This work was funded by the National Institutes of Health (OD/NICHD DP2HD083961 and NHBLI R01HL148104). Leo Q. Wan is a Pew Scholar in Biomedical Sciences (PEW 00026185), supported by the Pew Charitable Trusts. Haokang Zhang is supported by American Heart Association Predoctoral Fellowship (20PRE35210243).

1. Fabrication of polydimethylsiloxane (PDMS) stamps16
<ol>
	<li>Draw an array of microscale rings using CAD software, with an inner diameter of 250 &#181;m and an outer diameter of 450 &#181;m. The pattern used in this protocol is a 10 x 10 array with an 850 &#181;m distance between rings.</li>
	<li>Print a transparency mask of the pattern at the desired resolution using a microfabrication company&#39;s mask printing service (see Table of Materials). 
	NOTE: The provided d...

<ol>
	<li>Wan, L. Q., Chin, A. S., Worley, K. E., Ray, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+chirality:+emergence+of+asymmetry+from+cell+culture.">Cell chirality: emergence of asymmetry from cell culture.</a> Philosophical Transactions of the Royal Society B: Biological Sciences. 371, 20150413 (2016).</li><li>Rahman, T., Zhang, H., Fan, J., Wan, L. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+chirality+in+cardiovascular+development+and+disease.">Cell chirality in cardiovascular development and disease.</a> APL Bioengineering. 4 (3), (2020).</li><li>Inaki, M., Liu, J., Matsuno, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+chirality:+Its+origin+and+roles+in+left-right+asymmetric+development.">Cell chirality: Its origin and roles in left-right asymmetric development.</a> Philosophical Transactions of the Royal Society B: Biological Sciences. 371 (1710), 20150413 (2016).</li><li>Utsunomiya, 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=Cells+with+broken+left-right+symmetry:+Roles+of+intrinsic+cell+chirality+in+left-right+asymmetric+epithelial+morphogenesis.">Cells with broken left-right symmetry: Roles of intrinsic cell chirality in left-right asymmetric epithelial morphogenesis.</a> Symmetry. 11 (4), 505 (2019).</li><li>Tamada, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chiral+neuronal+motility:+The+missing+link+between+molecular+chirality+and+brain+asymmetry.">Chiral neuronal motility: The missing link between molecular chirality and brain asymmetry.</a> Symmetry. 11 (1), 102 (2019).</li><li>Tee, Y. 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=Cellular+chirality+arising+from+the+self-organization+of+the+actin+cytoskeleton.">Cellular chirality arising from the self-organization of the actin cytoskeleton.</a> Nature Cell Biology. 17 (4), 445-457 (2015).</li><li>Wan, L. Q., 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=Micropatterned+mammalian+cells+exhibit+phenotype-specific+left-right+asymmetry.">Micropatterned mammalian cells exhibit phenotype-specific left-right asymmetry.</a> Proceedings of the National Academy of Sciences of the United States of America. 108 (30), 12295-12300 (2011).</li><li>Fan, 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=Cell+chirality+regulates+intercellular+junctions+and+endothelial+permeability.">Cell chirality regulates intercellular junctions and endothelial permeability.</a> Science Advances. 4 (10), 2111 (2018).