This work was supported by grant 075-15-2019-1669 from the Ministry of Science and Higher Education of the Russian Federation (RT-PCR analysis) and by grant No. 19-15-00425 from the Russian Science Foundation (for all other work). The authors also thank Pavel Belikov for his help with the video editing. Figures in the manuscript were created with BioRender.com.

NOTE : Use sterile technique throughout the protocol, excluding steps 1.2 and 1.3. Warm all culture media and solutions to 37 &#176;C before applying to cells or organoids. Cultivate cells in a CO2 incubator at 37 &#176;C in 5% CO2 upon 80% humidity. The protocol scheme is shown in Figure 1.
1. Transforming Petri dishes into mini bioreactors
<ol>
	<li>Cut sterile 15 mL centrifuge tubes in rings of 7-8 mm in height; autoclave the rings.</li>
	<li>Break low-adhesion, untreated or microbiological Petri dishes into crumbs. Dissolve about 1 g of plastic crumbs in 10 mL of chloroform overnight to prepare liquid plastic. 
	&#8203;CAUTION: Work in a fume hood.</li>
	<li>Check that the resulting liquid plastic is viscous enough for pipetting; its drop retains a spherical form and does not spread on the surface. If it is very liquid, add more plastic crumbs. If it is thick, then add chloroform.</li>
	<li>Make a plastic knob in the center of a sterile ultra-low adhesion 6-cm Petri dish. There are two equally suitable ways, as detailed below.
	<ol>
		<li>Put the autoclaved plastic ring on the center and drop the liquid plastic to the inside of the ring.</li>
		<li>Without any plastic ring, drop the liquid plastic on the center of the Petri dish.</li>
	</ol>
	</li>
	<li>Leave the dishes open for 2-3 h in a laminar flow hood until dried complete. Treat the dried dishes with ultraviolet radiation for 15-20 min.</li>
</ol>
2. Induction of neuronal differentiation of iPSCs
<ol>
	<li>Cultivate iPSCs in the medium for pluripotent stem cells up to 75-90% confluence in 35 mm Petri dishes precoated with a matrix consisting of extracellular proteins.</li>
	<li>Prepare medium A-SR. See Table 1 for details.</li>
	<li>Aspirate the cultivation medium and add 2 mL of A-SR medium at Day 0 of differentiation.</li>
	<li>Prepare medium A (see Table 2).</li>
	<li>Cultivate cells in medium A for two weeks from Days 2-14, refreshing medium in Petri dishes every other day.</li>
</ol>
3. The formation of spheroids from neuroepithelial precursor cells at Day 14
<ol>
	<li>At Day 14, make spheroids from neuroepithelial precursor cells using a special 24-well culture plate containing approximately 1,200 microwells in each well (Figure 2C). Follow the procedure given below. 
	NOTE: At this differentiation stage, a 35 mm Petri dish usually contains 3 - 3.5 x 106 neuroepithelial precursor cells. Thus, one 35 mm Petri dish with neuroepithelial precursor cells is sufficient for 3 - 4 wells of 24-well culture plate with microwells.</li>
	<li>Prepare a 24-well culture plate with microwells: To each well, add 1 mL of medium A. Centrifuge briefly at 1,300 x g for 5 min in swinging bucket rotor fitted with plate holder. Control under the microscope that there are no bubbles in microwells.</li>
	<li>Prepare the medium B (Table 3).</li>
