Name: assessing functional metrics of skeletal muscle health in human skeletal muscle microtissues
Uploaded: 2021-02-18T15:00:00
Description: Watch this Scientific Journal Video about Assessing Functional Metrics of Skeletal Muscle Health in Human Skeletal Muscle Microtissues at JoVE.com

We would like to thank Mohammad Afshar, Haben Abraha, Mohsen Afshar-Bakooshli, and Sadegh Davoudi for contributing to the invention of the MyoTACTIC culture platform and establishing the fabrication and analysis methods described herein. HL received funding from a Natural Sciences and Engineering Research Council (NSERC) Training Program in Organ-on-a-Chip Engineering and Entrepreneurship Scholarship and a University of Toronto Wildcat graduate scholarships. PMG is the Canada Research Chair in Endogenous Repair and received support for this study from the Ontario Institute for Regenerative Medicine, the Stem Cell Network, and from Medicine by Design, a Canada First Research Excellence Program. Schematic diagrams were created with BioRender.com.

1. PDMS MyoTACTIC plate fabrication
NOTE: PDMS MyoTACTIC plate fabrication requires a PU&#160;negative mold, which can be manufactured as previously described30. The computer-aided design (CAD) SolidWorks file for the MyoTACTIC plate design has been made available on GitHub (https://github.com/gilbertlabcode/MyoTACTIC-SolidWork-CAD-file).
<ol>
	<li>Prepare ~ 110 g of PDMS polymer solution in a disposable plastic cup at a 1:15 ratio of monomer to curing agent using the...

