This work was supported by the Fonds Medizinische Forschung at the University of Zurich, Forschungskredit of the University of Zurich, The SCIEX NMSCh under Fellowships 10.216 and 12.176, The Swiss Society of Cardiology, The Swiss National Science Foundation under Grant [320030-122273] and [310030-143992], The 7th Framework Programme, Life Valve, European Commission under Grant [242008], the Olga Mayenfisch Foundation, the EMDO Foundation, the Start-up Grant 2012 of the University Hospital Zurich, and internal funding of the Mitchell Cancer Institute.

The protocol follows institutional guidelines of the ethics committee for human research. Written consent of the patient was obtained for using the amniotic fluid for research.
This protocol follows the policies of the Institutional Animal Care and Use Committee of the University of South Alabama.
1. Isolation and Culture of Primary Amniotic Mesenchymal Stem Cells
<ol>
	<li>Plating of amniotic fluid cells
	<ol>
		<li>Obtain a minimum of 2.5 mL of ...

<ol>
	<li>Takahashi, K., Yamanaka, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Induction+of+pluripotent+stem+cells+from+mouse+embryonic+and+adult+fibroblast+cultures+by+defined+factors.">Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors.</a> Cell. 126 (4), 663-676 (2006).</li><li>Yu, 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=Induced+Pluripotent+Stem+Cell+Lines+Derived+from+Human+Somatic+Cells.">Induced Pluripotent Stem Cell Lines Derived from Human Somatic Cells.</a> Science. 318 (5858), 1917-1920 (2007).</li><li>Trounson, A., DeWitt, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pluripotent+stem+cells+progressing+to+the+clinic.">Pluripotent stem cells progressing to the clinic.</a> Nat. Rev. Mol. Cell Biol. 17 (3), 194-200 (2016).</li><li>Schmidt, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prenatally+fabricated+autologous+human+living+heart+valves+based+on+amniotic+fluid+derived+progenitor+cells+as+single+cell+source.">Prenatally fabricated autologous human living heart valves based on amniotic fluid derived progenitor cells as single cell source.</a> Circulation. 116 (11 Suppl), I64-I70 (2007).</li><li>Weber, B., Zeisberger, S. M., Hoerstrup, S. 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Pathol. 25 (4), 300-305 (2016).</li><li>Slamecka, 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=Non-integrating+episomal+plasmid-based+reprogramming+of+human+amniotic+fluid+stem+cells+into+induced+pluripotent+stem+cells+in+chemically+defined+conditions.">Non-integrating episomal plasmid-based reprogramming of human amniotic fluid stem cells into induced pluripotent stem cells in chemically defined conditions.</a> Cell Cycle. 15 (2), 234-249 (2016).</li><li>Jiang, G., 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+Transgene-Free+Amniotic-Fluid-Derived+Induced+Pluripotent+Stem+Cells+for+Autologous+Cell+Therapy.">Human Transgene-Free Amniotic-Fluid-Derived Induced Pluripotent Stem Cells for Autologous Cell Therapy.</a> Stem Cells Dev. 23 (21), 2613-2625 (2014).</li><li>Pipino, C., 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=Trisomy+21+mid-trimester+amniotic+fluid+induced+pluripotent+stem+cells+maintain+genetic+signatures+during+reprogramming:+implications+for+disease+modeling+and+cryobanking.">Trisomy 21 mid-trimester amniotic fluid induced pluripotent stem cells maintain genetic signatures during reprogramming: implications for disease modeling and cryobanking.</a> Cell. 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Protoc. 8 (2), 223-253 (2013).</li><li>Chan, E. 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=Live+cell+imaging+distinguishes+bona+fide+human+iPS+cells+from+partially+reprogrammed+cells.">Live cell imaging distinguishes bona fide human iPS cells from partially reprogrammed cells.</a> Nat. Biotechnol. 27 (11), 1033-1037 (2009).</li><li>Adewumi, O., 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=Characterization+of+human+embryonic+stem+cell+lines+by+the+International+Stem+Cell+Initiative.">Characterization of human embryonic stem cell lines by the International Stem Cell Initiative.</a> Nat. Biotechnol. 25 (7), 803-816 (2007).</li><li>M&#252;ller, F. -. 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The authors declare that they have no competing financial interests.