	<li>Remove the medium from the Petri dish with neuroepithelial precursor cells; wash the cells with 2 mL of DMEM/F12. For the cell detachment, treat the cells with 1.5 mL of 0.48 mM EDTA solution prepared in PBS. Control the cell detachment under the microscope.</li>
	<li>Harvest the cells into a 15 mL tube. Add 5 mL of DMEM/F12 in the tube to wash the cells. Centrifuge at 200 x g for 5 min. Remove the supernatant and resuspend cells in 2 mL of medium B.</li>
	<li>Check the cell concentration and viability by Trypan Blue staining and a hemocytometer. Calculate the volume of suspension needed to contain 1 x 106 viable cells in total.</li>
	<li>Transfer the cell suspension containing 1 x 106 cells into each well of a 24-well plate with microwells. Add medium B up to 2 mL into each well, gently pipette cells up and down several times, and centrifuge briefly 100 x g for 1 min to capture cells in the microwells. 
	NOTE: The number of cells per well should not exceed 1 x 106. Otherwise, spheroids from neighboring microwells fuse.</li>
	<li>Check under the microscope that cells are evenly distributed in microwells. Repeat pipetting and centrifugation if cells are distributed unevenly.</li>
	<li>Incubate the plate overnight to let cells aggregate in spheroids.</li>
</ol>
4. Obtaining and cultivation of organoids
<ol>
	<li>The next morning (Day 15), check the quality of spheroids under the microscope. Ensure that they are transparent and smooth, if healthy (Figure 2A,B). Carefully collect the spheroids from each well into a 15 mL tube, leave the spheroids to precipitate by gravity for 2-3 min, and then remove the supernatant.</li>
	<li>Add to the spheroids 2 mL of the matrix thawed during the same time on ice. Mix gently by pipetting and incubate at room temperature for 30 min.</li>
	<li>To wash excess of the matrix, add to the tube 8 mL of medium B. Pipette gently, then centrifuge the tube for 1 min at 100 x g. 
	NOTE: Do not exceed the time and the speed of centrifugation to avoid the irreversible aggregation of spheroids.</li>
	<li>Remove the supernatant. Add to the tube 2&#160;mL of medium B, pipette gently. Split the spheroid suspension between two mini bioreactors, each containing 4 mL of medium B. Place the mini bioreactors into a 15 cm Petri dish to prevent the evaporation of water and to avoid contamination.</li>
	<li>Put the Petri dish with mini bioreactors on an orbital shaker. Cultivate the organoids at a rotation rate of 70-75 rpm.</li>
	<li>On Day 16, prepare medium C (Table 4).</li>
	<li>Transfer the organoids into 15 mL tube. For 5 min, let them fall to the bottom, aspirate the supernatant, add 5 mL of medium C. Return the organoids into the mini bioreactors. 
	NOTE: Be careful not to lose the spheroids, which are transparent and barely visible.</li>
	<li>Cultivate spheroids in medium C for two weeks, refreshing the medium every two days. At the end of these two weeks, leave about 100 spheroids per mini bioreactor for the following cultivation. Freeze excessive spheroids in a freezing medium in liquid nitrogen.</li>
	<li>On Day 30, prepare medium D (Table 5).</li>
	<li>Change the cultivation medium to medium D, which is a maturation medium. Refresh cultivation medium every 2-3 days for three weeks, then use medium D without BDNF and GDNF.</li>
</ol>

