This work was supported by The British Heart Foundation and The Oak Foundation.

Führen Sie alle Tierversuche nach Protokollen des Institutionellen Ausschusses für Benutzung und Pflege von Labortieren zugelassen. 1. Vorbereitung der Nährmedien <ol><li> Make Kulturmedien für den menschlichen Fibroblastenzelllinie CCL-153: F-12K-Medium, das 10% fötales Rinderserum (FBS) und 100 U / ml Penicillin und Streptomycin. </li><li> Stellen Reprogrammierung Medien für PiPSC Generation: Knockout Dulbeccos modifiziertem Eagle-Medium (DMEM), das 20% Knockout Serum Replacement, 0,1 mM β-Mercaptoethanol, 0,1 mM Minimum Essential Medium (MEM) Non-essentiellen Aminosäuren, 10 ng / ml Grund Fibroblasten-Wachstumsfaktor 2 (bFGF-2) und 100 U / ml Penicillin und Streptomycin. Frisch jedes Mal hinzufügen bFGF-2, bevor Sie die Medien. </li><li> Make Differenzierungsmedium (DM) zu der glatten Muskelzellen induzieren (SMC) Differenzierung: α-MEM-Medium, enthaltend 10% FBS, 0,1 mM β-Mercaptoethanol, 100 U / ml Penicillin und Streptomycin und 25 ng / ml Blutplättchen-Wachstumsfaktor(PDGF-ββ). </li><li> Make Endotheldifferenzierung Medien (EC-DM) von Endothelzellen (EC) Differenzierung zu induzieren: Endotheliale Wachstumsmedien-2 (EGM-2) Medien, die 50 ng / ml Vascular Endothelial Growth Factor (VEGF) und 100 U / ml Penicillin und Streptomycin. </li></ol> 2. Reprogramming menschlichen Fibroblasten in Teilweise induzierte pluripotente Stammzellen (PiPSC) <ol><li> Kultur menschlichen Fibroblasten-Zelllinie CCL-153 auf 0,04% Gelatinelösung beschichtet Kolben in Kulturmedium. </li><li> Passage-Zellen alle 3 Tage in einem Verhältnis von 1: 6. Verwenden Sie vor dem Durchgang 9 Zellen für eine optimale Effizienz der PiPSC Generation. Die Zellen sind bereit für die Transfektion bei Erreichen von 80 bis 90% Konfluenz. </li><li> Linearisieren polycistronischen Plasmid pCAG2LMKOSimO enthaltend 4 Reprogrammierungsfaktoren Octamer bindenden Transkriptionsfaktors 4 (OCT4) SOX2, Kruppel artigen Faktor 4 (KLF4) und C-MYC (pCAG-OSKM). Digest 5 ug Plasmid mit 5 Einheiten Restriktionsenzym PvuI 3 h bei 37 ° C. Reinigendas Plasmid mit einem kommerziellen Kit nach Herstellerprotokoll. </li><li> Transfizieren 2 x 10 6 menschlichen Fibroblasten, die mit 4 &amp; mgr; g linearisierter pCAG-OSKM Plasmid durch Elektroporation mit humanen dermalen Fibroblasten (NHDF) Nukleofektion Set nach dem Protokoll des Herstellers. Sanft Saatgut transfizierten Zellen auf Vor- 0,04% Gelatine beschichtete T25-Kolben mit 5 ml vorgewärmtem Reprogrammierung Medien. </li><li> Nach 24 Stunden wechseln Medium mit Ergänzungen von 25 ug / ml Neomycin, um eine reine Population transfizierter Zellen auszuwählen. </li><li> Ändern Medium jeden zweiten Tag bis zum Tag 4. Hinweis: Humane Fibroblasten werden PiPSC nach 4 Tagen der Umprogrammierung. </li></ol> 3. Differenzierung der PiPSC in Endothelzellen und glatte Muskelzellen <ol><li> Seed PiPSC auf Kollagen IV vorbeschichteten Schalen mit DM für 4 Tage, um die Differenzierung in SMCs induzieren. Ändern Medium jeden zweiten Tag bis zum Tag 4. </li><li> Seed PiPSC auf Kollagen IV vorbeschichtete Gerichte containing Endothel-DM für 6 Tage, um die Differenzierung zu Endothelzellen zu induzieren. Ändern Medium jeden zweiten Tag bis zum Tag 6. </li></ol> 4. Dezellularisierte Aorta Graft Vorbereitung Hinweis: Alle Lösungen und Geräte sollten steril sein. <ol><li> Opfern Sie die Maus durch Genickbruch und befestigen Sie die Maus in Rückenlage unter Dissektionsmikroskop. </li><li> Durch das Brustbein und um den Brustkorb geschnitten, um die Brusthöhle zu öffnen. Entfernen Sie die Herz, Lunge und Speiseröhre, um die Aorta aus. Entfernen Sie vorsichtig die peri-Aorta Fett mit einer Pinzette. </li><li> Schneiden Sie die Aorta vom vorderen Ende mit einer Schere und sanft halten Sie das Ende mit stumpfen Pinzette. Nehmen Sie die Aorta von der Wirbelsäule Spalte hinter stumpf. Alle Verzweigungs Arterien sorgfältig schließen aus der Aorta durch Ligation mit einem bipolaren Elektrokoagulator und Schneiden von dem fernen Ende der Ligation mit einer Schere. </li><li> Verwenden Sie ein 5-ml-Spritze, um die Aorta Lumen mit 3 m spülenl Kochsalzlösung, enthaltend 100 U Heparin, um die Bildung von Blutgerinnseln zu verhindern. </li><li> Schneiden Sie das hintere Ende der Aorta, bevor es von Verzweigungen in die Nieren. Beibehaltung der Unversehrtheit des Aorta ist das ganze Verfahren sehr wichtig. </li><li> Spülen Sie die Aorta Lumen mit 5 ml 0,075% Natriumdodecylsulfat (SDS) Lösung in Phosphat-gepufferter Salzlösung (PBS) verdünnt. </li><li> Weichen die Aorta in 0,075% SDS-Lösung in einer 10 cm Petrischale. Platzieren Sie die Petrischale auf einem Orbitalschüttler für 2 Stunden bei 150 Upm bei RT. </li><li> Spülen Sie die Aorta Lumen mit 5 ml PBS. </li><li> Weichen Sie die Aorta in PBS in einer 10 cm Petrischale. Platzieren Sie die Petrischale auf dem Orbitalschüttler für 2 Stunden bei 150 Upm bei RT. Aktualisieren PBS alle 20 min. </li><li> Spülen Sie die Aorta Lumen mit 5 ml PBS. </li><li> Halten dezellularisierten Transplantats Aorta in PBS bei 4 ° C für bis zu einer Woche. </li></ol> 5. Dual-Seeding von PiPSC und Bioreaktoranlage Hinweis: Alle Lösungs und Geräte sollten steril sein. Führen Sie alle Vorgänge in einer Gewebekultur Kapuze. <ol><li> Montieren Sie den Bioreaktor Strömungskreislauf, wie in Abbildung 1 dargestellt. Schließen Sie Inkubationskammer, Medienspeicher, Schlauchpumpe und Ausgleichkammer mit Schlauch. Minimal Volumen des Mediums für den Umlauf gebraucht wird, ist 40 ml. </li><li> Vorbedingung das dezellularisierte Gefäß mit Kulturmedium durch Einweichen der Aorta in DM Medium in einer 10 cm Petrischale. Platzieren Sie die Petrischale auf dem Orbitalschüttler für 1 Stunde bei 50 Umdrehungen pro Minute bei RT. </li><li> Setzen Sie 1 cm Länge Nylon Rohre (OD 0,9 mm, 0,75 