The initial phase of iPSC generation from fetal stem cells entails the extraction of the source cells from the fetal tissues, their culture, expansion, and introduction of the episomal reprogramming plasmids. This phase is followed by a culture period of around 14-18 days before the first fully reprogrammed colonies can be expanded. The final phase is maturation of the iPSC clones. The initial extraction of amniotic membrane stem cells is achieved by means of a combined mechanical and enzymatic digestion of the amnion. W...

The technology of induced pluripotent stem cells (iPSC) brings about potential cell replacement therapies, disease and developmental modeling, and drug and toxicological screening1,2,3. Replacement therapies can conceptually be achieved by cell injection, in-vitro differentiated tissue (such as cardiac patches) implantation, or guided regeneration by means of tissue engineering. Amniotic fluid (AFSC) and membrane stem cells (AMSC) are an excellent source of cells for these interventions either directly4,5,6,7 or as a starting cell population for reprogramming into pluripotency8,9,10,11,12.
Early approaches used undefined culture systems or reprogramming methods that require entail genomic integration of constructs9,10,11,12. A more recent study employed a xeno-free medium, even though a less defined basement membrane attachment matrix (BMM) was used, to generate iPSC from amniotic fluid epithelial cells. However, the teratoma formation assay was not included in the study along with a wealth of in-vitro and molecular data. Amniotic fluid epithelial cells were found to have a roughly 8-fold higher reprogramming efficiency when compared to neonatal fibroblasts13. In another study, mesenchymal stem cells from amniotic fluid were also found to be reprogrammed into iPSC with a much higher efficiency12.
Pluripotent stem cells can be differentiated into tissues representative of all 3 germ layers and thus have the broadest potential. Pediatric patients could benefit from the harvesting, reprogramming, and tissue engineering of their autologous amniotic fluid stem cells prenatally and amniotic membrane stem cells perinatally. Furthermore, the relatively low level of differentiation of fetal stem cells (lower than adult stem cells14,15) could theoretically aid in addressing the observed retention of epigenetic bias from source cells in iPSC16.
Here we present a protocol for reprogramming amniotic fluid and membrane stem cells to pluripotency in chemically defined xeno-free E8 medium on recombinant vitronectin17 (VTN) using episomal plasmids18. The main advantage of amniotic fluid and membrane cells as a source of cells for reprogramming lies in their availability pre- and perinatally and thus this approach would mainly benefit research into pediatric tissue engineering.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	
	<tbody>
		<tr >
			<td >Tumor Dissociation Kit, human</td>
			<td >Miltenyi Biotec</td>
			<td >130-095-929</td>
			<td >tissue dissociation system, reagent kit, includes tissue dissociation tubes and tissue dissociation enzymes</td>
		</tr>
		<tr >
			<td >gentleMACS Dissociator</td>
			<td >Miltenyi Biotec</td>
			<td >130-093-235</td>
			<td >tissue dissociation system, dissociator</td>
		</tr>
		<tr >
			<td >Thermo Scientific&#8482; Shandon&#8482; Disposable Scalpel No. 10, Sterile, Individually Wrapped, 5.75 (14.6cm)</td>
			<td >Thermo-Fisher</td>
			<td >3120032</td>
			<td ></td>
		</tr>
		<tr >
			<td >70 &#181;m cell strainers</td>
			<td >Corning</td>
			<td >10054-456</td>
			<td ></td>
		</tr>
		<tr >
			<td >RPMI 1640 medium</td>
			<td >Thermo-Fisher</td>
			<td >32404014&#160;</td>
			<td ></td>
		</tr>
		<tr >
			<td >rocking platform</td>
			<td >VWR</td>
			<td >40000-300</td>
			<td ></td>
		</tr>
		<tr >
