Gli autori sono grati al Dott. Thomas Rademacher per fornire il PPAM pianta vettore di espressione e Ibrahim Al Amedi per la coltivazione delle piante di tabacco utilizzate in questo studio. Vorremmo ringraziare il Dott. Richard M. Twyman per la sua assistenza con la modifica del manoscritto. Questo lavoro è stato in parte finanziato dalla Advanced Grant &quot;Future-Pharma&quot; Consiglio europeo della ricerca, il numero di proposta 269.110 e il Fraunhofer Zukunftsstiftung (Fraunhofer Future Foundation).

<ol>
	<li>Fischer, R., Emans, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+farming+of+pharmaceutical+proteins.">Molecular farming of pharmaceutical proteins.</a> Transgenic research. 9, 277-299 (2000).</li><li>Commandeur, U., Twyman, R. M., Fischer, 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+biosafety+of+molecular+farming+in+plants.">The biosafety of molecular farming in plants.</a> AgBiotechNet. 5, 9 (2003).</li><li>Shoji, Y., 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=A+plant-based+system+for+rapid+production+of+influenza+vaccine+antigens.">A plant-based system for rapid production of influenza vaccine antigens.</a> Influenza Other Resp. 6, 204-210 (2012).</li><li>Goodin, M. M., Zaitlin, D., Naidu, R. A., Lommel, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nicotiana+benthamiana:+Its+history+and+future+as+a+model+for+plant-pathogen+interactions.">Nicotiana benthamiana: Its history and future as a model for plant-pathogen interactions.</a> Mol Plant Microbe In. 21, 1015-1026 (2008).</li><li>Berg, R. H., Beachy, R. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescent+protein+applications+in+plants.">Fluorescent protein applications in plants.</a> Method Cell Biol. 85, 153 (2008).</li><li>Chung, S. M., Vaidya, M., Tzfira, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Agrobacterium+is+not+alone:+gene+transfer+to+plants+by+viruses+and+other+bacteria.">Agrobacterium is not alone: gene transfer to plants by viruses and other bacteria.</a> Trends in plant science. 11, 1-4 (2006).</li><li>Sheludko, Y. V., Sindarovska, Y. R., Gerasymenko, I. M., Bannikova, M. A., Kuchuk, N. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+several+Nicotiana+species+as+hosts+for+high-scale+Agrobacterium-mediated+transient+expression.">Comparison of several Nicotiana species as hosts for high-scale Agrobacterium-mediated transient expression.</a> Biotechnology and Bioengineering. 96, 608-614 (2007).</li><li>Wydro, M., Kozubek, E., Lehmann, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+transient+Agrobacterium-mediated+gene+expression+system+in+leaves+of+Nicotiana+benthamiana.">Optimization of transient Agrobacterium-mediated gene expression system in leaves of Nicotiana benthamiana.</a> Acta Biochimica Polonica. 53, 289-298 (2006).</li><li>Buyel, J. F., Fischer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Processing+heterogeneous+biomass:+Overcoming+the+hurdles+in+model+building.">Processing heterogeneous biomass: Overcoming the hurdles in model building.</a> Bioengineered. 4, (2013).</li><li>Fischer, R., Schillberg, S., Hellwig, S., Twyman, R. M., Drossard, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GMP+issues+for+recombinant+plant-derived+pharmaceutical+proteins.">GMP issues for recombinant plant-derived pharmaceutical proteins.</a> Biotechnol Adv. 30, 434-439 (2012).</li><li>Daniel, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One-at-a-time+plans.">One-at-a-time plans.</a> Journal of the American Statistical Association. 68, 353-360 (1973).</li><li>Czitrom, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One-Factor-at-a-Time+versus+Designed+Experiments+The+American+Statistician.">One-Factor-at-a-Time versus Designed Experiments The American Statistician.</a> 53, 6 (1999).</li><li>Anderson, M. J., Kraber, 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=Keys+to+successful+designed+experiments.">Keys to successful designed experiments.</a> ASQ - The global voice of quality. 6, 6 (1999).</li><li>Montgomery, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Design and Analysis of Experiments. , (2007).</li><li>Myers, R. H., Montgomery, D. C., Anderson-Cook, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Response Surface Methodology: Process and Product Optimization Using Designed Experiments. , (2009).</li><li>Piepel, G. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Programs+for+generating+extreme+vertices+and+centroids+of+linearly+constrained+experimental+regions.">Programs for generating extreme vertices and centroids of linearly constrained experimental regions.</a> J Qual Technol. 20, 15 (1988).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> FDA. , (2009).</li><li>Shivhare, M., McCreath, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Practical+Considerations+for+DoE+Implementation+in+Quality+By+Design.">Practical Considerations for DoE Implementation in Quality By Design.