</li><li>Singh, A. V., 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=Carbon+nanotube-induced+loss+of+multicellular+chirality+on+micropatterned+substrate+is+mediated+by+oxidative+stress.">Carbon nanotube-induced loss of multicellular chirality on micropatterned substrate is mediated by oxidative stress.</a> ACS Nano. 8 (3), 2196-2205 (2014).</li><li>Zhang, H., Fan, J., Zhao, Z., Wang, C., Wan, L. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effects+of+Alzheimer's+disease-related+proteins+on+the+chirality+of+brain+endothelial+cells.">Effects of Alzheimer's disease-related proteins on the chirality of brain endothelial cells.</a> Cellular and Molecular Bioengineering. 14, 231-240 (2021).</li><li>Chen, T. 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=Left-right+symmetry+breaking+in+tissue+morphogenesis+via+cytoskeletal+mechanics.">Left-right symmetry breaking in tissue morphogenesis via cytoskeletal mechanics.</a> Circulation Research. 110 (4), 551-559 (2012).</li><li>Ray, P., 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=Intrinsic+cellular+chirality+regulates+left-right+symmetry+breaking+during+cardiac+looping.">Intrinsic cellular chirality regulates left-right symmetry breaking during cardiac looping.</a> Proceedings of the National Academy of Sciences of the United States of America. 115 (50), 11568-11577 (2018).</li><li>Fan, J., Zhang, H., Rahman, T., Stanton, D. N., Wan, L. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+organelle-based+analysis+of+cell+chirality.">Cell organelle-based analysis of cell chirality.</a> Communicative and Integrative Biology. 12 (1), 78-81 (2019).</li><li>Chen, C. S., Mrksich, M., Huang, S., Whitesides, G. M., Ingber, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Geometric+control+of+cell+life+and+death.">Geometric control of cell life and death.</a> Science. 276 (5317), 1425-1428 (1997).</li><li>Liu, 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=Nanowire+magnetoscope+reveals+a+cellular+torque+with+left-right+bias.">Nanowire magnetoscope reveals a cellular torque with left-right bias.</a> ACS Nano. 10 (8), 7409-7417 (2016).</li><li>Wan, L. Q., 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=Geometric+control+of+human+stem+cell+morphology+and+differentiation.">Geometric control of human stem cell morphology and differentiation.</a> Integrative Biology. 2 (7-8), 346-353 (2010).</li><li>Circular Statistics Toolbox. MathWorks Available from: <a target="_blank" href="https://www.mathworks.com/matlabcentral/fileexchange/10676-circular-statistics-toolbox-directional-statistics">https://www.mathworks.com/matlabcentral/fileexchange/10676-circular-statistics-toolbox-directional-statistics</a> (2021)</li><li>Chin, A. S., Worley, K. E., Ray, P., Kaur, G., Fan, J., Wan, L. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epithelial+cell+chirality+revealed+by+three-dimensional+spontaneous+rotation.">Epithelial cell chirality revealed by three-dimensional spontaneous rotation.</a> Proceedings of the National Academy of Sciences of the United States of America. 115 (48), 12188-12193 (2018).</li><li>Worley, K. E., Chin, A. S., Wan, L. Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lineage-specific+chiral+biases+of+human+embryonic+stem+cells+during+differentiation.">Lineage-specific chiral biases of human embryonic stem cells during differentiation.</a> Stem Cells International. 2018, 1848605 (2018).</li></ol>

