Questo lavoro è stato finanziato da sovvenzioni a LKM-K dal National Institutes of Health / National Cancer Institute (R01CA129822 e R01CA140995). Dr. Medina-Kauwe ringrazia C. Rey, M. M-Kauwe e D. Revetto per il supporto continuo.

1. Consegna sistemica in vivo <ol><li> Mescolare abbastanza Herdox con soluzione salina sterile per equiparare 0,2 ml di una dose mg / kg 0,004 di Herdox per iniezione per 6-8 settimane vecchio mouse cuscinetti sottocutanei tumori xenotrapianto fianco bilaterali nu / nu. </li><li> Disegnare delicatamente il composto Herdox in una siringa da insulina 3/10 cc con ago 29G, evitando le bolle. </li><li> Anestesia è indotta da una breve esposizione isoflurano in una camera di induzione dotato di un sistema di evacuazione fumi gas (portate ossigeno: 0.5-1 L / min, concentrazione isoflurano: 3-4% (o inferiore). </li><li> Iniettare l&#39;intero contenuto nella vena della coda di un topo anestetizzato (0,2 ml per iniezione). IV iniezione può essere eseguita in un ambiente sobrio, topo non anestetizzati. </li><li> Ripetere iniezioni sullo stesso topo per sei giorni più sequenziali, una volta al giorno. </li></ol> 2. Fluorescence Imaging in vivo L&#39;accumulo di Herdox fluorescenza nei tumori puòessere rivelabile con l&#39;ultimo giorno di iniezione (giorno 7) con un imager multimodale. Le procedure sotto comportano l&#39;impiego di un macro-sistema di illuminazione e rilevazione personalizzata (Figura 1) 8. <ol><li> Accendere il Multimode In Imager ottico in vivo. </li><li> Selezionare un filtro passa-banda di emissione (590 nm ± 30 nm) adatto per doxorubicina rivelazione a fluorescenza. </li><li> Accendere Argon-Krypton laser e inserire un filtro passa-banda di eccitazione (488 nm ± 10 nm) nel percorso ottico laser. </li><li> Accendere il sistema di anestesia e quindi posizionare il mouse nella camera di anestetizzante (tassi di flusso di ossigeno: 0,5-1 L / min, concentrazione isoflurano: 3-4% (o inferiore) dotati di un sistema di evacuazione dei gas. </li><li> Passa il mouse dalla camera anestetizzante per la camera di imaging del Multimode In Imager ottica vivo quando il mouse è anestetizzato. </li><li> Posizionare un musetto sopra il naso del mouse e aprire il flusso di somministrare anestesia continuaSia durante l&#39;acquisizione dell&#39;immagine (tassi di flusso di ossigeno: 0,5-1 L / min, la concentrazione di isoflurano: 2-3% (o inferiore). </li><li> Acquisire immagini di fluorescenza utilizzando un tempo di esposizione di 5-15 sec. </li><li> Eseguire l&#39;analisi delle immagini e di elaborazione tra cui la correzione del fondo o di regolazione del contrasto. </li></ol> 3. Fluorescence Imaging ex vivo Herdox fluorescenza può essere ripreso in tumori e organi specifici (tra cui il fegato, reni, milza, cuore e muscolo scheletrico) raccolte da topi sacrificati a 24 ore dopo il (Giorno 7) ultima iniezione di Herdox. <ol><li> Accendere il Multimode In Imager ottico in vivo. </li><li> Selezionare un filtro passa-banda di emissione (580 nm ± 20 nm) per il rilevamento di fluorescenza doxorubicina. </li><li> Accendere Argon-Krypton laser e inserire un filtro passa-banda di eccitazione (488 nm ± 10 nm) nel percorso ottico laser. </li><li> Luogo tumori e organi specifici disposti su un piatto di Petri nella camera di imaging of il Multimode In Imager ottico in vivo. </li><li> Acquisire immagini di fluorescenza dei tessuti utilizzando un tempo di esposizione di 5-15 sec. Un esempio di acquisizione iniziale immagine di fluorescenza è mostrato in Figura 2a. Ripetere la stessa utilizzando un vuoto Petri-piatto, che fungerà da sfondo (Figura 2b). </li><li> Eseguire l&#39;analisi delle immagini e di elaborazione tra cui la correzione del fondo o di regolazione del contrasto. Un esempio di una immagine corretta viene mostrata in Figura 2c, risultante dalla sottrazione della Figura 2b dalla Figura 2a. </li></ol> 4. In situ Imaging confocale dei Tumori In situ confocale permette rilevazione e l&#39;analisi di accumulazione tumore Herdox a livello cellulare. <ol><li> Accendere una Leica SPE microscopio confocale. </li><li> Selezionare 488 nm luce laser per l&#39;eccitazione della doxorubicina e di emissione lunghezze d&#39;onda (560-620 nm) per la doxorubicinarivelazione della fluorescenza. </li><li> Selezionare un obiettivo 40X o 63X e olio di immersione goccia sulla lente dell&#39;obiettivo. </li><li> Estrarre i tumori freschi da topi eutanasia che in precedenza ricevuto trattamenti Herdox e finto come descritto nella procedura 2. </li><li> Luogo tumori su una piastra di Petri in ghiaccio per evitare il degrado del tessuto, e poi trasferire i tumori in una camera T Delta per l&#39;imaging confocale. </li><li> Acquisire le immagini confocale dei tumori a profondità focali sequenziali (dimensione del passo: 1 micron, spessore: 20 micron). Un esempio di immagini in sequenza-acquisite lungo l&#39;asse z è mostrato in Figura 3, pannello sinistro. </li><li> Eseguire intensità massima z-proiezione delle immagini. Una proiezione massima intensità di z-stack immagini è mostrato in Figura 3, pannello di destra. </li><li> Calcola significare intensità di fluorescenza della massima intensità Z -. Immagini di proiezione media intensità di fluorescenza delle immagini sopra il campo di vista generale sono stati calcolared usando ImageJ. </li></ol> 5. Ratiometrica Spectral Imaging e analisi Spectral Imaging ratiometrica e analisi consente la discriminazione tra Dox fluorescenza e autofluorescenza. <ol><li> Accendere una scansione laser a fluorescenza microscopio confocale. </li><li> Acquisire 15 immagini dei tumori Herdox-trattati e non a una profondità specificata nel range spettrale di 510-650 nm, con un passo di 10 nm, e eccitazione a 488 nm luce utilizzando un microscopio confocale Leica SPE. </li><li> Preparare una soluzione 100 mM di doxorubicina. </li><li> Eseguire l&#39;imaging spettrale della soluzione di doxorubicina 100 micron per ottenere la firma spettrale pura di Dox fluorescenza (campo spettrale: 510-650 nm, una dimensione del passo: 10 nm). Risultati tipici di acquisizione immagine da immagini spettrali e conseguente spettro di fluorescenza tracciati come un grafico sono mostrati in Figura 4. </li><li> Acquisire la firma spettrale autofluorescenza da un&#39;immagine cUbe (campo spettrale: 510-650 nm, una dimensione del passo: 10 nm) ottenuta da imaging spettrale di tumori non trattati. Risultati tipici di acquisizione immagine da immagini spettrali e conseguente spettro di fluorescenza tracciati come un grafico sono mostrati in Figura 5. </li><li> Genera quattro firme spettrali di riferimento (autofluorescenza puro, 0.1.doxorubin +0,9. Autofluorescenza, 0.2. Doxorubicina +0,8. Autofluorescenza, 0.3.doxorubin +0,7. Autofluorescenza) utilizzando il programma che abbiamo sviluppato 9. Una tipica curva che mostra quattro firme spettrali di riferimento è mostrato in Figura 6. </li><li> Eseguire la classificazione spettrale delle immagini come definito dalle firme spettrali di riferimento attraverso la misura di distanza euclidea che utilizzano il programma che precedentemente sviluppato 9. </li><li> Eseguire unmixing spettrale lineare di quelle immagini utilizzando un programma spettrale unmixing (plug-in in ImageJ) abbiamo sviluppato 7, 10, per il confronto con la rappresentazione spettrale raziometrico e analisi. Un indirizzo example di separare fluorescenza Herdox da autofluorescenza da unmixing spettrale lineare è mostrato in Figura 7. </li></ol>