			<td >50 ml centrifuge tubes</td>
			<td >Thermo-Fisher</td>
			<td >339652</td>
			<td ></td>
		</tr>
		<tr >
			<td >15 ml centrifuge tubes</td>
			<td >Thermo-Fisher</td>
			<td >339650</td>
			<td ></td>
		</tr>
		<tr >
			<td >EBM-2 basal medium</td>
			<td >Lonza</td>
			<td >CC-3156</td>
			<td >basal medium for AFMC medium</td>
		</tr>
		<tr >
			<td >FGF 2 Human (expressed in E. coli, non-glycosylated)</td>
			<td >Prospec Bio</td>
			<td >CYT-218</td>
			<td >bFGF, supplement for AFMC medium</td>
		</tr>
		<tr >
			<td >EGF Human, Pichia</td>
			<td >Prospec Bio</td>
			<td >CYT-332&#160;</td>
			<td >EGF, supplement for AFMC medium</td>
		</tr>
		<tr >
			<td >LR3 Insulin Like Growth Factor-1 Human Recombinant</td>
			<td >Prospec Bio</td>
			<td >CYT-022</td>
			<td >IGF, supplement for AFMC medium</td>
		</tr>
		<tr >
			<td >Fetal Bovine Serum, embryonic stem cell-qualified</td>
			<td >Thermo-Fisher</td>
			<td >10439024</td>
			<td >FBS</td>
		</tr>
		<tr >
			<td >Antibiotic-Antimycotic (100X)</td>
			<td >Thermo-Fisher</td>
			<td >15240062&#160;</td>
			<td >for primary AFSC/AMSC, for routine AFSC/AMSC it should not be necessary, do not use in medium for transfected cells!</td>
		</tr>
		<tr >
			<td >Accutase cell detachment solution</td>
			<td >StemCell Technologies</td>
			<td >07920</td>
			<td >cell detachment enzyme</td>
		</tr>
		<tr >
			<td >CryoStor&#8482; CS10</td>
			<td >StemCell Technologies</td>
			<td >07930</td>
			<td >complete freezing medium</td>
		</tr>
		<tr >
			<td >PBS, pH 7.4</td>
			<td >Thermo-Fisher Scientific</td>
			<td >10010023&#160;</td>
			<td ></td>
		</tr>
		<tr >
			<td >EndoFree Plasmid Maxi Kit (10)</td>
			<td >Qiagen</td>
			<td >12362</td>
			<td >for plasmid isolation</td>
		</tr>
		<tr >
			<td >pEP4 E02S EN2K</td>
			<td >Addgene</td>
			<td >20925</td>
			<td >EN2K, reprogramming factors Oct4+Sox2, Nanog+Klf4</td>
		</tr>
		<tr >
			<td >pEP4 E02S ET2K</td>
			<td >Addgene</td>
			<td >20927</td>
			<td >ET2K, reprogramming factors Oct4+Sox2, SV40LT+Klf4</td>
		</tr>
		<tr >
			<td >pCEP4-M2L</td>
			<td >Addgene</td>
			<td >20926</td>
			<td >M2L, reprogramming factors c-Myc+LIN28</td>
		</tr>
		<tr >
			<td >NanoDrop 2000c UV-Vis Spectrophotometer</td>
			<td >Thermo-Fisher</td>
			<td >ND-2000C</td>
			<td >spectrophotometer</td>
		</tr>
		<tr >
			<td >Neon&#174; Transfection System</td>
			<td >Thermo-Fisher</td>
			<td >MPK5000</td>
			<td >transfection system, components: 
			Neon pipette - transfection pipette 
			Neon device - transfection device</td>
		</tr>
		<tr >
			<td >Neon&#174; Transfection System 10 &#181;L Kit</td>
			<td >Thermo-Fisher</td>
			<td >MPK1025</td>
			<td >consumables kit for the Neon Transfection System, it contains: 
			Neon tip - transfection tip 
			Neon tube - transfection tube 
			buffer R - resuspension buffer 
			buffer E - electrolytic buffer</td>
		</tr>
		<tr >
			<td >Stemolecule&#8482; Sodium Butyrate</td>
			<td >StemGent</td>
			<td >04-0005</td>
			<td >small molecule enhancer of reprogramming</td>
		</tr>
		<tr >
			<td >TeSR-E8</td>
			<td >StemCell Technologies</td>
			<td >05940</td>
			<td >E8 medium</td>
		</tr>
		<tr >
			<td >Vitronectin XF&#8482;</td>
			<td >StemCell Technologies</td>
			<td >07180</td>
			<td >VTN, stock concentration 250 &#181;g/ml, used for coating at 1 &#181;g/cm2 in vitronectin dilution (CellAdhere) buffer</td>
		</tr>
		<tr >
			<td >CellAdhere&#8482; Dilution Buffer</td>
			<td >StemCell Technologies</td>
			<td >07183</td>
			<td >vitronectin dilution buffer</td>
		</tr>
		<tr >
			<td >UltraPure&#8482; 0.5M EDTA, pH 8.0</td>
			<td >Thermo-Fisher</td>
			<td >15575020</td>
			<td >dilute with PBS to 0.5 mM before use</td>
		</tr>
		<tr >
			<td >EVOS&#174; FL Imaging System</td>
			<td >Thermo-Fisher Scientific</td>