mm ID) in beiden Enden des dezellularisierten Gefäß unter dem Mikroskop. Binden Sie das Schiff und die Schläuche mit 8-0 Seidenfäden. </li><li> Montieren Sie die dezellularisierte Aorta Graft in die Inkubationskammer durch die Einlass- und Auslasskanäle (1/32 &quot;Schlauch) von der Kammerwand, welche die Nylonrohre. Pflegen Inkubationskammer mit 5mls mittel jedes Mal. </li><li> Trypsinieren PiPSC durch Zugabe von vorgewärmtenTrypsin, um die Kulturschale zu decken und schaukeln das Gericht 10 Mal. Entsorgen Sie die Trypsin und lassen Sie das Gericht in Inkubator für 2-3 min. In vorgewärmten Kulturmedium in die Schüssel und mischen Sie das Medium mit den Zellen. </li><li> Graf Zellzahl mit einer Zählkammer. Zentrifuge zwei Aliquots von Zellsuspension mit 5 x 10 5 Zellen je 5 min bei 300 x g. Saugen Sie den Überstand vollständig. </li><li> Nach Absaugen der Überstand vollständig resuspendieren ein Pellet der PiPS Zellpellets in 50 ul DM. Spritzen Sie diese Zellsuspension in die dezellularisierte Gefäßlumen. </li><li> Dann resuspendieren anderen PiPS Zellpellet in 100 &amp; mgr; l Matrigel. Beim Pipettieren der Mischung auf die dezellularisierte Aorta Graft. </li><li> Warten Sie 10 bis 15 Minuten, bis die Mischung in einen gelartigen Zustand und wickelt sich um den Behälter Außenfläche gleichmäßig. Füllen Sie die Inkubationskammer mit DM. </li><li> Setzen Sie den ganzen Bioreaktor Einstellung in einem 5% CO 2 Inkubator bei 37 ° C. Manuelles drehen Sie den dezellularisierten Transplantats 90 ° um die Längsachse jede halbe Stunde in der ersten 2 h. </li><li> Halten statischer Kultur für 12 Stunden, um die Zelladhäsion zu ermöglichen. </li><li> Liefern DM durch das Lumen durch die peristaltische Pumpe an der glatten Muskulatur-Zelldifferenzierung zu induzieren. Starten anfänglichen Flussrate bei 5 ml / min und die stufenweise Erhöhung auf 20 ml / min über 24 h. </li><li> Halten Sie das zirkulierende Medium Durchfluss bei 20 ml / min für 24 Stunden. </li><li> Halten Sie den Medienstrom und bewegen Sie den Bioreaktor Einstellung aus dem Inkubator. </li><li> Re-Samen das Lumen des Transplantats mit PiPSC. Trypsinieren, zählen und Zentrifuge 1 x 10 6 PiPSC wie in Schritten von 5,5 bis 5,6. Resuspendieren der Zellen in 50 &amp; mgr; l EGM-2-Medium, enthaltend 50 ng / ml VEGF. Spritzen den Zellgemisch in das Lumen des Transplantats. </li><li> Ändern Sie das Medium in der Inkubationskammer und Vollblutung EGM-2 Medium mit 50 ng / ml VEGF an endotheliale Differenzierung zu induzieren. </li><li> Bewegen Sie den Bioreaktor Einstellung zurück auf thE-Inkubator. Hand drehen das Transplantat 90 ° alle 30 Minuten in der ersten 2 h und dann halten eine statische Kultur für 12 Stunden. </li><li> Starten Zirkulationsströmung von 5 ml / min und der stufenweisen Erhöhung auf 35 ml / min. Halten der Strömungsrate auf 35 ml / min für 5 Tage. Ändern zirkulierenden und Kammer Medium jeden zweiten Tag. </li><li> Ernten Sie die entwickelt Transplantat für die weitere Veredelung zu Maus. </li></ol> 6. Pfropfen von Doppel ausgesät PiPSC Graft in Mäuse <ol><li> Verwenden NOD.CB17-Prkdc scid / NcrCrl männlichen Mäusen als Gefäßtransplantat-Empfänger. Achten Sie immer darauf, dass die Mäuse sind ca. 10 Wochen alt, wiegt etwa 25 - 35 g, und in einem guten gesundheitlichen Bedingungen. </li><li> Anesthetize Empfängermaus durch Verabreichung einer Kombination von Hypnorm (25 mg / kg) und Hypnovel (25 mg / kg) intraperitoneal. Bewerben Vaseline Augensalbe auf die Augen bis zur Trockenheit während der Narkose zu verhindern. Bestätigen effiziente Betäubung, indem sichergestellt wird, dass Mäuse entspannt Muskeln und stetig zu atmen. <ol><li> Befestigen Sie die Maus in Rückenlage mit seinem Hals rasiert und erweitert. Verabreichen Atropinsulfat (1,7 mg / kg) in Kombination mit den Anästhetika, um sicherzustellen, dass die Atemwege der Maus klar bleibt. </li></ol></li><li> Bereiten Sie ein Mittellinienschnitt aus dem Unterkiefer zu Brustbein der Maus. Unter einem Binokular mit 5- bis 10-fache Verstärkung, heben Sie die richtigen Speicheldrüsen seitlich und nehmen Sie die richtige sternocleidomastoideus, um die rechte Arteria carotis communis freizulegen. </li><li> Entfernen sanft angebracht Geweben, die rechte Arteria carotis communis aus dem distalen Ende zu dem proximalen Ende zu mobilisieren. Ligieren der mittlere Abschnitt der Arteria carotis communis zweimal mit einem 8-0-Seidenfaden und sezieren zwischen den beiden Bindungen. </li><li> Fahren Sie durch eine Manschette aus autoklavierbarem Nylonschlauch in jedem Gefäß Ende gemacht und fixieren Sie jedes Ende mit microhemostat Schellen. </li><li> Entfernen Nahtverbindungs ​​an einem Ende und einen Tropfen Heparin (100 U / ml). Unmittelbar danach invertieren das distale Ende des the Arterie, die ganze Manschette Körper bedecken und befestigen Sie den umgekehrten Gefäß mit einem 8-0 Seidennaht an der Manschette. <ol><li> Das Verfahren wird wiederholt, um den anderen Abschnitt der Arterie. Flush Arterie mit Kochsalzlösung, um Blutgerinnsel zu entfernen. </li></ol></li><li> Implantieren eine dezellularisierte Gefäßtransplantat zwischen zwei Enden der Halsschlagader durch Verschieben der dezellularisierten Gefäßenden die in den Arterien Bündchen und Befestigung mit 8-0 Seidenfäden. Entfernen Gefäßklemmen entweder endet, bevor die Bewertung der Pulsation des Transplantats. </li><li> Legen Sie den rechten Speicheldrüsen wieder in seine ursprüngliche Position. Schließen der Haut an der chirurgischen Stelle mit einer unterbrochenen Naht unter Verwendung eines 6-0 Polyglactin Naht. </li><li> Konsequent beobachten Vital Maus, nachdem die Prozedur abgeschlossen ist, bis es das Bewußtsein wieder. Sacrifice Empfängermäuse durch Genickbruch und Erntegefäßimplantate entweder 24 Stunden oder 3 Wochen später für weitere Analysen. </li></ol>

