Name: construction and characterization of a novel vocal fold bioreactor
Uploaded: 2014-08-01T13:00:00
Description: Watch this Scientific Journal Video about Construction and Characterization of a Novel Vocal Fold Bioreactor at JoVE.com

Wir danken Dr. Jeffrey Caplan für seine Ausbildung und Erfahrungsberichte zu konfokale Bildgebung. Wir danken auch dem Keck Electron Microscopy Lab und Dr. Chaoying Ni für die SEM-Unterstützung. Diese Arbeit wird von National Institutes of Health (NIDCD, R01DC008965 und R01DC011377) finanziert. ABZ erkennt NSF Integrative Graduate Education &amp; Research Traineeship (IGERT)-Programm für die Finanzierung.

1. Bioreaktor Versammlung (Video 1) <ol><li> Machen Sie eine Aluminiumform (kreisförmige Düse + Abstandsstift) mit vorgegebenen Innen-und Außenmaße (Abbildung 1). </li><li> Mit der Form aus Schritt 1.1, fabrizieren eine Silikonmembran (Durchmesser: 42 mm, Dicke: 1,5 mm, Abbildung 1) mit einem verschanzten Hülse (Durchmesser: 12 mm, Dicke ~ 0,25 mm, von der Abstandsstift in Abbildung 1 förmig) in die mittlere mit einem handelsüblichen Silikon-Elastomer-Kit. </li...

<ol>
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N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histologic+and+rheologic+characterization+of+vocal+fold+scarring.">Histologic and rheologic characterization of vocal fold scarring.</a> J. Voice. 16, 96-104 (2002).</li><li>Hansen, J. K., Thibeault, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Current+understanding+and+review+of+the+literature:+Vocal+fold+scarring.">Current understanding and review of the literature: Vocal fold scarring.</a> J. Voice. 20, 110-120 (2006).</li><li>Pittenger, M. 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L., Jia, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulating+the+behaviors+of+mesenchymal+stem+cells+via+the+combination+of+high-frequency+vibratory+stimulations+and+fibrous+scaffolds.">Modulating the behaviors of mesenchymal stem cells via the combination of high-frequency vibratory stimulations and fibrous scaffolds.</a> Tissue Eng. Part A. 19, 1862-1878 (2013).</li><li>Tong, Z., Sant, S., Khademhosseini, A., Jia, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Controlling+the+Fibroblastic+Differentiation+of+Mesenchymal+Stem+Cells+Via+the+Combination+of+Fibrous+Scaffolds+and+Connective+Tissue+Growth+Factor.">Controlling the Fibroblastic Differentiation of Mesenchymal Stem Cells Via the Combination of Fibrous Scaffolds and Connective Tissue Growth Factor.</a> Tissue Eng. Part A. 17, 2773-2785 (2011).</li><li>Jones, D. L., Wagers, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=No+place+like+home:+anatomy+and+function+of+the+stem+cell+niche.">No place like home: anatomy and function of the stem cell niche.</a> Nat. Rev. Mol. Cell Biol. 9, 11-21 (1038).</li><li>Wang, J. H., Thampatty, B. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanobiology+of+Adult+and+Stem+Cells.">Mechanobiology of Adult and Stem Cells.</a> Int. Rev. of Cell Mol. Biol. 271, 301-346 (2008).</li><li>Doroski, D. M., Levenston, M. E., Temenoff, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+tensile+culture+promotes+fibroblastic+differentiation+of+marrow+stromal+cells+encapsulated+in+poly+(ethylene+glycol)-based+hydrogels.">Cyclic tensile culture promotes fibroblastic differentiation of marrow stromal cells encapsulated in poly (ethylene glycol)-based hydrogels.</a> Tissue Eng. Part A. 16, 3457-3466 (2010).</li><li>Kim, B. S., Nikolovski, J., Bonadio, J., Mooney, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+mechanical+strain+regulates+the+development+of+engineered+smooth+muscle+tissue.">Cyclic mechanical strain regulates the development of engineered smooth muscle tissue.</a> Nat. Biotechnol. 17, 979-983 (1999).</li><li>Webb, K., 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=Cyclic+strain+increases+fibroblast+proliferation,+matrix+accumulation,+and+elastic+modulus+of+fibroblast-seeded+polyurethane+constructs.">Cyclic strain increases fibroblast proliferation, matrix accumulation, and elastic modulus of fibroblast-seeded polyurethane constructs.</a> J. Biomech. 39, 1136-1144 (2006).