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The authors have nothing to disclose.

The described protocol has two crucial steps allowing the generation of high-quality organoids of uniform size. First, the organoids grow from spheroids which are near identical in cell number and cell maturity. Second, the home-made bioreactors provide each organoid a uniform environment, where organoids do not crowd or stick together.
The cell quality and state of cell maturation are essential to perform the protocol. It is critical to start neuronal differentiation at 75-90% confluence of i...

Human iPSC-derived models are widely used in the studies of neurodevelopmental and neurodegenerative disorders1. Over the past decade, 3D brain tissue models, so-called brain organoids, essentially complemented traditional 2D neuronal cultures2. The organoids recapitulate to some extent the 3D architecture of the embryonic brain and allow more precise modeling. Many protocols are published for the generation of organoids representing different brain regions: cerebral cortex3,4,5, cerebellum6, midbrain, forebrain, hypothalamus7,8,9, and hippocampus10. There have been multiple examples of using organoids to study human nervous system diseases11. Also, the organoids were implemented in drug discoveries12 and used in studies of infectious diseases, including SARS-Cov-213,14.
The brain organoids can reach up to several millimeters in diameter. So, the inner zone of the organoid may suffer from hypoxia or malnutrition and eventually become necrotic. Therefore, many protocols include special bioreactors8, shakers, or microfluidic systems15. These devices may require large volumes of expensive cell culture media. Also, the cost of such equipment is usually high. Some bioreactors consist of many mechanical parts that make them difficult to sterilize for reuse.
Most protocols suffer from the &#34;batch effect&#34;16, which generates significant variability among organoids obtained from the identical iPSCs. This variability hinders drug testing or preclinical studies requiring uniformity. The high yield of organoids enough to select organoids of uniform size may partially solve this problem.
The time factor is also a significant problem. Matsui et al. (2018) showed that brain organoids require at least six months to reach maturity17. Trujillo et al. (2019) also demonstrated that electrophysiological activity occurred in organoids only after six months of cultivation18. Due to the long organoid maturation time, the researchers often launch new differentiation before completing the previous one. Multiple parallel processes of differentiation require additional expenses, equipment, and laboratory space.
We have recently developed a mini bioreactor that mainly solves the problems mentioned above19. This home-made bioreactor consists of an ultra-low adhesion or untreated Petri dish with a plastic knob in the center. This plastic knob prevents crowding of organoids and their conglutination in the center of the Petri dish, which is caused by the rotation of the shaker. This paper describes how this inexpensive and simple home-made mini bioreactor allows generating high-quality brain organoids in large quantities.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Advanced DMEM/F-12</td>
			<td>Gibco</td>
			<td>12634010</td>
			<td>DMEM/F-12</td>
		</tr>
		<tr>
			<td>AggreWell400</td>
			<td>STEMCELL Technologies Inc</td>
			<td>34425</td>
			<td>24-well culture plate with microwells</td>
		</tr>
		<tr>
			<td>B-27 Supplement</td>
			<td>Gibco</td>
			<td>17504044</td>
			<td>Neuronal supplement B</td>
		</tr>
		<tr>
			<td>GlutaMAX Supplement</td>
			<td>Gibco</td>
			<td>35050061</td>
			<td>200 mM L-alanyl-L-glutamine</td>
		</tr>
		<tr>
			<td>Human BDNF</td>
			<td>Miltenyi Biotec</td>
			<td>130-096-285</td>
			<td></td>
		</tr>
		<tr>
			<td>Human FGF-2</td>
			<td>Miltenyi Biotec</td>
			<td>130-093-839</td>
			<td></td>
		</tr>
		<tr>
			<td>Human GDNF</td>
			<td>Miltenyi Biotec</td>
			<td>130-096-290</td>
			<td></td>
		</tr>
		<tr>
			<td>KnockOut Serum Replacement</td>
			<td>Gibco</td>
			<td>10828028</td>
			<td>Serum replacement</td>
		</tr>
		<tr>
			<td>mTESR1</td>
			<td>STEMCELL Technologies Inc</td>
			<td>85850</td>
			<td>Pliripotent stem cell medium</td>
		</tr>
		<tr>
			<td>N2 Supplement</td>
			<td>Gibco</td>
			<td>17502001</td>
			<td></td>
		</tr>
		<tr>
			<td>Neurobasal Medium</td>
			<td>Gibco</td>
			<td>21103049</td>
			<td>Basal medium for neuronal cell maintenance</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin Solution</td>
			<td>Gibco</td>
			<td>15140130</td>
			<td></td>
		</tr>
		<tr>
			<td>Plasmocin</td>
			<td>InvivoGen</td>
			<td>ant-mpt-1</td>
			<td>Antimicrobials</td>
		</tr>
		<tr>
			<td>Purmorphamine</td>
			<td>EMD Millipore</td>
			<td>540220</td>
			<td></td>
		</tr>
		<tr>
			<td>StemMACS Y27632</td>
			<td>Miltenyi Biotec</td>
			<td>130-106-538</td>
			<td>Y27632</td>
		</tr>
		<tr>
			<td>StemMACS Dorsomorphin</td>
			<td>Miltenyi Biotec</td>
			<td>130-104-466</td>
			<td>Dorsomorphin</td>
		</tr>
		<tr>
			<td>StemMACS LDN-193189</td>
			<td>Miltenyi Biotec</td>
			<td>130-106-540</td>
			<td>LDN-193189</td>
		</tr>
		<tr>
			<td>StemMACS SB431542</td>
			<td>Miltenyi Biotec</td>
			<td>130-106-543</td>
			<td>SB431542</td>
		</tr>
		<tr>
			<td>Trypan Blue Solution</td>
			<td>Gibco</td>
			<td>15250061</td>
			<td></td>
		</tr>
		<tr>
			<td>Versen solution</td>
			<td>Gibco</td>
			<td>15040066</td>
			<td>0.48 mM EDTA in PBS</td>
		</tr>
		<tr>
			<td>&#946;-mercaptoethanol</td>
			<td>Gibco</td>
			<td>31350010</td>
			<td></td>
		</tr>
	</tbody>
</table>