</a> BioProcess International. 8, 9 (2010).</li><li>Buyel, J. F., Fischer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Predictive+models+for+transient+protein+expression+in+tobacco+(Nicotiana+tabacum+L.)+can+optimize+process+time,+yield,+and+downstream+costs.">Predictive models for transient protein expression in tobacco (Nicotiana tabacum L.) can optimize process time, yield, and downstream costs.</a> Biotechnology and bioengineering. 109, 2575-2588 (2012).</li><li>Buyel, J. F., Kaever, T., Buyel, J. J., Fischer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Predictive+models+for+the+accumulation+of+a+fluorescent+marker+protein+in+tobacco+leaves+according+to+the+promoter/5'UTR+combination.">Predictive models for the accumulation of a fluorescent marker protein in tobacco leaves according to the promoter/5'UTR combination.</a> Biotechnology and bioengineering. 110, 471-482 (2013).</li><li>Anderson, M. J., Whitcomb, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> DOE Simplified: Practical Tools for Effective Experimentation. , (2000).</li><li>Anderson, M. J., Whitcomb, P. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Response Surface Methods Simplified. , (2005).</li><li>De Gryze, S., Langhans, I., Vandebroek, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+the+correct+intervals+for+prediction:+A+tutorial+on+tolerance+intervals+for+ordinary+least-squares+regression.">Using the correct intervals for prediction: A tutorial on tolerance intervals for ordinary least-squares regression.</a> Chemometr Intell Lab. 87, 147-154 (2007).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Plasmid DNA purification User manual. , (2012).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> PCR clean-up Gel extraction User manual. , (2012).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Quick Ligation Protocol. 4, (2009).</li><li>Inoue, H., Nojima, H., Okayama, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-Efficiency+Transformation+of+Escherichia-Coli+with+Plasmids.">High-Efficiency Transformation of Escherichia-Coli with Plasmids.</a> Gene. 96, 23-28 (1990).</li><li>Main, G. D., Reynolds, S., Gartland, 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=Electroporation+protocols+for+Agrobacterium.">Electroporation protocols for Agrobacterium.</a> Methods in Molecular Biology. 44, 405-412 (1995).</li><li>Gruber, A. R., Lorenz, R., Bernhart, S. H., Neubock, R., Hofacker, I. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Vienna+RNA+websuite.">The Vienna RNA websuite.</a> Nucleic acids research. 36, 70-74 (2008).</li><li>Howell, S., Kenmore, M., Kirkland, M., Badley, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-density+immobilization+of+an+antibody+fragment+to+a+carboxymethylated+dextran-linked+biosensor+surface.">High-density immobilization of an antibody fragment to a carboxymethylated dextran-linked biosensor surface.</a> J Mol Recognit. 11, 200-203 (1998).</li><li>Newcombe, A. 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=Evaluation+of+a+biosensor+assay+to+quantify+polyclonal+IgG+in+ovine+serum+used+for+the+production+of+biotherapeutic+antibody+fragments.">Evaluation of a biosensor assay to quantify polyclonal IgG in ovine serum used for the production of biotherapeutic antibody fragments.</a> Process Biochem. 41, 842-847 (2006).</li><li>Peixoto, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hierarchical+Variable+Selection+in+Polynomial+Regression-Models.">Hierarchical Variable Selection in Polynomial Regression-Models.</a> Am Stat. 41, 311-313 (1987).</li><li>Peixoto, J. 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+Property+of+Well-Formulated+Polynomial+Regression-Models.">A Property of Well-Formulated Polynomial Regression-Models.</a> Am Stat. 44, 26-30 (1990).</li><li>Sanders, P. R., Winter, J. A., Barnason, A. R., Rogers, S. G., Fraley, R. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+cauliflower+mosaic+virus+35S+and+nopaline+synthase+promoters+in+transgenic+plants.">Comparison of cauliflower mosaic virus 35S and nopaline synthase promoters in transgenic plants.</a> Nucleic acids research. 15, 1543-1558 (1987).</li><li>Ma, J. K. 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=Generation+and+Assembly+of+Secretory+Antibodies+in+Plants.">Generation and Assembly of Secretory Antibodies in Plants.</a> Science. 268, 716-719 (1995).</li><li>Wycoff, K. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Secretory+IgA+antibodies+from+plants.">Secretory IgA antibodies from plants.</a> Curr Pharm Design. 11, 2429-2437 (2005).</li><li>Pace, C. N., Vajdos, F., Fee, L., Grimsley, G., Gray, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+to+measure+and+predict+the+molar+absorption+coefficient+of+a+protein.">How to measure and predict the molar absorption coefficient of a protein.</a> Protein Sci. 4, 2411-2423 (1995).</li></ol>

