DCH, MB und FK wurden von einem EPSRC Folgen auf Fonds unterstützt. BL-V und DS wurden jeweils durch MRC PhD student unterstützt. KC wurde durch Mittel aus dem UK Regenerative Medizin-Plattform unterstützt.

1. Synthese von PHNGAD (Poly [1,6-hexanodiol / Neopentylglykol / Di (ethylenglykol)--alt Adipinsäure] diol) <img alt="Schema 1" fo:content-width="5in" src="/files/ftp_upload/51723/51723scheme1.jpg" width="500" /> Schema 1: Synthese von PHNAGD Schematische Darstellung der Synthese von PHNAGD.. PHNAGD wurde durch Umsetzung von 1,6-Hexanodiol, Diethylenglykol, neoppentyl Glykol und Adipinsäure hergestellt. PHNAGD, Poly [1,6-hexanodiol / Neopentylglykol / Di (ethylenglykol)--alt Adipinsäure] diol. <ol><li> Anwenden der Wärmebehandlung auf die Monomeren, 1,6-Hexandiol, Di (ethylenglykol) und Neopentylglycol bei 40 ° C für 48 Stunden in einem Vakuumofen, um restliches Wasser zu entfernen. Lassen Sie die Kälte auf RT unter Vakuum. </li><li> Hinzufügen 22 mmol eines jeden Monomers und Adipinsäure (55 mMol) in einen Zweihalsrundkolben, der mit einem Rühren, ausgestattet und mit einer Dean-Stark-Apparatur angeschlossen. </li><li> Legen Sie die gesamte Baugruppe im Vakuum und sanft erhitzen glassware bei 40 ° C für 6 Stunden, um jegliche Feuchtigkeitsaufnahme während der Zugabe der Chemikalien in den Kolben zu verhindern. </li><li> Fügen über eine Spritze, Tropfen für Tropfen, 0,0055 mol des Katalysators Titan (IV) butylat. </li><li> Das Reaktionsgemisch wird bei 180 ° C unter einer N 2 Atmosphäre für 24 Stunden, zu sammeln und das restliche Wasser in einer Dean-Stark-Falle. Lassen Sie das Produkt auf RT abkühlen. </li></ol> 2. Synthese von PU134 <img alt="Schema 2" fo:content-width="5in" src="/files/ftp_upload/51723/51723scheme2.jpg" width="500" /> Schema 2: Synthese von PU134 Schematische Darstellung der Synthese von Polyurethan 134 PU134 wurde durch die Umsetzung von 1,0 Äquivalenten eines PHNGAD mit 2,0 Äquivalenten eines 4,4 &#39;-Methylenbis (phenylisocyanat) hergestellt, gefolgt von der Zugabe von 1,0. equiv eines 1,4-Butandiol Kettenverlängerungs. <ol><li> Mischen ein Äquivalent der Polyol PHNGAD (Mn ~ 1.800 Da, 3.2 mmol) mit zwei Äquivalenten 4&quot;4-Methylenbis (phenylisocyanat) (6,4 mmol) in wasserfreiem N, N-Dimethylformamid (12 ml). </li><li> Rühre das Reaktionsgemisch bei 70 ° C unter einer N 2 Atmosphäre. </li><li> Fügen über eine Spritze, Tropfen für Tropfen den Katalysator Titan (IV) butylat (0,8% wt). </li><li> Nach 1 Stunde, Hinzufügen eines Äquivalents des Kettenverlängerers 1,4-Butandiol (3,2 mmol). Erhöhung der Temperatur auf 90 ° C und rührt 24 h unter einer N 2 Atmosphäre. </li><li> Nach der Reaktion sammeln das Polyurethan durch Ausfällung durch Zugabe von Diethylether (Hexan oder Wasser kann auch verwendet werden) tropfenweise zu der Reaktionslösung, bis der Niederschlag auftritt. </li><li> Zentrifugieren der Lösung bei 5.300 × g für 5 min. </li><li> Dekantiert und trocknet bei 40 ° C in einem Vakuumofen, bis das Lösungsmittel verdampft. Hinweis: Um sicherzustellen, daß das Endprodukt der Reaktion besitzt die richtigen Parameter für den Molekulargewichtsverteilung, die funktionelle groups des Polymers und der Schmelz und Glasübergangstemperaturen können verschiedene analytische Techniken und Verfahren verwendet werden, wie Gelpermeationschromatographie oder FITR Spektroskopie. </li></ol> 3. Vorbereitung der PU134 Lösungen <ol><li> Wiegen 200 mg PU134 in eine Glasflasche. </li><li> Verdünnen PU134 bis zu einer Endkonzentration von 2% in einer Reihe von Lösemittel: Chloroform, eine Kombination von Chloroform und Toluol im Verhältnis 1: 1, Tetrahydrofuran und einer Kombination aus Tetrahydrofuran und Dichlormethan im Verhältnis 1: 1. Hinweis: Die Wahl der richtigen Lösungsmittel variiert in Abhängigkeit von dem Polymer zu verwenden. Unterschiedlichen Lösungsmitteln unterschiedliche Siedepunkte besitzen, die die Solubilisierung des Polymers beeinflussen kann. </li><li> Schütteln der Lösung kräftig für 20 min bei RT mit einer Schüttelmaschine bei einer Geschwindigkeit von 200 mot / min, bis die Lösung homogen wird und kein Niederschlag beobachtet. </li></ol> 4. Beschichtung von Glasobjektträger mit PU134 <ol><li> Legen Sie eine round 15 mm 2 Deckglas auf dem Spin Coater. </li><li> Bewerben 50 ul der PU134-Lösung in jede mit einer Pipette. Stellen Sie die Lautstärke