<ol>
	<li>Frontera, W. R., Ochala, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Skeletal+Muscle:+A+brief+review+of+structure+and+function.">Skeletal Muscle: A brief review of structure and function.</a> Calcified Tissue International. 96 (3), 183-195 (2015).</li><li>McGreevy, J. W., Hakim, C. H., McIntosh, M. A., Duan, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Animal+models+of+Duchenne+muscular+dystrophy:+From+basic+mechanisms+to+gene+therapy.">Animal models of Duchenne muscular dystrophy: From basic mechanisms to gene therapy.</a> DMM Disease Models and Mechanisms. 8 (3), 195-213 (2015).</li><li>Young, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MyoScreen,+a+high-throughput+phenotypic+screening+platform+enabling+muscle+drug+discovery.">MyoScreen, a high-throughput phenotypic screening platform enabling muscle drug discovery.</a> SLAS Discovery. 23 (8), 790-806 (2018).</li><li>DiMasi, J. A., Hansen, R. W., Grabowski, H. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+price+of+innovation:+New+estimates+of+drug+development+costs.">The price of innovation: New estimates of drug development costs.</a> Journal of Health Economics. 22 (2), 151-185 (2003).</li><li>Pampaloni, F., Reynaud, E. G., Stelzer, E. H. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+third+dimension+bridges+the+gap+between+cell+culture+and+live+tissue.">The third dimension bridges the gap between cell culture and live tissue.</a> Nature Reviews Molecular Cell Biology. 8 (10), 839-845 (2007).</li><li>Duval, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+physiological+events+in+2D+vs.+3D+cell+culture.">Modeling physiological events in 2D vs. 3D cell culture.</a> Physiology. 32 (4), 266-277 (2017).</li><li>Vandenburgh, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Drug-screening+platform+based+on+the+contractility+of+tissue-engineered+muscle.">Drug-screening platform based on the contractility of tissue-engineered muscle.</a> Muscle and Nerve. 37 (4), 438-447 (2008).</li><li>Vandenburgh, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+drug+screening+with+contractile+muscle+tissue+engineered+from+dystrophic+myoblasts.">Automated drug screening with contractile muscle tissue engineered from dystrophic myoblasts.</a> The FASEB Journal. 23 (10), 3325-3334 (2009).</li><li>Kim, J. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+bioprinted+human+skeletal+muscle+constructs+for+muscle+function+restoration.">3D bioprinted human skeletal muscle constructs for muscle function restoration.</a> Scientific Reports. 8 (1), 12307 (2018).</li><li>Takahashi, H., Shimizu, T., Okano, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engineered+human+contractile+myofiber+sheets+as+a+platform+for+studies+of+skeletal+muscle+physiology.">Engineered human contractile myofiber sheets as a platform for studies of skeletal muscle physiology.</a> Scientific Reports. 8 (1), 1-11 (2018).</li><li>Afshar Bakooshli, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+3D+culture+model+of+innervated+human+skeletal+muscle+enables+studies+of+the+adult+neuromuscular+junction.">A 3D culture model of innervated human skeletal muscle enables studies of the adult neuromuscular junction.</a> eLife. 8, 1-29 (2019).</li><li>Madden, L., Juhas, M., Kraus, W. E., Truskey, G. A., Bursac, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioengineered+human+myobundles+mimic+clinical+responses+of+skeletal+muscle+to+drugs.">Bioengineered human myobundles mimic clinical responses of skeletal muscle to drugs.</a> eLife. 2015 (4), 3-5 (2015).</li><li>Urciuolo, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engineering+a+3D+in+vitro+model+of+human+skeletal+muscle+at+the+single+fiber+scale.">Engineering a 3D in vitro model of human skeletal muscle at the single fiber scale.</a> PLoS One. 15 (5), 0232081 (2020).</li><li>Cvetkovic, C., Rich, M. H., Raman, R., Kong, H., Bashir, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+3D-printed+platform+for+modular+neuromuscular+motor+units.">A 3D-printed platform for modular neuromuscular motor units.