La tassa di pubblicazione è stato in parte sponsorizzato da aziende Statease, Inc. (USA) e Statcon (Germania), che non sono stati coinvolti nella coinvolti nella preparazione del manoscritto o responsabile per qualsiasi dei suoi contenuti.

Ogni esperimento richiede un&#39;attenta pianificazione, perché le risorse sono spesso scarse e costose. Ciò è particolarmente vero per le strategie DoE perché errori durante la fase di pianificazione (ad esempio la selezione di un modello di base che non copre tutte le interazioni significative dei fattori) possono diminuire sostanzialmente il potere predittivo dei modelli risultanti e quindi svalutare l&#39;intero esperimento. Tuttavia, questi errori possono essere facilmente evitati seguendo procedure di...

La produzione di proteine ​​biofarmaceutiche nelle piante è vantaggiosa perché le piante sono economici a crescere, la piattaforma può essere scalata solo crescendo più piante e patogeni umani sono in grado di replicare 1,2. Strategie espressione transiente basate per esempio sulla infiltrazione di foglie con Agrobacterium tumefaciens offre ulteriori vantaggi perché il tempo tra il punto di consegna del DNA e la consegna di un prodotto purificato è ridotto da anni a meno di 2 mesi 3. Espressione transiente è utilizzato anche per l&#39;analisi funzionale, ad esempio per testare geni per la loro capacità di complementare perdita di funzione mutanti o per indagare le interazioni proteina 4-6. Tuttavia, i livelli di espressione transiente tendono a mostrare una maggiore variazione da lotto a lotto di livelli di espressione in piante transgeniche 7-9. Ciò riduce la probabilità che i processi di produzione biofarmaceutica basati su espressione transiente will essere approvato nel contesto delle buone prassi di fabbricazione (GMP), perché la riproducibilità è un attributo di qualità critico ed è soggetta a valutazione del rischio 10. Tale variazione può anche mascherare tutte le interazioni che i ricercatori intendono studiare. Pertanto, abbiamo deciso di identificare i principali fattori che influenzano i livelli di espressione transitori nelle piante e per costruire un modello predittivo quantitativo di alta qualità. L&#39;approccio a un fattore-at-a-tempo (OFAT) è spesso usato per caratterizzare l&#39;impatto (effetto) di alcuni parametri (fattori) sull&#39;esito (risposta) di un esperimento 11. Ma questo è ottimale perché le prove individuali (va) durante l&#39;indagine (esperimento) saranno allineati come perle di una collana attraverso l&#39;area potenziale attraversato dai fattori che vengono testati (spazio di progettazione). La copertura dello spazio di progettazione e quindi il grado di informazioni derivate da dell&#39;esperimento èbasso, come mostrato nella Figura 1A 12. Inoltre, interdipendenze tra diversi fattori (interazioni factor) possono rimanere nascosti conseguente modelli poveri e / o la previsione di falsa Optima, come mostrato nella Figura 1B 13. Gli inconvenienti sopra descritti possono essere evitati utilizzando un disegno di avvicinamento esperimenti (DOE) in cui viene eseguito su un esperimento sono sparsi in modo più uniforme in tutto lo spazio di progettazione, il che significa che più di un fattore è variata tra due piste 14. Ci sono disegni specializzati per le miscele, screening fattori (disegni fattoriali) e la quantificazione degli impatti dei fattori sulle risposte (metodi di superficie di risposta, RSM s) 15. Inoltre, RSMS possono essere realizzati come disegni centrali-composito ma possono anche essere realizzati efficacemente con software specializzato che può applicare diversi criteri per la selezione di piste. Ad esempio, il cosiddetto D-optimality criterio selezionerà corre in modo da minimizzare l&#39;errore nei coefficienti del modello risultante, mentre il criterio IV-ottimalità seleziona piste che raggiungono la varianza previsione basso tutto lo spazio di progettazione 15,16. La RSM descriviamo qui permette la quantificazione precisa espressione transiente della proteina nelle piante, ma può essere facilmente trasferito su qualsiasi sistema che coinvolge vari (~ 5-8) fattori numerici (ad esempio temperatura, tempo, concentrazione) e alcuni (~ 2 - 4) fattori categorici (es. promoter, colore) in cui una descrizione meccanicistica non è disponibile o troppo complesso per modellare. L&#39;approccio DoE origine nelle scienze agrarie, ma si è diffuso ad altre zone, perché è trasferibile a qualsiasi situazione in cui è utile per ridurre il numero di corse necessarie per ottenere dati affidabili e generare modelli descrittivi per processi complessi. Questo a sua volta ha portato all&#39;inserimento del DoE nella &quot;Guida perIndustria, Q8 (R2) Pharmaceutical Development &quot;, pubblicato dalla Conferenza internazionale sull&#39;armonizzazione dei requisiti tecnici per la registrazione dei prodotti farmaceutici per uso umano (ICH) 17. DoE è ormai ampiamente utilizzato nella ricerca scientifica e l&#39;industria 18. Tuttavia, la cura deve essere presa durante la pianificazione e l&#39;esecuzione dell&#39;esperimento, perché la scelta di un grado del polinomio improprio per il modello multi-lineare di regressione (modello base) possono introdurre la necessità di corse aggiuntive per modellare correttamente tutti gli effetti dei fattori. Inoltre, danneggiati o dati mancanti generano modelli errati e viziata previsioni, e può anche impedire qualsiasi tentativo di costruzione del modello, come descritto nel protocollo e discussione sezioni 18. Nella sezione Protocollo, ci sarà inizialmente stabilito le fasi di pianificazione più importanti per un esperimento a base di RSM e poi spiegare il progetto sulla base del DoE software DesignExpert v8.1., ma disegni simili possono essere costruiti con altri includi softwareng JMP, Modde, e STATISTICA. Le procedure sperimentali sono seguite da istruzioni per l&#39;analisi e la valutazione dei dati. <img alt="Figura 1" fo:content-width="5in" fo:src="/files/ftp_upload/51216/51216fig1highres.jpg" src="/files/ftp_upload/51216/51216fig1.jpg" /> Figura 1. Confronto di OFAT e DoE. A. Variazione sequenziale di un fattore alla volta (OFAT) in un esperimento (nero, rosso e blu cerchi) raggiunge una bassa copertura dello spazio di progettazione (regioni tratteggiate). Al contrario, la variazione di più di un fattore alla volta utilizzando la progettazione di esperimenti (DoE) strategia (cerchi verdi) migliora la copertura e quindi la precisione dei modelli risultanti. B. La copertura dello spazio di progettazione di parte significa che gli esperimenti OFAT (cerchi neri) può anche non riuscire a identificare le regioni operative ottimali (rosso) e prevedere soluzioni sub-ottimali (grande cerchio nero), mentre DoE strategies (stelle nere) sono più propensi a identificare le condizioni preferibili (grande black star).