der PU134 Lösung entsprechend für die erforderliche Deck Größe halten die Volumen zu Oberfläche Verhältnis proportional. </li><li> Drehen Sie jedes Deckglas für 7 sec bei 23 x g. </li><li> Luft trocknen Deckglas bei RT für mindestens 24 Stunden vor der Sterilisation. </li></ol> 5. Die Bestrahlung von Coverslip <ol><li> Gamma-Bestrahlung mit Polymer beschichteten Deckglas durch Anlegen einer Dosis von 10 Graustufen mit einer Labor-Strahler für 12 min. </li><li> UV-Bestrahlung mit Polymer beschichtete Deckglas mit einer 30 W, UV-Lampe für 16 min auf jeder Seite. </li><li> Platzieren des mit Polymer beschichteten Deckglas in einem geeigneten Gewebekulturplatte nach dem Foliengröße. </li></ol> 6. Rasterelektronenmikroskopie <ol><li> Goldbeschichtungspolymer Deck durch Sputtern für 200 s in einer Atmosphäre von 5 x 10 -1 mbar Druck. </li><li> Capture the Mikrogrammraphs des mit Polymer beschichteten Deckglas mit einem Rasterelektronenmikroskop bei einer Beschleunigungsspannung von 20 kV in der Sekundärelektronenabbildungsmodus. </li></ol> 7. Atomic Force Microscopy Beobachtungen <ol><li> Abtasten einer Fläche von 20 x 20 um für die Polymeroberfläche. </li><li> Eine Scan-Rate von 1,32 Hz bis 1,60 Hz. </li><li> Einrichtung einer Auflösung von 512 x 512 Pixel in der abgetasteten Bereich. </li><li> Berechnen Sie das quadratische Mittel (RMS oder RQ) der Beschichtung durch Verwendung der durchschnittlichen Höhe der Abweichungen vom Mittelwert Bilddaten Ebene genommen, ausgedrückt als: <img fo:content-width="1in" src="/files/ftp_upload/51723/51723eq1.jpg" width="123" /> Wobei Zi die aktuelle Z-Wert ist, und N die Anzahl von Punkten innerhalb des bestimmten Gebiets. </li><li> 7.5 Berechnen Sie die Abweichung oder mittlere Oberflächenrauigkeit (Ra) des Bildes mit, <img fo:content-width="1.5in" src="/files/ftp_upload/51723/51723eq2.jpg" width="154" /> Wobei Z (x) ist die Funktion, t beschreibter Oberflächenprofil in der Höhe (Z) und Position (x) der Probe über die Bewertungslänge &quot;L&quot; analysiert. Ra stellt den Mittelwert der Oberfläche relativ zu der Mittelebene. </li></ol> 8. Zellkultur und Differenzierung <ol><li> Kultur und differenzieren die humane embryonale Stammzelllinie (hES) H9 als in Hay 17 beschrieben. </li><li> Lösen Zellen unter Verwendung eines Reagens Dissoziation und Ausstrich sie auf PU134 beschichtete Objektträger an Tag 9 des Differenzierungsprozesses, in Gegenwart von einem serumfreien Medium, wie in Szkolnicka 18,19 beschreiben. Anmerkung: Die Verwendung eines enzymatischen Zell Dissoziation physikalischen Zellablösung bevorzugt. </li></ol> 9. Cytochrom-P450-Funktionstest <ol><li> Messen CYP3A-Aktivität nach der Anleitung des Herstellers. </li><li> HESC abgeleitet Hepatozyten an Tag 13 oder Tag 19, und Medien inkubieren ohne Zellen - als Negativkontrolle, mit der entsprechenden substraß für 5 h bei 37 ° C aufweist. </li><li> Sammeln Ständen von Zellen und Medien, führen Sie den Test nach Anweisungen des Herstellers. </li><li> Messung der Höhe der CYP-Aktivität und normiert auf die Fläche (cm 2). </li></ol> 10. Immunfärbung <ol><li> Wasch hESC abgeleitet Hepatozyten mit PBS für 1 min, zwei Mal wiederholen. </li><li> Fügen eiskalten 100% Methanol, um Zellen zu fixieren, in -20 ° C für 10 min. </li><li> Waschen Sie die Zellen mit PBS für 5 min und zweimal wiederholen. </li><li> Inkubiere die Zellen mit PBS / T (0,1% Tween) / 10% BSA für 1 h bei RT. </li><li> Saugen Sie das PBST-Lösung und fügen Sie den entsprechenden primären Antikörpers in PBS / T (0,1% Tween) / 1% BSA verdünnt, Inkubation bei 4 ° C unter leichtem Schütteln O / N. </li><li> Waschen Sie die Zellen mit PBS / T (0,1% Tween) / 1% BSA für 5 min und dreimal wiederholen. </li><li> Verdünne die entsprechenden Antikörper in PBS / T (0,1% Tween) / 1% BSA, in den Zellen und Inkubation im Dunkeln bei Raumtemperatur 1 Stunde unter leichtem Schütteln. </li><li> Waschen Sie die Zellen mit PBS für 5 min und dreimal wiederholen. </li><li> Fügen MOWIOL 488 (mit DAPI 1: 1.000) in jede Vertiefung, fügen Sie ein Deckglas vorsichtig auf die Anzahl der Luftblasen zu reduzieren. Speicher fixierten Zellen bei 4 ° C im Dunkeln. Beachten Färbung unter Verwendung eines Mikroskops mit entsprechenden Filter und Leuchtstofflampen. Die optimierten primären und sekundären Antikörper sind in Tabelle 1 aufgelistet. </li></ol>