The authors have nothing to disclose.

The ring-shaped patterning assay described here provides an easy-to-use tool for quantitative characterization of multicellular chirality, capable of producing highly reliable and repeatable results. Rapid generation of identical defined microenvironments and unbiased analysis enables automated high-throughput processing of large size of samples. This protocol discusses the fabrication of the ring micropatterns, cell patterning, and automatic analysis of the biased cell alignment and directional motion. This method is co...

Left-right (LR) asymmetry of the cell, also known as cellular handedness or chirality, describes the cell polarity in the LR axis and is recognized to be a fundamental, conserved, biophysical property1,2,3,4,5. Cell chirality has been observed both in vivo and in vitro at multiple scales. Previous findings revealed chiral swirling of actin cytoskeleton in single cells seeded on circular islands6, biased migration and alignment of cells within confined boundaries7,8,9,10,11, and asymmetrical looping of chicken heat tube12.
At the multicellular level, cell chirality can be determined from directional migration or alignment, cellular rotation, cytoskeletal dynamics, and cell organelle positioning7,8,9,10,11,12,13. We have established a micropatterning-based14 assay to efficiently characterize the chiral bias of adherent cells7,8,9,10. With the ring-shaped micropatterns geometrically confining cell clusters, the cells collectively exhibit directional migration and biased alignment. A MATLAB program was developed to automatically detect and measure cell alignment in phase-contrast images of the ring. The direction of local cell alignment is quantified with a biased angle, depending on its deviation from the circumferential direction. Following statistical analysis, the ring pattern of cells is designated either as counterclockwise (CCW) biases or clockwise (CW) biases.
This assay has been used to characterize the chirality of multiple cell phenotypes (Table 1), and the LR asymmetry of cells has been found to be phenotype-specific7,11,15. Moreover, disruption to actin dynamics and morphology can result in a reversal of chiral bias7,8, and oxidative stress can alter cell chirality as well9. Because of the simplicity of the procedure and the robustness of the approach7,8,9,10, this 2D chirality assay provides an efficient and reliable tool for determining and studying multicellular chirality in vitro.
The purpose of this protocol is to demonstrate the use of this method to characterize cell chirality. This protocol describes how to fabricate patterned cellular arrays via microcontact printing technique and conduct chirality analysis in an automated fashion using the MATLAB program.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>200 proof ethanol</td>
			<td>Koptec</td>
			<td>DSP-MD-43</td>
			<td></td>
		</tr>
		<tr>
			<td>BZX microscope system</td>
			<td>Keyence</td>
			<td>BZX-600</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#39;s modified eagle medium (DMEM), high glucose</td>
			<td>Gibco</td>
			<td>11965092</td>
			<td></td>
		</tr>
		<tr>
			<td>Electron beam evaporator</td>
			<td>Temscal</td>
			<td>BJD-1800</td>
			<td>Gold-titanum film coating</td>
		</tr>
		<tr>
			<td>Fetal bovine serum</td>
			<td>VWR</td>
			<td>89510-186</td>
			<td></td>
		</tr>
		<tr>
			<td>Fibronectin from bovine plasma</td>
			<td>Sigma</td>
			<td>F1141-5MG</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass microscope slides</td>
			<td>VWR</td>
			<td>10024-048</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass tweezers</td>
			<td>Exelta</td>
			<td>390BSAPI</td>
			<td></td>
		</tr>
		<tr>
			<td>Gold evaporation pellets</td>
			<td>International Advanced Materials</td>
			<td>AU18</td>
			<td></td>
		</tr>
		<tr>
			<td>HS-(CH2)11-EG3-OH (EG3)</td>
			<td>Prochimia</td>
			<td>TH 001-m11.n3-0.2</td>
			<td></td>
		</tr>
		<tr>
			<td>MATLAB</td>
			<td>Mathworks</td>
			<td>MATLAB_R2020b</td>
			<td></td>
		</tr>
		<tr>
			<td>NIH/3T3 cells</td>
			<td>ATCC</td>
			<td>CRL-1658</td>
			<td></td>
		</tr>
		<tr>
			<td>OAI contact aligner</td>
			<td>OAI</td>
			<td>200</td>
			<td>UV photolithography</td>
		</tr>
		<tr>
			<td>Octadecanethiol (C18)</td>
			<td>Sigma</td>
			<td>O1858-25ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Orbital shaker</td>
			<td>VWR</td>
			<td>89032-088</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate buffered saline (PBS)</td>
			<td>Research product international</td>
			<td>P32080-100T</td>
			<td></td>
		</tr>
		<tr>
			<td>Polydimethylsiloxane Sylgard 184</td>
			<td>Dow Corning</td>
			<td>DC4019862</td>
			<td></td>
		</tr>
		<tr>
			<td>Silicon Wafer</td>
			<td>University Wafer</td>
			<td>ID#809</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium pyruvate</td>
			<td>Thermo fisher scientific</td>
			<td>11360-070</td>
			<td></td>
		</tr>
		<tr>
			<td>SU-8 3050 photoresist</td>
			<td>MicroChem</td>
			<td>Y311075 0500L1GL</td>
			<td></td>
		</tr>
		<tr>
			<td>Titanium evaporation pellets</td>
			<td>International Advanced Materials</td>
			<td>TI14</td>
			<td></td>
		</tr>
		<tr>
			<td>Transparency mask (with feature)</td>
			<td>Outputicity.com</td>
			<td>N/A</td>
			<td>Mask printing service</td>
		</tr>
		<tr>
			<td>Trypsin-EDTA (0.25%)</td>
			<td>Thermo fisher scientific</td>
			<td>25200-072</td>
			<td></td>
		</tr>
	</tbody>
</table>

