We would like to acknowledge the technical support from the Confocal and Specialized Microscopy Shared Resource of Herbert Irving Comprehensive Cancer Center at Columbia University, funded in part through NIH Center Grant (P30CA013696). This work is supported by NIH (R21NS133635, Y.-H.L.; UH3TR002151, K. W. L.). Figure 1A was created using BioRender.

Figure 1 presents an overview of the steps involved in this protocol. Detailed information regarding the reagents and materials utilized in this protocol is given in the Table of Materials. It is recommended that all the media should be prewarmed at 37 &#176;C before use unless specified otherwise. All the cell culture materials and supplies should be either autoclaved or sterile, and cell handling should be done in a biosafety cabinet. Additionally, the pH value of the collagen I mixture should be carefully adjusted to pH 7.3 to avoid possible solidification issues.
1. Human iPSC maintenance
<ol>
	<li>Thaw the basement membrane matrix extract on ice, gently shake the bottle to mix the solution, and make 0.5 mL aliquots in 1.5 mL microcentrifuge tubes using a P1000 pipette and pre-refrigerated tips. Store the aliquots at -20 &#176;C for up to 1 year.</li>
	<li>Thaw one aliquot of matrix extract (0.5 mL) on ice. Mix with 49.5 mL of pre-cooled DMEM/F12 medium in a 50 mL tube. Distribute the mixture to each well (1.5 mL/well) in 6-well plates and then gently shake the plate to ensure that the liquid solution covers the entire well. Seal the plates with paraffin film and store them at 4 &#176;C for up to 1 week.</li>
	<li>Prepare the hiPSC expansion medium as described in Table 1. Make aliquots of the complete medium (40 mL/tube) and store at -20 &#176;C for up to 1 year.</li>
	<li>Put a pre-coated plate in the 37 &#176;C incubator for 1 h prior to hiPSC culture.</li>
	<li>Prewarm hiPSC expansion medium (40 mL) at 37 &#176;C and prepare the hiPSC seeding medium as described in Table 2.</li>
	<li>Transfer the coated plate from the 37 &#176;C incubator to the biosafety cabinet. Replace the medium in the coated plate with hiPSC seeding medium (1 mL/well).</li>
	<li>Thaw a cryopreserved vial of hiPSCs from the cryotank in a 37 &#176;C water bath for 1 min.</li>
	<li>Transfer the cells to a 15 mL tube and then add 5 mL of DMEM/F12 medium, followed by centrifugation at 100 x g for 3 min at room temperature to collect the cells.</li>
	<li>Aspirate the supernatant and resuspend the cells with 1.5 mL of hiPSC seeding medium. Gently resuspend cells in the 15 mL tube.</li>
	<li>Aliquot 10 &#181;L of the cell suspension and mix with 10 &#181;L of trypan blue solution. Transfer 10 &#181;L mixture to the hemacytometer slide and cover it with a coverslip.</li>
	<li>Mount the slide on the holder and insert it into the automated cell counter. Wait for the instrument to find the focus or manually adjust the focus by pressing the focus +/- button on the screen. Afterward, use the default setting and press the Capture button. Use the LIVE cell density reading as the concentration of the hiPSC suspension prepared from step 1.9.</li>
	<li>Seed 2 &#215; 105 cells in each well and ensure that the cells are evenly distributed in the well.</li>
	<li>Culture the cells at 37 &#176;C with 5% CO2 and replace the medium with hiPSC expansion medium (1.5 mL/well) after 24 h.</li>
	<li>Change the medium daily until the cells reach a confluency of 80%. Check the cell morphology and colony size routinely to ensure no spontaneous differentiation. Discard the culture and restart with a new batch of hiPSCs if extensive (&#62;5%) spontaneous differentiation is observed.</li>
</ol>
2. EB formation (Day 0)
<ol>
	<li>On Day 0, prepare and prewarm the DMEM/F12 medium, hiPSC seeding medium&#160;and cell detachment solution at 37 &#176;C for 20-30 min.</li>
	<li>Remove the culture medium from the 6-well plate and add prewarmed cell detachment solution (1.5 mL/well). Incubate the plate at 37 &#176;C for 5-7 min.</li>
	<li>Transfer the plate to the biosafety cabinet, tap the plate to detach hiPSC colonies, and break up the aggregates.</li>
	<li>Transfer the cell suspension into a 15 mL tube. Add 4.5 mL of DMEM/F12 medium. Gently pipet the mixture up and down using a 10 mL serological pipet five times to dissociate cells into a single-cell suspension. Avoid generating bubbles.</li>
	<li>Centrifuge at 100 x g for 3 min at room temperature to collect the cells.</li>
	<li>Aspirate the supernatant and gently resuspend the cells with 1 mL of hiPSC seeding medium using a P1000 pipette.</li>
	<li>Mix 10 &#181;L of cell suspension with 10 &#181;L of trypan blue solution for cell counting. Transfer 10 &#181;L of the mixture to the hemacytometer slide and cover it with a coverslip. Mount the slide on the holder and insert it into the automated cell counter. After the instrument finds the focus, press the Capture button and use the LIVE cell density reading to determine the concentration of the hiPSC suspension.</li>
	<li>Seed the cells in the ultra low-attachment round bottom microwell plate with a density of 2.7 &#215; 105 cells/well to yield 500-1,000 cells per EB.</li>
	<li>Add 2 mL of hiPSC seeding medium to each well and mix the solution gently to distribute cells evenly.</li>
	<li>Culture the cells at 37 &#176;C with 5% CO2 for 24 h.</li>
</ol>
3. Vascular differentiation (Day 1 - 5)
<ol>
	<li>On Day 1, prepare the mesoderm induction medium (MIM) as described in Table 3 and Table 4 and prewarm it at 37 &#176;C for 20 min. The MIM medium must be made freshly.</li>
	<li>Use a P200 pipette to carefully aspirate the medium from the microwell plate without disturbing the EBs at the bottom.</li>
	<li>Add 2.5 mL of MIM slowly using a P200 pipette. Culture the EBs in MIM at 37 &#176;C with 5% CO2 for 2 days.</li>
	<li>On Day 3, gently replace the medium with prewarmed, freshly made 2.5 mL of the vascular differentiation medium 1 (VDM1, Table 5) without disturbing the EBs at the bottom of the microwell. Culture the cells at 37 &#176;C with 5% CO2 for another 2 days.</li>