</li><li>Kim, Y. J., Sah, R. L. Y., Grodzinsky, A. J., Plaas, A. H. K., Sandy, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+Regulation+of+Cartilage+Biosynthetic+Behavior+-+Physical+Stimuli..">Mechanical Regulation of Cartilage Biosynthetic Behavior - Physical Stimuli..</a> Arch. Biochem. Biophys. 311, 1-12 (1994).</li><li>Titze, I. R., 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=Design+and+validation+of+a+bioreactor+for+engineering+vocal+fold+tissues+under+combined+tensile+and+vibrational+stresses.">Design and validation of a bioreactor for engineering vocal fold tissues under combined tensile and vibrational stresses.</a> J. Biomech. 37, 1521-1529 (2004).</li><li>Kutty, J. K., Webb, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vibration+stimulates+vocal+mucosa-like+matrix+expression+by+hydrogel-encapsulated+fibroblasts.">Vibration stimulates vocal mucosa-like matrix expression by hydrogel-encapsulated fibroblasts.</a> J. Tissue Eng. Regen. Med. 4, 62-72 (2010).</li><li>Farran, A. J. E., 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=Design+and+Characterization+of+a+Dynamic+Vibrational+Culture+System.">Design and Characterization of a Dynamic Vibrational Culture System.</a> J. Tissue Eng. Regen. Med. , (2011).</li><li>Reneker, D. H., Yarin, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrospinning+jets+and+polymer+nanofibers.">Electrospinning jets and polymer nanofibers.</a> Polymer. 49, 2387-2425 (2008).</li><li>Wang, Y., Theobald, P., Tyrer, J., Lepper, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+application+of+scanning+vibrometer+in+mapping+ultrasound+fields.">The application of scanning vibrometer in mapping ultrasound fields.</a> J. Phys.: Conf. Ser. 1, 167-173 (2004).</li><li>Brown, W. S., Morris, R. J., Hollien, H., Howell, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Speaking+Fundamental-Frequency+Characteristics+as+a+Function+of+Age+and+Professional.">Speaking Fundamental-Frequency Characteristics as a Function of Age and Professional.</a> J. Voice. 5, 310-315 (1991).</li><li>Ingber, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cellular+mechanotransduction:+putting+all+the+pieces+together+again.">Cellular mechanotransduction: putting all the pieces together again.</a> Faseb J. 20, 811-827 (2006).</li><li>Titze, I. R., 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=Design+and+validation+of+a+bioreactor+for+engineering+vocal+fold+tissues+under+combined+tensile+and+vibrational+stresses.">Design and validation of a bioreactor for engineering vocal fold tissues under combined tensile and vibrational stresses.</a> J. Biomech. 37, 1521-1529 (2004).</li><li>Moore, J., Thibeault, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insights+Into+the+Role+of+Elastin+in+Vocal+Fold+Health+and+Disease.">Insights Into the Role of Elastin in Vocal Fold Health and Disease.</a> J. Voice. 26, 269-275 (2012).</li><li>Thibeault, S. L., Bless, D. M., Gray, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interstitial+protein+alterations+in+rabbit+vocal+fold+with+scar.">Interstitial protein alterations in rabbit vocal fold with scar.</a> J. Voice. 17, 377-383 (2003).</li><li>Branski, R. C., Verdolini, K., Sandulache, V., Rosen, C. A., Hebda, P. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vocal+fold+wound+healing:+A+review+for+clinicians.">Vocal fold wound healing: A review for clinicians.</a> J. Voice. 20, 432-442 (2006).</li><li>Clark, I. A., Swingler, T. E., Sampieri, C. L., Edwards, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+regulation+of+matrix+metalloproteinases+and+their+inhibitors.">The regulation of matrix metalloproteinases and their inhibitors.</a> Int. J. Biochem. Cell B. 40, 1362-1378 (2008).</li><li>Silver, F. H., Horvath, I., Foran, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Viscoelasticity+of+the+vessel+wall:+The+role+of+collagen+and+elastic+fibers.">Viscoelasticity of the vessel wall: The role of collagen and elastic fibers.</a> Crit. Rev. Biomed. Eng. 29, 279-301 (2001).</li><li>Kutty, J. K., Webb, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue+Engineering+Therapies+for+the+Vocal+Fold+Lamina+Propria.">Tissue Engineering Therapies for the Vocal Fold Lamina Propria.</a> Tissue Eng. Part B: Rev. 15, 249-262 (2009).</li></ol>