			<td >AMF4300</td>
			<td >LCD imaging microscope system</td>
		</tr>
		<tr >
			<td >CKX53 Inverted Microscope</td>
			<td >Olympus</td>
			<td ></td>
			<td >phase contrast cell culture microscope</td>
		</tr>
		<tr >
			<td >Pierce&#8482; 16% Formaldehyde (w/v), Methanol-free</td>
			<td >Thermo-Fisher</td>
			<td >28908</td>
			<td >dilute to 4% with PBS before use, diluted can be stored at 2-8 &#176;C for 1 week</td>
		</tr>
		<tr >
			<td >Perm Buffer III</td>
			<td >BD Biosciences</td>
			<td >558050</td>
			<td >permeabilization buffer, chill to -20 &#176;C before use</td>
		</tr>
		<tr >
			<td >Mouse IgG1, &#954; Isotype Control, Alexa Fluor&#174; 488</td>
			<td >BD Biosciences</td>
			<td >557782</td>
			<td >isotype control for Oct3/4A, Nanog</td>
		</tr>
		<tr >
			<td >Mouse IgG1, &#954; Isotype Control, Alexa Fluor&#174; 647</td>
			<td >BD Biosciences</td>
			<td >557783</td>
			<td >isotype control for Sox2</td>
		</tr>
		<tr >
			<td >Mouse anti-human Oct3/4 (Human Isoform A), Alexa Fluor&#174; 488</td>
			<td >BD Biosciences</td>
			<td >561628</td>
			<td ></td>
		</tr>
		<tr >
			<td >Mouse anti-human Nanog, Alexa Fluor&#174; 488</td>
			<td >BD Biosciences</td>
			<td >560791</td>
			<td ></td>
		</tr>
		<tr >
			<td >Mouse anti-human Sox-2, Alexa Fluor&#174; 647</td>
			<td >BD Biosciences</td>
			<td >562139</td>
			<td ></td>
		</tr>
		<tr >
			<td >Mouse IgGM, &#954; Isotype Control, Alexa Fluor&#174; 488</td>
			<td >BD Biosciences</td>
			<td >401617</td>
			<td >isotype control for TRA-1-60</td>
		</tr>
		<tr >
			<td >Mouse IgGM, &#954; Isotype Control, Alexa Fluor&#174; 647</td>
			<td >BD Biosciences</td>
			<td >401618</td>
			<td >isotype control for TRA-1-81</td>
		</tr>
		<tr >
			<td >Mouse anti-human TRA-1-60, Alexa Fluor&#174; 488</td>
			<td >BD Biosciences</td>
			<td >330613</td>
			<td ></td>
		</tr>
		<tr >
			<td >Mouse anti-human TRA-1-81, Alexa Fluor&#174; 647</td>
			<td >BD Biosciences</td>
			<td >330705</td>
			<td ></td>
		</tr>
		<tr >
			<td >Mouse IgG1, &#954; Isotype Control, Alexa Fluor&#174; 488</td>
			<td >BD Biosciences</td>
			<td >400129</td>
			<td >isotype control for SSEA-1</td>
		</tr>
		<tr >
			<td >Mouse IgG3, &#954; Isotype Control, Alexa Fluor&#174; 647</td>
			<td >BD Biosciences</td>
			<td >401321</td>
			<td >isotype control for SSEA-4</td>
		</tr>
		<tr >
			<td >Mouse anti-human SSEA-1, Alexa Fluor&#174; 488</td>
			<td >BD Biosciences</td>
			<td >323010</td>
			<td ></td>
		</tr>
		<tr >
			<td >Mouse anti-human SSEA-4, Alexa Fluor&#174; 647</td>
			<td >BD Biosciences</td>
			<td >330407</td>
			<td ></td>
		</tr>
		<tr >
			<td >Affinipure F(ab&#39;)2 Fragment Goat Anti-Mouse IgG+IgM, Alexa Fluor&#174; 488</td>
			<td >Jackson Immunoresearch</td>
			<td >115-606-068</td>
			<td >use at a dilution of 1:600 or further optimize</td>
		</tr>
		<tr >
			<td >Affinipure F(ab&#39;)2 Fragment Goat Anti-Mouse IgG+IgM, Alexa Fluor&#174; 647</td>
			<td >Jackson Immunoresearch</td>
			<td >115-546-068</td>
			<td >use at a dilution of 1:600 or further optimize</td>
		</tr>
		<tr >
			<td >DAPI</td>
			<td >Thermo-Fisher Scientific</td>
			<td >D21490</td>
			<td >stock solution 10 mM, further dilute to 1:12.000 for a working solution</td>
		</tr>
		<tr >
			<td >Corning&#174; Matrigel&#174; Growth Factor Reduced, Phenol Red-Free</td>
			<td >Corning</td>
			<td >356231</td>
			<td >basement membrane matrix (BMM)</td>
		</tr>
		<tr >
			<td >scid-beige mice, female</td>
			<td >Taconic</td>
			<td >CBSCBG-F</td>
			<td ></td>
		</tr>
		<tr >
			<td >RNeasy Plus Mini Kit (50)</td>
			<td >Qiagen</td>
			<td >74134</td>
			<td >RNA isolation kit</td>
		</tr>
		<tr >
			<td >T-25 flasks, tissue culture-treated</td>
			<td >Thermo-Fisher</td>
			<td >156367</td>
			<td ></td>