<table border="0" cellpadding="0" cellspacing="0" width="946">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Design-Expert(R) 8</td>
			<td style="width:195px;">Stat-Ease, Inc.</td>
			<td style="width:119px;">n.a.</td>
			<td style="width:272px;">DoE software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Tryptone</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">8952.2</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Yeast extract</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">2363.2</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Sodium chloride</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">P029.2</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Ampicillin</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">K029.2</td>
			<td>Antibiotic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Agar-Agar</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">5210.2</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Escherichia coli K12 DH5a</td>
			<td style="width:195px;">Life technologies</td>
			<td style="width:119px;">18263-012</td>
			<td>Microorganism</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">pPAM</td>
			<td style="width:195px;">GenBank</td>
			<td style="width:119px;">AY027531</td>
			<td>Cloning/expression vector;&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">NucleoSpin Plasmid&#160;</td>
			<td style="width:195px;">MACHEREY-NAGEL GmbH</td>
			<td style="width:119px;">740588.250</td>
			<td>Plasmid DNA isolation kit</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">NucleoSpin Gel and PCR Clean-up</td>
			<td style="width:195px;">MACHEREY-NAGEL GmbH</td>
			<td style="width:119px;">740609.250</td>
			<td>Plasmid DNA purification kit</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">NanoDrop 2000</td>
			<td style="width:195px;">Thermo Scientific</td>
			<td style="width:119px;">n.a.</td>
			<td>Spectrophotometer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">NcoI</td>
			<td style="width:195px;">New England Biolabs Inc.</td>
			<td style="width:119px;">R3193L</td>
			<td>Restrictionendonuclease</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">EcoRI</td>
			<td style="width:195px;">New England Biolabs Inc.</td>
			<td style="width:119px;">R3101L</td>
			<td>Restrictionendonuclease</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">AscI</td>
			<td style="width:195px;">New England Biolabs Inc.</td>
			<td style="width:119px;">R0558L</td>
			<td>Restrictionendonuclease</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">NEB 4</td>
			<td style="width:195px;">New England Biolabs Inc.</td>
			<td style="width:119px;">B7004S</td>
			<td>Restrictionendonuclease buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">TRIS</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">4855.3</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Disodium tetraborate</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">4403.3</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">EDTA</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">8040.2</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Agarose</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">6352.4</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Bromophenol blue</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">A512.1</td>
			<td>Color indicator</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Xylene cyanol</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">A513.1</td>
			<td>Color indicator</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Glycerol</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">7530.2</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Mini-Sub Cell GT Cell</td>
			<td style="width:195px;">BioRad</td>
			<td style="width:119px;">170-4406</td>
			<td>Gel electrophoresis chamber</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Agrobacterium tumefaciens strain GV3101:pMP90RK</td>
			<td style="width:195px;">DSMZ</td>
			<td style="width:119px;">12365</td>
			<td>Microorganism</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Electroporator 2510</td>
			<td style="width:195px;">Eppendorf</td>
			<td style="width:119px;">4307000.658</td>
			<td>Electroporator</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Beef extract</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">X975.2</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Peptone</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">2365.2</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Sucrose</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">4621.2</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Magnesium sulfate</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">0261.3</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Carbenicillin</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">6344.2</td>
			<td>Antibiotic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Kanamycin</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">T832.3</td>
			<td>Antibiotic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Rifampicin</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">4163.2</td>
			<td>Antibiotic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">FWD primer</td>
			<td style="width:195px;">Eurofins MWG Operon</td>
			<td style="width:119px;">n.a.</td>
			<td>CCT CAG GAA GAG CAA TAC</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">REV primer</td>
			<td style="width:195px;">Eurofins MWG Operon</td>
			<td style="width:119px;">n.a.</td>
			<td>CCA AAG CGA GTA CAC AAC</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">2720 Thermal cycler</td>
			<td style="width:195px;">Applied Biosystems</td>
			<td style="width:119px;">4359659</td>
			<td>Thermocycler</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">RNAfold webserver</td>
			<td style="width:195px;">University of Vienna</td>
			<td style="width:119px;">n.a.</td>
			<td>Software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Ferty 2 Mega</td>
			<td style="width:195px;">Kammlott</td>
			<td style="width:119px;">5.220072</td>
			<td>Fertilizer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Grodan Rockwool Cubes 10x10cm</td>
			<td style="width:195px;">Grodan</td>
			<td style="width:119px;">n.a.</td>
			<td>Rockwool block</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Greenhouse</td>
			<td style="width:195px;">n.a.</td>
			<td style="width:119px;">n.a.</td>
			<td>For plant cultivation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Phytotron</td>
			<td style="width:195px;">Ilka Zell</td>
			<td style="width:119px;">n.a.</td>
			<td>For plant cultivation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Omnifix-F Solo</td>
			<td style="width:195px;">B. Braun</td>
			<td style="width:119px;">6064204</td>
			<td>Syringe</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Murashige and Skoog salts</td>
			<td style="width:195px;">Duchefa</td>
			<td style="width:119px;">M 0222.0010</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Glucose</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">6780.2</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Acetosyringone</td>
			<td style="width:195px;">Sigma-Aldrich</td>
			<td style="width:119px;">D134406-5G</td>
			<td>Phytohormon analogon</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">&#160;BioPhotometer plus</td>
			<td style="width:195px;">Eppendorf</td>
			<td style="width:119px;">&#160;6132 000.008</td>
			<td>Photometer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Osram cool white 36 W</td>
			<td style="width:195px;">Osram</td>
			<td style="width:119px;">4930440</td>
			<td>Light source</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Disodium phosphate</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">&#160;4984.3&#160;</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Centrifuge 5415D</td>
			<td style="width:195px;">Eppendorf</td>
			<td style="width:119px;">5424 000.410</td>
			<td>Centrifuge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Forma -86C ULT freezer</td>
			<td style="width:195px;">ThermoFisher</td>
			<td style="width:119px;">88400</td>
			<td>Freezer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Synergy HT</td>
			<td style="width:195px;">BioTek</td>
			<td style="width:119px;">SIAFRT</td>
			<td>Fluorescence plate reader</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Biacore T200</td>
			<td style="width:195px;">GE Healthcare</td>
			<td style="width:119px;">n.a.</td>
			<td>SPR device</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Protein A</td>
			<td style="width:195px;">Life technologies</td>
			<td style="width:119px;">10-1006</td>
			<td>Antibody binding protein</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">HEPES</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">9105.3</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">Tween-20</td>
			<td style="width:195px;">Carl Roth GmbH</td>
			<td style="width:119px;">9127.3</td>
			<td>Media component</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:360px;">2G12 antibody</td>
			<td style="width:195px;">Polymun</td>
			<td style="width:119px;">AB002</td>
			<td>Reference antibody</td>
		</tr>
	</tbody>
</table>

characterization of complex systems using the design of experiments approach: transient protein expression in tobacco as a case study