brain organoid generation from induced pluripotent stem cells in home-made mini bioreactors

The iPSC-derived brain organoid is a promising technology for in vitro modeling the pathologies of the nervous system and drug screening. This technology has emerged recently. It is still in its infancy and has some limitations unsolved yet. The current protocols do not allow obtaining organoids to be consistent enough for drug discovery and preclinical studies. The maturation of organoids can take up to a year, pushing the researchers to launch multiple differentiation processes simultaneously. It imposes additional costs for the laboratory in terms of space and equipment. In addition, brain organoids often have a necrotic zone in the center, which suffers from nutrient and oxygen deficiency. Hence, most current protocols use a circulating system for culture medium to improve nutrition.
Meanwhile, there are no inexpensive dynamic systems or bioreactors for organoid cultivation. This paper describes a protocol for producing brain organoids in compact and inexpensive home-made mini bioreactors. This protocol allows obtaining high quality organoids in large quantities.

The protocol scheme is shown in Figure 1. The protocol included five media in which iPSCs differentiated into brain organoids during at least one month. The differentiation was started then iPSCs reached the 75-90% confluence (Figure 2A,B). The first signs of differentiation towards neurons were observed on days 10-11 of iPSC cultivation in medium A when cells began to cluster into &#34;rosettes&#34; (Figure 2C). At...

Watch this Scientific Journal Video about Brain Organoid Generation from Induced Pluripotent Stem Cells in Home-Made Mini Bioreactors at JoVE.com

Brain Organoid Generation from Induced Pluripotent Stem Cells in Home-Made Mini Bioreactors

Here we describe a protocol for generating brain organoids from human induced pluripotent stem cells (iPSCs). To obtain brain organoids in large quantities and of high quality, we use home-made mini bioreactors.

The iPSC-derived brain organoid is a promising technology for in vitro modeling the pathologies of the nervous system and drug screening. This technology ...

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Developmental Biology

5.1K Views.  Federal Medical Biological Agency. Here we describe a protocol for generating brain organoids from human induced pluripotent stem cells (iPSCs). To obtain brain organoids in large quantities and of high quality, we use home-made mini bioreactors.

Video: Brain Organoid Generation from Induced Pluripotent Stem Cells in Home-Made Mini Bioreactors

Generation of Induced Pluripotent Stem Cells from Frozen Buffy Coats using Non-integrating Episomal Plasmids

Somatic cells can be reprogrammed into induced pluripotent stem cells (iPSCs) by forcing the expression of four transcription factors (Oct-4, Sox-2, Klf-4, and c-Myc), typically expressed by human embryonic stem cells (hESCs). Due to their similarity with hESCs, iPSCs have become an important tool for potential patient-specific regenerative medicine, avoiding ethical issues associated with hESCs. In order to obtain cells suitable for clinical application, transgene-free iPSCs need to be generated to avoid transgene reactivation, altered gene expression and misguided differentiation. Moreover, a highly efficient and inexpensive reprogramming method is necessary to derive sufficient iPSCs for therapeutic purposes. Given this need, an efficient non-integrating episomal plasmid approach is the preferable choice for iPSC derivation. Currently the most common cell type used for reprogramming purposes are fibroblasts, the isolation of which requires tissue biopsy, an invasive surgical procedure for the patient. Therefore, human peripheral blood represents the most accessible and least invasive tissue for iPSC generation.
In this study, a cost-effective and viral-free protocol using non-integrating episomal plasmids is reported for the generation of iPSCs from human peripheral blood mononuclear cells (PBMNCs) obtained from frozen buffy coats after whole blood centrifugation and without density gradient separation.