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<li>Engler, A. J., Sen, S., Sweeney, H. L., Discher, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Matrix+elasticity+directs+stem+cell+lineage+specification%5BTitle%5D)+AND+%22Cell%22%5BJournal%5D)">Matrix elasticity directs stem cell lineage specification.</a> Cell. 126 (4), 677-689 (2006).</li>
<li>Dang, J. M., Leong, K. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Myogenic+Induction+of+Aligned+Mesenchymal+Stem+Cell+Sheets+by+Culture+on+Thermally+Responsive+Electrospun+Nanofibers%5BTitle%5D)+AND+%22Advanced+Materials%22%5BJournal%5D)">Myogenic Induction of Aligned Mesenchymal Stem Cell Sheets by Culture on Thermally Responsive Electrospun Nanofibers.</a> Advanced Materials. 19 (19), 2775-2779 (2007).</li>
<li>Azevedo, E. C., Nascimento, E. M., Chierice, G. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((UV+and+gamma+irradiation+effects+on+surface+properties+of+polyurethane+derivate+from+castor+oil%5BTitle%5D)+AND+%22Pol%C3%ADmeros%22%5BJournal%5D)">UV and gamma irradiation effects on surface properties of polyurethane derivate from castor oil.</a> Polímeros. 23 (3), 305-311 (2013).</li>
<li>Rosu, L., Cascaval, C. N., Ciobanu, C., Rosu, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Effect+of+UV+radiation+on+the+semi-interpenetrating+polymer+networks+based+on+polyurethane+and+epoxy+maleate+of+bisphenol+A%5BTitle%5D)+AND+%22Journal+of+Photochemistry+and+Photobilogy+A%3A+Chemistry%22%5BJournal%5D)">Effect of UV radiation on the semi-interpenetrating polymer networks based on polyurethane and epoxy maleate of bisphenol A.</a> Journal of Photochemistry and Photobilogy A: Chemistry. 169 (2), 177-185 (2005).</li>
<li>Yang, X. F., Tallman, D. E., Bierwagen, G. P., Croll, S. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Blistering+and+degradation+of+polyurethane+coatings+under+different+accelerated+weathering+tests%5BTitle%5D)+AND+%22Polymer+Degradation+and+Stability%22%5BJournal%5D)">Blistering and degradation of polyurethane coatings under different accelerated weathering tests.</a> Polymer Degradation and Stability. 77 (1), 103-109 (2002).</li>
</ol>

DCH ist CSO, Regisseur, Gründer und Gesellschafter der FibromEd Products Ltd MB und JPI sind Gründungsaktionäre in FibromEd Products Ltd

Viele der verwendeten Hepatozyten aus Stammzellen erzeugen aktuellen Methoden beruhen auf undefinierte Matrizen tierischen Ursprungs. Diese Substrate können kostspielig und sehr variabel sein und somit die Zellfunktion und der Stabilität, die ein großes Hindernis für Anwendung. Daher führten wir einen Bildschirm für synthetische Materialien, die die Kultur der Stammzell abgeleitet Hepatozyten zu unterstützen. Wir haben festgestellt, eine einfache Polyurethan (PU134) durch Polymerisation PHNGAD, MDI und ein Streck...