a micropatterning assay for measuring cell chirality

Chirality is an intrinsic cellular property, which depicts the asymmetry in terms of polarization along the left-right axis of the cell. As this unique property attracts increasing attention due to its important roles in both development and disease, a standardized quantification method for characterizing cell chirality would advance research and potential applications. In this protocol, we describe a multicellular chirality characterization assay that utilizes micropatterned arrays of cells. Cellular micropatterns are fabricated on titanium/gold-coated glass slides via microcontact printing. After seeding on the geometrically defined (e.g., ring-shaped), protein-coated islands, cells directionally migrate and form a biased alignment toward either the clockwise or the counterclockwise direction, which can be automatically analyzed and quantified by a custom-written MATLAB program. Here we describe in detail the fabrication of micropatterned substrates, cell seeding, image collection, and data analysis and show representative results obtained using the NIH/3T3 cells. This protocol has previously been validated in multiple published studies and is an efficient and reliable tool for studying cell chirality in vitro.

Fifteen minutes after the seeding of NIH/3T3 cells, cell adhesion on the ring pattern was visually confirmed by phase-contrast imaging. After subsequent culture of 24 h, cells on the patterns became confluent and elongated with clearly asymmetrical alignments, biased towards the clockwise direction (Figure 2). Directional migration of attached cells is recorded by time-lapse imaging, cell motility and morphogenesis can be quantified with further analyses of the video. To conduct chirality an...

Watch this Scientific Journal Video about A Micropatterning Assay for Measuring Cell Chirality at JoVE.com

A Micropatterning Assay for Measuring Cell Chirality

We present a protocol for determining multicellular chirality in vitro, using the micropatterning technique. This assay allows for automatic quantification of the left-right biases of various types of cells and can be used for screening purposes.

Chirality is an intrinsic cellular property, which depicts the asymmetry in terms of polarization along the left-right axis of the cell. As this unique ...