Erfolgreiche Engineering von funktionellen Stimmlippengewebe in vitro erfordert die Erholung von einem Stimmlippenartigen Mikroumgebung, um die Verhaltensweisen der multipotenten Zellen vermitteln. Es ist allgemein anerkannt, dass Gewebe-oder Organstrukturen spiegeln die Funktionen, die sie benötigt, um durchzuführen. Für 22 Stimmlippengewebe werden die hochfrequenten Schwingungen, die bei der Lautbildung auftreten vorgeschlagen wichtig für die Gewebereifung zu sein. In unserer Studie sind PCL Ge...

Der menschliche Stimmlippen, einer epithelialen Schicht, die Lamina propria (LP) und der M. vocalis, ist eine spezialisierte Weichgewebe die den Luftstrom aus der Lunge in akustische Wellen für die Klangerzeugung umwandelt. 1 Stimmlippen schwingen regelmäßig während der normalen Stimmbildung, bei Grundfrequenzen im Bereich aufweisen Stämme von bis zu 30% 100-300 Hz. 2 Erwachsene Stimmlippen LP ist eine Gradienten-Struktur einer oberflächlichen (SLP) zusammengesetzt ist, ein Zwischenprodukt (ILP) und eine Tiefe (DLP)-Schicht. Weitere Klassifikationsgruppen das Epithel und die SLP als Schleimhaut-Schicht und verbindet die ILP-und DLP in die Stimmbandes. 3 Die SLP Schicht enthält in erster Linie eine amorphe Matrix mit spärlich verteilt kollagenen Fasern, während das Band mit reifen Kollagen und Elastin-Fasern angereichert um eine ausreichende Festigkeit verfügen. 4. Die Struktur und Mechanik des Neugeborenen Stimmlippen deutlich von ihrer reifen Kollegen. Obwohl Mechanismuss Regelstimmlippen Entwicklung und Reifung sind noch nicht vollständig verstanden, experimentelle Beweise für die Definition von Rollen der Vokalisation abgeleitete mechanische Belastung hingewiesen. Mehrere medizinische Bedingungen, einschließlich Sprachmissbrauch, Infektionen, chemische Reizstoffe und chirurgische Verfahren, können die Stimmlippe beschädigen. Stimmlippe Störungen betreffen schätzungsweise 3-9% der US-Bevölkerung. Aktuelle Behandlungsmethoden für Erkrankungen der Stimmlippen sind begrenzt, 5 und eine Stammzellen-basierten Tissue-Engineering-Ansatz hat sich als vielversprechende Strategie zur Wiederherstellung der Stimmlippenfunktion entstanden. Mesenchymalen Stammzellen (MSC) sind eine geeignete Alternative zu den primären Stimmlippen Stimmlippen Fibroblasten für Tissue Engineering. 6-9 Stammzell Schicksal Spezifikation und anschließender Gewebeentwicklung werden durch die spezifische Nische sie wohnen, von denen der mechanische Zustand vermittelt ein entscheidender Faktor. 10. Mechanische Kräfte sind wesentliche Regulatoren der Morphogenese einnd Homöostase, vor allem für Gewebe, die routinemäßig von der Last. ausgesetzt sind 11 Aus einer Perspektive Tissue Engineering hat es sich gezeigt, dass die Exposition gegenüber physiologisch relevanten mechanischen Reize fördert die Stammzelldifferenzierung und gewebespezifischen Matrixumbau. 12-15 Gewebekulturbioreaktoren sind entworfen, um die gewünschte physiologische Umgebung für Zell-oder Gewebewachstum in vitro zu simulieren. Für Stimmlippen Tissue Engineering, ist es besonders wichtig, die mechanische Umgebung der phonating Stimmlippen neu zu erstellen. Eine ideale Stimmlippen Bioreaktor sollte Vibrations effektiv zu liefern Hinweise zur Kultivierung von Zellen, so dass eine leichte Kontrolle über die Frequenz, Amplitude und Dauer der Erschütterungen. Titze und Mitarbeiter entwickelten eine Stimmlippen Bioreaktor (T1 Bioreaktor) 16, die statische Strecke mit hoher Frequenz (20-200 Hz) Schwingungen, die zelluläre Produktion von Matrixproteinen stimulieren kombiniert. Das Arbeg dieser Bioreaktor, Webb und Kollegen 17 suchten die Auswirkungen der 10-Tage, 100-Hz-Schwingungen auf den dermalen Fibroblasten in einer Hyaluronsäure (HA)-basierte Hydrogel kultiviert. Konstrukte Vibrationen ausgesetzt zeigten eine erhöhte Expression von HA-Synthase-2 (HAS2), Decorin, Fibromodulin und Matrix-Metalloproteinase-1 (MMP1), bezogen auf die statische Kontrollen. Die stimulierende Wirkung wurde festgestellt, zeitabhängig sein. Vor kurzem, unsere Gruppe 18 stellte ein Stimmlippen Bioreaktor (J1 Bioreaktor) mit einem Leistungsverstärker, einen Funktionsgenerator, einen geschlossenen Lautsprecher und eine Umfangs verankert Silikonmembran, die die schwingende Luft auf die beigefügten Zellen überträgt. Neonatale Vorhautfibroblasten in der J1-Bioreaktor kultiviert wurden 1 h Vibration bei 60, 110 oder 300 Hz unterzogen wird, mit einer Dehnung in der Ebene von bis zu 0,05%. Die qPCR Ergebnisse zeigten, dass die Expression einiger Gene ECM mäßig in Abhängigkeit von der unterschiedlichen Schwingungsfrequenzen verändertund Amplituden. Diese Bioreaktor entwickelt, während faszinierend, haben mehrere Einschränkungen. Zum Beispiel erfordert die T1-System eine große Anzahl von Verbindungsstangen und für mechanische Kopplung, die Begrenzung der Maximalfrequenzen erreichbar. Darüber hinaus können Zellen, um unerwünschte mechanische Bewegung und Flüssigkeits Störung, die die Datenauswertung erschweren unterworfen werden. Die J1-Bioreaktor, auf der anderen Seite, zeigt relativ geringe Wirkungsgrad der Energieumwandlung und ist nicht benutzerfreundlich. Darüber hinaus löst Vibrationen häufig die Zellbeladenen Konstrukte aus der zugrunde liegenden Silikonmembran. Der J2 Stimmlippen Bioreaktor hier berichtet, basierend auf dem gleichen Prinzip wie die J1-Version entworfen, wird die Konsistenz und Reproduzierbarkeit optimiert. Die Stimmbildung ähnlicher Vibrationen sind aerodynamisch in individuell angepassten Vibrationskammern, in denen MSC besiedelten Faser Poly (ε-Caprolacton) (PCL) Gerüste sind effektiver erzeugtEly gesichert. Laservibrometrie (LDV) ermöglicht dem Benutzer, den Vibrationsprofils der Membran / Gerüstanordnung zu überprüfen. In unserer Demonstration werden MSCs 200-Hz-Sinusschwingungen mit einer 1-Stunden-on-1-h-aus (OF) Muster für insgesamt 12 Stunden täglich für 7 Tage ausgesetzt. Zelluläre Antworten auf die verhängte Vibrations Hinweise werden systematisch untersucht. Insgesamt bietet die J2 Stimmlippen die benutzerfreundlichen Funktionen, so dass dynamische Zellkulturstudien, in einem hohen Durchsatz und reproduzierbar durchgeführt werden.