Le piante offrono molteplici vantaggi per la produzione di biofarmaci tra cui bassi costi, scalabilità e sicurezza. Espressione transiente offre il vantaggio supplementare di brevi tempi di sviluppo e di produzione, ma i livelli di espressione può variare notevolmente tra i lotti dando così luogo a preoccupazioni di regolamentazione nel contesto delle buone prassi di fabbricazione. Abbiamo usato un disegno degli esperimenti (DoE) approccio per determinare l&#39;impatto dei principali fattori, quali elementi di regolamentazione del costrutto di espressione, la crescita delle piante e parametri di sviluppo, e le condizioni di incubazione durante espressione, sulla variabilità di espressione tra i lotti. Abbiamo testato piante che esprimono un modello anti-HIV anticorpo monoclonale (2G12) e una proteina marcatore fluorescente (DsRed). Discutiamo il razionale per la selezione di alcune proprietà del modello e identificare i suoi potenziali limiti. L&#39;approccio generale può essere facilmente trasferito ad altri problemi perché i principi del modello unre ampiamente applicabile: la selezione dei parametri basata sulla conoscenza, la riduzione della complessità suddividendo il problema iniziale in moduli più piccoli, l&#39;installazione guidata dal software di combinazioni ottimali di esperimento e graduale aumento del design. Pertanto, il metodo non è solo utile per caratterizzare l&#39;espressione della proteina nelle piante, ma anche per la ricerca di altri sistemi complessi privi descrizione meccanicistica. Le equazioni predittive che descrivono l&#39;interconnettività tra i parametri possono essere utilizzati per stabilire modelli meccanicistici per altri sistemi complessi.

Un modello descrittivo per l&#39;accumulo DsRed durante espressione transiente utilizzando diversi promotori e 5&#39;UTRs Fluorescenza DsRED in estratti di foglie è stato usato per indicare il livello di espressione della proteina ricombinante e quindi è stato usato come la risposta nella strategia DoE. La differenza minima rilevabile abbiamo considerato rilevante era di 20 mcg / ml e la deviazione standard stimata del sistema era di 8 mg / ml in base a esperimenti inizial...

Watch this Scientific Journal Video about Characterization of Complex Systems Using the Design of Experiments Approach: Transient Protein Expression in Tobacco as a Case Study at JoVE.com

Characterization of Complex Systems Using the Design of Experiments Approach: Transient Protein Expression in Tobacco as a Case Study

Descriviamo un disegno di esperimenti approccio che può essere utilizzato per determinare e modellare l&#39;influenza del transgene elementi regolatori, parametri di crescita e sviluppo delle piante, e condizioni di incubazione sulla espressione transiente di anticorpi monoclonali e proteine ​​reporter nelle piante.

Caratterizzazione dei sistemi complessi Utilizzando il Design of Experiments Approccio: Transient Protein Expression in tabacco come un caso di studio

Plants provide multiple benefits for the production of biopharmaceuticals including low costs, scalability, and safety. Transient expression offers the ...

characterization-complex-systems-using-design-experiments-approach

Research

JoVE Journal

Bioengineering

16.4K Views.  RWTH Aachen University.  Descriviamo un disegno di esperimenti approccio che può essere utilizzato per determinare e modellare l'influenza del transgene elementi regolatori, parametri di crescita e sviluppo delle piante, e condizioni di incubazione sulla espressione transiente di anticorpi monoclonali e proteine ​​reporter nelle piante. 

Video: Characterization of Complex Systems Using the Design of Experiments Approach: Transient Protein Expression in Tobacco as a Case Study

High-throughput Protein Expression Generator Using a Microfluidic Platform

Rapidly increasing fields, such as systems biology, require the development and implementation of new technologies, enabling high-throughput and high-fidelity measurements of large systems. Microfluidics promises to fulfill many of these requirements, such as performing high-throughput screening experiments on-chip, encompassing biochemical, biophysical, and cell-based assays1. Since the early days of microfluidics devices, this field has drastically evolved, leading to the development of microfluidic large-scale integration2,3. This technology allows for the integration of thousands of micromechanical valves on a single device with a postage-sized footprint (Figure 1). We have developed a high-throughput microfluidic platform for generating in vitro expression of protein arrays (Figure 2) named PING (Protein Interaction Network Generator). These arrays can serve as a template for many experiments such as protein-protein 4, protein-RNA5 or protein-DNA6 interactions.
The device consist of thousands of reaction chambers, which are individually programmed using a microarrayer. Aligning of these printed microarrays to microfluidics devices programs each chamber with a single spot eliminating potential contamination or cross-reactivity Moreover, generating microarrays using standard microarray spotting techniques is also very modular, allowing for the arraying of proteins7, DNA8, small molecules, and even colloidal suspensions. The potential impact of microfluidics on biological sciences is significant. A number of microfluidics based assays have already provided novel insights into the structure and function of biological systems, and the field of microfluidics will continue to impact biology.

We present a microfluidic approach for the expression of protein arrays. The device consists of thousands of reaction chambers controlled by micro-mechanical valves. The microfluidic device is mated to a microarray-printed gene library. These genes are then transcribed and translated on-chip, resulting in a protein array ready for experimental use.

High-throughput generatore di espressione delle proteine ​​Utilizzando una piattaforma microfluidica

Rapidly increasing fields, such as systems biology, require the development and implementation of new technologies, enabling high-throughput and ...