<ol>
	<li>Agadjanian, H., Chu, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemotherapy+Targeting+by+DNA+Capture+in+Viral+Protein+Particles.">Chemotherapy Targeting by DNA Capture in Viral Protein Particles.</a> Nanomedicine. 7 (3), 335-352 (2012).</li><li>Agadjanian, H., Ma, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+detection+and+elimination+by+a+targeted+gallium+corrole.">Tumor detection and elimination by a targeted gallium corrole.</a> Proc. Natl. Acad. Sci. U.S.A. 106 (15), 6105-6110 (2009).</li><li>Agadjanian, H., Weaver, J. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specific+delivery+of+corroles+to+cells+via+noncovalent+conjugates+with+viral+proteins.">Specific delivery of corroles to cells via noncovalent conjugates with viral proteins.</a> Pharm. Res. 23 (2), 367-377 (2006).</li><li>Medina-Kauwe, L. K., Maguire, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-viral+gene+delivery+to+human+breast+cancer+cells+by+targeted+Ad5+penton+proteins.">Non-viral gene delivery to human breast cancer cells by targeted Ad5 penton proteins.</a> Gene Therapy. , 81753-81761 (2001).</li><li>Medina-Kauwe, L. 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Y., Gross, Z., 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=Ratiometric+spectral+imaging+for+fast+tumor+detection+and+chemotherapy+monitoring+in+vivo.">Ratiometric spectral imaging for fast tumor detection and chemotherapy monitoring in vivo.</a> J. Biomed. Opt. 16 (6), 066007 (2011).</li><li>Fujimoto, J. G., Farkas, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Biomedical Optical Imaging. , (2009).</li><li>Hwang, J. Y., Moffatt-Blue, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multimode+optical+imaging+of+small+animals:+development+and+applications.">Multimode optical imaging of small animals: development and applications.</a> Proc. of SPIE. 6411, (2007).</li><li>Ducros, M., Moreaux, L., 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=Spectral+unmixing:+analysis+of+performance+in+the+olfactory+bulb+in+vivo.">Spectral unmixing: analysis of performance in the olfactory bulb in vivo.</a> PLoS One. 4 (2), e4418 (2009).</li><li>Zimmermann, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spectral+imaging+and+linear+unmixing+in+light+microscopy.">Spectral imaging and linear unmixing in light microscopy.</a> Adv. Biochem. Eng. Biotechnol. , 95245-95265 (2005).</li></ol>

L&#39;autore, Daniel Farkas, è Presidente di Spectral Imaging Molecolare. Gli autori restanti avere interessi in gioco.