</ol>
4. Hydrogel embedding (Day 5)
<ol>
	<li>Prepare the collagen I mixture as described in Table 6. Place a 50 mL tube on ice and add collagen I solution, H2O, 10&#215; DMEM/F12 medium, sodium bicarbonate&#160;and HEPES subsequently. Mix thoroughly by shaking the tube gently. Add 1 M NaOH solution dropwise while shaking the mixed solution to adjust the pH value to 7.3 and check the pH value of the mixture with a pH meter. 
	NOTE: All solutions should be pre-cooled on ice before use. Perform the procedure on ice in the biosafety cabinet all the time. Adding the NaOH solution is critical, and quick dispersion to make a homogenous solution is needed to avoid local curing of collagen I. The volume of NaOH may vary based on the lot number of collagen I solution used. Do not pipet vigorously for mixing, as shear stress could cause undesired pre-curing.</li>
	<li>Prepare the collagen I-basement membrane matrix mixture as described in Table 7. Add 1.25 mL of basement membrane matrix to the 5 mL collagen I mixture prepared from step 4.1. Mix the solution gently by shaking the tube.</li>
	<li>Place a 12-well plate on ice for 2 min.</li>
	<li>Add collagen I-basement membrane matrix mixture slowly to the 12-well plate (1.5 mL/well) using the wide-bore tips. Make sure the mixture is distributed evenly.</li>
	<li>Put the plate in the 37 &#176;C incubator for 2 h to solidify the first layer of hydrogel.</li>
	<li>Keep the remaining collagen I-basement membrane matrix mixture on ice for later use.</li>
	<li>Transfer ~60 cell aggregates into a 1.5 mL microcentrifuge tube and cool the tube on ice for 5 min. Carefully remove the medium with a P200 pipette tip. 
	NOTE: Start this step 1.5h after Step 4.5.</li>
	<li>Dropwise, add 1.5 mL of collagen I-basement membrane mixture to the aggregates and gently mix them using wide-bore P200 pipette tips.</li>
	<li>Transfer the plate with the first layer of hydrogel from the incubator (step 4.5) to the biosafety cabinet.</li>
	<li>Add 1.5 mL of the aggregate suspension onto the cured layer. Gently shake the plate to distribute the aggregates evenly. Avoid generating any bubbles.</li>
	<li>Incubate the plate at 37 &#176;C with 5% CO2 for another 2 h.</li>
	<li>Prepare the vascular differentiation medium 2 (VDM2; Table 8) and prewarm the medium in a 37 &#176;C water bath for 20 min prior to use.</li>
	<li>Add 2 mL of VDM2 to each well and culture the cells at 37 &#176;C with 5% CO2.</li>
	<li>Change the medium every 3 days with prewarmed, freshly-made VDM2. 
	NOTE: (Optional) Vascular organoids could be released from the gel mixture by removing the gel with a syringe needle. The vascular organoids retrieved from the gel can be maintained individually in a 96-well plate with VDM2 (200 &#181;L/well). Change the medium every 2-3 days.</li>
</ol>
5. 3D Immunofluorescent assay
<ol>
	<li>Vascular organoids should become mature roughly on Day 13. For organoids embedded in the hydrogel, aspirate the medium carefully and wash with 2 mL PBS three times (10 min each time). For organoids retrieved from the gel (after Step 4.14), collect 6-10 organoids in a 2 mL microcentrifuge tube, aspirate the media, and wash with 2 mL PBS three times (10 min each).</li>
	<li>Add 2 mL of 4% paraformaldehyde (PFA) to the sample and incubate at 4 &#176;C overnight with paraffin film sealing.</li>
	<li>Remove the PFA solution and wash the sample with 2 mL PBS four times (15 min each time).</li>
	<li>Add 2 mL of blocking buffer (Table 9) and incubate at room temperature for 2 h.</li>
	<li>Remove the blocking buffer and add 1.5 mL of primary antibodies (see Table of Materials for antibody information; antibodies should be diluted in the blocking buffer). Incubate the sample with primary antibodies at 4 &#176;C for 2 days with gentle shaking. 
	NOTE: The primary antibody (CD31, PDGFR&#946;, and ERG1) is recommended to be diluted in the blocking buffer at a ratio of 1:400 (see Table of Materials for more information).</li>
	<li>Remove the primary antibody solution and wash with 2 mL PBST for 1 h six times.</li>
	<li>Add 2 mL of secondary antibodies (see Table of Materials for the antibody information; antibodies should be diluted in PBST) to the sample. Wrap the plate with aluminum foil and incubate at 4 &#176;C for 2 days with gentle shaking. 
	NOTE: The secondary antibody is recommended to be diluted in PBST at a ratio of 1:1000 (see Table of Materials for more information). Keep the plate from the light during incubation and wash from this step afterward.</li>
	<li>Remove the secondary antibody solution and wash with 2 mL TBST six times (1 h each time). Add DAPI (1 &#181;g/mL) in the wash buffer used for the last wash step if nuclei staining is needed.</li>
	<li>For these gel-embedded organoids, cut the gel into 4 pieces and transfer them carefully to 2 mL microcentrifuge tubes with a spatula. For the retrieved organoids, remove the wash buffer.</li>
	<li>Use wipes to absorb the remaining solution without touching the gel or the organoids.</li>
	<li>Add 2 mL of water-soluble tissue-clearing reagent (Refraction Index = 1.49) to each tube. Incubate the samples with clearing reagent at room temperature in the dark until the organoids become clear (usually overnight). Do not shake the samples.</li>
	<li>Transfer the organoids with the clearing reagent carefully to the center of the glass-bottom dish using a spatula.</li>
	<li>Cover the organoids or gel piece with a 24 mm &#215; 24 mm coverslip.</li>
	<li>Push the coverslip down gently until it lays flat, and sandwich the samples with the glass bottom.</li>
	<li>Remove the redundant clearing reagent in the dish and seal the coverslip with nail polish.</li>
	<li>For 3D imaging, use a confocal microscope with a 10&#215; objective. Use tile scan and Z-stack scan to obtain whole-mount images of organoids.</li>
</ol>