</a> Microsystems &amp; Nanoengineering. 3 (1), 1-9 (2017).</li><li>Shima, A., Morimoto, Y., Sweeney, H. L., Takeuchi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+contractile+muscle+tissue+consisting+of+human+skeletal+myocyte+cell+line.">Three-dimensional contractile muscle tissue consisting of human skeletal myocyte cell line.</a> Experimental Cell Research. 370 (1), 168-173 (2018).</li><li>Capel, A. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Scalable+3D+printed+molds+for+human+tissue+engineered+skeletal+muscle.">Scalable 3D printed molds for human tissue engineered skeletal muscle.</a> Frontiers in Bioengineering and Biotechnology. 7, 20 (2019).</li><li>Gholobova, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+tissue-engineered+skeletal+muscle:+a+novel+3D+in+vitro+model+for+drug+disposition+and+toxicity+after+intramuscular+injection.">Human tissue-engineered skeletal muscle: a novel 3D in vitro model for drug disposition and toxicity after intramuscular injection.</a> Scientific Reports. 8 (1), 1-14 (2018).</li><li>Osaki, T., Uzel, S. G. M., Kamm, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microphysiological+3D+model+of+amyotrophic+lateral+sclerosis+(ALS)+from+human+iPS-derived+muscle+cells+and+optogenetic+motor+neurons.">Microphysiological 3D model of amyotrophic lateral sclerosis (ALS) from human iPS-derived muscle cells and optogenetic motor neurons.</a> Science Advances. 4 (10), 5847 (2018).</li><li>Rao, L., Qian, Y., Khodabukus, A., Ribar, T., Bursac, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Engineering+human+pluripotent+stem+cells+into+a+functional+skeletal+muscle+tissue.">Engineering human pluripotent stem cells into a functional skeletal muscle tissue.</a> Nature Communications. 9 (1), (2018).</li><li>Maffioletti, S. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+human+iPSC-derived+artificial+skeletal+muscles+model+muscular+dystrophies+and+enable+multilineage+tissue+engineering.">Three-dimensional human iPSC-derived artificial skeletal muscles model muscular dystrophies and enable multilineage tissue engineering.</a> Cell Reports. 23 (3), 899-908 (2018).</li><li>Chal, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+human+muscle+fibers+and+satellite-like+cells+from+human+pluripotent+stem+cells+in+vitro.">Generation of human muscle fibers and satellite-like cells from human pluripotent stem cells in vitro.</a> Nature Protocols. 11 (10), 1833-1850 (2016).</li><li>Khodabukus, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrical+stimulation+increases+hypertrophy+and+metabolic+flux+in+tissue-engineered+human+skeletal+muscle.">Electrical stimulation increases hypertrophy and metabolic flux in tissue-engineered human skeletal muscle.</a> Biomaterials. 198, 259-269 (2019).</li><li>Nagashima, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vitro+model+of+human+skeletal+muscle+tissues+with+contractility+fabricated+by+immortalized+human+myogenic+cells.">In vitro model of human skeletal muscle tissues with contractility fabricated by immortalized human myogenic cells.</a> Advanced Biosystems. , 2000121 (2020).</li><li>Mills, R. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+a+human+skeletal+micro+muscle+platform+with+pacing+capabilities.">Development of a human skeletal micro muscle platform with pacing capabilities.</a> Biomaterials. 198, 217-227 (2019).</li><li>Legant, W. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfabricated+tissue+gauges+to+measure+and+manipulate+forces+from+3D+microtissues.">Microfabricated tissue gauges to measure and manipulate forces from 3D microtissues.</a> Proceedings of the National Academy of Sciences of the United States of America. 106 (25), 10097-10102 (2009).