Dox fluorescenza può essere rilevabile in vivo utilizzando la termocamera multimode quando i tumori sono sottocutaneo. Tuttavia, la dose terapeuticamente efficace di Herdox (0,004 mg / kg) è al di sotto della soglia di rilevamento dopo una singola dose. Al contrario, dopo 7 iniezioni giornaliere (1x/day per 7 giorni), l&#39;accumulo tumore e ritenzione della particella è sufficiente per consentire la visualizzazione di Dox fluorescenza. È critico quando si lavora con Dox o quals...

Tumore-targeting della chemioterapia ha il potenziale per eliminare le cellule tumorali a dosi inferiori rispetto ai farmaci mirati perché più della terapia erogata può accumulare la destinazione prevista in luogo della distribuzione di tessuto non tumorale. Come quest&#39;ultima situazione sarebbe diluire la efficacia del farmaco e quindi richiedono dosi più elevate per essere efficace, tumore-targeting ha sia vantaggi terapeutici e di sicurezza oltre il trattamento non mirati standard. Targeting chemioterapia di incapsulamento in nanoparticelle auto-assemblati permette al farmaco di rimanere chimicamente non modificato in contrasto con i farmaci che sono covalentemente legati a molecole di targeting. Come tale collegamento ha il potenziale per alterare l&#39;attività sia del farmaco e la molecola di guida; assemblaggio non covalente permette potenza del farmaco da conservare. Abbiamo precedentemente dimostrato che il romanzo a tre componenti, complesso auto-assemblati, Herdox, rivolge HER2 + tumori <em&gt; In vivo e suscita l&#39;ablazione del tumore-crescita, risparmiando il tessuto normale, compreso il cuore 1. Herdox è formato attraverso interazioni non covalenti tra la proteina recettoriale cellula-penetrazione, HerPBK10, e l&#39;agente chemioterapico, doxorubicina (Dox), tramite una piccola linker acido nucleico. HerPBK10 lega il recettore del fattore di crescita epidermico umano (HER) e attiva endocitosi mediata da recettore 2-4, mentre endosomal penetrazione membrana viene realizzato attraverso incorporazione della adenovirus-derivato penton base di capside proteico 4-6. Un dominio carica positivamente sulla proteina permette acido nucleico legante 4, 5, attraverso il quale può essere trasportato Dox DNA-intercalato per la somministrazione mirata. Elettrofila, intercalazione, e possibilmente interazioni oligomerizzazione di proteine ​​facilitano l&#39;auto-assemblaggio in tutto 10-20 particelle nm che sono stabili nel sangue e sotto lo stoccaggio prolungato a temperature diverse 1. Preferenziale mira a LEI2 + cellule tumorali è facilitata dalla maggiore affinità ligando quando HER2 è elevata. Nostri studi precedenti hanno dimostrato che la consegna sistematica delle rese Herdox accumulo preferenziale nei tumori oltre tessuto non tumorale e in confronto a untargeted Dox 1, e la penetrazione nelle cellule tumorali in vivo 7. Abbiamo osservato che Herdox rilasci Dox dopo l&#39;entrata delle cellule tumorali, permettendo l&#39;accumulo di Dox nel nucleo 1. Tumore-accumulo sembra essere correlata con il livello recettoriale, come tumori esprimenti HER2-relativamente bassi accumulano meno Herdox rispetto a quelli con livelli relativamente più elevati HER2 1. Inoltre, la concentrazione effettiva morte cellulare presenta una correlazione inversa con HER2 visualizzazione su linee cellulari tumorali esprimenti differenti livelli di HER2 superficie cellulare 1. Herdox mostra un vantaggio terapeutico e di sicurezza oltre Dox non mirati, come l&#39;uccisione del tumore si verifica in più di dosi 10 volte inferiore rispetto a decomprimeregramme incentrato farmaco e non produce effetti avversi riscontrabili su cuore (rilevata mediante ecocardiografia e istologici macchia) o il fegato (riconosciuto mediante TUNEL macchia) dei tessuti, in contrasto untargeted Dox 1. Nonostante la sua derivazione da una proteina del capside virale, HerPBK10 presenta nessun immunogenicità rilevabile a livelli terapeutici 2. Mentre gli anticorpi preesistenti a tutto adenovirus possono riconoscere HerPBK10, non sono in grado di prevenire vincolante 2 cellule. Volume del tumore misurata nel tempo è un metodo standard di valutazione dell&#39;efficacia terapeutica delle terapie mirate, ed è stato impiegato per valutare l&#39;efficacia terapeutica di Herdox. Integrando questo approccio con in vivo e ex vivo imaging di fluorescenza intensità ci ha permesso di valutare meglio gli obiettivi di efficienza 7. Abbiamo specificatamente integrato in situ confocale di tumori asportati con analisi spettrale di Dox fluorescenza per verificare che non Herdoxt accumulato solo a tumori in vivo, ma penetrato nelle cellule tumorali e Dox consegnato nel citoplasma e nel nucleo 7. Analisi spettrale inoltre ci ha permesso di distinguere Dox fluorescenza da autofluorescenza 7. Qui mostriamo più in dettaglio il nostro approccio per la valutazione Herdox in vivo dopo la consegna sistemica, e, soprattutto, per valutare il targeting attraverso metodi di imaging multimodali e di analisi.

