT- 2021/05/17 06:06 PHST- 2020/10/25 00:00 [received] PHST- 2021/03/23 00:00 [accepted] PHST- 2021/05/17 06:06 [entrez] PHST- 2021/05/18 06:00 [pubmed] PHST- 2021/07/29 06:00 [medline] PHST- 2021/01/01 00:00 [pmc-release] AID - thnov11p6138 [pii] AID - 10.7150/thno.54999 [doi] PST - epublish SO - Theranostics. 2021 Apr 15;11(13):6138-6153. doi: 10.7150/thno.54999. eCollection 2021.