<table border="0" cellpadding="0" cellspacing="0" width="853">
	<tbody>
		<tr height="16">
			<td height="16" style="height:17px;width:248px;">silicone elastomer kit</td>
			<td style="width:188px;">Dow Corning</td>
			<td style="width:124px;">Sylgard 184</td>
			<td style="width:293px;">cure the membrane at 100 C for 2 hr</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">PCL</td>
			<td>Sigma Aldrich</td>
			<td>440744-500G</td>
			<td>Mn ~ 80 kDa, dissolve overnight</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">chloroform</td>
			<td>Sigma Aldrich</td>
			<td>C7559-5VL</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">human bone marrow-derived MSCs</td>
			<td>Lonza</td>
			<td>PT-2501</td>
			<td>received with passage 2</td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;">MSC maintenance media</td>
			<td>Lonza</td>
			<td>PT-3001</td>
			<td style="width:293px;">10% FBS in basal media supplemented 
			with L-glutamine, gentamicin and amphotericin</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">Accutase cell dissociation reagent</td>
			<td>Life Technologies</td>
			<td>A11105-01</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">ethanol</td>
			<td>Sigma Aldrich</td>
			<td>E7023-500ML</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">fibronectin</td>
			<td>Sigma Aldrich</td>
			<td>F2006-1MG</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">MMP1 DuoSet ELISA kit</td>
			<td>R&#38;D systems</td>
			<td>DY901</td>
			<td></td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">HA ELISA kit</td>
			<td>Echelon Biosciences</td>
			<td>&#160;K-1200&#160;&#160;</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">PBS</td>
			<td>Life Technologies</td>
			<td>14190-136</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">propidium iodide&#160;</td>
			<td>Life Technologies</td>
			<td>P1304MP</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">Syto-13&#160;</td>
			<td>Life Technologies</td>
			<td>S7575</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">QuantiTect reverse transcription kit&#160;</td>
			<td>Qiagen</td>
			<td>205311</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">SYBR Green PCR master mix</td>
			<td>Life Technologies</td>
			<td>4309155</td>
			<td></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;">replacement speaker</td>
			<td style="width:188px;">DAYTON audio 
			(via Parts Express)</td>
			<td>DS90-8</td>
			<td>paper cone, full range (80-13000 Hz), 85dB</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">Ergo Micro torque screwdriver</td>
			<td>Mountz</td>
			<td># 020377</td>
			<td>torque range: 20-120 cN.m</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">stereo speaker selector</td>
			<td>RadioShack</td>
			<td>40-244</td>
			<td>maximum power handling 50 W</td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">function generator&#160;</td>
			<td>Agilent&#160;</td>
			<td>33220A</td>
			<td>frequency range 1 &#181;Hz- 20 MHz</td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;">power amplifier&#160;</td>
			<td>PYLE audio</td>
			<td>PylePro PT2400</td>
			<td style="width:293px;">frequency response: 10 Hz-50 kHz, two speaker 
			channels</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">cell culture incubator&#160;</td>
			<td>Thermo Fisher&#160;</td>
			<td>Steri-Cult 3307</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">syringe pump&#160;</td>
			<td>New Era Pump Systems</td>
			<td>NE-300</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">High voltage power supply</td>
			<td>Spellman</td>
			<td>CZE 1000R</td>
			<td>output voltage: 0-30 kV</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">scanning electron microscope&#160;</td>
			<td>JEOL-USA</td>
			<td>JSM-7400F</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">desk gold sputter coater</td>
			<td>Denton Vacuum</td>
			<td>DSK00V-0013</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">Doppler laser vibrometer&#160;</td>
			<td>Polytec</td>
			<td>PDV-100</td>
			<td>non-contact velocity measurement (0-22 kHz)</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">PCR sequence detection system&#160;</td>
			<td>Applied Biosystems</td>
			<td>ABI7300</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">multiphoton confocal microscope</td>
			<td>Zeiss</td>
			<td>Zeiss 510Meta NLO</td>
			<td></td>
		</tr>
		<tr height="33">
			<td height="33" style="height:33px;">UV-VIS Spectrophotometer&#160;</td>
			<td style="width:188px;">NanoDrop Products 
			via Thermo Scientific</td>
			<td>ND-2000</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">VibSoft Data Acquisition Software</td>
			<td>Polytec</td>
			<td></td>
			<td>acquisition bandwidth up to 40 MHz</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">Origin 8.5 data analysis software&#160;</td>
			<td>OriginLab</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">qbasePlus qPCR data analysis software&#160;</td>
			<td>Biogazelle</td>
			<td>V2.3</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">aluminium alloy&#160;</td>
			<td>McMaster-Carr</td>
			<td>Alloy 6061</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">acrylic blocks</td>
			<td>McMaster-Carr</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="27">
			<td height="27" style="height:27px;">polycarbonate anti-humidity chamber</td>
			<td>McMaster-Carr</td>
			<td></td>
			<td style="width:293px;">Impact-Resistant&#160;Polycarbonate</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">screws&#160;</td>
			<td>McMaster-Carr</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">electronic cable/wire</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">medical grade PVC tubing</td>
			<td>US Plastic Corp.</td>
			<td>Tygon S-50-HL</td>
			<td>clear, biocompatible</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">10 mL syringe&#160;</td>
			<td>Becton Dickinson</td>
			<td>309604</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">21 G blunt ended needle</td>
			<td>Small Parts</td>
			<td>NE-213PL-25</td>
			<td>1-1/2&#34; length</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">Alligator clip adapters&#160;</td>
			<td>RadioShack</td>
			<td>270-354</td>
			<td>fully insulated</td>
		</tr>
		<tr height="17">
			<td height="17" style="height:17px;">8 mm biopsy punch</td>
			<td><a href="http://www.sklarcorp.com/ProductListUS.aspx?DepartmentID=10&amp;CategoryID=96">Sklar&#160;Surgical Instruments</a></td>
			<td>96-1152</td>
			<td>sterile, disposable</td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">12 mm biopsy punch</td>
			<td>Acuderm (via Fisher Scientific)</td>
			<td style="width:124px;">NC9998681</td>
			<td></td>
		</tr>
		<tr height="16">
			<td height="16" style="height:17px;">tissue culture flasks</td>
			<td>Corning</td>
			<td></td>
			<td>cell culture treated</td>
		</tr>
	</tbody>
</table>