<table border="1">
<tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments (optional)</th
 ></tr>
 <tr>
 <td >Fluorescence laser scanning confocal microscope</td>
 <td >Leica</td>
 <td >SPE</td>
 <td></td>
 </tr>
 <tr>
 <td>In Vivo Optical Imager</td>
 <td>Spectral Molecular Imaging</td>
 <td>Multimode In Vivo Optical Imager</td>
 <td></td>
 </tr>
 <tr>
 <td >Doxorubicin-HCl</td>
 <td >Sigma-Aldrich</td>
 <td >D4035</td>
 <td></td>
 </tr>
 <tr>
 <td >Nude (NU/NU) mouse, female, 6-8 week</td>
 <td >Charles River</td>
 <td >Strain code 088</td>
 <td></td>
 </tr>
 <tr>
 <td >MDA-MB-435 human HER2+ tumor cells</td>
 <td >NCI-Frederick Cancer DCTD Tumor/Cell Line Repository</td>
 <td >0507292</td>
 <td></td>
 </tr>
 <tr>
 <td >3/10 cc insulin syringe U-100 with 29G x 1/2" Ultra-FineIV permanently attached needle</td>
 <td >BD</td>
 <td >309301</td>
 <td></td>
 </tr>
 <tr>
 <td >Delta T chamber </td>
 <td >Bioptechs </td>
 <td >04200417B</td>
 <td></td>
 </tr>
 </tbody>
</table>

analysis of targeted viral protein nanoparticles delivered to her2+ tumors

La nanoparticella HER2 + tumore-mirato, Herdox, espone accumulo tumore preferenziale e ablazione del tumore-crescita in un modello animale di cancro HER2 +. Herdox è formato da non covalente auto-assemblaggio di un tumore mirato proteina penetrazione cella con l&#39;agente chemioterapico, doxorubicina, tramite una piccola linker acido nucleico. Una combinazione di elettrofilo, intercalazione, e le interazioni oligomerizzazione facilitare l&#39;auto-assemblaggio in tutto 10-20 particelle nm. Herdox esibisce la stabilità nel sangue e nella conservazione prolungata a temperature diverse. Consegna sistemica di Herdox in topi portatori di tumore provoca la morte delle cellule tumorali, senza effetti negativi rilevabili a tessuto non tumorale, tra il cuore e il fegato (che subiscono danni segnata da doxorubicina non mirati). HER2 elevazione facilita il targeting di cellule che esprimono il recettore del fattore di crescita epidermico umano, quindi tumori che presentavano livelli elevati di HER2 mostrano maggiore accumulo di Herdox rispetto alle cellule exprescantare livelli inferiori, sia in vitro che in vivo. L&#39;imaging di fluorescenza combinata con l&#39;analisi confocale e spettrale situ ha permesso di verificare in vivo del tumore targeting e la penetrazione delle cellule tumorali di Herdox dopo la consegna sistemica. Qui dettaglio i nostri metodi per la valutazione targeting tumorale tramite l&#39;imaging multimodale dopo la consegna sistemica.

La figura 1 mostra il vivo ottico prototipo imager, che è stato costruito a scopo di acquisizione di immagini in modalità multiple, tra intensità di fluorescenza, spettrale, durata, 2-fotone, confocale intra-vitale, e di imaging bioluminescenza in. Inoltre, la telecamera sensibile elevata raffreddata e linee laser ad alta potenza incorporato in questo sistema rese superiori contrasto immagini di fluorescenza rispetto ai sistemi di imaging ottico commerciali 11, in partico...

Watch this Scientific Journal Video about Analysis of Targeted Viral Protein Nanoparticles Delivered to HER2+ Tumors at JoVE.com

Analysis of Targeted Viral Protein Nanoparticles Delivered to HER2+ Tumors

Questo articolo descrive le procedure per l&#39;analisi di immagini ottiche delle nanoparticelle tumore-mirato, Herdox. In particolare, l&#39;uso dettagliato del dispositivo di imaging multimodale per la rilevazione del tumore orientare e valutare la penetrazione del tumore è descritta qui.

Analisi delle Targeted proteina virale nanoparticelle distribuito HER2 + Tumori

The HER2+ tumor-targeted nanoparticle, HerDox, exhibits tumor-preferential accumulation and tumor-growth ablation in an animal model of HER2+ cancer. ...

analysis-targeted-viral-protein-nanoparticles-delivered-to-her2

Research

JoVE Journal

Bioengineering

10.9K Views.  University of Southern California. Questo articolo descrive le procedure per l'analisi di immagini ottiche delle nanoparticelle tumore-mirato, Herdox. In particolare, l'uso dettagliato del dispositivo di imaging multimodale per la rilevazione del tumore orientare e valutare la penetrazione del tumore è descritta qui.

Video: Analysis of Targeted Viral Protein Nanoparticles Delivered to HER2+ Tumors

Introduction to the Ultrasound Targeted Microbubble Destruction Technique

In UTMD, bioactive molecules, such as negatively charged plasmid DNA vectors encoding a gene of interest, are added to the cationic shells of lipid microbubble contrast agents7-9. In mice these vector-carrying microbubbles can be administered intravenously or directly to the left ventricle of the heart. In larger animals they can also be infused through an intracoronary catheter. The subsequent delivery from the circulation to a target organ occurs by acoustic cavitation at a resonant frequency of the microbubbles. It seems likely that the mechanical energy generated by the microbubble destruction results in transient pore formation in or between the endothelial cells of the microvasculature of the targeted region10. As a result of this sonoporation effect, the transfection efficiency into and across the endothelial cells is enhanced, and transgene-encoding vectors are deposited into the surrounding tissue. Plasmid DNA remaining in the circulation is rapidly degraded by nucleases in the blood, which further reduces the likelihood of delivery to non-sonicated tissues and leads to highly specific target-organ transfection.