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Die Autoren haben keine widerstreitenden finanziellen Interessen.

Das aktuelle Protokoll wird der Ton, schnelle, einfache, effiziente und reproduzierbare Strategie, bei der funktionellen Tissue Engineering Tanks können über PiPSC aus humanen Fibroblasten erzeugt werden. Diese Technik stellt ein wertvolles Werkzeug für die regenerative Medizin, Tissue Engineering und möglicherweise patientenspezifischer Zelltherapie in naher Zukunft. Kritische Schritte, um die Wirksamkeit des Protokolls sicher umfassen die Herstellung von PiPSC, Herstellung von sterilen und voll dezellularisierten ...

Der Bau des vaskulären Conduits ist eine grundlegende Strategie für chirurgische Reparatur von beschädigten und verletzte Gefäße von Herz-Kreislauf- Erkrankungen resultieren. Bis heute sind in der Chirurgie Transplantatmaterialien biokompatible synthetische Polymere (Polytetrafluorethylen [Teflon], expandiertem Polytetrafluorethylen [ePTFE, Gore-Tex] oder Polyethylenterephthalat [Dacron]), allogene Transplantate, körpereigenes Gewebe (Herzbeutel oder Vena saphena) und Xenotransplantate 1. Während künstliche Transplantate (zB Gore-Tex und Dacron) werden am häufigsten verwendet, diese Materialien wahrscheinlich dazu führen zahlreiche kurz- und langfristige Komplikationen, die Stenose, Kalziumablagerung, thrombo-Embolisation und Infektionen gehören. Obwohl Patienten mit mit vorhandenen biologische Transplantate verringert thromboembolischer Ereignisse, sie immer noch Grenzen stoßen, wie sekundären Transplantatversagen und verkürzt die Haltbarkeit wegen Verkalkung Abbau 2. Daher ist trotz erheblichen Verbesserungen in der chirurgischen techniques über die Jahre, Forschern und Klinikern immer noch die Notwendigkeit zur Identifizierung der idealen Leitung für Gefäßerkrankungen belastet. In jüngerer Zeit hat sich die Forschung zur vaskulären Gewebetechnik, ein Konzept, bei dem Zellen in biologisch abbaubare Gerüst eingebaut, mit dem Ziel, einen biomimetischen Umgebung, die eine funktionelle Gefäß zur erfolgreichen Pfropfung 1 verkörpert erzeugt. Grundsätzlich ist der Erfolg der Gefäßkonstrukte hängen von drei wesentlichen Komponenten; Zellen, die das Gerüst, das heißt, eine Endothelzelle innere Schicht und eine glatte Muskelzellschicht, ein Gerüst, das die entsprechende extrazelluläre Matrix auf vergleichbare mechanische Eigenschaften der nativen Vaskulatur bereitzustellen, und das Molekular / zelluläre Signalübertragung, das zur Initiierung / Regel erforderliche umfassen Reparatur. Langzeittransplantatdurchgängigkeit und nachhaltige Entwicklung der neo-Gewebe sind in hohem Maße auf effektive Zellaussaat von Gerüsten, thereby Rendern der Entscheidung des Zelltyp von entscheidender Bedeutung. Mehrere Berichte zeigen die Verwendung von reifen Endothelzellen und glatte Muskelzellen aus verschiedenen Quellen, um Leitungen 3-6 kleinen Durchmesser zu entwickeln. Obwohl vielversprechend, um das Fehlen einer ausreichenden autologen Gefäße erhalten reifen Endothelzellen und glatte Muskelzellen vor eine erhebliche Belastung. In jüngerer Zeit haben Stammzellen aus verschiedenen Quellen für Gefäßgewebe-Engineering-Anwendungen genutzt. Tat eine Vielzahl von Stammzelltypen einschließlich embryonaler Stammzellen 7, pluripotenten Stammzellen (iPS) 8,9, PiPSC 10,11, Knochenmark stammenden mononukleären Zellen 12, mesenchymale Stammzellen 13, endotheliale Vorläuferzellen und adulte Gefßwand -abgeleiteten Stammzellenantigen-1 (Sca-1) + Stammzellen / Vorläuferzellen 14,15 wurden alle gezeigt, dass sie in der Lage, die Differenzierung werden entweder funktionelle Endothelzellen oder Zellen der glatten Muskulatur als Antwort auf definierten Medien undKulturbedingungen. Darüber hinaus machen die unbegrenzte Selbsterneuerungsfähigkeit der Stammzellen ihnen bessere Kandidaten Gegensatz reifen Endothelzellen und glatte Muskelzellen, die nur für eine begrenzte Anzahl von Malen teilen können vor einer Wachstumsarrest und Seneszenz. Die Auswahl der Gerüstmaterial für eine erfolgreiche Gewebezüchtung Behälter erzeugen für die Veredelung von mehreren Faktoren abhängig, wie Biokompatibilität, biomechanischen Eigenschaften und Geschwindigkeit des biologischen Abbaus. Grundsätzlich verwendeten Materialien, um Gerüste für Transplantate erstellen sollten biologisch abbaubar sein und wird nicht gemountet unnötige Empfänger Immunantworten. Darüber hinaus müssen sie eine geeignete Porosität und Mikrostruktur für die Zellanheftung und anschließende Überlebens umfassen. Bis heute sind die am häufigsten für Gerüste in vaskulären Gewebetechnik verwendeten Materialien umfassen Polymere von Polyglykolsäure, Polymilchsäure und Poly-ε-caprolacton 16. In jüngerer Zeit haben dezellularisierten biologischen Materialienauch mit einigem Erfolg angewendet. Mehrere Labors haben gezeigt, dass der Aussaat dezellularisierte Mensch, Hund oder Schwein Gefäße mit patienteneigenen Zellen ein biologischen Transplantats, die Blutgerinnung und Intimahyperplasie 17-19 widerstanden. Andere Strategien in der Gefäß Tissue Engineering sind extrazellulären Matrixproteinen basierenden Gefäßprothesen zB Aussaat Zellen in Fibrin-Gel 13 und das Erzeugen Zellschichten ohne Stützträger 20, 21. Die aktuelle Protokoll zeigt die Differenzierung von humanen PiPSC in funktionelle Endothel- und glatte Muskelzellen, die Erzeugung von einem Bioreaktor, bestehend aus einer dezellularisierten Gefäßgerüst funktionelle PiPSC abgeleiteten Gefäßzellen beherbergen, und Pfropfen der Gewebezüchtung Gefäßen in severe combined immunodeficiency (SCID ) Mäusen. PiPSC sind eine optimale Zelltyp für das Tissue Engineering von Gefäßtransplantaten zu verwenden, da diese Zellen nicht-Tumoren in Mäusen bilden oder ethische undallo-Immunantworten. Darüber hinaus haben wir gezeigt, dass die Strategie zur Erzeugung von pips-Endothelzellen und Zacken-glatten Muskelzellen ist effiziente und reproduzierbare 10,11. Danach haben wir eine dezellularisierte Gefäß für die Aussaat von PiPSC abgeleiteten Gefäßzellen, um die Matrixproteine, die in einem nativen Gefäß existiert genau imitieren und somit eine Verbesserung Pfropfen und Überleben Wirksamkeit. Ferner die Dezellularisierung der Gefäße vor PiPSC Aussaat verhindert das Auftreten von entzündlichen Reaktionen, die durch Immunzelltypen montiert, wie Makrophagen. Noch wichtiger ist, hat das Protokoll nicht nur stellen eine Methode zur Erzeugung von vielversprechenden Gefäßleitungen für die Übersetzung in Menschen, sondern auch eine wertvolle Hilfe von Studium und Verständnis der molekularen Mechanismen, die Gefäßgeweberegeneration durch Mausmodellen zu regieren.