The micropatterning bast cell chirality assay is a powerful tool for studying multicellular chiral morphogenesis in development of disease. It is also important for cell research. This macropattern system is easy to fabricate and use, is capable of producing highly reliable and repeatable results, and it's also compatible with automated high-throughput processing for large sample size.Start by cutting the titanium gold-coated slide into small square pieces of approximately 12 by 12 millimeters. Using a glass cutter, slide across the surface to leave a dented track, then hold the glass slide at both sides and bend at the dent to break into small quarters. To clean the slide, soak it with the gold side up in 100%ethanol contained in a Petri dish on an orbital shaker for at least 10 minutes.After aspirating the ethanol, dry the slide by blowing with a nitrogen stream. Clean the polydimethylsiloxane or PDMS stamps with soapy water before drying the stamp with nitrogen gas. Dissolve 5.74 milligrams of octadecanethiol or C18 in 10 milliliters of 100%ethanol to make two millimolar C18 solution, then clean the PDMS stamps with 100%ethanol.Soak the PDMS stamp with the pattern surface facing down in C18 solution for 10 seconds and then gently dry it with nitrogen gas for 60 seconds. Once dried, lay the stamp facing down onto the gold slide for 60 seconds before removal. To ensure proper stamping, gently tap the tweezers onto the stamp to properly transfer the patterns.Next, prepare the humidity chambers by pipetting one milliliter of 70%ethanol into an inverted Petri dish lid. And using the tweezers, lay down a piece of parafilm to cover the surface ensuring no bubbles remain. Remove the excess ethanol if required.Add 40 microliter droplets of EG3 solution for each quarter glass slide onto the parafilm in the humidity chamber, leaving enough space between droplets to account for the spacing of the gold slides. Use tweezers to place the C18 printed gold slide facing down onto the droplet, ensuring no bubbles remain under the slide. Gently push the slides together without lifting them to minimize evaporation.After sealing the Petri dish tightly with parafilm, leave it at room temperature for at least three hours. In a biosafety cabinet, soak and rinse the gold slide facing up three times in 70%ethanol to remove EG3, then leave in ethanol for 10 minutes for sterilization. After aspirating the ethanol, add sterile PBS.Prepare another humidity chamber with PBS instead of ethanol as demonstrated. Next, add 50 microliter droplets of fibronectin solution for each quarter slide onto the parafilm, leaving some space between droplets. Then place the slide facing down onto the droplet as demonstrated previously and leave the Petri dish in the biosafety cabinet for 30 minutes.After rinsing the gold-coated slide thrice, place the slide facing up in PBS. Before seeding the cells, warm the media and trypsin in a water bath tempered at 37 degrees Celsius. For better cell attachment, soak the pattern slide in a 12-well plate containing culture media and warm it at 37 degrees Celsius in the incubator.Once the cells are trypsinized, neutralize the cells with FBS containing media, pellet down the cells at 100 times G for three minutes and then resuspend the cell pellet in fresh media. Count the cells and dilute the cell suspension to achieve the concentration of 200, 000 cells per milliliter. Add 0.5 milliliters of the cell suspension to each well containing one gold slide.Gently shake the plate a few times for uniform cell seeding before incubating for 15 minutes for cell attachment. After 15 minutes, check the cell attachment under a microscope, and if required, incubate for some more time. Once the cells are attached, aspirate out the media containing unattached cells from each well and add one milliliter of fresh culture media.Culture the cells in the incubator for 24 hours and check confluency to determine if chirality has formed. When the required confluency is achieved, fix the cells by removing the culture media. After rinsing with PBS once, add 4%paraformaldehyde solution to the slide and incubate room temperature for 15 minutes before rinsing again with PBS three times.To acquire the images, use a phase contrast microscope with camera functionality and capture each ring on the slide at high resolution. For chirality characterization, download the MATLAB code files, add the code folder and subfolders to the MATLAB path and open the ROI_selection. m file.In line four, change the directory to the desired data folder. Change the image size in line 14 with the first two figures representing the inner circle size of the ring while the other two representing the outer. To determine the region of interest or ROI in the phase contrast images, execute the MATLAB code ROI_selection.m by clicking the run button. Manually drag the selection square to fit the ring, then double click on the image to confirm the selection. After selecting ROI from all the images in the folder, a mat file will be generated to store the ROI information for each image.Then open the analysis_batch. m file and change the directory of the folder as demonstrated before. Click on the run button to execute the code analysis_batch.m to determine the chirality of multiple cellular ring patterns. A datatoexcel. txt file will be generated containing circular statistics for each ring, as well as the numbers of clockwise non-chiral and anti-clockwise rings.The current findings demonstrate the utility of the developed ring pattern chirality assay experimentally as well as the sensitivity of this assay to alterations in the cytoskeleton. In the present study, it was found that by disrupting the actin polymerization with 50 nanomolar latrunculin A treatment, the mouse myoblast C2C12 cells exhibited an alteration of counterclockwise or CCW chiral bias into clockwise or CW.In addition, the human umbilical vascular endothelial cells or hUVECs that were treated with 12-o-tetradecanoyl-phorbol-13-acetate or TPA to activate the protein kinase C displayed a dose-dependent shift of cell chirality from CW to CCW. After cell seeding to the patterns, chemicals or drugs can be supplemented to the medium to study response, and the transwell system can be incorporated to study cell co-culture.This assay provides an efficient tool for investigating multicellular chirality under different experimental settings offers important insights into the role of cell chirality in various biological phenomena and processes.

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2.2K vistas.  Rensselaer Polytechnic Institute. El ensayo de quiralidad de células bast de micropatrones es una herramienta poderosa para estudiar la morfogénesis quiral multicelular en el desarrollo de la enfermedad. También es importante para la investigación celular. Este sistema de macropatrones es fácil de fabricar y usar, es capaz de producir resultados altamente confiables y repetibles, y también es compatible con el procesamiento automatizado de alto rendimiento para un gran tamaño de muestra.Comience cortando la corr...