construction and characterization of a novel vocal fold bioreactor

In vitro engineering of mechanically active tissues requires the presentation of physiologically relevant mechanical conditions to cultured cells. To emulate the dynamic environment of vocal folds, a novel vocal fold bioreactor capable of producing vibratory stimulations at fundamental phonation frequencies is constructed and characterized. The device is composed of a function generator, a power amplifier, a speaker selector and parallel vibration chambers. Individual vibration chambers are created by sandwiching a custom-made silicone membrane between a pair of acrylic blocks. The silicone membrane not only serves as the bottom of the chamber but also provides a mechanism for securing the cell-laden scaffold. Vibration signals, generated by a speaker mounted underneath the bottom acrylic block, are transmitted to the membrane aerodynamically by the oscillating air. Eight identical vibration modules, fixed on two stationary metal bars, are housed in an anti-humidity chamber for long-term operation in a cell culture incubator. The vibration characteristics of the vocal fold bioreactor are analyzed non-destructively using a Laser Doppler Vibrometer (LDV). The utility of the dynamic culture device is demonstrated by culturing cellular constructs in the presence of 200-Hz sinusoidal vibrations with a mid-membrane displacement of 40 &#181;m. Mesenchymal stem cells cultured in the bioreactor respond to the vibratory signals by altering the synthesis and degradation of vocal fold-relevant, extracellular matrix components. The novel bioreactor system presented herein offers an excellent in vitro platform for studying vibration-induced mechanotransduction and for the engineering of functional vocal fold tissues.

Die PCL-Scaffolds durch Elektrospinning hergestellt enthalten mikrometergroßen Poren und Zwischen zufällig verstrickt Fasern mit einem durchschnittlichen Durchmesser von 4,7 um (Abbildung 4A). Bei einer höheren Vergrößerung, nanoskalige Rillen und Poren auf einzelnen Fasern (4B) sichtbar. Die Beschichtung der Gerüste mit Fibronektin verbessert Hydrophilie und erleichtert die anfängliche Zelladhäsion / Verteilung auf der PCL-Gerüst (unveröffentlichte Beobachtung). <p class=...

Watch this Scientific Journal Video about Construction and Characterization of a Novel Vocal Fold Bioreactor at JoVE.com

Construction and Characterization of a Novel Vocal Fold Bioreactor

A novel vocal fold bioreactor capable of delivering physiologically relevant, vibratory stimulation to cultured cells is constructed and characterized. This dynamic culture device, when combined with a fibrous poly(&#949;-caprolactone) scaffold, creates a vocal fold-mimetic environment that modulates the behaviors of mesenchymal stem cells.

Konstruktion und Charakterisierung eines neuartigen Bioreaktor Stimmlippen

In vitro engineering of mechanically active tissues requires the presentation of physiologically relevant mechanical conditions to cultured cells. To ...

construction-and-characterization-of-a-novel-vocal-fold-bioreactor

Research

JoVE Journal

Bioengineering

Engineering Biological-Based Vascular Grafts Using a Pulsatile Bioreactor

Much effort has been devoted to develop and advance the methodology to regenerate functional small-diameter arterial bypasses. In the physiological environment, both mechanical and chemical stimulation are required to maintain the proper development and functionality of arterial vessels1,2.
Bioreactor culture systems developed by our group are designed to support vessel regeneration within a precisely controlled chemo-mechanical environment mimicking that of native vessels. Our bioreactor assembly and maintenance procedures are fairly simple and highly repeatable3,4. Smooth muscle cells (SMCs) are seeded onto a tubular polyglycolic acid (PGA) mesh that is threaded over compliant silicone tubing and cultured in the bioreactor with or without pulsatile stimulation for up to 12 weeks. There are four main attributes that distinguish our bioreactor from some predecessors. 1) Unlike other culture systems that simulate only the biochemical surrounding of native blood vessels, our bioreactor also creates a physiological pulsatile environment by applying cyclic radial strain to the vessels in culture. 2) Multiple engineered vessels can be cultured simultaneously under different mechanical conditions within a controlled chemical environment. 3) The bioreactor allows a mono layer of endothelial cells (EC) to be easily coated onto the luminal side of engineered vessels for animal implantation models. 4) Our bioreactor can also culture engineered vessels with different diameter size ranged from 1 mm to 3 mm, saving the effort to tailor each individual bioreactor to fit a specific diameter size. 
The engineered vessels cultured in our bioreactor resemble native blood vessels histologically to some degree. Cells in the vessel walls express mature SMC contractile markers such as smooth muscle myosin heavy chain (SMMHC)3. A substantial amount of collagen is deposited within the extracellular matrix, which is responsible for ultimate mechanical strength of the engineered vessels5. Biochemical analysis also indicates that collagen content of engineered vessels is comparable to that of native arteries6. Importantly, the pulsatile bioreactor has consistently regenerated vessels that exhibit mechanical properties that permit successful implantation experiments in animal models3,7. Additionally, this bioreactor can be further modified to allow real-time assessment and tracking of collagen remodeling over time, non-invasively, using a non-linear optical microscopy (NLOM)8. To conclude, this bioreactor should serve as an excellent platform to study the fundamental mechanisms that regulate the regeneration of functional small-diameter vascular grafts.

Our group has developed a bioreactor culture system that mimics the physiological pulsatile stresses of the cardiovascular system to regenerate implantable small-diameter vascular grafts.