		</tr>
		<tr >
			<td >T-75 flasks, tissue culture-treated</td>
			<td >Thermo-Fisher</td>
			<td >156499</td>
			<td ></td>
		</tr>
		<tr >
			<td >Nunc&#8482; tissue-culture dish</td>
			<td >Thermo-Fisher</td>
			<td >12-567-650&#160;</td>
			<td >10 cm tissue culture dish</td>
		</tr>
		<tr >
			<td >6-well plates, tissue-culture treated</td>
			<td >Thermo-Fisher</td>
			<td >140675</td>
			<td ></td>
		</tr>
		<tr >
			<td >Neubauer counting chamber (hemacytometer)</td>
			<td >VWR</td>
			<td >15170-173</td>
			<td ></td>
		</tr>
		<tr >
			<td >Mr. Frosty&#8482; Freezing Container</td>
			<td >Thermo-Fisher</td>
			<td >5100-0001&#160;</td>
			<td >freezing container</td>
		</tr>
		<tr >
			<td >FACS tubes, Round Bottom Polystyrene Test Tube, 5ml</td>
			<td >Corning</td>
			<td >352058</td>
			<td >5 ml polystyrene tubes</td>
		</tr>
		<tr >
			<td >Eppendorf tubes, 1.5 ml</td>
			<td >Thermo-Fisher</td>
			<td >05-402-96</td>
			<td >1.5 ml microcentrifuge tubes</td>
		</tr>
		<tr >
			<td >PCR tubes, 200 &#181;l</td>
			<td >Thermo-Fisher</td>
			<td >14-222-262</td>
			<td ></td>
		</tr>
		<tr >
			<td >pipette tips, 100 to 1250 &#181;l</td>
			<td >Thermo-Fisher</td>
			<td >02-707-407</td>
			<td >narrow-bore 1 mL tips</td>
		</tr>
		<tr >
			<td >pipette tips, 5 to 300 &#181;l</td>
			<td >Thermo-Fisher</td>
			<td >02-707-410</td>
			<td ></td>
		</tr>
		<tr >
			<td >pipette tips, 0.1 to 10 &#181;l</td>
			<td >Thermo-Fisher</td>
			<td >02-707-437</td>
			<td ></td>
		</tr>
		<tr >
			<td >wide-bore pipette tips, 1000 &#181;l</td>
			<td >VWR</td>
			<td >89049-166</td>
			<td >wide-bore 1 mL tips</td>
		</tr>
		<tr >
			<td >glass Pasteur pipettes</td>
			<td >Thermo-Fisher</td>
			<td >13-678-20A</td>
			<td ></td>
		</tr>
		<tr >
			<td >ethanol, 200 proof</td>
			<td >Thermo-Fisher</td>
			<td >04-355-451</td>
			<td ></td>
		</tr>
		<tr >
			<td >vortex mixer</td>
			<td >VWR</td>
			<td >10153-842</td>
			<td ></td>
		</tr>
		<tr >
			<td >chambered coverglass, 8-well, 1.5mm borosilicate glass</td>
			<td >Thermo-Fisher</td>
			<td >155409</td>
			<td >glass-bottom confocal-grade cultureware</td>
		</tr>
		<tr >
			<td >22G needles</td>
			<td >VWR</td>
			<td >82002-366</td>
			<td ></td>
		</tr>
		<tr >
			<td >insulin syringes</td>
			<td >Thermo-Fisher</td>
			<td >22-253-260</td>
			<td ></td>
		</tr>
		<tr >
			<td >Formalin solution, neutral buffered, 10%</td>
			<td >Sigma-Aldrich</td>
			<td >HT501128-4L</td>
			<td >fixation of explanted teratomas</td>
		</tr>
		<tr >
			<td >Illumina HT-12 v4 Expression BeachChip</td>
			<td >Illumina</td>
			<td >BD-103-0204</td>
			<td >expression microarray, supported by PluriTest, discontinued by manufacturer</td>
		</tr>
		<tr >
			<td >PrimeView Human Genome U219 Array Plate</td>
			<td >Thermo-Fisher</td>
			<td >901605</td>
			<td >expression microarray (formerly Affymetrix brand), soon to be supported by PluriTest</td>
		</tr>
		<tr >
			<td >GeneChip&#8482; Human Genome U133 Plus 2.0 Array</td>
			<td >Thermo-Fisher</td>
			<td >902482</td>
			<td >expression microarray (formerly Affymetrix brand), supported by CellNet, soon to be supported by PluriTest</td>
		</tr>
		<tr >
			<td >PluriTest&#174;</td>
			<td >Coriell Institute</td>
			<td ></td>
			<td >www.pluritest.org, free service for bioinformatic assessment of pluripotency, accepts microarray data - *.idat files from HT-12 v4 platform, soon to support U133, U219 microarray and RNA sequencing data</td>
		</tr>
		<tr >
			<td >CellNet</td>
			<td >Johns Hopkins University</td>
			<td ></td>
			<td >cellnet.hms.harvard.edu, free service for bioinformatic identification of cell type, including plutipotent stem cells, based on U133 microarray data - *.cel files, soon to support RNA sequencing data</td>
		</tr>
	</tbody>
</table>