Induced pluripotent stem cells (iPSCs) represent a source of patient-specific tissues for clinical applications and basic research. Here, we present a detailed protocol to reprogram human peripheral blood mononuclear cells (PBMNCs) obtained from frozen buffy coats into viral-free iPSCs using non-integrating episomal plasmids.

Somatic cells can be reprogrammed into induced pluripotent stem cells (iPSCs) by forcing the expression of four transcription factors (Oct-4, Sox-2, ...

Generation of Integration-free Human Induced Pluripotent Stem Cells Using Hair-derived Keratinocytes

Recent advances in reprogramming allow us to turn somatic cells into human induced pluripotent stem cells (hiPSCs). Disease modeling using patient-specific hiPSCs allows the study of the underlying mechanism for pathogenesis, also providing a platform for the development of in vitro drug screening and gene therapy to improve treatment options. The promising potential of hiPSCs for regenerative medicine is also evident from the increasing number of publications (>7000) on iPSCs in recent years. Various cell types from distinct lineages have been successfully used for hiPSC generation, including skin fibroblasts, hematopoietic cells and epidermal keratinocytes. While skin biopsies and blood collection are routinely performed in many labs as a source of somatic cells for the generation of hiPSCs, the collection and subsequent derivation of hair keratinocytes are less commonly used. Hair-derived keratinocytes represent a non-invasive approach to obtain cell samples from patients. Here we outline a simple non-invasive method for the derivation of keratinocytes from plucked hair. We also provide instructions for maintenance of keratinocytes and subsequent reprogramming to generate integration-free hiPSC using episomal vectors.

This manuscript provides a step-by-step procedure for the derivation and maintenance of human keratinocytes from plucked hair and subsequent generation of integration-free human induced pluripotent stem cells (hiPSCs) by episomal vectors.

Recent advances in reprogramming allow us to turn somatic cells into human induced pluripotent stem cells (hiPSCs). Disease modeling using ...

Generation of Induced Pluripotent Stem Cells from Human Peripheral T Cells Using Sendai Virus in Feeder-free Conditions

Recently, iPSCs have attracted attention as a new source of cells for regenerative therapies. Although the initial method for generating iPSCs relied on dermal fibroblasts obtained by invasive biopsy and retroviral genomic insertion of transgenes, there have been many efforts to avoid these disadvantages. Human peripheral T cells are a unique cell source for generating iPSCs. iPSCs derived from T cells contain rearrangements of the T cell receptor (TCR) genes and are a source of antigen-specific T cells. Additionally, T cell receptor rearrangement in the genome has the potential to label individual cell lines and distinguish between transplanted and donor cells. For safe clinical application of iPSCs, it is important to minimize the risk of exposing newly generated iPSCs to harmful agents. Although fetal bovine serum and feeder cells have been essential for pluripotent stem cell culture, it is preferable to remove them from the culture system to reduce the risk of unpredictable pathogenicity. To address this, we have established a protocol for generating iPSCs from human peripheral T cells using Sendai virus to reduce the risk of exposing iPSCs to undefined pathogens. Although handling Sendai virus requires equipment with the appropriate biosafety level, Sendai virus infects activated T cells without genome insertion, yet with high efficiency. In this protocol, we demonstrate the generation of iPSCs from human peripheral T cells in feeder-free conditions using a combination of activated T cell culture and Sendai virus.