Ricerca

Bioingegneria

Environmentally-controlled Microtensile Testing of Mechanically-adaptive Polymer Nanocomposites for ex vivo Characterization

Implantable microdevices are gaining significant attention for several biomedical applications1-4. Such devices have been made from a range of materials, each offering its own advantages and shortcomings5,6. Most prominently, due to the microscale device dimensions, a high modulus is required to facilitate implantation into living tissue. Conversely, the stiffness of the device should match the surrounding tissue to minimize induced local strain7-9. Therefore, we recently developed a new class of bio-inspired materials to meet these requirements by responding to environmental stimuli with a change in mechanical properties10-14. Specifically, our poly(vinyl acetate)-based nanocomposite (PVAc-NC) displays a reduction in stiffness when exposed to water and elevated temperatures (e.g. body temperature). Unfortunately, few methods exist to quantify the stiffness of materials in vivo15, and mechanical testing outside of the physiological environment often requires large samples inappropriate for implantation. Further, stimuli-responsive materials may quickly recover their initial stiffness after explantation. Therefore, we have developed a method by which the mechanical properties of implanted microsamples can be measured ex vivo, with simulated physiological conditions maintained using moisture and temperature control13,16,17. 
To this end, a custom microtensile tester was designed to accommodate microscale samples13,17 with widely-varying Young's moduli (range of 10 MPa to 5 GPa). As our interests are in the application of PVAc-NC as a biologically-adaptable neural probe substrate, a tool capable of mechanical characterization of samples at the microscale was necessary. This tool was adapted to provide humidity and temperature control, which minimized sample drying and cooling17. As a result, the mechanical characteristics of the explanted sample closely reflect those of the sample just prior to explantation.
The overall goal of this method is to quantitatively assess the in vivo mechanical properties, specifically the Young's modulus, of stimuli-responsive, mechanically-adaptive polymer-based materials. This is accomplished by first establishing the environmental conditions that will minimize a change in sample mechanical properties after explantation without contributing to a reduction in stiffness independent of that resulting from implantation. Samples are then prepared for implantation, handling, and testing (Figure 1A). Each sample is implanted into the cerebral cortex of rats, which is represented here as an explanted rat brain, for a specified duration (Figure 1B). At this point, the sample is explanted and immediately loaded into the microtensile tester, and then subjected to tensile testing (Figure 1C). Subsequent data analysis provides insight into the mechanical behavior of these innovative materials in the environment of the cerebral cortex.

Environmentally-controlled Microtensile Testing of Mechanically-adaptive Polymer Nanocomposites for ex vivo Characterization

A method is discussed by which the in vivo mechanical behavior of stimuli-responsive materials is monitored as a function of time. Samples are tested ex vivo using a microtensile tester with environmental controls to simulate the physiological environment. This work further promotes understanding the in vivo behavior of our material.

Test microtrazione Environmentally-controllato di meccanica-adattivi nanocompositi polimerici per<em&gt; Ex vivo</em&gt; Caratterizzazione

Implantable microdevices are gaining significant attention for several biomedical applications1-4. Such devices have been made from a range of materials, ...

A Versatile Automated Platform for Micro-scale Cell Stimulation Experiments

Study of cells in culture (in vitro analysis) has provided important insight into complex biological systems. Conventional methods and equipment for in vitro analysis are well suited to study of large numbers of cells (&ge;105) in milliliter-scale volumes (&ge;0.1 ml). However, there are many instances in which it is necessary or desirable to scale down culture size to reduce consumption of the cells of interest and/or reagents required for their culture, stimulation, or processing. Unfortunately, conventional approaches do not support precise and reproducible manipulation of micro-scale cultures, and the microfluidics-based automated systems currently available are too complex and specialized for routine use by most laboratories. To address this problem, we have developed a simple and versatile technology platform for automated culture, stimulation, and recovery of small populations of cells (100 - 2,000 cells) in micro-scale volumes (1 - 20 &mu;l). The platform consists of a set of fibronectin-coated microcapillaries ("cell perfusion chambers"), within which micro-scale cultures are established, maintained, and stimulated; a digital microfluidics (DMF) device outfitted with "transfer" microcapillaries ("central hub"), which routes cells and reagents to and from the perfusion chambers; a high-precision syringe pump, which powers transport of materials between the perfusion chambers and the central hub; and an electronic interface that provides control over transport of materials, which is coordinated and automated via pre-determined scripts. As an example, we used the platform to facilitate study of transcriptional responses elicited in immune cells upon challenge with bacteria. Use of the platform enabled us to reduce consumption of cells and reagents, minimize experiment-to-experiment variability, and re-direct hands-on labor. Given the advantages that it confers, as well as its accessibility and versatility, our platform should find use in a wide variety of laboratories and applications, and prove especially useful in facilitating analysis of cells and stimuli that are available in only limited quantities.

We have developed an automated cell culture and interrogation platform for micro-scale cell stimulation experiments. The platform offers simple, versatile, and precise control in cultivating and stimulating small populations of cells, and recovering lysates for molecular analyses. The platform is well suited to studies that use precious cells and/or reagents.

Una piattaforma automatizzata versatile per micro-scala Cellulari esperimenti di stimolazione

Study of cells in culture (in vitro analysis) has provided important insight into complex biological systems. Conventional methods and equipment for in ...

