We thank Dr. Soshana Svendsen for critical review and editing of this report.&#160; This work was contributed to by the NIH/NINDS 1U24NS078370-01 and CIRM DR2A-05320.

The authors have nothing to disclose.

<img alt="Figure 6" fo:content-width="5in" src="/files/ftp_upload/51219/51219fig6highres.jpg" width="500" /> 
Figure 6.&#160;Chopping Schematic. Expanding spheroid stem/progenitor cells in culture using the mechanical chopping method.
Critical Steps
An overview of the chopping expansion paradigm is shown in Figure 6. hNPC sphere size is one of the important criteria to observe before passag...

A correction was made to <a href="/video/51219">A cGMP-applicable Expansion Method for Aggregates of Human Neural Stem and Progenitor Cells Derived From Pluripotent Stem Cells or Fetal Brain Tissue</a>. The corresponding author was changed from:
Brandon C. Shelley 
to:
Clive Svendsen

A correction was made to <a href="/video/51219">A cGMP-applicable Expansion Method for Aggregates of Human Neural Stem and Progenitor Cells Derived From Pluripotent Stem Cells or Fetal Brain Tissue</a>. The corresponding author was changed.

Erratum: A cGMP-applicable Expansion Method for Aggregates of Human Neural Stem and Progenitor Cells Derived From Pluripotent Stem Cells or Fetal Brain Tissue

There is a long history of expanding rodent neural stem cells in culture as either a monolayer1-3 or aggregate neurospheres4-7. In addition, human neural progenitor cells (hNPCs) isolated from various regions of the developing central nervous system8-17 have been expanded in vitro. These cells are bi-potent, capable of differentiating into both astrocytes and neurons and have been a very useful tool in studying neural development18,19 and disease mechanism20,21. hNPCs have also been transplanted into many different animal models of central nervous system disease with varying levels of integration, survival and functional effects22-24.
Traditionally, rodent or human fetal-derived NPCs are exposed to growth factors &#8211; often epidermal growth factor (EGF) and/or fibroblast growth factor-2 (FGF-2)25-28 &#8211; and both adherent29 and three-dimensional spheroid systems are typically passaged using enzymatic dissociation into a single-cell suspension30-34. The standard method to expand cells for research or clinical use is as an adherent monolayer due to easy manipulation. However, we have shown that passaging monolayer and neurosphere hNPCs with enzymatic or chemical solutions resulted in early senescence35. In addition, enzymatic dissociation may result in increased levels of differentiation and karyotypic abnormalities based on data demonstrated with embryonic stem cells36-38. Although the standard method of passaging hNPCs has produced current good manufacturing practice (cGMP) grade products that have gone into phase 1 clinical trials (Stem Cells Inc., Neuralstem Inc.), the method permitted only a few rounds of cell amplification, limiting the banking potential.
Clearly, large research experiments and future clinical trials could benefit from the ability to propagate cells in bulk and with delayed senescence to permit large-scale growth and cell banking. To address this need, we developed a novel and automated way of mechanically passaging intact neurospheres by &#8220;chopping&#8221; them into small clusters to maintain cell-to-cell contact. This method greatly increased their lifespan39 and suspension culture permits a more efficient use of incubator space compared to monolayer cultures, as seen with an alternative 3D bioreactor culture method40. The provided chopping protocol allows for the production of large-scale banks from one fetal sample greater than passage 10, an unlikely feat using standard passaging methods. While this method for passaging hNPCs is unconventional, it is growing in popularity and was recently, published with other cell types such as neural stem cells derived from human embryonic and induced pluripotent stem cells, enabling large scale expansion for various applications including in vitro disease modeling41-46. Importantly, a cGMP-grade hNPC cell bank has already been produced with the chopping method, demonstrating that the technique can be applied towards future clinical applications.