reprogramming primary amniotic fluid and membrane cells to pluripotency in xeno-free conditions

Autologous cell-based therapies got a step closer to reality with the introduction of induced pluripotent stem cells. Fetal stem cells, such as amniotic fluid and membrane mesenchymal stem cells, represent a unique type of undifferentiated cells with promise in tissue engineering and for reprogramming into iPSC for future pediatric interventions and stem cell banking. The protocol presented here describes an optimized procedure for extracting and culturing primary amniotic fluid and membrane mesenchymal stem cells and generating episomal induced pluripotent stem cells from these cells in fully chemically defined culture conditions utilizing human recombinant vitronectin and the E8 medium. Characterization of the new lines by applying stringent methods &#8211; flow cytometry, confocal imaging, teratoma formation and transcriptional profiling &#8211; is also described. The newly generated lines express markers of embryonic stem cells &#8211; Oct3/4A, Nanog, Sox2, TRA-1-60, TRA-1-81, SSEA-4 &#8211; while being negative for the SSEA-1 marker. The stem cell lines form teratomas in scid-beige mice in 6-8 weeks and the teratomas contain tissues representative of all three germ layers. Transcriptional profiling of the lines by submitting global expression microarray data to a bioinformatic pluripotency assessment algorithm deemed all lines pluripotent and therefore, this approach is an attractive alternative to animal testing. The new iPSC lines can readily be used in downstream experiments involving the optimization of differentiation and tissue engineering.