Biologische Materialien sind weit verbreitet bei der Aufrechterhaltung und Differenzierung von pluripotenten Stammzellen 1 verwendet. Und ermöglichen, enthalten diese biologischen Substraten oft eine Vielzahl von unbestimmten Komponenten. Matrigel ist eine häufig verwendete Substrat für die Stammzellkultur und Differenzierung. Leider beeinflusst die variable Zusammensetzung der Zellfunktion und Phänotyp. Obwohl eine Vielzahl von alternativen, definierten biologischen Matrices wurden verwendet, 2-7, ihre tierischen Ursprungs oder schlechte Skalierbarkeit macht sie ungeeignete Kandidaten für die industrielle Fertigung. Daher ist die Identifizierung von synthetischen Alternativen, mit definierter Zusammensetzung und zuverlässige Leistung, sind wichtige Ziele in der Stammzellforschung. In einem Versuch, die Grenzen der undefinierten Zellkultursubstraten zu überwinden, sind interdisziplinäre Kooperationen zwischen Chemie und Biologie synthetischen Materialien mit der Fähigkeit, Zell-Phänotyp unterstützt identifiziert. SynthWDV-Substrate sind skalierbar, kostengünstig und kann in komplexe 3D-Strukturen hergestellt werden, imitiert die in vivo-Umgebung. Aufgrund dieser Eigenschaften synthetischen Substraten sind weit verbreitet zu unterstützen und zu fahren Differenzierung vieler Zelltypen 8-10. Erweiterte und Hochdurchsatz-Assays haben die schnelle Screening von synthetischen Materialien erleichtert, von großen Bibliotheken, und lieferte neuartige Materialien mit flexiblen Eigenschaften mit breiten Anwendungen in der biomedizinischen Forschung und Entwicklung 11-13. Verwendung von Hochdurchsatz-, Polymer-Mikroarray-Screening-Technologie, haben wir schnell eine einfache Polyurethan (PU134), geeignet für die Instandhaltung von menschlichen Stammzellen abgeleiteten Hepatozyten identifiziert. Dieses Polymer wurde zu überlegen Tieren stamm Substrate hinsichtlich Hepatozyten-Differenzierung und-Funktion 14-16 sein. Wir haben anschließend die Beschichtungsbedingungen, Topographie und Sterilisationsverfahren, Effekte zugreifen optimiertauf Polymer Leistung bei der Stabilisierung Hepatozyten Funktion und Lebensdauer. Dies hat erhebliche Auswirkungen in Bezug auf das Verständnis der Biologie Grundlagen der Hepatozyten für Zell-basierte Modellierung und Anwendungen der regenerativen Medizin. Die hier beschriebene Technologie ist ein Beispiel, wie die Oberfläche eines synthetischen Polymers kann optimiert werden, um Zell-Phänotyp zu bewahren. Wir glauben, dass die Kombination dieser Technologie mit einer effizienten serumfreien Hepatozyten Differenzierungsprotokoll hat das Potenzial, eine skalierbare Herstellung von Hepatozyten zur Verwendung in in vitro-Modellierung und regenerative Medizin bereitzustellen.