Engineering Biological-Based Gefäßprothesen Mit einem Pulsatile Bioreaktor

Much effort has been devoted to develop and advance the methodology to regenerate functional small-diameter arterial bypasses. In the physiological ...

Forschung

Biotechnik

Synthetic, Multi-Layer, Self-Oscillating Vocal Fold Model Fabrication

Sound for the human voice is produced via flow-induced vocal fold vibration. The vocal folds consist of several layers of tissue, each with differing material properties 1. Normal voice production relies on healthy tissue and vocal folds, and occurs as a result of complex coupling between aerodynamic, structural dynamic, and acoustic physical phenomena. Voice disorders affect up to 7.5 million annually in the United States alone 2 and often result in significant financial, social, and other quality-of-life difficulties. Understanding the physics of voice production has the potential to significantly benefit voice care, including clinical prevention, diagnosis, and treatment of voice disorders.
Existing methods for studying voice production include in vivo experimentation using human and animal subjects, in vitro experimentation using excised larynges and synthetic models, and computational modeling. Owing to hazardous and difficult instrument access, in vivo experiments are severely limited in scope. Excised larynx experiments have the benefit of anatomical and some physiological realism, but parametric studies involving geometric and material property variables are limited. Further, they are typically only able to be vibrated for relatively short periods of time (typically on the order of minutes).
Overcoming some of the limitations of excised larynx experiments, synthetic vocal fold models are emerging as a complementary tool for studying voice production. Synthetic models can be fabricated with systematic changes to geometry and material properties, allowing for the study of healthy and unhealthy human phonatory aerodynamics, structural dynamics, and acoustics. For example, they have been used to study left-right vocal fold asymmetry 3,4, clinical instrument development 5, laryngeal aerodynamics 6-9, vocal fold contact pressure 10, and subglottal acoustics 11 (a more comprehensive list can be found in Kniesburges et al. 12)
Existing synthetic vocal fold models, however, have either been homogenous (one-layer models) or have been fabricated using two materials of differing stiffness (two-layer models). This approach does not allow for representation of the actual multi-layer structure of the human vocal folds 1 that plays a central role in governing vocal fold flow-induced vibratory response. Consequently, one- and two-layer synthetic vocal fold models have exhibited disadvantages 3,6,8 such as higher onset pressures than what are typical for human phonation (onset pressure is the minimum lung pressure required to initiate vibration), unnaturally large inferior-superior motion, and lack of a "mucosal wave" (a vertically-traveling wave that is characteristic of healthy human vocal fold vibration).
In this paper, fabrication of a model with multiple layers of differing material properties is described. The model layers simulate the multi-layer structure of the human vocal folds, including epithelium, superficial lamina propria (SLP), intermediate and deep lamina propria (i.e., ligament; a fiber is included for anterior-posterior stiffness), and muscle (i.e., body) layers 1. Results are included that show that the model exhibits improved vibratory characteristics over prior one- and two-layer synthetic models, including onset pressure closer to human onset pressure, reduced inferior-superior motion, and evidence of a mucosal wave.

The methodology for fabricating synthetic vocal fold models is described. The models are life-sized and mimic the multi-layer structure of the human vocal folds. Results show the models to self-oscillate at pressures comparable to lung pressure and demonstrate flow-induced vibratory responses that are similar to those of human vocal folds.

Synthetische Multi-Layer-, Selbst-Oszillierende Stimmlippen Modell Fabrication

Sound for the human voice is produced via flow-induced vocal fold vibration. The vocal folds consist of several layers of tissue, each with differing ...

Design of a Biaxial Mechanical Loading Bioreactor for Tissue Engineering

We designed a loading device that is capable of applying uniaxial or biaxial mechanical strain to a tissue engineered biocomposites fabricated for transplantation. While the device primarily functions as a bioreactor that mimics the native mechanical strains, it is also outfitted with a load cell for providing force feedback or mechanical testing of the constructs. The device subjects engineered cartilage constructs to biaxial mechanical loading with great precision of loading dose (amplitude and frequency) and is compact enough to fit inside a standard tissue culture incubator. It loads samples directly in a tissue culture plate, and multiple plate sizes are compatible with the system. The device has been designed using components manufactured for precision-guided laser applications. Bi-axial loading is accomplished by two orthogonal stages. The stages have a 50 mm travel range and are driven independently by stepper motor actuators, controlled by a closed-loop stepper motor driver that features micro-stepping capabilities, enabling step sizes of less than 50 nm. A polysulfone loading platen is coupled to the bi-axial moving platform. Movements of the stages are controlled by Thor-labs Advanced Positioning Technology (APT) software. The stepper motor driver is used with the software to adjust load parameters of frequency and amplitude of both shear and compression independently and simultaneously. Positional feedback is provided by linear optical encoders that have a bidirectional repeatability of 0.1 &mu;m and a resolution of 20 nm, translating to a positional accuracy of less than 3 &mu;m over the full 50 mm of travel. These encoders provide the necessary position feedback to the drive electronics to ensure true nanopositioning capabilities. In order to provide the force feedback to detect contact and evaluate loading responses, a precision miniature load cell is positioned between the loading platen and the moving platform. The load cell has high accuracies of 0.15% to 0.25% full scale.

We designed a novel mechanical loading bioreactor that can apply uniaxial or biaxial mechanical strain to a cartilage biocomposite prior to transplantation into an articular cartilage defect.

Entwurf eines Biaxiale Mechanische Belastung Bioreaktor für Tissue Engineering

We  designed a loading device that is capable of applying uniaxial or biaxial  mechanical strain to a tissue engineered biocomposites fabricated for  ...