Informed written consent was obtained from patients before harvesting amniotic fluid for genetic testing purposes and dedicating a small aliquot of the fluid for research. No consent is required for the use of the amniotic membrane in research as the placenta represents medical waste. Amniotic fluid and membrane stem cells display typical mesenchymal properties, morphologically their cells are spindle-shaped and phase-bright. Upon reprogramming, the cells undergo mesenchymal-to-epithelial...

Watch this Scientific Journal Video about Reprogramming Primary Amniotic Fluid and Membrane Cells to Pluripotency in Xeno-free Conditions at JoVE.com

Reprogramming Primary Amniotic Fluid and Membrane Cells to Pluripotency in Xeno-free Conditions

This protocol describes the reprogramming of primary amniotic fluid and membrane mesenchymal stem cells into induced pluripotent stem cells using a non-integrating episomal approach in fully chemically defined conditions. Procedures of extraction, culture, reprogramming, and characterization of the resulting induced pluripotent stem cells by stringent methods are detailed.

Autologous cell-based therapies got a step closer to reality with the introduction of induced pluripotent stem cells. Fetal stem cells, such as amniotic ...

The overall goal of this procedure is to efficiently derive induced pluripotent stem cells by means of episomal reprogramming from two different kinds of fetal stem cells. This method can help provide a source of pluripotent stem cells for tissue engineering, disease modeling, basic research, or longitudinal studies. The main advantage of this technique is that the reprogramming and the maturation of iPSCs transpires in chemically defined conditions while being available early for potential pediatric cell-based therapies.Demonstrating this procedure will be Steven McClellan, the principal investigator, and myself. Obtain placentas as soon as possible following birth. Cut nine-squared centimeter segment of the amnion, and wash it in a 50-millimeter centrifuge tube with 30 milliliters of PBS supplemented with antibiotic, antimycotic solution.Remove blood clots from the membranes, and then use a pair of fine scalpels to mince the membranes into fine pieces in a sterile 10-centimeter tissue culture dish. Use the scalpel blades to transfer the minced membrane tissue mass into one tissue dissociation tube containing 4.7 milliliters of RPMI-1640 medium. Mix in the dissociation enzymes.Mount the tube onto the tissue dissociator, and run program h_tumor_01. Then incubate the tube at 37 degrees Celsius on a rocking platform for 30 minutes. Further dilute the suspension with 35 milliliters of RPMI-1640, and apply to a 70-micron strainer placed over a 50-milliliter centrifuge tube.Centrifuge for five minutes at 200 times g at room temperature. After discarding the supernatant, resuspend the pellet in five milliliters of RPMI-1640, and count the cells using a hemocytometer. Seed the cells in cell clusters at a density of roughly 10, 000 cells per square centimeter into tissue culture flasks with freshly prepared AFMC medium supplemented with antibiotic, antimycotic solution.Harvest low passage number amniotic fluid and membrane stem cells for reprogramming from one T75 flask by adding two milliliters of cell detachment enzyme to the cell sheet. Incubate at 37 degrees Celsius for five to eight minutes. After centrifugation at 200 times g for 45 minutes, resuspend the pellet in one milliliter of PBS, and mix well to wash away serum components.Count the cells using a hemocytometer. Then adjust the cell density to 100, 000 cells per milliliter of PBS, and now quad into 1.5-milliliter microcentrifuge tubes. Place the microcentrifuge tubes in five-milliliter polystyrene tubes to allow centrifugation in a regular swing rudder, and centrifuge at 200 times g for four minutes at room temperature.After the spin, invert the tubes, and discard the supernatant into a waste container, and then perform an additional centrifugation step at 200 times g for three minutes. After the spin, use a 200-microliter pipette to carefully aspirate the remaining liquid from the tubes. Place transfection tips, tube, resuspension buffer, and electrolytic buffer into the tissue culture cabinet.Move the transfection device close so that its tube station can be placed directly into the cabinet. Fill one transfection tube with three milliliters of electrolytic buffer, and mount the tube into the station by pushing it all the way inside the slot. Take previously prepared aliquots of reprogramming plasmid solution out of the minus 80 degrees Celsius storage, and allow them