<table><tbody><tr><td colspan="4">&lt;strong&gt;Synthesis, preparation, coating and characterization of polymer PU134 coated coverslips&lt;/strong&gt;</td></tr><tr><td>Shaker</td><td>Edmun B&amp;uuml;hler</td><td>KS-15</td><td></td></tr><tr><td>Irradiator</td><td>CIS Biointernational</td><td>IBL 637&amp;nbsp;</td><td></td></tr><tr><td>Spin coater</td><td>Specialty Coating System</td><td>P-6708</td><td></td></tr><tr><td>Scanning Electron Microscope&amp;nbsp;</td><td>Philips</td><td>XL30CPSEM</td><td></td></tr><tr><td>Atomic Force Microscope</td><td>DimensionV Nanoscope, VEECO</td><td></td><td></td></tr><tr><td>p4-GLO CYP3A4</td><td>Promega</td><td>V8902</td><td></td></tr><tr><td>UV bulb</td><td>ESCO</td><td></td><td></td></tr><tr><td>NanoScope analysis software</td><td>VEECO</td><td></td><td>version 1.20</td></tr><tr><td>Fluorescence microscope</td><td>Olympus</td><td>TH45200</td><td>Use Volocity 4 Software</td></tr><tr><td>Tissue culture plates</td><td>Corning, UK&amp;nbsp;</td><td>3527</td><td></td></tr><tr><td>glass slides</td><td>Scientific Laboratory Supplies</td><td>MIC3308</td><td></td></tr><tr><td>Diethylene glycol</td><td>Sigma&amp;ndash;Aldrich</td><td>93171</td><td></td></tr><tr><td>1,6-hexanediol</td><td>Sigma&amp;ndash;Aldrich</td><td>240117</td><td></td></tr><tr><td>Neopentyl glycol</td><td>Sigma&amp;ndash;Aldrich</td><td>408255</td><td></td></tr><tr><td>Adipic acid</td><td>Sigma&amp;ndash;Aldrich</td><td>9582</td><td></td></tr><tr><td>anhydrous &lt;em&gt;N,N&lt;/em&gt;-Dimethylformamide</td><td>Sigma&amp;ndash;Aldrich</td><td>227056</td><td></td></tr><tr><td>Diethyl ether</td><td>Sigma&amp;ndash;Aldrich</td><td>676845</td><td></td></tr><tr><td>titanium (IV) butoxide&amp;nbsp;</td><td>Sigma&amp;ndash;Aldrich</td><td>244112</td><td></td></tr><tr><td>1,4-butanediol&amp;nbsp;</td><td>Sigma&amp;ndash;Aldrich</td><td>493732</td><td></td></tr><tr><td>Vacuum oven</td><td>Thermoscientific</td><td></td><td></td></tr><tr><td>4,4&amp;rsquo;-Methylenebis(phenyl isocyanate)</td><td>Sigma&amp;ndash;Aldrich</td><td>101688</td><td></td></tr><tr><td>Tetrahydrofurane</td><td>Sigma&amp;ndash;Aldrich</td><td>401757</td><td></td></tr><tr><td>Sputter coater</td><td>Bal-Tec SCD 050</td><td></td><td></td></tr><tr><td colspan="4">&lt;strong&gt;Inmunostaining&lt;/strong&gt;</td></tr><tr><td>Phosphate buffer saline (-MgCl&lt;sub&gt;2&lt;/sub&gt;, -CaCl&lt;sub&gt;2&lt;/sub&gt;)</td><td>Gibco</td><td>10010031</td><td>Store at room temperature</td></tr><tr><td>PBST, PBS made up with 0.1% TWEEN 20&amp;nbsp;</td><td>&amp;nbsp; Scientific Laboratory Supplies Ltd</td><td>EC607&amp;nbsp;</td><td></td></tr><tr><td>Methanol</td><td>&amp;nbsp; Scientific Laboratory Supplies Ltd</td><td>CHE5010</td><td></td></tr><tr><td>Bovine Serum Albumin</td><td>Sigma-Aldrich, UK</td><td>A7906</td><td></td></tr><tr><td>MOWIOL 488 DAPI</td><td>Calbiochem</td><td>475904</td><td>Made up in Tris HCl and glycerol as per manufacturers instructions</td></tr><tr><td colspan="4">&lt;strong&gt;Cell culture and Functional assay&lt;/strong&gt;</td></tr><tr><td>CYP3A activity pGLO kit</td><td>Promega</td><td>V8902</td><td></td></tr><tr><td>Hepatozyme</td><td>Gibco</td><td>17705021</td><td></td></tr><tr><td>TryLE express</td><td>Life Technologies</td><td>&lt;a href=&quot;http://www.lifetechnologies.com/order/catalog/product/12604013&quot;&gt;12604013&lt;/a&gt;</td><td></td></tr></tbody></table>

stabilizing hepatocellular phenotype using optimized synthetic surfaces

Currently, one of the major limitations in cell biology is maintaining differentiated cell phenotype. Biological matrices are commonly used for culturing and maintaining primary and pluripotent stem cell derived hepatocytes. While biological matrices are useful, they permit short term culture of hepatocytes, limiting their widespread application. We have attempted to overcome the limitations using a synthetic polymer coating. Polymers represent one of the broadest classes of biomaterials and possess a wide range of mechanical, physical and chemical properties, which can be fine-tuned for purpose. Importantly, such materials can be scaled to quality assured standards and display batch-to-batch consistency. This is essential if cells are to be expanded for high through-put screening in the pharmaceutical testing industry or for cellular based therapy. Polyurethanes (PUs) are one group of materials that have shown promise in cell culture. Our recent progress in optimizing a polyurethane coated surface, for long-term culture of human hepatocytes displaying stable phenotype, is presented and discussed.

Polymerlösungsmittel beeinflusst die Topographie des mit Polymer beschichteten Oberfläche Polyurethan-134 wurde in Chloroform gelöst, entweder allein oder in Kombination mit Toluol oder Tetrahydrofuran oder Dichlormethan, und die Objektträger aus Glas mit den verschiedenen Formulierungen schleudert. Rasterelektronenmikroskopie (SEM) und Rasterkraftmikroskopie (AFM) wurden zur Charakterisierung der physikalischen Eigenschaften der Polymerschichten (Abbildung 1).</...

Watch this Scientific Journal Video about Stabilizing Hepatocellular Phenotype Using Optimized Synthetic Surfaces at JoVE.com

Stabilizing Hepatocellular Phenotype Using Optimized Synthetic Surfaces

Dieser Artikel wird auf die Entwicklung von Polymer-beschichteten Oberflächen für die langfristige Ausrichtung, stabile Kultur der Stammzell abgeleitet humanen Hepatozyten.

Stabilisierung Leberzell Phänotyp mit optimierten Surfaces

Currently, one of the major limitations in cell biology is maintaining differentiated cell phenotype. Biological matrices are commonly used for culturing ...

stabilizing-hepatocellular-phenotype-using-optimized-synthetic

Research

JoVE Journal

Chemistry

10.2K Aufrufe.  University of Edinburgh.  Dieser Artikel wird auf die Entwicklung von Polymer-beschichteten Oberflächen für die langfristige Ausrichtung, stabile Kultur der Stammzell abgeleitet humanen Hepatozyten. 