hiPSC-Derived Vascular Organoids for Drug Screening and Disease Modeling

<ol>
	<li>Park, S. E., Georgescu, A., Huh, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organoids-on-a-chip.">Organoids-on-a-chip.</a> Science. 364 (6444), 960-965 (2019).</li><li>Takebe, T., Wells, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Organoids+by+design.">Organoids by design.</a> Science. 364 (6444), 956-959 (2019).</li><li>Griffith, L. G., Swartz, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Capturing+complex+3d+tissue+physiology+in+vitro.">Capturing complex 3d tissue physiology in vitro.</a> Nat Rev Mol Cell Bio. 7 (3), 211-224 (2006).</li><li>Lancaster, 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=Cerebral+organoids+model+human+brain+development+and+microcephaly.">Cerebral organoids model human brain development and microcephaly.</a> Nature. 501 (7467), 373-379 (2013).</li><li>Pasca, A. 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=Functional+cortical+neurons+and+astrocytes+from+human+pluripotent+stem+cells+in+3d+culture.">Functional cortical neurons and astrocytes from human pluripotent stem cells in 3d culture.</a> Nat Methods. 12 (7), 671-678 (2015).</li><li>Takasato, 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=Kidney+organoids+from+human+iPS+cells+contain+multiple+lineages+and+model+human+nephrogenesis.">Kidney organoids from human iPS cells contain multiple lineages and model human nephrogenesis.</a> Nature. 526 (7574), 564-568 (2015).</li><li>Koike, 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=Modelling+human+hepato-biliary-pancreatic+organogenesis+from+the+foregut-midgut+boundary.">Modelling human hepato-biliary-pancreatic organogenesis from the foregut-midgut boundary.</a> Nature. 574 (7776), 112-116 (2019).</li><li>Takebe, 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=Vascularized+and+functional+human+liver+from+an+iPSC-derived+organ+bud+transplant.">Vascularized and functional human liver from an iPSC-derived organ bud transplant.</a> Nature. 499 (7459), 481-484 (2013).</li><li>Osakada, F., 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=Toward+the+generation+of+rod+and+cone+photoreceptors+from+mouse,+monkey+and+human+embryonic+stem+cells.">Toward the generation of rod and cone photoreceptors from mouse, monkey and human embryonic stem cells.</a> Nat Biotechnol. 26 (2), 215-224 (2008).</li><li>Potente, M., Gerhardt, H., Carmeliet, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basic+and+therapeutic+aspects+of+angiogenesis.">Basic and therapeutic aspects of angiogenesis.</a> Cell. 146 (6), 873-887 (2011).</li><li>Wimmer, R. A., Leopoldi, A., Aichinger, M., Kerjaschki, D., Penninger, J. M. <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+blood+vessel+organoids+from+human+pluripotent+stem+cells.">Generation of blood vessel organoids from human pluripotent stem cells.</a> Nat Protoc. 14 (11), 3082-3100 (2019).</li><li>Wimmer, R. 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=Human+blood+vessel+organoids+as+a+model+of+diabetic+vasculopathy.">Human blood vessel organoids as a model of diabetic vasculopathy.</a> Nature. 565 (7740), 505-510 (2019).</li><li>He, 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=Mapping+morphological+malformation+to+genetic+dysfunction+in+blood+vessel+organoids+with+22q11.2+deletion+syndrome.">Mapping morphological malformation to genetic dysfunction in blood vessel organoids with 22q11.2 deletion syndrome.</a> Biorxiv. , (2021).</li><li>He, 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=Human+vascular+organoids+with+a+mosaic+akt1+mutation+recapitulate+proteus+syndrome.">Human vascular organoids with a mosaic akt1 mutation recapitulate proteus syndrome.</a> Biorxiv. , (2024).</li><li>Chen, Y., 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+versatile+polypharmacology+platform+promotes+cytoprotection+and+viability+of+human+pluripotent+and+differentiated+cells.">A versatile polypharmacology platform promotes cytoprotection and viability of human pluripotent and differentiated cells.</a> Nat Methods. 18 (5), 528-541 (2021).</li><li>Ungrin, M. D., Joshi, C., Nica, A., Bauwens, C., Zandstra, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reproducible,+ultra+high-throughput+formation+of+multicellular+organization+from+single+cell+suspension-derived+human+embryonic+stem+cell+aggregates.">Reproducible, ultra high-throughput formation of multicellular organization from single cell suspension-derived human embryonic stem cell aggregates.</a> PLoS ONE. 3 (2), e1565 (2008).</li><li>Hwang, Y. -. 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=Microwell-mediated+control+of+embryoid+body+size+regulates+embryonic+stem+cell+fate+via+differential+expression+of+wnt5a+and+wnt11.">Microwell-mediated control of embryoid body size regulates embryonic stem cell fate via differential expression of wnt5a and wnt11.</a> Proc Natl Acad Sci. 106 (40), 16978-16983 (2009).</li><li>Antonchuk, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+embryoid+bodies+from+human+pluripotent+stem+cells+using+aggrewell+plates.">Formation of embryoid bodies from human pluripotent stem cells using aggrewell plates.</a> Methods Mol Biol. 946, 523-533 (2013).</li><li>Lippmann, E. 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=Derivation+of+blood-brain+barrier+endothelial+cells+from+human+pluripotent+stem+cells.">Derivation of blood-brain barrier endothelial cells from human pluripotent stem cells.</a> Nat Biotechnol. 30 (8), 783-791 (2012).</li><li>Nishihara, 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=Differentiation+of+human+pluripotent+stem+cells+to+brain+microvascular+endothelial+cell-like+cells+suitable+to+study+immune+cell+interactions.">Differentiation of human pluripotent stem cells to brain microvascular endothelial cell-like cells suitable to study immune cell interactions.</a> Star Protoc. 2 (2), 100563 (2021).</li><li>Qian, 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=Directed+differentiation+of+human+pluripotent+stem+cells+to+blood-brain+barrier+endothelial+cells.">Directed differentiation of human pluripotent stem cells to blood-brain barrier endothelial cells.</a> Sci Adv. 3 (11), e1701679 (2017).</li><li>Stebbins, M. 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=Human+pluripotent+stem+cell-derived+brain+pericyte-like+cells+induce+blood-brain+barrier+properties.">Human pluripotent stem cell-derived brain pericyte-like cells induce blood-brain barrier properties.</a> Sci Adv. 5 (3), eaau7375 (2019).</li><li>Campisi, 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=3D+self-organized+microvascular+model+of+the+human+blood-brain+barrier+with+endothelial+cells,+pericytes+and+astrocytes.">3D self-organized microvascular model of the human blood-brain barrier with endothelial cells, pericytes and astrocytes.</a> Biomaterials. 180, 117-129 (2018).</li><li>Osaki, T., Sivathanu, V., 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=Engineered+3D+vascular+and+neuronal+networks+in+a+microfluidic+platform.">Engineered 3D vascular and neuronal networks in a microfluidic platform.</a> Sci Rep. 8 (1), 5168 (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> Sci Adv. 4 (10), eaat5847 (2018).</li><li>Sakurai, Y., 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+microengineered+vascularized+bleeding+model+that+integrates+the+principal+components+of+hemostasis.">A microengineered vascularized bleeding model that integrates the principal components of hemostasis.</a> Nat Commun. 9 (1), 509 (2018).</li><li>Kim, 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=Engineering+of+a+biomimetic+pericyte-covered+3d+microvascular+network.">Engineering of a biomimetic pericyte-covered 3d microvascular network.</a> PLoS ONE. 10 (7), e0133880 (2015).</li><li>Kosyakova, 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=Differential+functional+roles+of+fibroblasts+and+pericytes+in+the+formation+of+tissue-engineered+microvascular+networks+in+vitro.">Differential functional roles of fibroblasts and pericytes in the formation of tissue-engineered microvascular networks in vitro.</a> Biorxiv. , (2019).</li><li>Whisler, J. A., Chen, M. B., 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=Control+of+perfusable+microvascular+network+morphology+using+a+multiculture+microfluidic+system.">Control of perfusable microvascular network morphology using a multiculture microfluidic system.</a> Tissue Eng Part C Methods. 20 (7), 543-552 (2013).</li><li>Haase, K., 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=Advances+in+on-chip+vascularization.">Advances in on-chip vascularization.</a> Regen Med. 12 (3), 285-302 (2017).</li><li>Wong, K. H. K., Chan, J. M., Kamm, R. D., Tien, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic+models+of+vascular+functions.">Microfluidic models of vascular functions.</a> Annu Rev Biomed Eng. 14 (1), 205-230 (2012).</li><li>Boerckel, J. D., Uhrig, B. A., Willett, N. J., Huebsch, N., Guldberg, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+regulation+of+vascular+growth+and+tissue+regeneration+in+vivo.">Mechanical regulation of vascular growth and tissue regeneration in vivo.</a> Proc Natl Acad Sci. 108 (37), E674-E680 (2011).</li><li>Homan, K. 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=Flow-enhanced+vascularization+and+maturation+of+kidney+organoids+in+vitro.">Flow-enhanced vascularization and maturation of kidney organoids in vitro.</a> Nat Methods. 16 (3), 255 (2019).</li><li>Mansour, A. 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=An+in+vivo+model+of+functional+and+vascularized+human+brain+organoids.">An in vivo model of functional and vascularized human brain organoids.</a> Nat Biotechnol. 36 (5), 432-441 (2018).</li></ol>