</li><li>Pr&#252;ller, J., Mannhardt, I., Eschenhagen, T., Zammit, P. S., Figeac, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Satellite+cells+delivered+in+their+niche+efficiently+generate+functional+myotubes+in+three-dimensional+cell+culture.">Satellite cells delivered in their niche efficiently generate functional myotubes in three-dimensional cell culture.</a> PLOS One. 13 (9), 0202574 (2018).</li><li>Sakar, M. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+and+optogenetic+control+of+engineered+3D+skeletal+muscle+bioactuators.">Formation and optogenetic control of engineered 3D skeletal muscle bioactuators.</a> Lab on a Chip. 12 (23), 4976-4985 (2012).</li><li>Zhang, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+system+to+monitor+statin-induced+myopathy+in+individual+engineered+skeletal+muscle+myobundles.">A system to monitor statin-induced myopathy in individual engineered skeletal muscle myobundles.</a> Lab on a Chip. 18 (18), 2787-2796 (2018).</li><li>Rajabian, N., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioengineered+skeletal+muscle+as+a+model+of+muscle+aging+and+regeneration.">Bioengineered skeletal muscle as a model of muscle aging and regeneration.</a> Tissue Engineering Part A. 27 (1-2), 74-86 (2020).</li><li>Afshar, M. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+96-well+culture+platform+enables+longitudinal+analyses+of+engineered+human+skeletal+muscle+microtissue+strength.">A 96-well culture platform enables longitudinal analyses of engineered human skeletal muscle microtissue strength.</a> Scientific Reports. 10 (1), 6918 (2020).</li><li>Mamchaoui, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immortalized+pathological+human+myoblasts:+Towards+a+universal+tool+for+the+study+of+neuromuscular+disorders.">Immortalized pathological human myoblasts: Towards a universal tool for the study of neuromuscular disorders.</a> Skeletal Muscle. 1 (1), 34 (2011).</li><li>Halldorsson, S., Lucumi, E., G&#243;mez-Sj&#246;berg, R., Fleming, R. M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advantages+and+challenges+of+microfluidic+cell+culture+in+polydimethylsiloxane+devices.">Advantages and challenges of microfluidic cell culture in polydimethylsiloxane devices.</a> Biosensors and Bioelectronics. 63, 218-231 (2015).</li><li>Chen, T. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasensitive+fluorescent+proteins+for+imaging+neuronal+activity.">Ultrasensitive fluorescent proteins for imaging neuronal activity.</a> Nature. 499 (7458), 295-300 (2013).</li><li>Bakooshli, M. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+3D+model+of+human+skeletal+muscle+innervated+with+stem+cell-derived+motor+neurons+enables+epsilon-subunit+targeted+myasthenic+syndrome+studies.">A 3D model of human skeletal muscle innervated with stem cell-derived motor neurons enables epsilon-subunit targeted myasthenic syndrome studies.</a> BioRxiv. , 275545 (2018).</li><li>Vandenburgh, H. H., Karlisch, P., Farr, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maintenance+of+highly+contractile+tissue-cultured+avian+skeletal+myotubes+in+collagen+gel.">Maintenance of highly contractile tissue-cultured avian skeletal myotubes in collagen gel.</a> Vitro Cellular &amp; Developmental Biology. 24 (3), 166-174 (1988).</li><li>Bell, E., Ivarsson, B., Merrill, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+a+tissue-like+structure+by+contraction+of+collagen+lattices+by+human+fibroblasts+of+different+proliferative+potential+in+vitro.">Production of a tissue-like structure by contraction of collagen lattices by human fibroblasts of different proliferative potential in vitro.</a> Proceedings of the National Academy of Sciences of the United States of America. 76 (3), 1274-1278 (1979).</li><li>Hinds, S., Bian, W., Dennis, R. G., Bursac, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+extracellular+matrix+composition+in+structure+and+function+of+bioengineered+skeletal+muscle.">The role of extracellular matrix composition in structure and function of bioengineered skeletal muscle.</a> Biomaterials. 32 (14), 3575-3583 (2011).</li></ol>