Serie: Stabilizing Hepatocellular Phenotype Using Optimized Synthetic Surfaces

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.

Definierte und Scalable Generierung von Leber-ähnlichen Zellen aus humanen pluripotenten Stammzellen

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

Forschung

Entwicklungsbiologie

Using Human Induced Pluripotent Stem Cell-derived Hepatocyte-like Cells for Drug Discovery

The ability to differentiate human induced pluripotent stem cells (iPSCs) into hepatocyte-like cells (HLCs) provides new opportunities to study inborn errors in hepatic metabolism. However, to provide a platform that supports the identification of small molecules that can potentially be used to treat liver disease, the procedure requires a culture format that is compatible with screening thousands of compounds. Here, we describe a protocol using completely defined culture conditions, which allow the reproducible differentiation of human iPSCs to hepatocyte-like cells in 96-well tissue culture plates. We also provide an example of using the platform to screen compounds for their ability to lower Apolipoprotein B (APOB) produced from iPSC-derived hepatocytes generated from a familial hypercholesterolemia patient. The availability of a platform that is compatible with drug discovery should allow researchers to identify novel therapeutics for diseases that affect the liver.

The protocol presented here describes a platform for identifying small molecules for the treatment of liver disease. A step-by-step description is presented detailing how to differentiate iPSCs into cells with hepatocyte characteristics in 96-well plates, and to use the cells to screen for small molecules with potential therapeutic activity.

Menschen mit induzierten pluripotenten Stammzellen gewonnenen Hepatozyten-ähnliche Zellen für die Wirkstoffforschung

The ability to differentiate human induced pluripotent stem cells (iPSCs) into hepatocyte-like cells (HLCs) provides new opportunities to study inborn ...

Semi-automated Production of Hepatocyte Like Cells from Pluripotent Stem Cells

Human pluripotent stem cells represent a renewable source of human tissue. Our research is focused on generating human liver tissue from human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs). Current differentiation procedures generate human hepatocyte-like cells (HLCs) displaying a mixture of fetal and adult traits. To improve cell phenotype, we have fully defined our differentiation procedure and the cell niche, resulting in the generation of cell populations which display improved gene expression and&#160;function. While these studies mark progress, the ability to generate large quantities of multi well plates for screening has been limited by labour intensive procedures and batch to batch variation. To tackle this issue, we have developed a semi-automated platform to differentiate pluripotent stem cells into HLCs. Stem cell seeding and differentiation were performed using liquid handling and automatic pipetting systems in&#160;96-well plate format. Following the differentiation, cell phenotype was analyzed using automated microscopy and a multi well luminometer.

This protocol describes a semi-automated approach to produce hepatocyte-like cells from human pluripotent stem cells in a 96 well plate format. This process is rapid and cost-effective, allowing the production of quality assured batches of hepatocyte-like cells for basic and applied human research.

Halbautomatische Herstellung von Hepatozyten wie Zellen aus pluripotenten Stammzellen

Human pluripotent stem cells represent a renewable source of human tissue. Our research is focused on generating human liver tissue from human embryonic ...

Serum Free Production of Three-dimensional Human Hepatospheres from Pluripotent Stem Cells

The development of renewable sources of liver tissue is required to improve cell-based modelling, and develop human tissue&#160;for transplantation. Human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs) represent promising sources of human liver spheres. We have developed a serum free and defined method of cellular differentiation to generate three-dimensional human liver spheres formed from human pluripotent stem cells. A potential limitation of the technology is the production of dense spheres with dead material inside. In order to circumvent this, we have employed agarose microwell technology at defined cell densities to control the size of the 3D spheres, preventing the generation of apoptotic and/or necrotic cores.&#160; Notably, the spheres generated by our approach display liver function and stable phenotype, representing a valuable resource for basic and applied scientific research. We believe that our approach could be used as a platform technology to develop further tissues to model and treat human disease and in the future may permit the generation of human tissue with complex tissue architecture.

This protocol describes an approach to produce hepatospheres from human pluripotent stem cells using a defined culture system and cell self-assembly. This protocol is reproducible in a number of cell lines, cost effective and allows the production of stable human hepatospheres for biomedical application.

Serumfreie Produktion dreidimensionaler menschlicher Hepatosphären aus pluripotenten Stammzellen

The development of renewable sources of liver tissue is required to improve cell-based modelling, and develop human tissue&#160;for transplantation. Human ...