The authors declare no competing financial interest.

The described protocol includes two key modifications for homogenous and reproducible generation of high-quality vascular organoids. The first modification is the use of a microwell plate to enable better control of the EB uniformity. As a starting point of vascular differentiation, the size of EBs is critical as it regulates the stem cell fate and differentiation efficacy towards different lineages. Variations in EB size usually lead to heterogeneous organoids with inconsistent structure and organization<sup class="xref...

In vitro microphysiological models, including organoid and tissue-on-a-chip systems, have emerged over the past decade1,2,3. These three-dimensional (3D), human cell-derived systems address the limitations in conventional two-dimensional (2D) cell culture and animal models, such as the lack of many components in the physiological microenvironment and genetic differences across species, respectively. They provide more physiological insights and are more suitable for disease modeling and drug screening than conventional models. Among the microphysiological models, organoids derived from human induced pluripotent stem cells (hiPSCs) have been proven to recapitulate the architectural features of native human tissues effectively and have been developed to mimic different human organs, including the brain4,5, kidney6, liver7,8&#160;and retina9. Here, we particularly focus on the generation of vascular organoids from hiPSCs and outline a streamlined protocol that aims to minimize the variations between different organoid samples and batches, thereby improving the overall reproducibility.
Vasculature plays a crucial role in maintaining physiological homeostasis across all human organs. The formation of vasculature involves the processes of vasculogenesis and angiogenesis, orchestrated through the interactions between endothelial and mural (e.g., pericytes and vascular smooth muscle cells) cells and influenced by various stimuli10. Penninger, Wimmer&#160;and colleagues developed the first vascular organoid generation method11,12 that mimics these two processes. With the organoids generated from this method, their group12 and us13,14 have demonstrated the potential of vascular organoids for modeling vascular malfunctions in diseases. For example, in our recent works13,14, distinct phenotypes were observed, such as vessel sprouting and mural cell composition variations, between disease-mimicking vascular organoids and their wild-type counterparts. These examples highlight that the vascular&#160;organoid model could serve as a platform for drug screening by mimicking disease-related vascular malfunctions.
Built upon the initial vascular organoid generation works11,12, a revised protocol is presented that includes the use of microwell to facilitate homogenous embryoid body (EB) formation, a critical factor in minimizing the variations often seen within the same organoid generation batch. Additionally, the CEPT cocktail, a combination of chroman 1, emricasan, polyamines&#160;and the integrated stress response inhibitor (trans-ISRIB)15, is employed&#160;to improve the viability of hiPSCs and differentiated cells during the EB formation process. This modification is mainly to reduce the variations between different organoid samples and batches. Uniform vascular organoids can be produced with this roughly two-week-long protocol, where vasculogenesis is induced to help endothelium organize into primitive tubular networks on Day 1, followed by angiogenesis induction on Day 5 to develop complex vascular networks in organoids. On Day 12-15, the generated organoids should show mature vascular networks composed of both endothelium and mural cells.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>2-Mercaptoethanol (1000x)</td>
			<td>Gibco</td>
			<td>21985023</td>
			<td></td>
		</tr>
		<tr>
			<td>Accutase</td>
			<td>Sigma-Aldrich</td>
			<td>A6964</td>
			<td></td>
		</tr>
		<tr>
			<td>Alexa Fluor 488 AffiniPure F(ab&#39;)2 Fragment Donkey Anti-Rabbit IgG (H+L)</td>
			<td>Jackson Immuno Research Labs</td>
			<td>711-546-152</td>
			<td>reconstitute with 0.25 mL 50% glycerol,&#160; store at -20 &#176;C for up to 1 year, dilution ratio for use: 1:1000</td>
		</tr>
		<tr>
			<td>Alexa Fluor 647 AffiniPure F(ab&#39;)2 Fragment Donkey Anti-Goat IgG (H+L)&#160;</td>
			<td>Jackson Immuno Research Labs</td>
			<td>705-606-147</td>
			<td>reconstitute with 0.25 mL 50% glycerol,&#160; store at -20&#176;C for up to 1 year, dilution ratio for use: 1:1000</td>
		</tr>
		<tr>
			<td>B27 supplement minus vitamin A (50x)</td>
			<td>Gibco</td>
			<td>12587010</td>
			<td>thaw at 4 &#176;C, aliquot and store at -20 &#176;C, avoid freeze-thaw cycle</td>
		</tr>
		<tr>
			<td>BMP4</td>
			<td>ProSpec</td>
			<td>CYT-081</td>
			<td>reconstitute with sterile ddH2O at a concentration of 100 ng/&#181;L, aliquot and store at -20 &#176;C</td>
		</tr>
		<tr>
			<td>CD31 antibody&#160;</td>
			<td>abcam</td>
			<td>ab28364</td>
			<td>dilution ratio: 1:400</td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Eppendorf</td>
			<td>022626001</td>
			<td></td>
		</tr>
		<tr>
			<td>CHIR99021</td>
			<td>Tocris Bioscience</td>
			<td>4423/10</td>
			<td>make the stock solution at 12 mM with DMSO, and store at -20 &#176;C for up to 1 year.</td>
		</tr>
		<tr>
			<td>Chroman 1</td>
			<td>Tocris</td>
			<td>7163/10</td>
			<td>make the stock solution at 100 &#181;M with DMSO, and store at -20 &#176;C for up to 1 year.</td>
		</tr>
		<tr>
			<td>Collagen I&#160;</td>