<table border="0" cellpadding="0" cellspacing="0" >
	<tbody>
		<tr >
			<td >Human Fibroblasts CCL-153</td>
			<td >ATCC</td>
			<td >CCL-153</td>
			<td>Prenatal human embryonic fibroblasts</td>
		</tr>
		<tr >
			<td >ATCC F-12K Medium (Kaighn&#39;s Modification of Ham&#39;s F-12 Medium)</td>
			<td >ATCC</td>
			<td >30-2004</td>
			<td></td>
		</tr>
		<tr >
			<td >Fetal Bovine Serum</td>
			<td >ATCC</td>
			<td >30-2020</td>
			<td></td>
		</tr>
		<tr >
			<td >Knockout DMEM medium optimized for embryonic stem cells</td>
			<td >Life technologies (Gibco)</td>
			<td >12660-012</td>
			<td></td>
		</tr>
		<tr >
			<td >Knockout Serum Replacement</td>
			<td >Life technologies (Invitrogen)</td>
			<td >10828-028</td>
			<td></td>
		</tr>
		<tr >
			<td >Human Basic FGF-2&#160;</td>
			<td >Miltenyi Biotech</td>
			<td >130-093-837</td>
			<td></td>
		</tr>
		<tr >
			<td >alpha-MEM medium</td>
			<td >Life technologies (Invitrogen)</td>
			<td >32571093</td>
			<td></td>
		</tr>
		<tr >
			<td >Human PDGF</td>
			<td >R&#38;D System</td>
			<td >120-HD-001</td>
			<td></td>
		</tr>
		<tr >
			<td >Gelatin Solution 2%</td>
			<td >Sigma</td>
			<td >G1393</td>
			<td></td>
		</tr>
		<tr >
			<td >Plasmid 20866: pCAG2LMKOSimO (SOX2, OCT4, KLF4, C-MYC)</td>
			<td >Addgene</td>
			<td >20866</td>
			<td></td>
		</tr>
		<tr >
			<td >&#160;PvuI Restriction Enzyme</td>
			<td >New England Biolabs</td>
			<td >RO150S</td>
			<td></td>
		</tr>
		<tr >
			<td >SureClean Plus</td>
			<td >Bioline</td>
			<td >BIO-37047</td>
			<td></td>
		</tr>
		<tr >
			<td >Nucelofection Kit (NHDF Kit)</td>
			<td >LONZA</td>
			<td >VPD-1001</td>
			<td></td>
		</tr>
		<tr >
			<td >Neomycin</td>
			<td >SIGMA</td>
			<td >G418</td>
			<td>Selection of&#160;</td>
		</tr>
		<tr >
			<td >KL 1500 LCD, Illumination for Stereo Microscopy</td>
			<td >SCHOTT</td>
			<td >KL 1500 LCD</td>
			<td>Cold light illumination for stereo microscopy</td>
		</tr>
		<tr >
			<td >Nikon Zoom Steromicroscope SMZ800</td>
			<td >Nikon</td>
			<td >SMZ800</td>
			<td></td>
		</tr>
		<tr >
			<td >Heparin sodium salt</td>
			<td >Sigma</td>
			<td >H3393</td>
			<td></td>
		</tr>
		<tr >
			<td >10% SDS Stock Solution Molecular Biology Reagent</td>
			<td >Severn Biotech</td>
			<td >CAS 151-21-3</td>
			<td></td>
		</tr>
		<tr >
			<td >Dulbecco&#39;s Phosphate Buffered Saline</td>
			<td >Sigma</td>
			<td >D8537</td>
			<td></td>
		</tr>
		<tr >
			<td >Matrigel (10mg/ml)</td>
			<td >BD</td>
			<td >A6661</td>
			<td></td>
		</tr>
		<tr >
			<td >Shaker IKA Vibrax with Shaking platform VX 7&#160;</td>
			<td >Jepson Bolton&#39;s, Janke&#38;Kunkel</td>
			<td >S32-102</td>
			<td></td>
		</tr>
		<tr >
			<td >Masterflex L/S Digital Pump Drive</td>
			<td >Cole-Parmer</td>
			<td >WZ-07523-80</td>
			<td></td>
		</tr>
		<tr >
			<td >Masterflex L/S 6-channel, 6-roller cartridge pump head</td>
			<td >Cole-Parmer</td>
			<td >EW-07519-15</td>
			<td></td>
		</tr>
		<tr >
			<td >Masterflex L/S large cartridges for pump head</td>
			<td >Cole-Parmer</td>
			<td >EW-07519-75</td>
			<td></td>
		</tr>
		<tr >
			<td >Masterflex platinum-cured silicone pump tubing, L/S 14, 25 ft</td>
			<td >Cole-Parmer&#160;</td>
			<td >WZ-96410-14</td>
			<td >Tubing goes through the peristaltic pump</td>
		</tr>
		<tr >
			<td >0.5mm ID, 0.8 mm OD Silicone Tubing</td>
			<td >SILEX</td>
			<td >N/A</td>
			<td>Tubings connect incubation chamber, media reservoir and compliance chamber&#160;</td>
		</tr>
		<tr >
			<td >Fitting Reducer 0.5 to 1.6, natural Polypropyline</td>
			<td >Ibidi</td>
			<td >10829</td>
			<td>Adapter connect above two types of tubings</td>
		</tr>
		<tr >
			<td >1/32&#34; Tubing, ID 0.01&#34; (250&#181;m) Material: PEEK</td>
			<td >LabSmith</td>
			<td >T-132-010P</td>
			<td>Tubing through the incubation chamber wall which connects the graft with outside tubing</td>
		</tr>
		<tr >
			<td >One-Piece Fittings&#160;</td>
			<td >LabSmith</td>
			<td >T-132-100</td>
			<td>Fix the above tubings through the incubation chamber wall</td>
		</tr>
		<tr >
			<td >Nylon tubes (OD 0.9mm, ID 0.75mm)&#160;</td>
			<td >Smiths Medical</td>
			<td >N/A</td>
			<td>Tubings insert into two ends of the aorta graft</td>
		</tr>
		<tr >
			<td >NOD.CB17-Prkdcscid/NcrCrl mouse</td>
			<td >Charles River</td>
			<td ></td>
			<td ></td>
		</tr>
		<tr >
			<td >Surgical sutures, 8-0&#160; silk</td>
			<td >ETHICON</td>
			<td >W819</td>
			<td ></td>
		</tr>
		<tr >
			<td >Hypnorm</td>
			<td >Vetapharm</td>
			<td >Vm21757/4000</td>
			<td >Neuroleptanalgesic for use in mice</td>
		</tr>
		<tr >
			<td >Hypnovel (Midazolam)</td>
			<td >Roche</td>
			<td >59467-70-8</td>
			<td >Induction of anaesthesia</td>
		</tr>
		<tr >
			<td >Dissecting microscope</td>
			<td >Carl Zeiss</td>
			<td >Stemi 2000</td>
			<td ></td>
		</tr>
		<tr >
			<td >Nylon Tubing</td>
			<td >Portex LTD</td>
			<td >800/200/100/200</td>
			<td >0.65 mm in diameter and 1 mm in length; to make artery cuff</td>
		</tr>
		<tr >
			<td >Electrocoagulator</td>
			<td >Martin&#160;</td>
			<td >SN 54.131</td>
			<td >Ligation of artery branches on aorta</td>
		</tr>
		<tr >
			<td >Bipolar micro hemostat forceps</td>
			<td >Martin</td>
			<td >80-91-12-04</td>
			<td >Fixation of vessel ends</td>
		</tr>
		<tr >
			<td >Vessel Dilator</td>
			<td >S&#38;T</td>
			<td >JFX-7</td>
			<td ></td>
		</tr>
		<tr >
			<td >Vessel Dilator</td>
			<td >S&#38;T</td>
			<td >JFL-3dZ</td>
			<td ></td>
		</tr>
		<tr >
			<td >Vessel Dilator</td>
			<td >S&#38;T</td>
			<td >D-5aZ</td>
			<td ></td>
		</tr>
		<tr >
			<td >Mini applier&#160;</td>
			<td >AESCULAP</td>
			<td >FE572K</td>
			<td ></td>
		</tr>
		<tr >
			<td >Micro hemostats clips</td>
			<td >AESCULAP</td>
			<td >FE720K</td>
			<td ></td>
		</tr>
		<tr >
			<td >Surgical sutures, 6-0 VICRYL</td>
			<td >ETHICON</td>
			<td >V489</td>
			<td ></td>
		</tr>
	</tbody>
</table>