Ultrasound Targeted Microbubble Destruction (UTMD) can be used to direct site-specific delivery of bioactive molecules, including therapeutic genes, to target organs accessible to ultrasound, such as the heart and liver1-6.

Introduzione alla tecnica di distruzione mirata ad ultrasuoni microbolle

In UTMD, bioactive molecules, such as negatively charged plasmid DNA vectors encoding a gene of interest, are added to the cationic shells of lipid ...

Ricerca

Bioingegneria

Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves

The aortic valve, located between the left ventricle and the aorta, allows for unidirectional blood flow, preventing backflow into the ventricle. Aortic valve leaflets are composed of interstitial cells suspended within an extracellular matrix (ECM) and are lined with an endothelial cell monolayer. The valve withstands a harsh, dynamic environment and is constantly exposed to shear, flexion, tension, and compression. Research has shown calcific lesions in diseased valves occur in areas of high mechanical stress as a result of endothelial disruption or interstitial matrix damage1-3. Hence, it is not surprising that epidemiological studies have shown high blood pressure to be a leading risk factor in the onset of aortic valve disease4. 
The only treatment option currently available for valve disease is surgical replacement of the diseased valve with a bioprosthetic or mechanical valve5. Improved understanding of valve biology in response to physical stresses would help elucidate the mechanisms of valve pathogenesis. In turn, this could help in the development of non-invasive therapies such as pharmaceutical intervention or prevention. Several bioreactors have been previously developed to study the mechanobiology of native or engineered heart valves6-9. Pulsatile bioreactors have also been developed to study a range of tissues including cartilage10, bone11 and bladder12. The aim of this work was to develop a cyclic pressure system that could be used to elucidate the biological response of aortic valve leaflets to increased pressure loads. 
The system consisted of an acrylic chamber in which to place samples and produce cyclic pressure, viton diaphragm solenoid valves to control the timing of the pressure cycle, and a computer to control electrical devices. The pressure was monitored using a pressure transducer, and the signal was conditioned using a load cell conditioner. A LabVIEW program regulated the pressure using an analog device to pump compressed air into the system at the appropriate rate. The system mimicked the dynamic transvalvular pressure levels associated with the aortic valve; a saw tooth wave produced a gradual increase in pressure, typical of the transvalvular pressure gradient that is present across the valve during diastole, followed by a sharp pressure drop depicting valve opening in systole. The LabVIEW program allowed users to control the magnitude and frequency of cyclic pressure. The system was able to subject tissue samples to physiological and pathological pressure conditions. This device can be used to increase our understanding of how heart valves respond to changes in the local mechanical environment.

Design of a Cyclic Pressure Bioreactor for the Ex Vivo Study of Aortic Heart Valves

A cyclic pressure bioreactor capable of subjecting heart valve tissue to physiological and pathological pressure conditions has been designed. A LabVIEW program allows users to control pressure magnitude, amplitude and frequency. This device can be used to study the mechanobiology of heart valve tissue or isolated cells.

Progettazione di un bioreattore per la pressione ciclica Ex Vivo Studio delle valvole cardiache aortica

The aortic valve, located between the left ventricle and the aorta, allows for unidirectional blood flow, preventing backflow into the ventricle. Aortic ...

Cellular Lipid Extraction for Targeted Stable Isotope Dilution Liquid Chromatography-Mass Spectrometry Analysis

The metabolism of fatty acids, such as arachidonic acid (AA) and linoleic acid (LA), results in the formation of oxidized bioactive lipids, including numerous stereoisomers1,2. These metabolites can be formed from free or esterified fatty acids. Many of these oxidized metabolites have biological activity and have been implicated in various diseases including cardiovascular and neurodegenerative diseases, asthma, and cancer3-7. Oxidized bioactive lipids can be formed enzymatically or by reactive oxygen species (ROS). Enzymes that metabolize fatty acids include cyclooxygenase (COX), lipoxygenase (LO), and cytochromes P450 (CYPs)1,8. Enzymatic metabolism results in enantioselective formation whereas ROS oxidation results in the racemic formation of products.
While this protocol focuses primarily on the analysis of AA- and some LA-derived bioactive metabolites; it could be easily applied to metabolites of other fatty acids. Bioactive lipids are extracted from cell lysate or media using liquid-liquid (l-l) extraction. At the beginning of the l-l extraction process, stable isotope internal standards are added to account for errors during sample preparation. Stable isotope dilution (SID) also accounts for any differences, such as ion suppression, that metabolites may experience during the mass spectrometry (MS) analysis9. After the extraction, derivatization with an electron capture (EC) reagent, pentafluorylbenzyl bromide (PFB) is employed to increase detection sensitivity10,11. Multiple reaction monitoring (MRM) is used to increase the selectivity of the MS analysis. Before MS analysis, lipids are separated using chiral normal phase high performance liquid chromatography (HPLC). The HPLC conditions are optimized to separate the enantiomers and various stereoisomers of the monitored lipids12. This specific LC-MS method monitors prostaglandins (PGs), isoprostanes (isoPs), hydroxyeicosatetraenoic acids (HETEs), hydroxyoctadecadienoic acids (HODEs), oxoeicosatetraenoic acids (oxoETEs) and oxooctadecadienoic acids (oxoODEs); however, the HPLC and MS parameters can be optimized to include any fatty acid metabolites13.
Most of the currently available bioanalytical methods do not take into account the separate quantification of enantiomers. This is extremely important when trying to deduce whether or not the metabolites were formed enzymatically or by ROS. Additionally, the ratios of the enantiomers may provide evidence for a specific enzymatic pathway of formation. The use of SID allows for accurate quantification of metabolites and accounts for any sample loss during preparation as well as the differences experienced during ionization. Using the PFB electron capture reagent increases the sensitivity of detection by two orders of magnitude over conventional APCI methods. Overall, this method, SID-LC-EC-atmospheric pressure chemical ionization APCI-MRM/MS, is one of the most sensitive, selective, and accurate methods of quantification for bioactive lipids.