			<td>Corning</td>
			<td>40236</td>
			<td></td>
		</tr>
		<tr>
			<td>Confocal Microscope</td>
			<td>Nikon</td>
			<td>AXRMP/Ti2</td>
			<td></td>
		</tr>
		<tr>
			<td>Corning Elplasia Plates</td>
			<td>Corning</td>
			<td>4441</td>
			<td></td>
		</tr>
		<tr>
			<td>Countess II FL automated cell counter</td>
			<td>Thermo Fisher</td>
			<td>AMQAF1000</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM/F-12, GlutaMAX supplement</td>
			<td>Gibco</td>
			<td>10565018</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM/F-12, powder</td>
			<td>Gibco</td>
			<td>12500062</td>
			<td>make 10x stock solution with biograde ddH2O and sterilize it with a 0.2 &#181;m filter. Store at 4 &#176;C.</td>
		</tr>
		<tr>
			<td>Edi042A</td>
			<td>Cedars Sinai</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Emricasan</td>
			<td>Medchemexpress LLC</td>
			<td>HY1039610MG</td>
			<td>make the stock solution at 1 mM with DMSO, and store at -20 &#176;C for up to 1 year.</td>
		</tr>
		<tr>
			<td>ERG antibody</td>
			<td>Cell Singali Technology</td>
			<td>97249</td>
			<td>dilution ratio: 1:400</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum - Premium</td>
			<td>Atlanta Biologicals</td>
			<td>S11150</td>
			<td>thaw at 4 &#176;C&#160; and aliquot, store at&#160; -20 &#176;C for up to five years, or store at 4 &#176;C for up to a month</td>
		</tr>
		<tr>
			<td>FGF2</td>
			<td>ProSpec</td>
			<td>CYT557</td>
			<td>reconstitute with sterile ddH2O at a concentration of 100 ng/&#181;L, aliquot and store at -20 &#176;C</td>
		</tr>
		<tr>
			<td>Fluorodish Cell Culture Dish</td>
			<td>World Precision Instruments</td>
			<td>FD35-100</td>
			<td></td>
		</tr>
		<tr>
			<td>Forskolin</td>
			<td>Tocris Bioscience</td>
			<td>1099</td>
			<td>reconstitute with DMSO at a concentration of 12 mM, aliquot and store at -20 &#176;C</td>
		</tr>
		<tr>
			<td>Gentamicin (50 mg/mL)</td>
			<td>Gibco</td>
			<td>15710064</td>
			<td></td>
		</tr>
		<tr>
			<td>GlutaMAX supplement (100x)</td>
			<td>Gibco</td>
			<td>35050061</td>
			<td></td>
		</tr>
		<tr>
			<td>Heparin, 100 kU</td>
			<td>MilliporeSigma</td>
			<td>375095100KU</td>
			<td>reconstitute with sterile ddH2O at a concentration of 4 kU/mL</td>
		</tr>
		<tr>
			<td>HEPES (1 M)</td>
			<td>Gibco</td>
			<td>15630080</td>
			<td></td>
		</tr>
		<tr>
			<td>Incubator</td>
			<td>Thermo Scientific</td>
			<td>13998123</td>
			<td></td>
		</tr>
		<tr>
			<td>Knockout Serum Replacement</td>
			<td>Gibco</td>
			<td>10828028</td>
			<td>thaw at 4 &#176;C, aliquot and store at -20&#176;C, avoid freeze-thaw cycle</td>
		</tr>
		<tr>
			<td>Matrigel, GFR Basement Membrane Matrix</td>
			<td>Corning</td>
			<td>356230</td>
			<td>thaw at 4 &#176;C, aliquot and store at -80&#176;C, avoid freeze-thaw cycle</td>
		</tr>
		<tr>
			<td>MEM Non-Essential Amino Acids Solution (NEAA, 100x)</td>
			<td>Gibco</td>
			<td>11140050</td>
			<td></td>
		</tr>
		<tr>
			<td>Molecular Biology Grade Water</td>
			<td>Corning</td>
			<td>46000CV</td>
			<td></td>
		</tr>
		<tr>
			<td>mTeSR plus kit</td>
			<td>STEMCELL Technologies</td>
			<td>1001130</td>
			<td>thaw at 4 &#176;C, aliquot and store at -20&#176;C, avoid freeze-thaw cycle</td>
		</tr>
		<tr>
			<td>N2 supplement (100x)</td>
			<td>Gibco</td>
			<td>17502048</td>
			<td>thaw at 4 &#176;C, aliquot and store at -20&#176;C, avoid freeze-thaw cycle</td>
		</tr>
		<tr>
			<td>NaOH solution (1 M)</td>
			<td>Cytiva&#160;HyClone</td>
			<td>SH31088.01</td>
			<td></td>
		</tr>
		<tr>
			<td>NeuroBasal medium</td>
			<td>Gibco</td>
			<td>21103049</td>
			<td></td>
		</tr>
		<tr>
			<td>NIS-Elements, ver 5.42</td>
			<td>Nikon</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Normal Donkey Serum</td>
			<td>Jackson Immuno Research Labs</td>
			<td>17000121</td>
			<td>reconstitute with 10 mL sterile ddH2O, store at 4 &#176;C for up to two weeks</td>
		</tr>
		<tr>
			<td>paraformaldehyde, 20%</td>
			<td>Electron Microscopy Sciences</td>
			<td>15713S</td>
			<td>dilute with PBS</td>
		</tr>
		<tr>
			<td>PBST, 20x</td>
			<td>Thermofisher</td>
			<td>28352</td>
			<td></td>
		</tr>
		<tr>
			<td>PDGFR&#946; antibody</td>
			<td>R&#38;D</td>
			<td>AF385</td>
			<td>dilution ratio: 1:400</td>
		</tr>
		<tr>
			<td>polyamine supplement (1000x)</td>
			<td>Sigma-Aldrich</td>
			<td>P8483</td>
			<td></td>
		</tr>
		<tr>
			<td>Rapiclear clearing reagent, 1.49</td>
			<td>SUNJIN LAB</td>
			<td>RC149001</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium Bicarbonate (7.5%)</td>
			<td>Gibco</td>
			<td>25080094</td>
			<td></td>
		</tr>
		<tr>
			<td>Sodium deoxycholate monohydrate</td>
			<td>Thermofisher</td>
			<td>J6228822</td>
			<td>dissolve with ddH2O for 1% (wt/v) stock solution</td>
		</tr>
		<tr>
			<td>TBST, 20x</td>
			<td>Thermofisher</td>
			<td>28360</td>
			<td></td>
		</tr>
		<tr>
			<td>trans-ISRIB</td>
			<td>Tocris Bioscience</td>
			<td>5284/10</td>
			<td>make the stock solution at 1 mM with DMSO, and store at -20&#176;C for up to 1 year.</td>
		</tr>
		<tr>
			<td>Tritin X-100</td>
			<td>Sigma-Aldrich</td>
			<td>T8787-50ML</td>
			<td></td>
		</tr>
		<tr>
			<td>Trypan Blue Stain (0.4%)</td>
			<td>Thermo Fisher</td>
			<td>15250061</td>
			<td></td>
		</tr>
		<tr>
			<td>Tween 20</td>
			<td>Sigma-Aldrich</td>
			<td>P7949-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>VEGF-A</td>
			<td>ProSpec</td>
			<td>CYT-116</td>
			<td>reconstitute with sterile ddH2O at a concentration of 100 ng/&#181;L, aliquot and store at -20&#176;C</td>
		</tr>
	</tbody>
</table>