generation and grafting of tissue-engineered vessels in a mouse model

The construction of vascular conduits is a fundamental strategy for surgical repair of damaged and injured vessels resulting from cardiovascular diseases. The current protocol presents an efficient and reproducible strategy in which functional tissue engineered vessel grafts can be generated using partially induced pluripotent stem cell (PiPSC) from human fibroblasts. We designed a decellularized vessel scaffold bioreactor, which closely mimics the matrix protein structure and blood flow that exists within a native vessel, for seeding of PiPSC-endothelial cells or smooth muscle cells prior to grafting into mice. This approach was demonstrated to be advantageous because immune-deficient mice engrafted with the PiPSC-derived grafts presented with markedly increased survival rate 3 weeks after surgery. This protocol represents a valuable tool for regenerative medicine, tissue engineering and potentially patient-specific cell-therapy in the near future.

Die erfolgreiche Generation von PiPSC wurde 4 Tage nach der bestätigten nucleofecting menschlichen Fibroblasten mit einem linea pCAG2LMKOSimO Plasmid, das 4-Transkriptionsfaktoren, OCT4, SOX2, Klf4 und c-MYC (OSKM). PiPSC zeigte eine deutlich unterschiedliche Phänotyp im Vergleich zu Fibroblasten (2A) und drückte die 4 Reprogrammierungsfaktoren an mRNA (2B) und Eiweiß (2C) Ebenen 10. Die Wirksamkeit eines PiPSC Basis Gefßtransplantat ist stark abhängig ...

Watch this Scientific Journal Video about Generation and Grafting of Tissue-engineered Vessels in a Mouse Model at JoVE.com

Generation and Grafting of Tissue-engineered Vessels in a Mouse Model

Hier zur Gewebezüchtung Gefäßimplantate, die zum Pfropfen in Mäusen durch Impfen Doppel partiell pluripotenten Stammzellen funktional erzeugen präsentieren wir ein Protokoll (PiPSC) - abgeleiteten glatten Muskelzellen und PiPSC - abgeleitete Endothelzellen auf einer dezellularisierten Gefäßgerüst Bioreaktor.

Generierung und Pfropfen von Tissue Engineering Gefäße in einem Maus-Modell

The construction of vascular conduits is a fundamental strategy for surgical repair of damaged and injured vessels resulting from cardiovascular diseases. ...

generation-and-grafting-of-tissue-engineered-vessels-in-a-mouse-model

Universidad de Cartagena UDEC

Research

JoVE Journal

Bioengineering

11.9K Aufrufe.  King's College London BHF Centre.  Hier zur Gewebezüchtung Gefäßimplantate, die zum Pfropfen in Mäusen durch Impfen Doppel partiell pluripotenten Stammzellen funktional erzeugen präsentieren wir ein Protokoll (PiPSC) - abgeleiteten glatten Muskelzellen und PiPSC - abgeleitete Endothelzellen auf einer dezellularisierten Gefäßgerüst Bioreaktor. 