This protocol describes how to generate induced pluripotent stem cells (iPSCs) from human peripheral T cells in feeder-free conditions using a combination of matrigel and Sendai virus vectors containing reprogramming factors.

Recently, iPSCs have attracted attention as a new source of cells for regenerative therapies. Although the initial method for generating iPSCs relied on ...

Generation of Induced-pluripotent Stem Cells Using Fibroblast-like Synoviocytes Isolated from Joints of Rheumatoid Arthritis Patients

Mature somatic cells can be reversed into a pluripotent stem cell-like state using a defined set of reprogramming factors. Numerous studies have generated induced-Pluripotent Stem Cells (iPSCs) from various somatic cell types by transducing four Yamanaka transcription factors: Oct4, Sox2, Klf4 and c-Myc. The study of iPSCs remains at the cutting edge of biological and clinical research. In particular, patient-specific iPSCs can be used as a pioneering tool for the study of disease pathobiology, since iPSCs can be induced from the tissue of any individual. Rheumatoid arthritis (RA) is a chronic inflammatory disease, classified by the destruction of cartilage and bone structure in the joint. Synovial hyperplasia is one of the major reasons or symptoms that lead to these results in RA. Fibroblast-like Synoviocytes (FLSs) are the main component cells in the hyperplastic synovium. FLSs in the joint limitlessly proliferate, eventually invading the adjacent cartilage and bone. Currently, the hyperplastic synovium can be removed only by a surgical procedure. The removed synovium is used for RA research as a material that reflects the inflammatory condition of the joint. As a major player in the pathogenesis of RA, FLSs can be used as a material to generate and investigate the iPSCs of RA patients. In this study, we used the FLSs of a RA patient to generate iPSCs. Using a lentiviral system, we discovered that FLSs can generate RA patient-specific iPSC. The iPSCs generated from FLSs can be further used as a tool to study the pathophysiology of RA in the future.

Here we describe a protocol for generating human induced-pluripotent stem cells from patient-derived fibroblast-like synoviocytes, using a lentiviral system without feeder cells.

Mature somatic cells can be reversed into a pluripotent stem cell-like state using a defined set of reprogramming factors. Numerous studies have generated ...

Generation of Induced Pluripotent Stem Cells from Human Melanoma Tumor-infiltrating Lymphocytes

Adoptive transfer of ex vivo expanded autologous tumor-infiltrating lymphocytes (TILs) can mediate durable and complete responses in significant subsets of patients with metastatic melanoma. Major obstacles of this approach are the reduced viability of transferred T cells, caused by telomere shortening, and the limited number of TILs obtained from patients. Less-differentiated T cells with long telomeres would be an ideal T cell subset for adoptive T cell therapy;however, generating large numbers of these less-differentiated T cells is problematic. This limitation of adoptive T cell therapy can be theoretically overcome by using induced pluripotent stem cells (iPSCs) that self-renew, maintain pluripotency, have elongated telomeres, and provide an unlimited source of autologous T cells for immunotherapy. Here, we present a protocol to generate iPSCs using Sendai virus vectors for the transduction of reprogramming factors into TILs. This protocol generates fully reprogrammed, vector-free clones. These TIL-derived iPSCs might be able to generate less-differentiated patient- and tumor-specific T cells for adoptive T cell therapy.

The goal of this protocol is to show the protocol for reprogramming melanoma tumor-infiltrating lymphocytes into induced pluripotent stem cells.

Adoptive transfer of ex vivo expanded autologous tumor-infiltrating lymphocytes (TILs) can mediate durable and complete responses in significant subsets ...