vascular organoid generation from human-induced pluripotent stem cells

Vascular organoids derived from human induced pluripotent stem cells (hiPSCs) recapitulate the cell type diversity and complex architecture of human vascular networks. This three-dimensional (3D) model holds substantial potential for vascular pathology modeling and in vitro drug screening. Despite recent advances, a key technical challenge remains in reproducibly generating organoids with consistent quality, which is crucial for downstream assays and applications. Here, a modified protocol is presented that improves both the homogeneity and reproducibility of vascular organoid generation. The modified protocol incorporates the use of microwells and the CEPT cocktail (chroman 1, emricasan, polyamines, and the integrated stress response inhibitor, trans-ISRIB) to improve embryoid body formation and cell survival. Differentiated, mature vascular organoids generated using this protocol are characterized by whole-mount 3D immunofluorescence microscopy to analyze their morphology and complex vasculature. This protocol enables the production of high-quality vascular organoids in a scalable manner, potentially facilitating their use in disease modeling and drug screening applications.

Figure 1A presents the scheme of this protocol, including the key components used in each stage. The differentiation started with the EB formation, followed by mesoderm induction and vascular lineage specification (Figure 1B-D). The aggregates grew larger and less spherical over time. Organoids started showing rough edges on Day 5. After embedded in the collagen I-basement membrane matrix mixture, vascular endothelial cells and ...

Author Spotlight: Improving Reproducibility in Vascular Organoids Using ROCK Inhibitors and Microwell Confinement

This protocol presents a method for generating vascular organoids using human pluripotent stem cells.

Vascular Organoid Generation from Human-Induced Pluripotent Stem Cells

Vascular organoids derived from human induced pluripotent stem cells (hiPSCs) recapitulate the cell type diversity and complex architecture of human ...

vascular-organoid-generation-from-human-induced-pluripotent-stem-cells

Research

JoVE Journal

Bioengineering

1.3K Views.  Columbia University. This protocol presents a method for generating vascular organoids using human pluripotent stem cells.

Video: Author Spotlight: Improving Reproducibility in Vascular Organoids Using ROCK Inhibitors and Microwell Confinement

Development, Expansion, and In vivo Monitoring of Human NK Cells from Human Embryonic Stem Cells (hESCs) and Induced Pluripotent Stem Cells (iPSCs)

We present a method for deriving natural killer (NK) cells from undifferentiated hESCs and iPSCs using a feeder-free approach. This method gives rise to high levels of NK cells after 4 weeks culture and can undergo further 2-log expansion with artificial antigen presenting cells. hESC- and iPSC-derived NK cells developed in this system have a mature phenotype and function. The production of large numbers of genetically modifiable NK cells is applicable for both basic mechanistic as well as anti-tumor studies. Expression of firefly luciferase in hESC-derived NK cells allows a non-invasive approach to follow NK cell engraftment, distribution, and function. We also describe a dual-imaging scheme that allows separate monitoring of two different cell populations to more distinctly characterize their interactions in vivo. This method of derivation, expansion, and dual in vivo imaging provides a reliable approach for producing NK cells and their evaluation which is necessary to improve current NK cell adoptive therapies.

Development, Expansion, and In vivo Monitoring of Human NK Cells from Human Embryonic Stem Cells hESCs and Induced Pluripotent Stem Cells iPSCs

This protocol describes the development, expansion, and in vivo imaging of NK cells derived from hESCs and iPSCs.

We present a method for deriving natural killer (NK) cells from undifferentiated hESCs and iPSCs using a feeder-free approach. This method gives rise to ...

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

Patient-derived iPSCs could be an invaluable source of cells for future autologous cell therapy protocols. iPSC-derived myogenic stem/progenitor cells similar to pericyte-derived mesoangioblasts (iPSC-derived mesoangioblast-like stem/progenitor cells: IDEMs) can be established from iPSCs generated from patients affected by different forms of muscular dystrophy. Patient-specific IDEMs can be genetically corrected with different strategies (e.g. lentiviral vectors, human artificial chromosomes) and enhanced in their myogenic differentiation potential upon overexpression of the myogenesis regulator MyoD. This myogenic potential is then assessed in vitro with specific differentiation assays and analyzed by immunofluorescence. The regenerative potential of IDEMs is further evaluated in vivo, upon intramuscular and intra-arterial transplantation in two representative mouse models displaying acute and chronic muscle regeneration. The contribution of IDEMs to the host skeletal muscle is then confirmed by different functional tests in transplanted mice. In particular, the amelioration of the motor capacity of the animals is studied with treadmill tests. Cell engraftment and differentiation are then assessed by a number of histological and immunofluorescence assays on transplanted muscles. Overall, this paper describes the assays and tools currently utilized to evaluate the differentiation capacity of IDEMs, focusing on the transplantation methods and subsequent outcome measures to analyze the efficacy of cell transplantation.

Induced pluripotent stem cell (iPSC)-derived myogenic progenitors are promising candidates for cell therapy strategies to treat muscular dystrophies. This protocol describes transplantation and functional measurements required to evaluate the engraftment and differentiation of iPSC-derived mesoangioblasts (a type of muscle progenitors) in mouse models of acute and chronic muscle regeneration.

Patient-derived iPSCs could be an invaluable source of cells for future autologous cell therapy protocols. iPSC-derived myogenic stem/progenitor cells ...

Isolation of Adult Human Dermal Fibroblasts from Abdominal Skin and Generation of Induced Pluripotent Stem Cells Using a Non-Integrating Method

Induced pluripotent stem cells (iPSCs) could be considered, to date, a promising source of pluripotent cells for the management of currently untreatable diseases, for the reconstitution and regeneration of injured tissues and for the development of new drugs. Despite all the advantages related to the use of iPSCs, such as the low risk of rejection, the lessened ethical issues, and the possibility to obtain them from both young and old patients without any difference in their reprogramming potential, problems to overcome are still numerous. In fact, cell reprogramming conducted with viral and integrating viruses can cause infections and the introduction of required genes can induce a genomic instability of the recipient cell, impairing their use in clinic. In particular, there are many concerns about the use of c-Myc gene, well-known from several studies for its mutation-inducing activity. Fibroblasts have emerged as the suitable cell population for cellular reprogramming as they are easy to isolate and culture and are harvested by a minimally invasive skin punch biopsy. The protocol described here provides a detailed step-by-step description of the whole procedure, from sample processing to obtain cell cultures, choice of reagents and supplies, cleaning and preparation, to cell reprogramming by the means of a commercial non-modified RNAs (NM-RNAs)-based reprogramming kit. The chosen reprogramming kit allows an effective reprogramming of human dermal fibroblast to iPSCs and small colonies can be seen as early as 24 h after the first transfection, even with modifications with the respect to the standard datasheet. The reprogramming procedure used in this protocol offers the advantage of a safe reprogramming, without the risk of infections caused by viral vector-based methods, reduces the cellular defense mechanisms, and allows the generation of xeno-free iPSCs, all critical features that are mandatory for further clinical applications.