Serie: Generation and Grafting of Tissue-engineered Vessels in a Mouse Model

Protocol for Relative Hydrodynamic Assessment of Tri-leaflet Polymer Valves

Limitations of currently available prosthetic valves, xenografts, and homografts have prompted a recent resurgence of developments in the area of tri-leaflet polymer valve prostheses. However, identification of a protocol for initial assessment of polymer valve hydrodynamic functionality is paramount during the early stages of the design process. Traditional in vitro pulse duplicator systems are not configured to accommodate flexible tri-leaflet materials; in addition, assessment of polymer valve functionality needs to be made in a relative context to native and prosthetic heart valves under identical test conditions so that variability in measurements from different instruments can be avoided. Accordingly, we conducted hydrodynamic assessment of i) native (n = 4, mean diameter, D = 20 mm), ii) bi-leaflet mechanical (n= 2, D = 23 mm) and iii) polymer valves (n = 5, D = 22 mm) via the use of a commercially available pulse duplicator system (ViVitro Labs Inc, Victoria, BC) that was modified to accommodate tri-leaflet valve geometries. Tri-leaflet silicone valves developed at the University of Florida comprised the polymer valve group. A mixture in the ratio of 35:65 glycerin to water was used to mimic blood physical properties. Instantaneous flow rate was measured at the interface of the left ventricle and aortic units while pressure was recorded at the ventricular and aortic positions. Bi-leaflet and native valve data from the literature was used to validate flow and pressure readings. The following hydrodynamic metrics were reported: forward flow pressure drop, aortic root mean square forward flow rate, aortic closing, leakage&#160;and regurgitant volume, transaortic closing, leakage, and total energy losses. Representative results indicated that hydrodynamic metrics from the three valve groups could be successfully obtained by incorporating a custom-built assembly into a commercially available pulse duplicator system and subsequently, objectively compared to provide insights on functional aspects of polymer valve design.

There has been renewed interest in developing polymer valves. Here, the objectives are to demonstrate the feasibility of modifying a commercial pulse duplicator to accommodate tri-leaflet geometries and to define a protocol to present polymer valve hydrodynamic data in comparison to native and prosthetic valve data collected under near-identical conditions.

Protokoll für Relative Hydrodynamische Beurteilung der Tri-Polymer Merkblatt Ventile

Limitations of currently available prosthetic valves, xenografts, and homografts have prompted a recent resurgence of developments in the area of ...

Forschung

Biotechnik

Surgical Technique for the Implantation of Tissue Engineered Vascular Grafts and Subsequent In Vivo Monitoring

The development of Tissue Engineered Vessels (TEVs) is advanced by the ability to routinely and effectively implant TEVs (4-5 mm in diameter) into a large animal model. A step by-step protocol for inter-positional placement of the TEV and real-time digital assessment of the TEV and native carotid arteries is described here. In vivo monitoring is made possible by the implantation of flow probes, catheters and ultrasonic crystals (capable of recording dynamic diameter changes of implanted TEVs and native carotid arteries) at the time of surgery. Once implanted, researchers can calculate arterial blood flow patterns, invasive blood pressure and artery diameter yielding parameters such as pulse wave velocity, augmentation index, pulse pressures and compliance. Data acquisition is accomplished using a single computer program for analysis throughout the duration of the experiment. Such invaluable data provides insight into TEV matrix remodeling, its resemblance to native/sham controls and overall TEV performance in vivo.

Surgical Technique for the Implantation of Tissue Engineered Vascular Grafts and Subsequent In Vivo Monitoring

A step-by-step protocol for the inter-positional placement of Tissue Engineered Vessels (TEVs) into the carotid artery of a sheep using end-to-end anastomosis and real-time digital assessment in vivo until animal sacrifice.

Operationstechnik zur Implantation von Tissue Engineered Gefäßprothesen und Folge<em&gt; In-vivo-</em&gt; Überwachung

The development of Tissue Engineered Vessels (TEVs) is advanced by the ability to routinely and effectively implant TEVs (4-5 mm in diameter) into a large ...

Generation of a Three-dimensional Full Thickness Skin Equivalent and Automated Wounding

In vitro models are a cost effective and ethical alternative to study cutaneous wound healing processes. Moreover, by using human cells, these models reflect the human wound situation better than animal models. Although two-dimensional models are widely used to investigate processes such as cellular migration and proliferation, models that are more complex are required to gain a deeper knowledge about wound healing. Besides a suitable model system, the generation of precise and reproducible wounds is crucial to ensure comparable results between different test runs. In this study, the generation of a three-dimensional full thickness skin equivalent to study wound healing is shown. The dermal part of the models is comprised of human dermal fibroblast embedded in a rat-tail collagen type I hydrogel. Following the inoculation with human epidermal keratinocytes and consequent culture at the air-liquid interface, a multilayered epidermis is formed on top of the models. To study the wound healing process, we additionally developed an automated wounding device, which generates standardized wounds in a sterile atmosphere.

The goal of this protocol is to build up a three-dimensional full thickness skin equivalent, which resembles natural skin. With a specifically constructed automated wounding device, precise and reproducible wounds can be generated under maintenance of sterility.

Erzeugung eines dreidimensionalen Vollhaut Equivalent und automatisierte Verwundung

In vitro models are a cost effective and ethical alternative to study cutaneous wound healing processes. Moreover, by using human cells, these models ...

Production, Characterization and Potential Uses of a 3D Tissue-engineered Human Esophageal Mucosal Model

The incidence of both esophageal adenocarcinoma and its precursor, Barrett&#8217;s Metaplasia, are rising rapidly in the western world. Furthermore esophageal adenocarcinoma generally has a poor prognosis, with little improvement in survival rates in recent years. These are difficult conditions to study and there has been a lack of suitable experimental platforms to investigate disorders of the esophageal mucosa.
A model of the human esophageal mucosa has been developed in the MacNeil laboratory which, unlike conventional 2D cell culture systems, recapitulates the cell-cell and cell-matrix interactions present in vivo and produces a mature, stratified epithelium similar to that of the normal human esophagus. Briefly, the model utilizes non-transformed normal primary human esophageal fibroblasts and epithelial cells grown within a porcine-derived acellular esophageal scaffold. Immunohistochemical characterization of this model by CK4, CK14, Ki67 and involucrin staining demonstrates appropriate recapitulation of the histology of the normal human esophageal mucosa.
This model provides a robust, biologically relevant experimental model of the human esophageal mucosa. It can easily be manipulated to investigate a number of research questions including the effectiveness of pharmacological agents and the impact of exposure to environmental factors such as alcohol, toxins, high temperature or gastro-esophageal refluxate components. The model also facilitates extended culture periods not achievable with conventional 2D cell culture, enabling, inter alia, the study of the impact of repeated exposure of a mature epithelium to the agent of interest for up to 20 days. Furthermore, a variety of cell lines, such as those derived from esophageal tumors or Barrett&#8217;s Metaplasia, can be incorporated into the model to investigate processes such as tumor invasion and drug responsiveness in a more biologically relevant environment.