Real Time Monitoring of Intracellular Bile Acid Dynamics Using a Genetically Encoded FRET-based Bile Acid Sensor

F&#246;rster Resonance Energy Transfer (FRET) has become a powerful tool for monitoring protein folding, interaction and localization in single cells. Biosensors relying on the principle of FRET have enabled real-time visualization of subcellular signaling events in live cells with high temporal and spatial resolution. Here, we describe the application of a genetically encoded Bile Acid Sensor (BAS) that consists of two fluorophores fused to the farnesoid X receptor ligand binding domain (FXR-LBD), thereby forming a bile acid sensor that can be activated by a large number of bile acids species and other (synthetic) FXR ligands. This sensor can be targeted to different cellular compartments including the nucleus (NucleoBAS) and cytosol (CytoBAS) to measure bile acid concentrations locally. It allows rapid and simple quantitation of cellular bile acid influx, efflux and subcellular distribution of endogenous bile acids without the need for labeling with fluorescent tags or radionuclei. Furthermore, the BAS FRET sensors can be useful for monitoring FXR ligand binding. Finally, we show that this FRET biosensor can be combined with imaging of other spectrally distinct fluorophores. This allows for combined analysis of intracellular bile acid dynamics and i) localization and/or abundance of proteins of interest, or ii) intracellular signaling in a single cell.

We provide a detailed protocol to study bile acid dynamics in living cells using a genetically encoded BAS FRET sensor. This Bile Acid Sensor represents a unique tool to study (regulation of) bile acid transport and FXR activation in a wide range of cell types.

Monitoraggio in tempo reale di intracellulare Bile Acid Dynamics Utilizzando una sede a FRET geneticamente codificato Bile Acid sensore

F&#246;rster Resonance Energy Transfer (FRET) has become a powerful tool for monitoring protein folding, interaction and localization in single cells. ...

Detection of Endotoxin in Nano-formulations Using Limulus Amoebocyte Lysate (LAL) Assays

When present in pharmaceutical products, a Gram-negative bacterial cell wall component endotoxin (often also called lipopolysaccharide) can cause inflammation, fever, hypo- or hypertension, and, in extreme cases, can lead to tissue and organ damage that may become fatal. The amounts of endotoxin in pharmaceutical products, therefore, are strictly regulated. Among the methods available for endotoxin detection and quantification, the Limulus Amoebocyte Lysate (LAL) assay is commonly used worldwide. While any pharmaceutical product can interfere with the LAL assay, nano-formulations represent a particular challenge due to their complexity. The purpose of this paper is to provide a practical guide to researchers inexperienced in estimating endotoxins in engineered nanomaterials and nanoparticle-formulated drugs. Herein, practical recommendations for performing three LAL formats including turbidity, chromogenic and gel-clot assays are discussed. These assays can be used to determine endotoxin contamination in nanotechnology-based drug products, vaccines, and adjuvants.

Detection of Endotoxin in Nano-formulations Using Limulus Amoebocyte Lysate LAL Assays

Detection of endotoxins in engineered nanomaterials represents one of the grand challenges in the field of nanomedicine. Here, we present a case study that describes the framework composed of three different LAL formats to estimate potential endotoxin contamination in nanoparticles.

Rilevamento dell'endotossina in Nano-formulazioni utilizzando dosaggi di Limulus Amoebocyte Lysate (LAL)

When present in pharmaceutical products, a Gram-negative bacterial cell wall component endotoxin (often also called lipopolysaccharide) can cause ...

Transient Expression in Red Beet of a Biopharmaceutical Candidate Vaccine for Type-1 Diabetes

Plant molecular farming is the use of plants to produce molecules of interest. In this perspective, plants may be used both as bioreactors for the production and subsequent purification of the final product and for the direct oral delivery of heterologous proteins when using edible plant species. In this work, we present the development of a candidate oral vaccine against Type 1 Diabetes (T1D) in edible plant systems using deconstructed plant virus-based recombinant DNA technology, delivered with vacuum infiltration. Our results show that a red beet is a suitable host for the transient expression of a human derived autoantigen associated to T1D, considered to be a promising candidate as a T1D vaccine. Leaves producing the autoantigen were thoroughly characterized for their resistance to gastric digestion, for the presence of residual bacterial charge and for their secondary metabolic profile, giving an overview of the process production for the potential use of plants for direct oral delivery of a heterologous protein. Our analysis showed almost complete degradation of the freeze-dried candidate oral vaccine following a simulated gastric digestion, suggesting that an encapsulation strategy in the manufacture of the plant-derived GAD vaccine is required.

Here, we present a protocol to produce an oral vaccine candidate against Type 1 diabetes in an edible plant.

Espressione transiente in barbabietola rossa di un vaccino di biofarmaceutica candidato per il diabete di tipo 1

Plant molecular farming is the use of plants to produce molecules of interest. In this perspective, plants may be used both as bioreactors for the ...

A Multilayer Microfluidic Platform for the Conduction of Prolonged Cell-Free Gene Expression

The limitations of cell-based synthetic biology are becoming increasingly apparent as researchers aim to develop larger and more complex synthetic genetic regulatory circuits. The analysis of synthetic genetic regulatory networks in vivo is time consuming and suffers from a lack of environmental control, with exogenous synthetic components interacting with host processes resulting in undesired behavior. To overcome these issues, cell-free characterization of novel circuitry is becoming more prevalent. In vitro transcription and translation (IVTT) mixtures allow the regulation of the experimental environment and can be optimized for each unique system. The protocols presented here detail the fabrication of a multilayer microfluidic device that can be utilized to sustain IVTT reactions for prolonged durations. In contrast to batch reactions, where resources are depleted over time and (by-) products accumulate, the use of microfluidic devices allows the replenishment of resources as well as the removal of reaction products. In this manner, the cellular environment is emulated by maintaining an out-of-equilibrium environment in which the dynamic behavior of gene circuits can be investigated over extended periods of time. To fully exploit the multilayer microfluidic device, hardware and software have been integrated to automate the IVTT reactions. By combining IVTT reactions with the microfluidic platform presented here, it becomes possible to comprehensively analyze complex network behaviors, furthering our understanding of the mechanisms that regulate cellular processes.