Robust Generation of Hepatocyte-like Cells from Human Embryonic Stem Cell Populations

Despite progress in modelling human drug toxicity, many compounds fail during clinical trials due to unpredicted side effects. The cost of clinical studies are substantial, therefore it is essential that more predictive toxicology screens are developed and deployed early on in drug development (Greenhough et al 2010). Human hepatocytes represent the current gold standard model for evaluating drug toxicity, but are a limited resource that exhibit variable function. Therefore, the use of immortalised cell lines and animal tissue models are routinely employed due to their abundance. While both sources are informative, they are limited by poor function, species variability and/or instability in culture (Dalgetty et al 2009). Pluripotent stem cells (PSCs) are an attractive alternative source of human hepatocyte like cells (HLCs) (Medine et al 2010). PSCs are capable of self renewal and differentiation to all somatic cell types found in the adult and thereby represent a potentially inexhaustible source of differentiated cells. We have developed a procedure that is simple, highly efficient, amenable to automation and yields functional human HLCs (Hay et al 2008 ; Fletcher et al 2008 ; Hannoun et al 2010 ; Payne et al 2011 and Hay et al 2011). We believe our technology will lead to the scalable production of HLCs for drug discovery, disease modeling, the construction of extra-corporeal devices and possibly cell based transplantation therapies.

This article will focus on the generation of human hepatic endoderm from human embryonic stem cell populations.

Robuste Generierung von Leber-ähnlichen Zellen aus humanen embryonalen Stammzell-Populationen

Despite progress in modelling human drug toxicity, many compounds fail during clinical trials due to unpredicted side effects. The cost of clinical ...

Biologie

Protocol for Isolation of Primary Human Hepatocytes and Corresponding Major Populations of Non-parenchymal Liver Cells

Beside parenchymal hepatocytes, the liver consists of non-parenchymal cells (NPC) namely Kupffer cells (KC), liver endothelial cells (LEC) and hepatic Stellate cells (HSC). Two-dimensional (2D) culture of primary human hepatocyte (PHH) is still considered as the &#34;gold standard&#34; for in vitro testing of drug metabolism and hepatotoxicity. It is well-known that the 2D monoculture of PHH suffers from dedifferentiation and loss of function. Recently it was shown that hepatic NPC play a central role in liver (patho-) physiology and the maintenance of PHH functions. Current research focuses on the reconstruction of in vivo tissue architecture by 3D- and co-culture models to overcome the limitations of 2D monocultures. Previously we published a method to isolate human liver cells and investigated the suitability of these cells for their use in cell cultures in Experimental Biology and Medicine1. Based on the broad interest in this technique the aim of this article was to provide a more detailed protocol for the liver cell isolation process including a video, which will allow an easy reproduction of this technique.
Human liver cells were isolated from human liver tissue samples of surgical interventions by a two-step EGTA/collagenase P perfusion technique. PHH were separated from the NPC by an initial centrifugation at 50 x g. Density gradient centrifugation steps were used for removal of dead cells. Individual liver cell populations were isolated from the enriched NPC fraction using specific cell properties and cell sorting procedures. Beside the PHH isolation we were able to separate KC, LEC and HSC for further cultivation.
Taken together, the presented protocol allows the isolation of PHH and NPC in high quality and quantity from one donor tissue sample. The access to purified liver cell populations could allow the creation of in vivo like human liver models.

A technique to isolate human hepatocytes and non-parenchymal liver cells from the same donor is described. The different liver cell types build the basis for functional liver models and tissue engineering. This new method aims to isolate liver cells in a high yield and viability.

Protokoll für die Isolierung von primären humanen Hepatozyten und entsprechende Hauptpopulationen von Nicht-parenchymale Leberzellen

Beside parenchymal hepatocytes, the liver consists of non-parenchymal cells (NPC) namely Kupffer cells (KC), liver endothelial cells (LEC) and hepatic ...

Isolation of Regenerating Hepatocytes after Partial Hepatectomy in Mice

Partial hepatectomy has been widely used to investigate liver regeneration in mice, but the isolation of high yields of viable hepatocytes for downstream single-cell applications is challenging. A marked accumulation of lipids within regenerating hepatocytes is observed during the first 2 days of normal liver regeneration in mice. This so-called transient regeneration-associated steatosis (TRAS) is temporary but partially overlaps the major proliferative phase. Density-gradient purification is the backbone of most existing protocols for the isolation of primary hepatocytes. As gradient purification relies on the density and size of cells, it separates non-steatotic from steatotic hepatocyte populations. Therefore, fatty hepatocytes often are lost, yielding non-representative hepatocyte fractions. 
The presented protocol describes an easy and reliable method for the in vivo isolation of regenerating hepatocytes regardless of their lipid content. Hepatocytes from male C57BL/6 mice are isolated 24-48 h after hepatectomy by a classic two-step collagenase perfusion approach. A standard peristaltic pump drives the warmed solutions via the catheterized inferior vena cava into the remnant, using a retrograde perfusion technique with outflow through the portal vein. Hepatocytes are dissociated by collagenase for their release from the Glisson's capsule. After washing and careful centrifugation, the hepatocytes can be used for any downstream analyses. In conclusion, this paper describes a straightforward and reproducible technique for the isolation of a representative population of regenerating hepatocytes after partial hepatectomy in mice. The method may also aid the study of fatty liver disease.