This manuscript describes methods to fabricate and analyze a 3D hMMT culture model that can be applied to studies of basic muscle biology, disease modeling, or for candidate molecule testing. The MyoTACTIC platform is cost-friendly, easy to manufacture, and requires a relatively small number of cells to produce skeletal muscle microtissues. hMMTs formed within the MyoTACTIC culture platform are comprised of aligned, multinucleated, and striated myotubes, and respond to electrical stimuli by initiating calcium transients ...

Skeletal muscle is one of the most abundant tissues in the human body and supports key body functions such as locomotion, heat homeostasis and metabolism1. Historically, animal models and two-dimensional (2D) cell culture systems have been used to study biological processes and disease pathogenesis, as well as for testing pharmacological compounds in the treatment of skeletal muscle diseases2,3. While animal models have greatly improved our knowledge of skeletal muscle in health and in disease, their translational impact has been hampered by high costs, ethical considerations and interspecies differences2,4. In turning to human cell-based systems to study skeletal muscle, 2D cell culture systems are favorable due to their simplicity. However, there is a limitation. This format often fails to recapitulate the cell-cell and cell-extracellular matrix interactions that occur naturally within the body5,6. Over the last several years, three dimensional (3D) skeletal muscle models have emerged as a powerful alternative to whole animal models and conventional 2D culture systems by allowing the modeling of physiologically and pathologically relevant processes ex vivo7,8. Indeed, a plethora of studies have reported strategies to model human skeletal muscle in a bioartificial 3D culture format1. One limitation for many of these studies is that active force is quantified following the removal of the muscle tissues from the culture platforms and attachment to a force transducer, which is destructive and hence, limited to serving as an endpoint assay9,10,11,12,13,14,15,16,17,18,19,20,21. Others have designed culture systems that allow for non-invasive methods of measuring active force, but not all are amenable to high content molecule testing applications7,8,9,10,14,18,22,23,24,25,26,27,28,29.
This protocol describes a detailed method to fabricate human muscle microtissues (hMMTs) in the skeletal muscle (Myo) microTissue Array deviCe To Investigate forCe (MyoTACTIC) platform; a 96 well plate device that supports the bulk production of 3D skeletal muscle microtissues30. The MyoTACTIC plate fabrication method enables generation of a 96 well polydimethylsiloxane (PDMS) culture plate and all corresponding well features in a single casting step, whereby each well requires a relatively small number of cells for microtissue formation. Microtissues formed within MyoTACTIC contain aligned, striated, and multinucleated myotubes that are reproducible from well to well of the device, and upon maturation, can respond to chemical and electrical stimuli in situ30. Herein, the technique to manufacture a PDMS MyoTACTIC culture plate device from a polyurethane (PU) replica, an optimized method to implement immortalized human myogenic progenitor cells to fabricate hMMTs, and the functional assessment of engineered hMMT force generation and calcium handling properties are outlined and discussed.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
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		<tr>
			<td>0.9% Saline Solution, Sterile</td>
			<td>House Brand</td>
			<td>1010</td>
			<td>10 mL aliquots of the solution are made and stored at 4&#176;C</td>
		</tr>
		<tr>
			<td>25G Needle</td>
			<td>BD, Medstore, University of Toronto</td>
			<td>2548-CABD305127</td>
			<td></td>
		</tr>
		<tr>
			<td>6-Aminocaproic Acid, &#8805;99% (titration), Powder</td>
			<td>Sigma - Aldrich</td>
			<td>A2504-100G</td>
			<td>A 50 mg / mL stock solution is generated by dissolving 5 mg of 6-aminocaproic acid powder in 100 mL of autoclaved, distilled water. The solution is vaccum filtered and 10 mL aliquots are stored at 4&#176;C</td>
		</tr>
		<tr>
			<td>6.35 mm ID Tubing</td>
			<td>VWR</td>
			<td>60985-528</td>
			<td></td>
		</tr>
		<tr>
			<td>AB1167 Myoblast Cell Line</td>
			<td>Institut de Myologie (Paris, France)</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Arbitrary Waveform Generator</td>
			<td>Rigol</td>
			<td>DG1022Z</td>
			<td></td>
		</tr>
		<tr>
			<td>Basement Membrane Extract (Geltrex)</td>
			<td>Thermo Fisher Scientific</td>
			<td>A14132-02</td>
			<td>Stored as aliquots of 50 &#181;L or 100 &#181;L at -80&#176;C</td>
		</tr>
		<tr>
			<td>Benchtop Vacuum Chamber</td>
			<td>Sigma - Aldrich</td>
			<td>D2672</td>
			<td></td>
		</tr>
		<tr>
			<td>BNC to Aligator Clip Cable</td>
			<td></td>
			<td></td>
			<td>Ordered from Amazon</td>