Operation of a Benchtop Bioreactor

Fermentation systems are used to provide an optimal growth environment for many different types of cell cultures. The ability afforded by fermentors to carefully control temperature, pH, and dissolved oxygen concentrations in particular makes them essential to efficient large scale growth and expression of fermentation products. This video will briefly describe the advantages of the fermentor over the shake flask. It will also identify key components of a typical benchtop fermentation system and give basic instruction on setup of the vessel and calibration of its probes. The viewer will be familiarized with the sterilization process and shown how to inoculate the growth medium in the vessel with culture. Basic concepts of operation, sampling, and harvesting will also be demonstrated. Simple data analysis and system cleanup will also be discussed.

Fermentors are used to increase culture yield and productivity of bioengineered cells. After screening multiple microbial or animal cell culture candidates in shake flasks, the next logical step is to increase the selected culture&#x2019;s biomass with the fermentor. This video demonstrates the setup and operation of a typical benchtop bioreactor system.

Betrieb einer Tischbioreaktor

Fermentation systems are used to provide an optimal growth environment for many different types of cell cultures. The ability afforded by fermentors to ...

Investigating the Three-dimensional Flow Separation Induced by a Model Vocal Fold Polyp

The fluid-structure energy exchange process for normal speech has been studied extensively, but it is not well understood for pathological conditions. Polyps and nodules, which are geometric abnormalities that form on the medial surface of the vocal folds, can disrupt vocal fold dynamics and thus can have devastating consequences on a patient&#39;s ability to communicate. Our laboratory has reported particle image velocimetry (PIV) measurements, within an investigation of a model polyp located on the medial surface of an in&#160;vitro driven vocal fold model, which show that such a geometric abnormality considerably disrupts the glottal jet behavior. This flow field adjustment is a likely reason for the severe degradation of the vocal quality in patients with polyps. A more complete understanding of the formation and propagation of vortical structures from a geometric protuberance, such as a vocal fold polyp, and the resulting influence on the aerodynamic loadings that drive the vocal fold dynamics, is necessary for advancing the treatment of this pathological condition. The present investigation concerns the three-dimensional flow separation induced by a wall-mounted prolate hemispheroid with a 2:1 aspect ratio in cross flow, i.e. a model vocal fold polyp, using an oil-film visualization technique. Unsteady, three-dimensional flow separation and its impact of the wall pressure loading are examined using skin friction line visualization and wall pressure measurements.

Vocal fold polyps can disrupt vocal fold dynamics and thus can have devastating consequences on a patient&#39;s ability to communicate. Three-dimensional flow separation induced by a wall-mounted model polyp and its impact on the wall pressure loading are examined using particle image velocimetry, skin friction line visualization, and wall pressure measurements.

Untersuchung der dreidimensionalen Strömungstrennung, die durch ein Modell Vocal Fold Polyp induziert wird

The fluid-structure energy exchange process for normal speech has been studied extensively, but it is not well understood for pathological conditions. ...

Characterization of Leukocyte-platelet Rich Fibrin, A Novel Biomaterial

Autologous platelet concentrates represent promising innovative tools in the field of regenerative medicine and have been extensively used in oral surgery. Unlike platelet rich plasma (PRP) that is a gel or a suspension, Leukocyte-Platelet Rich Fibrin (L-PRF) is a solid 3D fibrin membrane generated chair-side from whole blood containing no anti-coagulant. The membrane has a dense three dimensional fibrin matrix with enriched platelets and abundant growth factors. L-PRF is a popular adjunct in surgeries because of its superior handling characteristics as well as its suturability to the wound bed. The goal of the study is to demonstrate generation as well as provide detailed characterization of relevant properties of L-PRF that underlie its clinical success.

Leucocyte-Platelet Rich Fibrin (L-PRF) represents an FDA cleared preparation of autologous platelet concentrates that possesses unique fibrin architecture, enriched platelets and abundant growth factors. Here, we present a protocol for chair-side generation of L-PRF as well as evaluate its mechanical properties including uniaxial testing and suture retention strength testing.

Charakterisierung von Leukozyten-Thrombozyten-Rich-Fibrin, ein neuartiges Biomaterial

Autologous platelet concentrates represent promising innovative tools in the field of regenerative medicine and have been extensively used in oral ...

A Novel Bioreactor for High Density Cultivation of Diverse Microbial Communities

A novel reactor design, coined a high density bioreactor (HDBR), is presented for the cultivation and study of high density microbial communities. Past studies have evaluated the performance of the reactor for the removal of COD1 and nitrogen species2-4 by heterotrophic and chemoautotrophic bacteria, respectively. The HDBR design eliminates the requirement for external flocculation/sedimentation processes while still yielding effluent containing low suspended solids. In this study, the HDBR is applied as a photobioreactor (PBR) in order to characterize the nitrogen removal characteristics of an algae-based photosynthetic microbial community. As previously reported for this HDBR design, a stable biomass zone was established with a clear delineation between the biologically active portion of the reactor and the recycling reactor fluid, which resulted in a low suspended solid effluent. The algal community in the HDBR was observed to remove 18.4% of total nitrogen species in the influent. Varying NH4+ and NO3- concentrations in the feed did not have an effect on NH4+ removal (n=44, p=0.993 and n=44, p=0.610 respectively) while NH4+ feed concentration was found to be negatively related with NO3- removal (n=44, p=0.000) and NO3- feed concentration was found to be positively correlated with NO3- removal (n=44, p=0.000). Consistent removal of NH4+, combined with the accumulation of oxidized nitrogen species at high NH4+ fluxes indicates the presence of ammonia- and nitrite-oxidizing bacteria within the microbial community.