Lipid-laden hepatocytes are inherent to liver regeneration but are usually lost upon density-gradient centrifugation. Here, we present an optimized cell isolation protocol that retains steatotic hepatocytes, yielding representative populations of regenerating hepatocytes after partial hepatectomy in mice.

Isolierung regenerierender Hepatozyten nach partieller Hepatektomie bei Mäusen

Partial hepatectomy has been widely used to investigate liver regeneration in mice, but the isolation of high yields of viable hepatocytes for downstream ...

Medizin

Hepatic Progenitor Specification from Pluripotent Stem Cells using a Defined Differentiation System

Liver disease is an escalating global health issue. While liver transplantation is an effective mode of therapy, patient mortality has increased due to shortages in donor organ availability. Organ scarcity also affects the routine supply of human hepatocytes for basic research and the clinic. Therefore, the development of renewable sources of human liver progenitor cells is desirable and is the goal of this study. To be able to effectively generate and deploy human liver progenitors on a large scale, a reproducible hepatic progenitor differentiation system was developed. This protocol aids experimental reproducibility between users in a range of cell cultureware formats and permits differentiations using both, human embryonic and induced pluripotent stem cell lines. These are important advantages over current differentiation systems that will enhance the basic research and may pave the way towards clinical product development.

The goal of this article is to provide a standardized approach to induce human hepatic progenitor differentiation from pluripotent stem cells. The development of this procedure with ready-to-use media formulations offer the user a facile system to generate human liver cells for biomedical research and translation.

Hepatischer Vorläufer aus pluripotenten Stammzellen unter Verwendung eines definierten Differenzierungssystems

Liver disease is an escalating global health issue. While liver transplantation is an effective mode of therapy, patient mortality has increased due to ...

Establishment and Genetic Manipulation of Murine Hepatocyte Organoids

The liver is the largest organ in mammals. It plays an important role in glucose storage, protein secretion, metabolism and detoxification. As the executor for most of the liver functions, primary hepatocytes have limited proliferating capacity. This requires the establishment of ex vivo hepatocyte expansion models for liver physiological and pathological research. Here, we isolated murine hepatocytes by two steps of collagenase perfusion and established a 3D organoid culture as the 'mini-liver' to recapitulate cell-cell interactions and physical functions. The organoids consist of heterogeneous cell populations including progenitors and mature hepatocytes. We introduce the process in detailed to isolate and culture the murine hepatocytes or fetal hepatocyte to form organoids within 2-3 weeks and show how to passage them by mechanically pipetting up and down. In addition, we will also introduce how to digest the organoids into single cells for lentivirus infection of shRNA/ectopic construction, siRNA transfection and CRISPR-Cas9 engineering. The organoids can be used for drug screens, disease modelling, and basic liver research by modeling liver biology and pathobiology.

A long-term ex vitro 3D organoid culture system was established from mouse hepatocytes. These organoids can be passaged and genetically manipulated by lentivirus infection of shRNA/ectopic construction, siRNA transfection and CRISPR-Cas9 engineering.

Etablierung und genetische Manipulation von murinen Hepatozyten-Organoiden

The liver is the largest organ in mammals. It plays an important role in glucose storage, protein secretion, metabolism and detoxification. As the ...

Ein physiologisch relevantes humanes 2D+-Lebersystem für die Wirkstoffforschung

An All-Human Hepatic Culture System for Drug Development Applications

Finding a long-term, human-relevant culture model for primary human hepatocytes (PHHs) for pharmacological and toxicological studies remains a challenge. Current in vitro model platforms are often inconvenient and complex, lack phenotypic stability over time, and do not support multiple PHH lots, lacking experimental reproducibility and flexibility. Here, we provide a detailed protocol for the thawing, plating, and maintenance of an all-human 2D+ hepatic system (TV2D+), which takes advantage of standard two-dimensional (2D) culture techniques and equipment while maintaining the longevity and phenotypic stability over time that typically accompany more complex three-dimensional (3D) systems. The results show attachment and percent plateability in TV2D+ as a function of PHH seeding density, as well as stable functionality for at least 2 weeks in culture. A range of PHH seeding densities are assessed to achieve a successful long-term culture. When established properly, the PHHs in TV2D+ organize into hepatocyte colonies, express a hepatic-specific marker, and maintain viability, architectural integrity, and physiologically relevant levels of albumin and urea. This unique combination of attributes makes the TV2D+ system a suitable hepatic model for a variety of pharmacological and toxicological applications.

Autor im Rampenlicht: Entwicklung eines einfachen und robusten Lebermodells für pharmakologische und toxikologische Anwendungen 

Recent technical advances enabled the scaled production of an in vitro platform for drug metabolism and toxicity applications. An all-human 2D+ hepatic system (TV2D+) provides physiologically relevant results using traditional two-dimensional culture methods. This protocol will support end-users in the setup, maintenance, and application of the system.

Ein rein humanes Leberkultursystem für Anwendungen in der Arzneimittelentwicklung

Finding a long-term, human-relevant culture model for primary human hepatocytes (PHHs) for pharmacological and toxicological studies remains a challenge. ...