This protocol will demonstrate the extraction and analysis of free and esterified bioactive fatty acids from cells. Fatty acids are accurately quantified using stable isotope dilution, chiral liquid chromatography, electron capture atmospheric chemical ionization multiple reaction monitoring mass spectrometry (SID-LC-ECAPCI-MRM/MS).

Estrazione dei lipidi cellulari per analisi mirate Stabile diluizione isotopica cromatografia liquida-spettrometria di massa

The metabolism of fatty acids, such as arachidonic acid (AA) and linoleic acid (LA), results in the formation of oxidized bioactive lipids, including ...

Therapeutic Gene Delivery and Transfection in Human Pancreatic Cancer Cells using Epidermal Growth Factor Receptor-targeted Gelatin Nanoparticles

More than 32,000 patients are diagnosed with pancreatic cancer in the United States per year and the disease is associated with very high mortality 1. Urgent need exists to develop novel clinically-translatable therapeutic strategies that can improve on the dismal survival statistics of pancreatic cancer patients. Although gene therapy in cancer has shown a tremendous promise, the major challenge is in the development of safe and effective delivery system, which can lead to sustained transgene expression. 
Gelatin is one of the most versatile natural biopolymer, widely used in food and pharmaceutical products. Previous studies from our laboratory have shown that type B gelatin could physical encapsulate DNA, which preserved the supercoiled structure of the plasmid and improved transfection efficiency upon intracellular delivery. By thiolation of gelatin, the sulfhydryl groups could be introduced into the polymer and would form disulfide bond within nanoparticles, which stabilizes the whole complex and once disulfide bond is broken due to the presence of glutathione in cytosol, payload would be released 2-5. Poly(ethylene glycol) (PEG)-modified GENS, when administered into the systemic circulation, provides long-circulation times and preferentially targets to the tumor mass due to the hyper-permeability of the neovasculature by the enhanced permeability and retention effect 6. Studies have shown over-expression of the epidermal growth factor receptor (EGFR) on Panc-1 human pancreatic adenocarcinoma cells 7. In order to actively target pancreatic cancer cell line, EGFR specific peptide was conjugated on the particle surface through a PEG spacer.8
Most anti-tumor gene therapies are focused on administration of the tumor suppressor genes, such as wild-type p53 (wt-p53), to restore the pro-apoptotic function in the cells 9. The p53 mechanism functions as a critical signaling pathway in cell growth, which regulates apoptosis, cell cycle arrest, metabolism and other processes 10. In pancreatic cancer, most cells have mutations in p53 protein, causing the loss of apoptotic activity. With the introduction of wt-p53, the apoptosis could be repaired and further triggers cell death in cancer cells 11. 
Based on the above rationale, we have designed EGFR targeting peptide-modified thiolated gelatin nanoparticles for wt-p53 gene delivery and evaluated delivery efficiency and transfection in Panc-1 cells.

Type B gelatin-based engineered nanovectors system (GENS) was developed for systemic gene delivery and transfection in the treatment of pancreatic cancer. By modification with epidermal growth factor receptor (EGFR) specific peptide on the surface of nanparticles, they could target on EGFR receptor and release plasmid under reducing environment, such as high intracellular glutathione concentrations.

Consegna dei geni e trasfezione in cellule umane di cancro al pancreas con Epidermal Growth Factor Receptor mirati Nanovectors Progettato a base di gelatina

More than 32,000 patients are diagnosed with pancreatic cancer in the United States per year and the disease is associated with very high mortality 1. ...