Cell reprogramming requires the introduction of key genes, which regulate and maintain the pluripotent cell state. The protocol described enables the formation of induced pluripotent stem cells (iPSCs) colonies from human dermal fibroblasts without viral/integrating methods but using non-modified RNAs (NM-RNAs) combined with immune evasion factors reducing cellular defense mechanisms.

Induced pluripotent stem cells (iPSCs) could be considered, to date, a promising source of pluripotent cells for the management of currently untreatable ...

Scalable Generation of Mature Cerebellar Organoids from Human Pluripotent Stem Cells and Characterization by Immunostaining

The cerebellum plays a critical role in the maintenance of balance and motor coordination, and a functional defect in different cerebellar neurons can trigger cerebellar dysfunction. Most of the current knowledge about disease-related neuronal phenotypes is based on postmortem tissues, which makes understanding of disease progression and development difficult. Animal models and immortalized cell lines have also been used as models for neurodegenerative disorders. However, they do not fully recapitulate human disease. Human induced pluripotent stem cells (iPSCs) have great potential for disease modeling and provide a valuable source for regenerative approaches. In recent years, the generation of cerebral organoids from patient-derived iPSCs improved the prospects for neurodegenerative disease modeling. However, protocols that produce large numbers of organoids and a high yield of mature neurons in 3D culture systems are lacking. The protocol presented is a new approach for reproducible and scalable generation of human iPSC-derived organoids under chemically-defined conditions using scalable single-use bioreactors, in which organoids acquire cerebellar identity. The generated organoids are characterized by the expression of specific markers at both mRNA and protein level. The analysis of specific groups of proteins allows the detection of different cerebellar cell populations, whose localization is important for the evaluation of organoid structure. Organoid cryosectioning and further immunostaining of organoid slices are used to evaluate the presence of specific cerebellar cell populations and their spatial organization.

This protocol describes a dynamic culture system to produce controlled size aggregates of human pluripotent stem cells and further stimulate differentiation in cerebellar organoids under chemically-defined and feeder-free conditions using a single-use bioreactor.

The cerebellum plays a critical role in the maintenance of balance and motor coordination, and a functional defect in different cerebellar neurons can ...

Guided Differentiation of Mature Kidney Podocytes from Human Induced Pluripotent Stem Cells Under Chemically Defined Conditions

Kidney disease affects more than 10% of the global population and costs billions of dollars in federal expenditures. The most severe forms of kidney disease and eventual end-stage renal failure are often caused by the damage to the glomerular podocytes, which are the highly specialized epithelial cells that function together with endothelial cells and the glomerular basement membrane to form the kidney&#8217;s filtration barrier. Advances in renal medicine have been hindered by the limited availability of primary tissues and the lack of robust methods for the derivation of functional human kidney cells, such as podocytes. The ability to derive podocytes from renewable sources, such as stem cells, could help advance current understanding of the mechanisms of human kidney development and disease, as well as provide new tools for therapeutic discovery. The goal of this protocol was to develop a method to derive mature, post-mitotic podocytes from human induced pluripotent stem (hiPS) cells with high efficiency and specificity, and under chemically defined conditions. The hiPS cell-derived podocytes produced by this method express lineage-specific markers (including nephrin, podocin, and Wilm&#8217;s Tumor 1) and exhibit the specialized morphological characteristics (including primary and secondary foot processes) associated with mature and functional podocytes. Intriguingly, these specialized features are notably absent in the immortalized podocyte cell line widely used in the field, which suggests that the protocol described herein produces human kidney podocytes that have a developmentally more mature phenotype than the existing podocyte cell lines typically used to study human kidney biology.

Presented here is a chemically defined protocol for the derivation of human kidney podocytes from induced pluripotent stem cells with high efficiency (&#62;90%) and independent of genetic manipulations or subpopulation selection. This protocol produces the desired cell type within 26 days and could be useful for nephrotoxicity testing and disease modeling.

Kidney disease affects more than 10% of the global population and costs billions of dollars in federal expenditures. The most severe forms of kidney ...

Single-Cell Optical Action Potential Measurement in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Conventional intracellular microelectrode techniques to quantify cardiomyocyte electrophysiology are extremely complex, labor intensive, and typically carried out in low throughput. Rapid and ongoing expansion of induced pluripotent stem cell (iPSC) technology presents a new standard in cardiovascular research and alternate methods are now necessary to increase throughput of electrophysiological data at a single cell level. VF2.1Cl is a recently derived voltage sensitive dye which provides a rapid single channel, high magnitude response to fluctuations in membrane potential. It possesses kinetics superior to those of other existing voltage indicators and makes available functional data equivalent to that of traditional microelectrode techniques. Here, we demonstrate simplified, non-invasive action potential characterization in externally paced human iPSC derived cardiomyocytes using a modular and highly affordable photometry system.

Here we describe optical acquisition and characterization of action potentials from induced pluripotent stem cell derived cardiomyocytes using a high-speed modular photometry system.

Conventional intracellular microelectrode techniques to quantify cardiomyocyte electrophysiology are extremely complex, labor intensive, and typically ...

Isogenic Kidney Glomerulus Chip Engineered from Human Induced Pluripotent Stem Cells

Chronic kidney disease (CKD) affects 15% of the U.S. adult population, but the establishment of targeted therapies has been limited by the lack of functional models that can accurately predict human biological responses and nephrotoxicity. Advancements in kidney precision medicine could help overcome these limitations. However, previously established in vitro models of the human kidney glomerulus-the primary site for blood filtration and a key target of many diseases and drug toxicities-typically employ heterogeneous cell populations with limited functional characteristics and unmatched genetic backgrounds. These characteristics significantly limit their application for patient-specific disease modeling and therapeutic discovery. 
This paper presents a protocol that integrates human induced pluripotent stem (iPS) cell-derived glomerular epithelium (podocytes) and vascular endothelium from a single patient to engineer an isogenic and vascularized microfluidic kidney glomerulus chip. The resulting glomerulus chip is comprised of stem cell-derived endothelial and epithelial cell layers that express lineage-specific markers, produce basement membrane proteins, and form a tissue-tissue interface resembling the kidney's glomerular filtration barrier. The engineered glomerulus chip selectively filters molecules and recapitulates drug-induced kidney injury. The ability to reconstitute the structure and function of the kidney glomerulus using isogenic cell types creates the opportunity to model kidney disease with patient specificity and advance the utility of organs-on-chips for kidney precision medicine and related applications.