		</tr>
		<tr>
			<td>Culture Plastics</td>
			<td>Sarstedt</td>
			<td></td>
			<td>Includes culture plates, serological pipettes, etc</td>
		</tr>
		<tr>
			<td>Dimethyl Sulfoxide</td>
			<td>Sigma - Aldrich</td>
			<td>D8418-250ML</td>
			<td></td>
		</tr>
		<tr>
			<td>DPBS, Powder, No Calcium, No Magnesium</td>
			<td>Thermo Fisher Scientific</td>
			<td>21600069</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s Modified Eagle Medium (DMEM) (1X)</td>
			<td>Gibco</td>
			<td>11995-065</td>
			<td>This is a high glucose DMEM with L-glutamine and sodium pyruvate</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Fisher Scientific</td>
			<td>10437028</td>
			<td></td>
		</tr>
		<tr>
			<td>Fibrinogen from Bovine Plasma</td>
			<td>Sigma - Aldrich</td>
			<td>F8630-5G</td>
			<td>Aliquots ranging from 7 - 10 mg of fibrinogen powder are made and stored at -20&#176;C</td>
		</tr>
		<tr>
			<td>Filtropur Syringe Filter, 0.22um Pore Size</td>
			<td>Sarstedt</td>
			<td>83.1826.001</td>
			<td></td>
		</tr>
		<tr>
			<td>Horse Serum</td>
			<td>Gibco</td>
			<td>16050-122</td>
			<td></td>
		</tr>
		<tr>
			<td>Human Recombinant Insulin</td>
			<td>Sigma - Aldrich</td>
			<td>91077C</td>
			<td>Stock solution is 100X and made by dissolving 1 mg of human recombinant insulin in 1 mL of DMEM and 1 &#181;L of NaOH 10N. Solution is filtered and stored as 1 mL aliquots at 4&#176;C</td>
		</tr>
		<tr>
			<td>Image Acquisition Software</td>
			<td>Olympus</td>
			<td>cellSens Dimension</td>
			<td></td>
		</tr>
		<tr>
			<td>Image Processing Software</td>
			<td>National Institutes of Health</td>
			<td>ImageJ</td>
			<td></td>
		</tr>
		<tr>
			<td>Isotemp Oven</td>
			<td>Thermo Fisher Scientific</td>
			<td>201</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Olympus</td>
			<td>IX83</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope - Camera Mount</td>
			<td>Labcam</td>
			<td>Labcam for iPhone</td>
			<td>Ordered from Amazon</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin (10,000 U/mL)</td>
			<td>Gibco</td>
			<td>15140-122</td>
			<td></td>
		</tr>
		<tr>
			<td>Plastic Disposable Syringes, 1cc</td>
			<td>BD</td>
			<td>2606-309659</td>
			<td></td>
		</tr>
		<tr>
			<td>Plastic Disposable Syringes, 50cc</td>
			<td>BD</td>
			<td>2612-309653</td>
			<td></td>
		</tr>
		<tr>
			<td>Pluronic F-127, Powder, BioReagent</td>
			<td>Sigma - Aldrich</td>
			<td>P2443-250G</td>
			<td>A 5% stock solution of pluronic acid is made by dissolving 5 g of pluronic acid powder in 100 mL of chilled, autoclaved, distilled water. The solution is vaccum filtered and 10 mL aliquots are stored at 4&#176;C</td>
		</tr>
		<tr>
			<td>Polydimethylsiloxane (Sylgard 184 Silicone Elastomer Kit)</td>
			<td>Dow</td>
			<td>4019862</td>
			<td>Kits are also available at Thermo Fisher Scientific, Sigma - Aldrich, etc.</td>
		</tr>
		<tr>
			<td>Polyurethane Negative Mold</td>
			<td>In House</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Release Agent</td>
			<td>Mann Release Technologies</td>
			<td>200</td>
			<td></td>
		</tr>
		<tr>
			<td>Rotary Vane Vacuum Pump</td>
			<td>Edwards</td>
			<td>A65401906</td>
			<td></td>
		</tr>
		<tr>
			<td>Scalpel</td>
			<td>Almedic, Medstore, University of Toronto</td>
			<td>2586-M36-0100</td>
			<td></td>
		</tr>
		<tr>
			<td>Single Edge Razor Blade</td>
			<td>VWR</td>
			<td>55411-050</td>
			<td></td>
		</tr>
		<tr>
			<td>Skeletal Muscle Cell Basal Medium</td>
			<td>Promocell</td>
			<td>C-23260</td>
			<td>30 mL aliquotes are generated and at stored at 4&#176;C.</td>
		</tr>
		<tr>
			<td>Skeletal Muscle Cell Growth Medium (Ready-to-use)</td>
			<td>Promocell</td>
			<td>C-23060</td>
			<td>42 mL aliquots are generated and stored at 4&#176;C.</td>
		</tr>
		<tr>
			<td>Smartphone (iPhone)</td>
			<td>Apple</td>
			<td>SE</td>
			<td></td>
		</tr>
		<tr>
			<td>Standard Duty Dry Vacuum Pump</td>
			<td>Welch</td>
			<td>2546B-01</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterilization Bag</td>
			<td>Alliance</td>
			<td>211-SCM2</td>
			<td></td>
		</tr>
		<tr>
			<td>Thimble</td>
			<td>Igege</td>
			<td></td>
			<td>Ordered from Amazon</td>
		</tr>
		<tr>
			<td>Thrombin from human plasma</td>
			<td>Sigma - Aldrich</td>
			<td>T6884-250UN</td>
			<td>100 units of thrombin is dissolved in 1 mL of a 0.1% BSA solution. 10 &#181;L aliquots are prepared and stored at - 20&#176;C.</td>
		</tr>
		<tr>
			<td>Tin coated copper wire</td>
			<td>Arco</td>
			<td>B8871K48</td>
			<td>Ordered from Amazon</td>
		</tr>
		<tr>
			<td>Trypan Blue Solution, 0.4%</td>
			<td>Thermo Scientific</td>
			<td>15250061</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypsin-EDTA, 0.25%</td>
			<td>Thermo FIsher Scientific</td>
			<td>25200072</td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum Chamber 2</td>
			<td>SP Bel-Art</td>
			<td>F42027-0000</td>
			<td></td>
		</tr>
	</tbody>
</table>