to thaw at room temperature in the culture cabinet.Set the transfection parameters on the device to deliver one pulse of 40 milliseconds at 950 volts. Resuspend the pellet containing 100, 000 cells in 10 microliters of resuspension buffer. Working quickly, add 1/10 of the reprogramming plasmid solution to the resuspended cells.Mount the transfection tip onto the transfection pipette. Then aspirate the cell suspension into the transfection tip carefully avoiding formation of air bubbles. Insert the transfection pipette into the transfection tube.And press the start button on the screen at the transfection device. Wait for the screen message regarding the success of the transfection. Then remove the pipette from the tube immediately.Expel the suspension into one well of the target six-well plates. Mix in the medium from a neighboring well, and distribute the suspension equally into both wells. Repeat the transfection for each microcentrifuge tube with cells.Begin by adding 30 microliters of 0.5 millimolar EDTA, and PBS to five PCR tubes. Then load a tip onto a 10-microliter pipette set to two microliters. Hold the pipette tip at an angle at the colony edge, and carefully and gradually scrape the whole colony off the surface.Immediately aspirate the whole colony into the pipette tip, and transfer it into one of the prepared PCR tubes with EDTA. After repeating the process with four other colonies, incubate at room temperature for four to six minutes. Use a larger pipette tip to pipette each cell suspension up and down gently to break the colony down into smaller clumps.Avoid creating a single-cell suspension. Then plate the suspension directly into the target well of a recombinant vitronectin-coated 24-well plate. After repeating the process for the remaining colonies, incubate for three to six days.After four to six days, when the colonies have grown and become compact, wash the cell sheets with 300 microliters of 0.5 millimolar EDTA, and aspirate immediately. Then add another 300 microliters, and incubate at room temperature for five minutes. After aspirating the EDTA, set a one-milliliter pipette to capacity, mount to one milliliter wide bore tip, and aspirate E8 medium from the target well of a vitronectin-coated six-well plate.Squirt a stream of the medium at one well of the source plate to wash off the iPSC culture. Then transfer the suspension into the target well, and pipette up and down several times to break up the colonies into clumps of 20 to 40 cells. After plating all cells, ensure that the clumps are distributed evenly by gently rocking and shaking the plate.Then return the plate into the incubator for clump adhesion and colony growth. The amniotic fluid and membrane stem cells, which represent source cells for reprogramming display a typical mesenchymal morphology elongated and phase-bright. The cells acquire epithelial properties after they undergo the mesenchymal-to-epithelial transition, which leads to the formation of colonies with cobblestone-like cells.These colonies proliferate and create irregular cellular masses of MET cells. At the later stages of reprogramming, colonies of fully reprogrammed cells emerge, individually discernible cells with well-defined borders. These fully reprogrammed cells are present alongside MET colonies that are more numerous.A fully reprogrammed isolated mature clone is shown here. Following iPSC derivation and maturation, they can be subjected to detail characterization, and direct the differentiation into a variety of cell types. Don't forget that working with human tissues that have not been tested for the presence of pathogens can be extremely hazardous, and precautions such as personal protective equipment, and working in the biosafety cabinet should always be taken while performing this procedure.After watching this video, you should have a good understanding of how to induce pluripotency in fetal stem cells, what reagents and equipment to use, and how to routinely culture pluripotent stem cells.

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JoVE Journal

Developmental Biology

9.2K visualizações.  University of South Alabama. The overall goal of this procedure is to efficiently derive induced pluripotent stem cells by means of episomal reprogramming from two different kinds of fetal stem cells. This method can help provide a source of pluripotent stem cells for tissue engineering, disease modeling, basic research, or longitudinal studies. The main advantage of this technique is that the reprogramming and the maturation of iPSCs transpires in chemically defined conditions while being available early for potential p...