Viral Nanoparticles for In vivo Tumor Imaging

The use of nanomaterials has the potential to revolutionize materials science and medicine. Currently, a number of different nanoparticles are being investigated for applications in imaging and therapy. Viral nanoparticles (VNPs) derived from plants can be regarded as self-assembled bionanomaterials with defined sizes and shapes. Plant viruses under investigation in the Steinmetz lab include icosahedral particles formed by Cowpea mosaic virus (CPMV) and Brome mosaic virus (BMV), both of which are 30 nm in diameter. We are also developing rod-shaped and filamentous structures derived from the following plant viruses: Tobacco mosaic virus (TMV), which forms rigid rods with dimensions of 300 nm by 18 nm, and Potato virus X (PVX), which form filamentous particles 515 nm in length and 13 nm in width (the reader is referred to refs. 1 and 2 for further information on VNPs).
From a materials scientist's point of view, VNPs are attractive building blocks for several reasons: the particles are monodisperse, can be produced with ease on large scale in planta, are exceptionally stable, and biocompatible. Also, VNPs are "programmable" units, which can be specifically engineered using genetic modification or chemical bioconjugation methods 3. The structure of VNPs is known to atomic resolution, and modifications can be carried out with spatial precision at the atomic level4, a level of control that cannot be achieved using synthetic nanomaterials with current state-of-the-art technologies.
In this paper, we describe the propagation of CPMV, PVX, TMV, and BMV in Vigna ungiuculata and Nicotiana benthamiana plants. Extraction and purification protocols for each VNP are given. Methods for characterization of purified and chemically-labeled VNPs are described. In this study, we focus on chemical labeling of VNPs with fluorophores (e.g. Alexa Fluor 647) and polyethylene glycol (PEG). The dyes facilitate tracking and detection of the VNPs 5-10, and PEG reduces immunogenicity of the proteinaceous nanoparticles while enhancing their pharmacokinetics 8,11. We demonstrate tumor homing of PEGylated VNPs using a mouse xenograft tumor model. A combination of fluorescence imaging of tissues ex vivo using Maestro Imaging System, fluorescence quantification in homogenized tissues, and confocal microscopy is used to study biodistribution. VNPs are cleared via the reticuloendothelial system (RES); tumor homing is achieved passively via the enhanced permeability and retention (EPR) effect12. The VNP nanotechnology is a powerful plug-and-play technology to image and treat sites of disease in vivo. We are further developing VNPs to carry drug cargos and clinically-relevant imaging moieties, as well as tissue-specific ligands to target molecular receptors overexpressed in cancer and cardiovascular disease.

Viral Nanoparticles for In vivo Tumor Imaging

Plant viral nanoparticles (VNPs) are promising platforms for applications in biomedicine. Here, we describe the procedures for plant VNP propagation, purification, characterization, and bioconjugation. Finally, we show the application of VNPs for tumor homing and imaging using a mouse xenograft model and fluorescence imaging.

Nanoparticelle virali per<em&gt; In vivo</em&gt; Imaging Tumore

The use of nanomaterials has the potential to revolutionize materials science and medicine. Currently, a number of different nanoparticles are being ...

Evaluation of Polymeric Gene Delivery Nanoparticles by Nanoparticle Tracking Analysis and High-throughput Flow Cytometry

Non-viral gene delivery using polymeric nanoparticles has emerged as an attractive approach for gene therapy to treat genetic diseases1 and as a technology for regenerative medicine2. Unlike viruses, which have significant safety issues, polymeric nanoparticles can be designed to be non-toxic, non-immunogenic, non-mutagenic, easier to synthesize, chemically versatile, capable of carrying larger nucleic acid cargo and biodegradable and/or environmentally responsive. Cationic polymers self-assemble with negatively charged DNA via electrostatic interaction to form complexes on the order of 100 nm that are commonly termed polymeric nanoparticles. Examples of biomaterials used to form nanoscale polycationic gene delivery nanoparticles include polylysine, polyphosphoesters, poly(amidoamines)s and polyethylenimine (PEI), which is a non-degradable off-the-shelf cationic polymer commonly used for nucleic acid delivery1,3 . Poly(beta-amino ester)s (PBAEs) are a newer class of cationic polymers4 that are hydrolytically degradable5,6 and have been shown to be effective at gene delivery to hard-to-transfect cell types such as human retinal endothelial cells (HRECs)7, mouse mammary epithelial cells8, human brain cancer cells9 and macrovascular (human umbilical vein, HUVECs) endothelial cells10.
A new protocol to characterize polymeric nanoparticles utilizing nanoparticle tracking analysis (NTA) is described. In this approach, both the particle size distribution and the distribution of the number of plasmids per particle are obtained11. In addition, a high-throughput 96-well plate transfection assay for rapid screening of the transfection efficacy of polymeric nanoparticles is presented. In this protocol, poly(beta-amino ester)s (PBAEs) are used as model polymers and human retinal endothelial cells (HRECs) are used as model human cells. This protocol can be easily adapted to evaluate any polymeric nanoparticle and any cell type of interest in a multi-well plate format.

A protocol for nanoparticle tracking analysis (NTA) and high-throughput flow cytometry to evaluate polymeric gene delivery nanoparticles is described. NTA is utilized to characterize the nanoparticle particle size distribution and the plasmid per particle distribution. High-throughput flow cytometry enables quantitative transfection efficacy evaluation for a library of gene delivery biomaterials.

Valutazione della consegna del gene polimerici Nanoparticelle per l&#39;analisi delle nanoparticelle Monitoraggio e High-throughput Citometria a Flusso

Non-viral gene delivery using polymeric nanoparticles has emerged as an attractive approach for gene therapy to treat genetic diseases1 and as a ...

Harmonic Nanoparticles for Regenerative Research

In this visualized experiment, protocol details are provided for in vitro labeling of human embryonic stem cells (hESC) with second harmonic generation nanoparticles (HNPs). The latter are a new family of probes recently introduced for labeling biological samples for multi-photon imaging. HNPs are capable of doubling the frequency of excitation light by the nonlinear optical process of second harmonic generation with no restriction on the excitation wavelength.
Multi-photon based methodologies for hESC differentiation into cardiac clusters (maintained as long term air-liquid cultures) are presented in detail. In particular, evidence on how to maximize the intense second harmonic (SH) emission of isolated HNPs during 3D monitoring of beating cardiac tissue in 3D is shown. The analysis of the resulting images to retrieve 3D displacement patterns is also detailed.