This manuscript describes the production, characterization and potential uses of a tissue engineered 3D esophageal construct prepared from normal primary human esophageal fibroblast and squamous epithelial cells seeded within a de-cellularized porcine scaffold. The results demonstrate the formation of a mature stratified epithelium similar to the normal human esophagus.

Herstellung, Charakterisierung und Einsatzmöglichkeiten von 3D-Tissue-Engineering Menschen Ösophagus-Schleimhaut-Modell

The incidence of both esophageal adenocarcinoma and its precursor, Barrett&#8217;s Metaplasia, are rising rapidly in the western world. Furthermore ...

A Combined 3D Tissue Engineered In Vitro/In Silico Lung Tumor Model for Predicting Drug Effectiveness in Specific Mutational Backgrounds

In the present study, we combined an in vitro 3D lung tumor model with an in silico model to optimize predictions of drug response based on a specific mutational background. The model is generated on a decellularized porcine scaffold that reproduces tissue-specific characteristics regarding extracellular matrix composition and architecture including the basement membrane. We standardized a protocol that allows artificial tumor tissue generation within 14 days including three days of drug treatment. Our article provides several detailed descriptions of 3D read-out screening techniques like the determination of the proliferation index Ki67 staining&#39;s, apoptosis from supernatants by M30-ELISA and assessment of epithelial to mesenchymal transition (EMT), which are helpful tools for evaluating the effectiveness of therapeutic compounds. We could show compared to 2D culture a reduction of proliferation in our 3D tumor model that is related to the clinical situation. Despite of this lower proliferation, the model predicted EGFR-targeted drug responses correctly according to the biomarker status as shown by comparison of the lung carcinoma cell lines HCC827 (EGFR -mutated, KRAS wild-type) and A549 (EGFR wild-type, KRAS-mutated) treated with the tyrosine-kinase inhibitor (TKI) gefitinib. To investigate drug responses of more advanced tumor cells, we induced EMT by long-term treatment with TGF-beta-1 as assessed by vimentin/pan-cytokeratin immunofluorescence staining. A flow-bioreactor was employed to adjust culture to physiological conditions, which improved tissue generation. Furthermore, we show the integration of drug responses upon gefitinib treatment or TGF-beta-1 stimulation - apoptosis, proliferation index and EMT - into a Boolean in silico model. Additionally, we explain how drug responses of tumor cells with a specific mutational background and counterstrategies against resistance can be predicted. We are confident that our 3D in vitro approach especially with its in silico expansion provides an additional value for preclinical drug testing in more realistic conditions than in 2D cell culture.

A Combined 3D Tissue Engineered In Vitro/In Silico Lung Tumor Model for Predicting Drug Effectiveness in Specific Mutational Backgrounds

We present a three-dimensional (3D) lung cancer model based on a biological collagen scaffold to study sensitivity towards non-small-cell-lung-cancer-(NSCLC)-targeted therapies. We demonstrate different read-out techniques to determine the proliferation index, apoptosis and epithelial-mesenchymal transition (EMT) status. Collected data are integrated into an in silico model for prediction of drug sensitivity.

Ein kombiniertes 3D-Gewebezüchtungen<em&gt; In Vitro</em&gt; /<em&gt; In Silico</em&gt; Lungentumormodell für Hintergründe in bestimmten Mutations Drug Wirksamkeit vorhersagen

In the present study, we combined an in vitro 3D lung tumor model with an in silico model to optimize predictions of drug response based on a specific ...

Applications of In Vivo Functional Testing of the Rat Tibialis Anterior for Evaluating Tissue Engineered Skeletal Muscle Repair

Despite the regenerative capacity of skeletal muscle, permanent functional and/or cosmetic deficits (e.g., volumetric muscle loss (VML) resulting from traumatic injury, disease and various congenital, genetic and acquired conditions are quite common. Tissue engineering and regenerative medicine technologies have enormous potential to provide a therapeutic solution. However, utilization of biologically relevant animal models in combination with longitudinal assessments of pertinent functional measures are critical to the development of improved regenerative therapeutics for treatment of VML-like injuries. In that regard, a commercial muscle lever system can be used to measure length, tension, force and velocity parameters in skeletal muscle. We used this system, in conjunction with a high power, bi-phase stimulator, to measure in vivo force production in response to activation of the anterior crural compartment of the rat hindlimb. We have previously used this equipment to assess the functional impact of VML injury on the tibialis anterior (TA) muscle, as well as the extent of functional recovery following treatment of the injured TA muscle with our tissue engineered muscle repair (TEMR) technology. For such studies, the left foot of an anaesthetized rat is securely anchored to a footplate linked to a servomotor, and the common peroneal nerve is stimulated by two percutaneous needle electrodes to elicit muscle contraction and dorsiflexion of the foot. The peroneal nerve stimulation-induced muscle contraction is measured over a range of stimulation frequencies (1-200 Hz), to ensure an eventual plateau in force production that allows for an accurate determination of peak tetanic force. In addition to evaluation of the extent of VML injury as well as the degree of functional recovery following treatment, this methodology can be easily applied to study diverse aspects of muscle physiology and pathophysiology. Such an approach should assist with the more rational development of improved therapeutics for muscle repair and regeneration.

Applications of In Vivo Functional Testing of the Rat Tibialis Anterior for Evaluating Tissue Engineered Skeletal Muscle Repair

We describe an in vivo protocol to measure dorsiflexion of the foot following stimulation of the peroneal nerve and contraction of the anterior crural compartment of the rat hindlimb. Such measurements are an indispensable translational tool for evaluating skeletal muscle pathology and tissue engineering approaches to muscle repair and regeneration.

Anwendungen<em&gt; In Vivo</em&gt; Funktionstest der Ratte Vorderer Schienbeingewebe Skeletal Muscle Repair Engineered für die Bewertung

Despite the regenerative capacity of skeletal muscle, permanent functional and/or cosmetic deficits (e.g., volumetric muscle loss (VML) resulting from ...