A novel reactor design, coined a high density bioreactor (HDBR), is presented for the cultivation and study of high density microbial communities. Here, the HDBR is successfully applied in a photobioreactor (PBR) configuration for the study of nitrogen metabolism by a mixed high density algal community.

A Novel Bioreaktor für High Density Anbau von Diverse mikrobiellen Gemeinschaften

A novel reactor design, coined a high density bioreactor (HDBR), is presented for the cultivation and study of high density microbial communities. Past ...

Construction and Setup of a Bench-scale Algal Photosynthetic Bioreactor with Temperature, Light, and pH Monitoring for Kinetic Growth Tests

The optimal design and operation of photosynthetic bioreactors (PBRs) for microalgal cultivation is essential for improving the environmental and economic performance of microalgae-based biofuel production. Models that estimate microalgal growth under different conditions can help to optimize PBR design and operation. To be effective, the growth parameters used in these models must be accurately determined. Algal growth experiments are often constrained by the dynamic nature of the culture environment, and control systems are needed to accurately determine the kinetic parameters. The first step in setting up a controlled batch experiment is live data acquisition and monitoring. This protocol outlines a process for the assembly and operation of a bench-scale photosynthetic bioreactor that can be used to conduct microalgal growth experiments. This protocol describes how to size and assemble a flat-plate, bench-scale PBR from acrylic. It also details how to configure a PBR with continuous pH, light, and temperature monitoring using a data acquisition and control unit, analog sensors, and open-source data acquisition software.

This paper describes the assembly process and operation of a bench-scale photosynthetic bioreactor that can be used, in conjunction with other methods, to estimate pertinent kinetic growth parameters. This system continuously monitors the pH, light, and temperature using sensors, a data acquisition and control unit, and open-source data acquisition software.

Aufbau und Aufbau eines handelsüblichen Algen-Photosynthese-Bioreaktors mit Temperatur-, Licht- und pH-Monitoring für kinetische Wachstumstests

The optimal design and operation of photosynthetic bioreactors (PBRs) for microalgal cultivation is essential for improving the environmental and economic ...

Preparation and Characterization of Novel HDL-mimicking Nanoparticles for Nerve Growth Factor Encapsulation

The objective of this article is to introduce preparation and characterization methods for nerve growth factor (NGF)-loaded, high-density, lipoprotein (HDL)-mimicking nanoparticles (NPs). HDLs are endogenous NPs and have been explored as vehicles for the delivery of therapeutic agents. Various methods have been developed to prepare HDL-mimicking NPs. However, they are generally complicated, time consuming, and difficult for industrial scale-up. In this study, one-step homogenization was used to mix the excipients and form the prototype NPs. NGF is a water-soluble protein of 26 kDa. To facilitate the encapsulation of NGF into the lipid environment of HDL-mimicking NPs, protamine USP was used to form an ion-pair complex with NGF to neutralize the charges on the NGF surface. The NGF/protamine complex was then introduced into the prototype NPs. Apolipoprotein A-I was finally coated on the surface of the NPs. NGF HDL-mimicking NPs showed preferable properties in terms of particle size, size distribution, entrapment efficiency, in vitro release, bioactivity, and biodistribution. With the careful design and exploration of homogenization in HDL-mimicking NPs, the procedure was greatly simplified, and the NPs were made scalable. Moreover, various challenges, such as separating unloaded NGF from the NPs, conducting reliable in vitro release studies, and measuring the bioactivity of the NPs, were overcome.

Simple homogenization was used to prepare novel, high-density, lipoprotein-mimicking nanoparticles to encapsulate nerve growth factor. Challenges, detailed protocols for nanoparticle preparation, in vitro characterization, and in vivo studies are described in this article.

Vorbereitung und Charakterisierung von neuartigen HDL-imitierenden Nanopartikeln für die Nervenwachstumsfaktorverkapselung

The objective of this article is to introduce preparation and characterization methods for nerve growth factor (NGF)-loaded, high-density, lipoprotein ...

Fabrication and Characterization of Optical Tissue Phantoms Containing Macrostructure

The rapid development of new optical imaging techniques is dependent on the availability of low-cost, customizable, and easily reproducible standards. By replicating the imaging environment, costly animal experiments to validate a technique may be circumvented. Predicting and optimizing the performance of in vivo and ex vivo imaging techniques requires testing on samples that are optically similar to tissues of interest. Tissue-mimicking optical phantoms provide a standard for evaluation, characterization, or calibration of an optical system. Homogenous polymer optical tissue phantoms are widely used to mimic the optical properties of a specific tissue type within a narrow spectral range. Layered tissues, such as the epidermis and dermis, can be mimicked by simply stacking these homogenous slab phantoms. However, many in vivo imaging techniques are applied to more spatially complex tissue where three dimensional structures, such as blood vessels, airways, or tissue defects, can affect the performance of the imaging system. 
This protocol describes the fabrication of a tissue-mimicking phantom that incorporates three-dimensional structural complexity using material with optical properties of tissue. Look-up tables provide India ink and titanium dioxide recipes for optical absorption and scattering targets. Methods to characterize and tune the material optical properties are described. The phantom fabrication detailed in this article has an internal branching mock airway void; however, the technique can be broadly applied to other tissue or organ structures.

Optical tissue phantoms are essential tools for calibration and characterization of optical imaging systems and validation of theoretical models. This article details a method for phantom fabrication that includes replication of tissue optical properties and three-dimensional tissue structure.

Herstellung und Charakterisierung von optischen Gewebe Phantome, die Makrostruktur enthalten

The rapid development of new optical imaging techniques is dependent on the availability of low-cost, customizable, and easily reproducible standards. By ...