Induced Pluripotent Stem Cell Generation from Blood Cells Using Sendai Virus and Centrifugation

The recent development of human induced pluripotent stem cells (hiPSCs) proved that mature somatic cells can return to an undifferentiated, pluripotent state. Now, reprogramming is done with various types of adult somatic cells: keratinocytes, urine cells, fibroblasts, etc. Early experiments were usually done with dermal fibroblasts. However, this required an invasive surgical procedure to obtain fibroblasts from the patients. Therefore, suspension cells, such as blood and urine cells, were considered ideal for reprogramming because of the convenience of obtaining the primary cells. Here, we report an efficient protocol for iPSC generation from peripheral blood mononuclear cells (PBMCs). By plating the transduced PBMCs serially to a new, matrix-coated plate using centrifugation, this protocol can easily provide iPSC colonies. This method is also applicable to umbilical cord blood mononuclear cells (CBMCs). This study presents a simple and efficient protocol for the reprogramming of PBMCs and CBMCs.

We propose a protocol for reprogramming peripheral blood mononuclear cells (PBMCs) into induced pluripotent stem cells (iPSCs). By plating the transduced blood cells onto matrix-coated plates with centrifugation, iPSCs are successfully induced from floating cells. This technique suggests a simple and effective reprogramming protocol for cells such as PBMCs and CBMCs.

The recent development of human induced pluripotent stem cells (hiPSCs) proved that mature somatic cells can return to an undifferentiated, pluripotent ...

Generation of Integration-free Induced Pluripotent Stem Cells from Human Peripheral Blood Mononuclear Cells Using Episomal Vectors

Induced Pluripotent Stem Cells (iPSCs) hold great promise for disease modeling and regenerative therapies. We previously reported the use of Episomal Vectors (EV) to generate integration-free iPSCs from peripheral blood mononuclear cells (PB MNCs). The episomal vectors used are DNA plasmids incorporated with oriP and EBNA1 elements from the Epstein-Barr (EB) virus, which&#160;allow for replication and long-term retainment of plasmids in mammalian cells, respectively. With further optimization, thousands of iPSC colonies can be obtained from 1 mL of peripheral blood. Two critical factors for achieving high reprogramming efficiencies&#160;are: 1) the use of a 2A &#34;self-cleavage&#34; peptide to link OCT4 and SOX2, thus achieving equimolar expression of the two factors; 2) the use of two vectors to express MYC and KLF4 individually. Here we describe a step-by-step protocol for generating integration-free iPSCs from adult peripheral blood samples. The generated iPSCs are integration-free as residual episomal plasmids are undetectable after five passages. Although the reprogramming efficiency is comparable to that of Sendai Virus (SV) vectors, EV plasmids are considerably more economical than the commercially available SV vectors. This affordable EV reprogramming system holds potential for clinical applications in regenerative medicine and provides an approach for the direct reprogramming of PB MNCs to integration-free mesenchymal stem cells, neural stem cells, etc.

This protocol describes a detailed method for efficient generation of integration-free iPSCs from human adult peripheral blood cells. With the use of four oriP/EBNA-based episomal vectors to express the reprogramming factors, KLF4, MYC, BCL-XL, or OCT4 and SOX2, thousands of iPSC colonies can be obtained from 1 mL of peripheral blood.

Induced Pluripotent Stem Cells (iPSCs) hold great promise for disease modeling and regenerative therapies. We previously reported the use of Episomal ...

Defined and Scalable Generation of Hepatocyte-like Cells from Human Pluripotent Stem Cells

Human pluripotent stem cells (hPSCs) possess great value for biomedical research. hPSCs can be scaled and differentiated to all cell types found in the human body. The differentiation of hPSCs to human hepatocyte-like cells (HLCs) has been extensively studied, and efficient differentiation protocols have been established. The combination of extracellular matrix and biological stimuli, including growth factors, cytokines, and small molecules, have made it possible to generate HLCs that resemble primary human hepatocytes. However, the majority of procedures still employ undefined components, giving rise to batch-to-batch variation. This serves as a significant barrier to the application of the technology. To tackle this issue, we developed a defined system for hepatocyte differentiation using human recombinant laminins as extracellular matrices in combination with a serum-free differentiation process. Highly efficient hepatocyte specification was achieved, with demonstrated improvements in both HLC function and phenotype. Importantly, this system is easy to scale up using research and GMP-grade hPSC lines&#160;promising advances in cell-based modelling and therapies.