Three-dimensional Tissue Engineered Aligned Astrocyte Networks to Recapitulate Developmental Mechanisms and Facilitate Nervous System Regeneration

Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to replace lost neurons and regenerate axonal pathways. However, during nervous system development, neuronal migration and axonal extension often occur along pathways formed by other cells, referred to as &#34;living scaffolds&#34;. Seeking to emulate these mechanisms and to design a strategy that circumvents the inhibitory environment of the CNS, this manuscript presents a protocol to fabricate tissue engineered astrocyte-based &#34;living scaffolds&#34;. To create these constructs, we employed a novel biomaterial encasement scheme to induce astrocytes to self-assemble into dense three-dimensional bundles of bipolar longitudinally-aligned somata and processes. First, hollow hydrogel micro-columns were assembled, and the inner lumen was coated with collagen extracellular-matrix. Dissociated cerebral cortical astrocytes were then delivered into the lumen of the cylindrical micro-column and, at a critical inner diameter of &#60;350 &#181;m, spontaneously self-aligned and contracted to produce long fiber-like cables consisting of dense bundles of astrocyte processes and collagen fibrils measuring &#60;150 &#181;m in diameter yet extending several cm in length. These engineered living scaffolds exhibited &#62;97% cell viability and were virtually exclusively comprised of astrocytes expressing a combination of the intermediate filament proteins glial-fibrillary acidic protein (GFAP), vimentin, and nestin. These aligned astrocyte networks were found to provide a permissive substrate for neuronal attachment and aligned neurite extension. Moreover, these constructs maintain integrity and alignment when extracted from the hydrogel encasement, making them suitable for CNS implantation. These preformed constructs structurally emulate key cytoarchitectural elements of naturally occurring glial-based &#34;living scaffolds&#34; in vivo. As such, these engineered living scaffolds may serve as test-beds to study neurodevelopmental mechanisms in vitro or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding following CNS degeneration in vivo.

We showcase the development of self-assembled, three-dimensional bundles of longitudinally aligned astrocytic somata and processes within a novel biomaterial encasement. These engineered &#34;living scaffolds&#34;, exhibiting micron-scale diameter yet extending centimeters in length, may serve as test-beds to study neurodevelopmental mechanisms or facilitate neuroregeneration by directing neuronal migration and/or axonal pathfinding.

Dreidimensionale Gewebezüchtungen ausgerichtet Astrozyten Netzwerke Nervensystem Regeneration zu rekapitulieren Entwicklungsmechanismen

Neurotrauma and neurodegenerative disease often result in lasting neurological deficits due to the limited capacity of the central nervous system (CNS) to ...

A Novel Tenorrhaphy Suture Technique with Tissue Engineered Collagen Graft to Repair Large Tendon Defects

Surgical management of large tendon defects with tendon grafts is challenging, as there are a finite number of sites where donors can be readily identified and used. Currently, this gap is filled with tendon auto-, allo-, xeno-, or artificial grafts, but clinical methods to secure them are not necessarily translatable to animals because of the scale. In order to evaluate new biomaterials or study a tendon graft made up of collagen type 1, we have developed a modified suture technique to help maintain the engineered tendon in alignment with the tendon ends. Mechanical properties of these grafts are inferior to the native tendon. To incorporate engineered tendon into clinically relevant models of loaded repair, a strategy was adopted to offload the tissue engineered tendon graft and allow for the maturation and integration of the engineered tendon in vivo until a mechanically sound neo-tendon was formed. We describe this technique using incorporation of the collagen type 1 tissue engineered tendon construct.

In this paper, we present an in vitro and in situ protocol to repair a tendon gap of up to 1.5 cm by filling it with engineered collagen graft. This was performed by developing a modified suture technique to take the mechanical load until the graft matures into the host tissue.

Eine neuartige Tenorrhaphy-Nahttechnik mit tissue engineered Collagen Graft zur Reparatur großer Sehnendefekte

Surgical management of large tendon defects with tendon grafts is challenging, as there are a finite number of sites where donors can be readily ...

Seeding and Implantation of a Biosynthetic Tissue-engineered Tracheal Graft in a Mouse Model

Treatment options for congenital or secondary long segment tracheal defects have historically been limited due to an inability to replace functional tissue. Tissue engineering holds great promise as a potential solution with its ability to integrate cells and signaling molecules into a 3-dimensional scaffold. Recent work with tissue engineered tracheal grafts (TETGs) has seen some success but their translation has been limited by graft stenosis, graft collapse, and delayed epithelialization. In order to investigate the mechanisms driving these issues, we have developed a mouse model for tissue engineered tracheal graft implantation. TETGs were constructed using electrospun polymers polyethylene terephthalate (PET) and polyurethane (PU) in a mixture of PET and PU (20:80 percent weight). Scaffolds were then seeded using bone marrow mononuclear cells isolated from 6-8 week-old C57BL/6 mice by gradient centrifugation. Ten million cells per graft were seeded onto the lumen of the scaffold and allowed to incubate overnight before implantation between the third and seventh tracheal rings. These grafts were able to recapitulate the findings of stenosis and delayed epithelialization as demonstrated by histological analysis and lack of Keratin 5 and Keratin 14 basal epithelial cells on immunofluorescence. This model will serve as a tool for investigating cellular and molecular mechanisms involved in host remodeling.

Graft stenosis poses a critical obstacle in tissue engineered airway replacement. To investigate cellular mechanisms underlying stenosis, we utilize a murine model of tissue engineered tracheal replacement with seeded bone marrow mononuclear cells (BM-MNC). Here, we detail our protocol, including scaffold manufacturing, BM-MNC isolation, graft seeding, and implantation.

Aussaat und Implantation von einem biosynthetischen Tissue-Engineering trachealen Transplantat in einem Mausmodell

Treatment options for congenital or secondary long segment tracheal defects have historically been limited due to an inability to replace functional ...

Tissue-Engineered Graft for Circumferential Esophageal Reconstruction in Rats

The use of biocompatible materials for circumferential esophageal reconstruction is a technically challenging task in rats and requires an optimal implant technique with nutritional support. Recently, there have been many attempts at esophageal tissue engineering, but the success rate has been limited due to difficulty in early epithelization in the special environment of peristalsis. Here, we developed an artificial esophagus that can improve the regeneration of the esophageal mucosa and muscle layers through a two-layered tubular scaffold, a mesenchymal stem cell-based bioreactor system, and a bypass feeding technique with modified gastrostomy. The scaffold is made of polyurethane (PU) nanofibers in a cylindrical shape with a three-dimensional (3D) printed polycaprolactone strand wrapped around the outer wall. Prior to transplantation, human-derived mesenchymal stem cells were seeded into the lumen of the scaffold, and bioreactor cultivation was performed to enhance cellular reactivity. We improved the graft survival rate by applying surgical anastomosis and covering the implanted prosthesis with a thyroid gland flap, followed by temporary nonoral gastrostomy feeding. These grafts were able to recapitulate the findings of initial epithelialization and muscle regeneration around the implanted sites, as demonstrated by histological analysis. In addition, increased elastin fibers and neovascularization were observed in the periphery of the graft. Therefore, this model presents a potential new technique for circumferential esophageal reconstruction.

Esophageal reconstruction is a challenging procedure, and development of a tissue-engineered esophagus that enables regeneration of esophageal mucosa and muscle and that can be implanted as an artificial graft is necessary. Here, we present our protocol to generate an artificial esophagus, including scaffold manufacturing, bioreactor cultivation, and various surgical techniques.

The use of biocompatible materials for circumferential esophageal reconstruction is a technically challenging task in rats and requires an optimal implant ...

Generierung und Pfropfen von Tissue Engineering Gefäße in einem Maus-Modell

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