The fabrication process of a PDMS-based, multilayer, microfluidic device that allows in vitro transcription and translation (IVTT) reactions to be performed over prolonged periods is described. Furthermore, a comprehensive overview of the hardware and software required to automate and maintain these reactions for prolonged durations is provided.

Una piattaforma microfluidica multistrato per la conduzione di un'espressione genica prolungata senza cellule

The limitations of cell-based synthetic biology are becoming increasingly apparent as researchers aim to develop larger and more complex synthetic genetic ...

In Vesiculo Synthesis of Peptide Membrane Precursors for Autonomous Vesicle Growth

Compartmentalization of biochemical reactions is a central aspect of synthetic cells. For this purpose, peptide-based reaction compartments serve as an attractive alternative to liposomes or fatty acid-based vesicles. Externally or within the vesicles, peptides can be easily expressed and simplify the synthesis of membrane precursors. Provided here is a protocol for the creation of vesicles with diameters of ~200 nm based on the amphiphilic elastin-like polypeptides (ELP) utilizing dehydration-rehydration from glass beads. Also presented are protocols for bacterial ELP expression and purification via inverse temperature cycling, as well as their covalent functionalization with fluorescent dyes. Furthermore, this report describes a protocol to enable the transcription of RNA aptamer dBroccoli inside ELP vesicles as a less complex example for a biochemical reaction. Finally, a protocol is provided, which allows in vesiculo expression of fluorescent proteins and the membrane peptide, whereas synthesis of the latter results in vesicle growth.

Presented here are protocols for the creation of peptide-based small unilamellar vesicles capable of growth. To facilitate in vesiculo production of the membrane peptide, these vesicles are equipped with a transcription-translation system and the peptide-encoding plasmid.

In Vesiculo Synthesis of Peptide Membrane Precursori per la crescita autonoma della vescicola

Compartmentalization of biochemical reactions is a central aspect of synthetic cells. For this purpose, peptide-based reaction compartments serve as an ...

High-Throughput Identification of Resistance to Pseudomonas syringae pv. Tomato in Tomato using Seedling Flood Assay

Tomato is an agronomically important crop that can be infected by Pseudomonas syringae, a Gram-negative bacterium, resulting in bacterial speck disease. The tomato-P. syringae pv. tomato pathosystem is widely used to dissect the genetic basis of plant innate responses and disease resistance. While disease was successfully managed for many decades through the introduction of the Pto/Prf gene cluster from Solanum pimpinellifolium into cultivated tomato, race 1 strains of P. syringae have evolved to overcome resistance conferred by the Pto/Prf gene cluster and occur worldwide.
Wild tomato species are important reservoirs of natural diversity in pathogen recognition, because they evolved in diverse environments with different pathogen pressures. In typical screens for disease resistance in wild tomato, adult plants are used, which can limit the number of plants that can be screened due to their extended growth time and greater growth space requirements. We developed a method to screen 10-day-old tomato seedlings for resistance, which minimizes plant growth time and growth chamber space, allows a rapid turnover of plants, and allows large sample sizes to be tested. Seedling outcomes of survival or death can be treated as discrete phenotypes or on a resistance scale defined by amount of new growth in surviving seedlings after flooding. This method has been optimized to screen 10-day-old tomato seedlings for resistance to two P. syringae strains and can easily be adapted to other P. syringae strains.

High-Throughput Identification of Resistance to Pseudomonas syringae pv. Tomato in Tomato using Seedling Flood Assay

The seedling flood assay facilitates rapid screening of wild tomato accessions for the resistance to the Pseudomonas syringae bacterium. This assay, used in conjunction with the seedling bacterial growth assay, can assist in further characterizing the underlying resistance to the bacterium, and can be used to screen mapping populations to determine the genetic basis of resistance.

Identificazione ad alto contenuto di velocità effettiva della resistenza a Pseudomonas syringae pv. Pomodoro nel pomodoro utilizzando Seedling Flood Assay

Tomato is an agronomically important crop that can be infected by Pseudomonas syringae, a Gram-negative bacterium, resulting in bacterial speck disease. ...

Layer Microdissection of Tricuspid Valve Leaflets for Biaxial Mechanical Characterization and Microstructural Quantification

The tricuspid valve (TV) regulates the unidirectional flow of unoxygenated blood from the right atrium to the right ventricle. The TV consists of three leaflets, each with unique mechanical behaviors. These variations among the three TV leaflets can be further understood by examining their four anatomical layers, which are the atrialis (A), spongiosa (S), fibrosa (F), and ventricularis (V). While these layers are present in all three TV leaflets, there are differences in their thicknesses and microstructural constituents that further influence their respective mechanical behaviors. 
This protocol includes four steps to elucidate the layer-specific differences: (i) characterize the mechanical and collagen fiber architectural behaviors of the intact TV leaflet, (ii) separate the composite layers (A/S and F/V) of the TV leaflet, (iii) carry out the same characterizations for the composite layers, and (iv) perform post-hoc histology assessment. This experimental framework uniquely allows the direct comparison of the intact TV tissue to each of its composite layers. As a result, detailed information regarding the microstructure and biomechanical function of the TV leaflets can be collected with this protocol. Such information can potentially be used to develop TV computational models that seek to provide guidance for the clinical treatment of TV disease.

This protocol describes the biaxial mechanical characterization, polarized spatial frequency domain imaging-based collagen quantification, and microdissection of tricuspid valve leaflets. The provided method elucidates how the leaflet layers contribute to the holistic leaflet behaviors.

Microdissezione a strati di foglietti valvolari tricuspidi per caratterizzazione meccanica biassiale e quantificazione microstrutturale

The tricuspid valve (TV) regulates the unidirectional flow of unoxygenated blood from the right atrium to the right ventricle. The TV consists of three ...