<table border="0" cellpadding="0" cellspacing="0" width="1230">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;">Beaker, 50 mL</td>
			<td style="width:159px;">Fisherbrand</td>
			<td>FB-100-50</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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			<td style="width:128px;">SG-603A</td>
			<td style="width:464px;">4 ft. or 6 ft. model.&#160; 6 ft. model recommended; multiple manufacturers/suppliers</td>
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			<td style="width:159px;">Personna</td>
			<td style="width:128px;">74-0002</td>
			<td style="width:464px;">multiple manufacturers/suppliers.&#160; CAUTION: Sharp</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Cell Freezing Media</td>
			<td style="width:159px;">Sigma-Aldrich</td>
			<td style="width:128px;">C6295-50ML</td>
			<td style="width:464px;">DMSO, serum-free</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Centrifuge, swing-bucket with 15 mL inserts</td>
			<td style="width:159px;">Eppendorf</td>
			<td style="width:128px;">5810 R</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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			<td height="21" style="height:21px;width:479px;">Conical Tubes, 15 mL</td>
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			<td style="width:128px;">S50712</td>
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			<td style="width:128px;">353045</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Culture Flask, Vented, T75&#160;</td>
			<td style="width:159px;">BD Falcon</td>
			<td style="width:128px;">353110</td>
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			<td height="21" style="height:21px;width:479px;">Filter, 0.22 &#181;m, attached cup, 1 L</td>
			<td style="width:159px;">Millipore</td>
			<td style="width:128px;">SCGPU11RE</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Filter, 0.22 &#181;m, attached cup, 150 mL</td>
			<td style="width:159px;">Millipore</td>
			<td style="width:128px;">SCGVU01RE</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Filter, 0.22 &#181;m, attached cup, 500 mL</td>
			<td style="width:159px;">Millipore</td>
			<td style="width:128px;">SCGPU05RE</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Filter, 0.22 &#181;m, attached cup, 50 mL</td>
			<td style="width:159px;">Millipore</td>
			<td style="width:128px;">SCGP00525</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Filter Paper, 8.5 cm circles</td>
			<td style="width:159px;">Whatman/GE</td>
			<td style="width:128px;">1001-085</td>
			<td style="width:464px;"></td>
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			<td height="21" style="height:21px;width:479px;">Forceps, Standard Pattern - Serrated/Curved/18 cm</td>
			<td style="width:159px;">Fine Science Tools</td>
			<td style="width:128px;">11001-18</td>
			<td style="width:464px;"></td>
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			<td height="21" style="height:21px;width:479px;">Freezing Chamber, Isopropyl Alcohol</td>
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			<td style="width:464px;">&#34;Mr. Frosty&#34;</td>
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			<td height="21" style="height:21px;width:479px;">Incubator, 37&#176;C/5% CO2</td>
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			<td style="width:128px;">370 series</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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			<td style="width:159px;">Hausser Scientific</td>
			<td style="width:128px;">1475</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">McIlwain Tissue Chopper</td>
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			<td style="width:464px;">&#160;Petri dish modification required.&#160;&#160; CAUTION:&#160; Moving, sharp blade.</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Micropipettor, 1 - 10 &#956;L</td>
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			<td style="width:128px;">F144562</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Micropipettor, 100 - 1000 &#956;L (starter kit)</td>
			<td style="width:159px;">Gilson</td>
			<td style="width:128px;">F167700</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Micropipettor, 2 - 20 &#956;L (starter kit)</td>
			<td style="width:159px;">Gilson</td>
			<td style="width:128px;">F167700</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Micropipettor, 20 - 200 &#956;L (starter kit)</td>
			<td style="width:159px;">Gilson</td>
			<td style="width:128px;">F167700</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
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			<td style="width:159px;">Steritool</td>
			<td style="width:128px;">10302</td>
			<td style="width:464px;"></td>
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		<tr height="21">
			<td height="21" style="height:21px;">Pasteur Pipets, cotton-plugged</td>
			<td style="width:159px;">Fisherbrand</td>
			<td style="width:128px;">13-678-8B</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Petri Dish, Glass, Autoclavable</td>
			<td style="width:159px;">Corning</td>
			<td style="width:128px;">3160-100</td>
			<td style="width:464px;"></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Pipet Aid</td>
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			<td style="width:128px;">4-000-101</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Shim disc</td>
			<td style="width:159px;">McMaster-Carr</td>
			<td style="width:128px;">VARIABLE</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Sterile barrier pipet tips, 10 &#956;L</td>
			<td style="width:159px;">AvantGuard</td>
			<td style="width:128px;">AV10R-H</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Sterile barrier pipet tips, 1000 &#956;L</td>
			<td style="width:159px;">AvantGuard</td>
			<td style="width:128px;">AV1000</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Sterile barrier pipet tips, 20 &#956;L</td>
			<td style="width:159px;">AvantGuard</td>
			<td style="width:128px;">AV20-H</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Sterile barrier pipet tips, 200 &#956;L</td>
			<td style="width:159px;">AvantGuard</td>
			<td style="width:128px;">AV200-H</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Sterile Disposable pipettes, all-plastic wrap, 10 mL</td>
			<td style="width:159px;">Fisherbrand</td>
			<td style="width:128px;">13-676-10J</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Sterile Disposable pipettes, all-plastic wrap, 2 mL</td>
			<td style="width:159px;">Fisherbrand</td>
			<td style="width:128px;">13-675-3C</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Sterile Disposable pipettes, all-plastic wrap, 25 mL</td>
			<td style="width:159px;">Fisherbrand</td>
			<td style="width:128px;">13-676-10K</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Sterile Disposable pipettes, all-plastic wrap, 5 mL</td>
			<td style="width:159px;">Fisherbrand</td>
			<td style="width:128px;">13-676-10H</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Sterilization Pouches, 19 x 33 cm</td>
			<td style="width:159px;">Crosstex</td>
			<td style="width:128px;">SCL</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="24">
			<td height="24" style="height:24px;width:479px;">Strainer, 40 &#181;m</td>
			<td style="width:159px;">BD Falcon</td>
			<td style="width:128px;">352340</td>
			<td style="width:464px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Tissue Culture Dishes, 60 mm</td>
			<td style="width:159px;">BD Falcon</td>
			<td style="width:128px;">351007</td>
			<td style="width:464px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Tube Racks, Interlocking Four-Way</td>
			<td style="width:159px;">Fisherbrand</td>
			<td style="width:128px;">03-448-17</td>
			<td style="width:464px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Water Bath</td>
			<td style="width:159px;">Fisherbrand</td>
			<td>S52602Q</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;"></td>
			<td style="width:159px;"></td>
			<td></td>
			<td style="width:464px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Neural Progenitor Cell-Specific Processing Reagents</td>
			<td style="width:159px;"></td>
			<td style="width:128px;"></td>
			<td style="width:464px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Neural Stem Cell Expansion Medium (Stemline)</td>
			<td style="width:159px;">Sigma-Aldrich</td>
			<td style="width:128px;">S3194-500ML</td>
			<td style="width:464px;">Important to use the Stemline brand</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Recombinant Human Epidermal Growth Factor (EGF)</td>
			<td style="width:159px;">Millipore</td>
			<td style="width:128px;">GF316</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Recombinant Human Leukemia Inhibitory Factor (LIF)</td>
			<td style="width:159px;">Millipore</td>
			<td style="width:128px;">LIF1010</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">Trypan Blue (0.4%)</td>
			<td style="width:159px;">Sigma-Aldrich</td>
			<td style="width:128px;">T8154-100ML</td>
			<td style="width:464px;">multiple manufacturers/suppliers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:479px;">TrypLE Select (1X)</td>
			<td style="width:159px;">Life Technologies</td>
			<td style="width:128px;">12563-011</td>
			<td style="width:464px;"></td>
		</tr>
	</tbody>
</table>