assessing functional metrics of skeletal muscle health in human skeletal muscle microtissues

Three-dimensional (3D) in vitro models of skeletal muscle are a valuable advancement in biomedical research as they afford the opportunity to study skeletal muscle reformation and function in a scalable format that is amenable to experimental manipulations. 3D muscle culture systems are desirable as they enable scientists to study skeletal muscle ex vivo in the context of human cells. 3D in vitro&#160;models closely mimic aspects of the native tissue structure of adult skeletal muscle. However, their universal application is limited by the availability of platforms that are simple to fabricate, cost and user-friendly, and yield relatively high quantities of human skeletal muscle tissues. Additionally, since skeletal muscle plays an important functional role that is impaired over time in many disease states, an experimental platform for microtissue studies is most practical when minimally invasive calcium transient and contractile force measurements can be conducted directly within the platform itself. In this protocol, the fabrication of a 96-well platform known as &#39;MyoTACTIC&#39;, and en masse production of 3D human skeletal muscle microtissues (hMMTs) is described. In addition, the methods for a minimally invasive application of electrical stimulation that enables repeated measurements of skeletal muscle force and calcium handling of each microtissue over time are reported.

Described herein are methods to cast a 96-well PDMS-based MyoTACTIC culture platform from a PU mold, to fabricate arrays of hMMT replica tissues, and to analyze two aspects of hMMT function within the culture device-force generation and calcium handling. Figure 1 offers a schematic overview of the preparation of MyoTACTIC culture wells before hMMT seeding. PDMS is a widely used silicone-based polymer, that can be easily molded to create complex devices32. A PDMS-based...

Watch this Scientific Journal Video about Assessing Functional Metrics of Skeletal Muscle Health in Human Skeletal Muscle Microtissues at JoVE.com

Assessing Functional Metrics of Skeletal Muscle Health in Human Skeletal Muscle Microtissues

This manuscript describes a detailed protocol to produce arrays of 3D human skeletal muscle microtissues and minimally invasive downstream in situ assays of function, including contractile force and calcium handling analyses.

Three-dimensional (3D) in vitro models of skeletal muscle are a valuable advancement in biomedical research as they afford the opportunity to study ...

Research

JoVE Journal

Bioengineering

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Transplantation of Induced Pluripotent Stem Cell-derived Mesoangioblast-like Myogenic Progenitors in Mouse Models of Muscle Regeneration

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Cardiac Muscle-cell Based Actuator and Self-stabilizing Biorobot - PART 1

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Cardiac Muscle Cell-based Actuator and Self-stabilizing Biorobot - Part 2

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Semiautomated Longitudinal Microcomputed Tomography-based Quantitative Structural Analysis of a Nude Rat Osteoporosis-related Vertebral Fracture Model

Osteoporosis-related vertebral compression fractures (OVCFs) are a common and clinically unmet need with increasing prevalence as the world population ...

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