Presented here is a protocol to engineer a personalized organ-on-a-chip system that recapitulates the structure and function of the kidney glomerular filtration barrier by integrating genetically matched epithelial and vascular endothelial cells differentiated from human induced pluripotent stem cells. This bioengineered system can advance kidney precision medicine and related applications.

Chronic kidney disease (CKD) affects 15% of the U.S. adult population, but the establishment of targeted therapies has been limited by the lack of ...

Generation of Human Blood Vessel Organoids from Pluripotent Stem Cells

An organoid is defined as an engineered multicellular in vitro tissue that mimics its corresponding in vivo organ such that it can be used to study defined aspects of that organ in a tissue culture dish. The breadth and application of human pluripotent stem cell (hPSC)-derived organoid research have advanced significantly to include the brain, retina, tear duct, heart, lung, intestine, pancreas, kidney, and blood vessels, among several other tissues. The development of methods for the generation of human microvessels, specifically, has opened the way for modeling human blood vessel development and disease in vitro and for the testing and analysis of new drugs or tissue tropism in virus infections, including SARS-CoV-2. Complex and lengthy protocols lacking visual guidance hamper the reproducibility of many stem cell-derived organoids. Additionally, the inherent stochasticity of organoid formation processes and self-organization necessitates the generation of optical protocols to advance the understanding of cell fate acquisition and programming. Here, a visually guided protocol is presented for the generation of 3D human blood vessel organoids (BVOs) engineered from hPSCs. Presenting a continuous basement membrane, vascular endothelial cells, and organized articulation with mural cells, BVOs exhibit the functional, morphological, and molecular features of human microvasculature. BVO formation is initiated through aggregate formation, followed by mesoderm and vascular induction. Vascular maturation and network formation are initiated and supported by embedding aggregates in a 3D collagen and solubilized basement membrane matrix. Human vessel networks form within 2-3 weeks and can be further grown in scalable culture systems. Importantly, BVOs transplanted into immunocompromised mice anastomose with the endogenous mouse circulation and specify into functional arteries, veins, and arterioles. The present visually guided protocol will advance human organoid research, particularly in relation to blood vessels in normal development, tissue vascularization, and disease.

This protocol describes the generation of self-organizing blood vessels from human pluripotent and induced pluripotent stem cells. These blood vessel networks exhibit an extensive and connected endothelial network surrounded by pericytes, smooth muscle actin, and a continuous basement membrane.

An organoid is defined as an engineered multicellular in vitro tissue that mimics its corresponding in vivo organ such that it can be used to study ...

Reconstituting Cytoarchitecture and Function of Human Epithelial Tissues on an Open-Top Organ-Chip

Nearly all human organs are lined with epithelial tissues, comprising one or multiple layers of tightly connected cells organized into three-dimensional (3D) structures. One of the main functions of epithelia is the formation of barriers that protect the underlining tissues against physical and chemical insults and infectious agents. In addition, epithelia mediate the transport of nutrients, hormones, and other signaling molecules, often creating biochemical gradients that guide cell positioning and compartmentalization within the organ. Owing to their central role in determining organ-structure and function, epithelia are important therapeutic targets for many human diseases that are not always captured by animal models. Besides the obvious species-to-species differences, conducting research studies on barrier function and transport properties of epithelia in animals is further compounded by the difficulty of accessing these tissues in a living system. While two-dimensional (2D) human cell cultures are useful for answering basic scientific questions, they often yield poor in vivo predictions. To overcome these limitations, in the last decade, a plethora of micro-engineered biomimetic platforms, known as organs-on-a-chip, have emerged as a promising alternative to traditional in vitro and animal testing. Here, we describe an Open-Top Organ-Chip (or Open-Top Chip), a platform designed for modeling organ-specific epithelial tissues, including skin, lungs, and the intestines. This chip offers new opportunities for reconstituting the multicellular architecture and function of epithelial tissues, including the capability to recreate a 3D stromal component by incorporating tissue-specific fibroblasts and endothelial cells within a mechanically active system. This Open-Top Chip provides an unprecedented tool for studying epithelial/mesenchymal and vascular interactions at multiple scales of resolution, from single cells to multi-layer tissue constructs, thus allowing molecular dissection of the intercellular crosstalk of epithelialized organs in health and disease.

The present protocol describes the capabilities and the essential culture modalities of the Open-Top Organ-Chip for the successful establishment and maturation of full-thickness organ-on-chip cultures of primary tissues (skin, alveolus, airway, and intestine), providing the opportunity to investigate different functional aspects of the human epithelial/mesenchymal and vascular niche interface in vitro.

Nearly all human organs are lined with epithelial tissues, comprising one or multiple layers of tightly connected cells organized into three-dimensional ...

Generation, High-Throughput Screening, and Biobanking of Human-Induced Pluripotent Stem Cell-Derived Cardiac Spheroids

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are of paramount importance for human cardiac disease modeling and therapeutics. We recently published a cost-effective strategy for the massive expansion of hiPSC-CMs in two dimensions (2D). Two major limitations are cell immaturity and a lack of three-dimensional (3D) arrangement and scalability in high-throughput screening (HTS) platforms. To overcome these limitations, the expanded cardiomyocytes form an ideal cell source for the generation of 3D cardiac cell culture and tissue engineering techniques. The latter holds great potential in the cardiovascular field, providing more advanced and physiologically relevant HTS. Here, we describe an HTS-compatible workflow with easy scalability for the generation, maintenance, and optical analysis of cardiac spheroids (CSs) in a 96-well-format. These small CSs are essential to fill the gap present in current in vitro disease models and/or generation for 3D tissue engineering platforms. The CSs present a highly structured morphology, size, and cellular composition. Furthermore, hiPSC-CMs cultured as CSs display increased maturation and several functional features of the human heart, such as spontaneous calcium handling and contractile activity. By automatization of the complete workflow, from the generation of CSs to functional analysis, we increase intra- and inter-batch reproducibility as demonstrated by high-throughput (HT) imaging and calcium handling analysis. The described protocol allows modeling of cardiac diseases and assessing drug/therapeutic effects at the single-cell level within a complex 3D cell environment in a fully automated HTS workflow. In addition, the study describes a straightforward procedure for long-term preservation and biobanking of whole-spheroids, thereby providing researchers the opportunity to create next-generation functional tissue storage. HTS combined with long-term storage will substantially contribute to translational research in a wide range of areas, including drug discovery and testing, regenerative medicine, and the development of personalized therapies.

Presented here is a set of protocols for the generation and cryopreservation of cardiac spheroids (CSs) from human-induced pluripotent stem cell-derived cardiomyocytes cultured in a high-throughput, multidimensional format. This three-dimensional model functions as a robust platform for disease modeling, high-throughput screenings, and maintains its functionality after cryopreservation.

Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are of paramount importance for human cardiac disease modeling and therapeutics. We ...