Protocol details are provided for in vitro labeling human embryonic stem cells with second harmonic generating nanoparticles. Methodologies for hESC investigation by multi-photon microscopy and their differentiation into cardiac clusters are also presented.

Harmonic Nanoparticelle for Regenerative ricerca

In this visualized experiment, protocol details are provided for in vitro labeling of human embryonic stem cells (hESC) with second harmonic generation ...

Production of Metal Nanoparticles by Pulsed Laser-ablation in Liquids: A Tool for Studying the Antibacterial Properties of Nanoparticles

The emergence of multidrug-resistant bacteria is a global clinical concern leading some to speculate about our return to a "pre-antibiotics" era of medicine. In addition to efforts to identify novel small-molecule antimicrobial drugs, there has been great interest in the use of metal nanoparticles as coatings for medical devices, wound dressings, and consumer packaging, due to their antimicrobial properties. The wide variety of methods available for nanoparticle synthesis results in a broad spectrum of chemical and physical properties which can affect antibacterial efficacy. This manuscript describes the pulsed laser-ablation in liquids (PLAL) method to create nanoparticles. This approach allows for the fine tuning of nanoparticle size, composition, and stability using post-irradiation methods as well as the addition of surfactants or volume excluders. By controlling particle size and composition, a large range of physical and chemical properties of metal nanoparticles can be explored which may contribute to their antimicrobial efficacy thereby opening new avenues for antibacterial development.

The antimicrobial properties of metals such as copper and silver have been recognized for centuries. This protocol describes pulsed laser-ablation in liquids, a method of synthesizing metal nanoparticles that provides the ability to fine tune the properties of these nanoparticles to optimize their antimicrobial effects.

Produzione di nanoparticelle metalliche mediante ablazione laser pulsata nei liquidi: uno strumento per studiare le proprietà antibatteriche delle nanoparticelle

The emergence of multidrug-resistant bacteria is a global clinical concern leading some to speculate about our return to a "pre-antibiotics" era of ...

Correlative Light Electron Microscopy (CLEM) for Tracking and Imaging Viral Protein Associated Structures in Cryo-immobilized Cells

Due to its high resolution, electron microscopy (EM) is an indispensable tool for virologists. However, one of the main difficulties when analyzing virus-infected or transfected cells via EM are the low efficiencies of infection or transfection, hindering the examination of these cells. In order to overcome this difficulty, light microscopy (LM) can be performed first to allocate the subpopulation of infected or transfected cells. Thus, taking advantage of the use of fluorescent proteins (FPs) fused to viral proteins, LM is used here to record the positions of the "positive-transfected" cells, expressing a FP and growing on a support with an alphanumeric pattern. Subsequently, cells are further processed for EM via high pressure freezing (HPF), freeze substitution (FS) and resin embedding. The ultra-rapid freezing step ensures excellent membrane preservation of the selected cells that can then be analyzed at the ultrastructural level by transmission electron microscopy (TEM). Here, a step-by-step correlative light electron microscopy (CLEM) workflow is provided, describing sample preparation, imaging and correlation in detail. The experimental design can be also applied to address many cell biology questions.

Correlative Light Electron Microscopy CLEM for Tracking and Imaging Viral Protein Associated Structures in Cryo-immobilized Cells

A correlative light electron microscopy (CLEM) method is applied to image virus-induced intracellular structures via electron microscopy (EM) in cells that are previously selected by light microscopy (LM). LM and EM are combined as a hybrid imaging approach to achieve an integrated view of virus-host interactions.

Microscopia a luce correlativa (CLEM) per il monitoraggio e la proteina virale di Imaging strutture in cellule di Cryo-immobilizzata associate

Due to its high resolution, electron microscopy (EM) is an indispensable tool for virologists. However, one of the main difficulties when analyzing ...

Protein Kinase C-delta Inhibitor Peptide Formulation using Gold Nanoparticles

Protein kinase C-delta inhibitor (PKC&#948;i) is a promising drug to prevent ischemia-reperfusion-induced organ injury. It is usually conjugated to a cell-penetrating peptide, TAT, for intracellular delivery. However, TAT has shown non-specific biological activities. Gold nanoparticles (GNPs) can be used as drug delivery carriers without recognized toxicity. Therefore, we have used a GNP/peptide hybrid to deliver PKC&#948;i. Two short peptides (P2: CAAAAE and P4: CAAAAW), at a 95:5 ratio, were used to modify the surface properties of GNP. GNPs conjugated with PKC&#948;i (GNP/PKCi) are stable in distilled water, 0.9% NaCl, and phosphate-buffered saline (PBS) containing bovine serum albumin or fetal bovine serum. Intravenous injection of GNP-PKCi was previously shown to prevent ischemia-reperfusion injury of the lung. This article outlines a protocol to formulate GNP/PKCi and assess the physiochemical properties of GNP/PKCi. We have used similar methods to formulate other peptide-based drugs with GNP. This article will hopefully draw more attention to this novel intracellular drug delivery technology and its applications in vivo.

We have previously used a gold nanoparticle peptide hybrid to intravenously deliver a synthetic peptide, protein kinase C-delta inhibitor, which reduced ischemia-reperfusion-induced acute lung injury. Here we show the detailed protocol of the drug formulation. Other intracellular peptides can be formulated similarly.

Proteina chinasi C-delta inibitore Peptide formulazione usando nanoparticelle d'oro

Protein kinase C-delta inhibitor (PKC&#948;i) is a promising drug to prevent ischemia-reperfusion-induced organ injury. It is usually conjugated to a ...