a cgmp-applicable expansion method for aggregates of human neural stem and progenitor cells derived from pluripotent stem cells or fetal brain tissue

A cell expansion technique to amass large numbers of cells from a single specimen for research experiments and clinical trials would greatly benefit the stem cell community. Many current expansion methods are laborious and costly, and those involving complete dissociation may cause several stem and progenitor cell types to undergo differentiation or early senescence. To overcome these problems, we have developed an automated mechanical passaging method referred to as &#8220;chopping&#8221; that is simple and inexpensive. This technique avoids chemical or enzymatic dissociation into single cells and instead allows for the large-scale expansion of suspended, spheroid cultures that maintain constant cell/cell contact. The chopping method has primarily been used for fetal brain-derived neural progenitor cells or neurospheres, and has recently been published for use with neural stem cells derived from embryonic and induced pluripotent stem cells. The procedure involves seeding neurospheres onto a tissue culture Petri dish and subsequently passing a sharp, sterile blade through the cells effectively automating the tedious process of manually mechanically dissociating each sphere. Suspending cells in culture provides a favorable surface area-to-volume ratio; as over 500,000 cells can be grown within a single neurosphere of less than 0.5 mm in diameter. In one T175 flask, over 50 million cells can grow in suspension cultures compared to only 15 million in adherent cultures. Importantly, the chopping procedure has been used under current good manufacturing practice (cGMP), permitting mass quantity production of clinical-grade cell products.

<img alt="Figure 5" fo:content-width="5in" src="/files/ftp_upload/51219/51219fig5highres.jpg" width="500" /> 
Figure 5.&#160;Representative data. A) Projected cell numbers of hNPCs frozen at p19, then thawed and expanded as an adherent monolayer using enzymatic dissociation compared to neurospheres passaged via the chopping method. Day 0 represents when the cells were thawed at p20. B) Representative images of spheres pre-chop, ...

Watch this Scientific Journal Video about A cGMP-applicable Expansion Method for Aggregates of Human Neural Stem and Progenitor Cells Derived From Pluripotent Stem Cells or Fetal Brain Tissue at JoVE.

A cGMP-applicable Expansion Method for Aggregates of Human Neural Stem and Progenitor Cells Derived From Pluripotent Stem Cells or Fetal Brain Tissue

This protocol describes a novel mechanical chopping method that allows the expansion of spherical neural stem and progenitor cell aggregates without dissociation to a single cell suspension.&#160; Maintaining cell/cell contact allows rapid and stable growth for over 40 passages.

A cell expansion technique to amass large numbers of cells from a single specimen for research experiments and clinical trials would greatly benefit the ...

a-cgmp-applicable-expansion-method-for-aggregates-human-neural-stem

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JoVE Journal

Neuroscience

13.4K Views.  Cedars-Sinai Medical Center. This protocol describes a novel mechanical chopping method that allows the expansion of spherical neural stem and progenitor cell aggregates without dissociation to a single cell suspension.  Maintaining cell/cell contact allows rapid and stable growth for over 40 passages.

Video: A cGMP-applicable Expansion Method for Aggregates of Human Neural Stem and Progenitor Cells Derived From Pluripotent Stem Cells or Fetal Brain Tissue