The method presented here describes a scalable and good manufacturing practice (GMP)-ready differentiation system to generate human hepatocyte-like cells from pluripotent stem cells. It serves as a cost-effective and standardized system to generate human hepatocyte-like cells for basic and applied human liver research.

Human pluripotent stem cells (hPSCs) possess great value for biomedical research. hPSCs can be scaled and differentiated to all cell types found in the ...

Generation of Standardized and Reproducible Forebrain-type Cerebral Organoids from Human Induced Pluripotent Stem Cells

The human cortex is highly expanded and exhibits a complex structure with specific functional areas, providing higher brain function, such as cognition. Efforts to study human cerebral cortex development have been limited by the availability of model systems. Translating results from rodent studies to the human system is restricted by species differences and studies on human primary tissues are hampered by a lack of tissue availability as well as ethical concerns. Recent development in human pluripotent stem cell (PSC) technology include the generation of three-dimensional (3D) self-organizing organotypic culture systems, which mimic to a certain extent human-specific brain development in vitro. Currently, various protocols are available for the generation of either whole brain or brain-region specific organoids. The method for the generation of homogeneous and reproducible forebrain-type organoids from induced PSC (iPSC), which we previously established and describe here, combines the intrinsic ability of PSC to self-organize with guided differentiation towards the anterior neuroectodermal lineage and matrix embedding to support the formation of a continuous neuroepithelium. More specifically, this protocol involves: (1) the generation of iPSC aggregates, including the conversion of iPSC colonies to a confluent monolayer culture; (2) the induction of anterior neuroectoderm; (3) the embedding of neuroectodermal aggregates in a matrix scaffold; (4) the generation of forebrain-type organoids from neuroectodermal aggregates; and (5) the fixation and validation of forebrain-type organoids. As such, this protocol provides an easily applicable system for the generation of standardized and reproducible iPSC-derived cortical tissue structures in vitro.

Cerebral organoids represent a new model system to investigate early human brain development in vitro. This article provides the detailed methodology to efficiently generate homogeneous dorsal forebrain-type organoids from human induced pluripotent stem cells including critical characterization and validation steps.

The human cortex is highly expanded and exhibits a complex structure with specific functional areas, providing higher brain function, such as cognition. ...

Generation of 3D Skin Organoid from Cord Blood-derived Induced Pluripotent Stem Cells

The skin is the body&#8217;s largest organ and has many functions. The skin acts as a physical barrier and protector of the body and regulates bodily functions. Biomimetics is the imitation of the models, systems, and elements of nature for the purpose of solving complex human problems1. Skin biomimetics is a useful tool for in vitro disease research and in vivo regenerative medicine. Human induced pluripotent stem cells (iPSCs) have the characteristic of unlimited proliferation and the ability of differentiation to three germ layers. Human iPSCs are generated from various primary cells, such as blood cells, keratinocytes, fibroblasts, and more. Among them, cord blood mononuclear cells (CBMCs) have emerged as an alternative cell source from the perspective of allogeneic regenerative medicine. CBMCs are useful in regenerative medicine because human leukocyte antigen (HLA) typing is essential to the cell banking system. We provide a method for the differentiation of CBMC-iPSCs into keratinocytes and fibroblasts and for generation of a 3D skin organoid. CBMC-iPSC-derived keratinocytes and fibroblasts have characteristics similar to a primary cell line. The 3D skin organoids are generated by overlaying an epidermal layer onto a dermal layer. By transplanting this 3D skin organoid, a humanized mice model is generated. This study shows that a 3D human iPSC-derived skin organoid may be a novel, alternative tool for dermatologic research in vitro and in vivo.

We propose a protocol that shows how to differentiate induced pluripotent stem cell-derived keratinocytes and fibroblasts and generate a 3D skin organoid, using these keratinocytes and fibroblasts. This protocol contains an additional step of generating a humanized mice model. The technique presented here will improve dermatologic research.

The skin is the body&#8217;s largest organ and has many functions. The skin acts as a physical barrier and protector of the body and regulates bodily ...