This research was supported by the "Development of technologies for safety evaluation and standardization of nanomaterials and nanoproducts" (10059135)" through the Korea Evaluation Institute of Industrial Technology by the Korean Ministry of Trade, Industry &amp; Energy.

1. Preparazione di strumenti e campioni <ol><li> abrasore <ol><li> Sulla base di un tester di abrasione, utilizzare un abrasore con uno stadio di rotazione del campione (140 mm di diametro), due supporti delle ruote all&#39;abrasione, e una velocità di rotazione di 30 - 80 rpm. </li><li> Utilizzare un peso per fissare la ruota abrasione al titolare della ruota abrasione, che si applica anche carico al provino. </li><li> Installare una presa d&#39;aria supplementare per fornire una migliore sospensione per le particelle abrasa, come mostrato in figura 3. Utilizzare un 1/8 &quot;del diametro del tubo situato a 15 mm al di sopra e lontano dal centro del provino 40 mm. </li></ol></li><li> ruota di abrasione <ol><li> Avvolgere la ruota abrasione (diametro 55 mm, spessore 13 mm), con carta abrasiva (grana 100 e nuovo di zecca). </li></ol></li><li> Campione <ol><li> Esemplare è un composto contenente nanomateriali per prova di abrasione. Per installato abrasore, il campione dovrebbe essere il motto di spirito preparatoh 140 mm di diametro. </li></ol></li><li> Camera <ol><li> Utilizzare acciaio inox per le pareti della camera per evitare il deposito di particelle a causa di forza elettrostatica. Posizionare il abrasore all&#39;interno della camera (volume 1 m 3) (Tabella 1), e individuare l&#39;ingresso e l&#39;uscita nella parte superiore e inferiore della camera, rispettivamente. Utilizzare un miscelatore, costituito da tre piastre forate, all&#39;uscita dell&#39;aria per ottenere un flusso di particelle uniformemente miscelato. </li></ol></li><li> Neutralizer <ol><li> Come particelle elettrostaticamente caricata aumentano deposito di particelle sulle pareti della camera, utilizzare un neutralizzatore (raggi X molli ionizzatore) per minimizzare lo stato carica delle particelle. </li></ol></li><li> Strumenti di misura linea 12, 13 <ol><li> Utilizzare un CPC e OPC per misurare la concentrazione del numero di particelle e la distribuzione delle dimensioni delle particelle secondo le istruzioni del produttore. </li><li> Installare il CPC e OPC al Outlet della camera per la misura della concentrazione del numero di particelle e la distribuzione granulometrica. </li></ol></li><li> Strumenti campionamento delle particelle <ol><li> Assaggiate le particelle rilasciate utilizzando un supporto di filtro di prelievo delle particelle che contengono o una griglia TEM per analizzare la morfologia delle particelle e componenti. </li><li> Installare i mezzi filtranti campionatore di particelle contenenti o una griglia TEM all&#39;uscita della camera di analizzare la morfologia delle particelle di rilascio. </li></ol></li></ol> 2. prova di abrasione per nanoparticelle di uscita Utilizzando Sistema Camerale NOTA: Le condizioni di prova di abrasione sono descritte in Tabella 2. <ol><li> Individuare il abrasore nel centro della camera. </li><li> Installare il provino sul palco di rotazione del campione del abrasore. </li><li> Bloccare le ruote abrasione dei supporti delle ruote abrasione con un peso di 1000 g per applicare il carico al provino. </li><li> Individuare il neutralizzatore (raggi X molli ionizzatore)28 cm di distanza dal centro del provino a 45 °, come mostrato nella figura 2, per ridurre la deposizione delle particelle elettrostatiche sulle pareti della camera. NOTA: Il neutralizzatore elimina la forza elettrostatica in caso di esposizione del fascio. Tuttavia, poiché le ruote di ingresso e abrasione si trovano sopra la fase di rotazione del campione, ciò limita l&#39;accesso del fascio neutralizzatore alla superficie del provino. Pertanto, il neutralizzatore si trova diagonalmente che il raggio di raggiungere il più della superficie del campione possibile. </li><li> Azionare il soffiatore installato all&#39;uscita della camera ad una velocità di flusso / min 50 L. </li><li> Alimentazione 25 L / min d&#39;aria supplementare sospensione priva di particelle utilizzando un compressore d&#39;aria attraverso la presa d&#39;aria supplementare. NOTA: Le particelle, che sono generati da abrasione, sono stati depositati sulla superficie delle ruote campione e all&#39;abrasione, fortemente. Pertanto, è difficile misurare le particelle abrasa. La presa d&#39;aria supplementare può help per risolvere questo problema di sospensione di particelle. </li><li> Controllare il fondo particelle concentrazione del numero all&#39;interno della camera per raggiungere una concentrazione media del numero di particelle per 1 h di sotto di 1 # / cc con CPC, come descritto nella Figura 4. </li><li> Azionare la fase di rotazione del campione del abrasore utilizzando un motore passo-passo che ruota la fase di rotazione del campione a 72 giri al minuto con 1.000 rotazioni. </li><li> Misurare e registrare la distribuzione delle particelle liberato concentrazione numero e la dimensione delle particelle utilizzando il CPC e OPC. NOTA: Le particelle rilasciate dai nanocompositi sono sospese e trasportato dall&#39;aria che viene pompato. Queste particelle sospese vengono infine trasportati alla presa in seguito alla corrente d&#39;aria. Le particelle rilasciate vengono quindi rilevati dal CPC e OPC all&#39;uscita della camera. Un CPC e OPC sono più frequentemente utilizzati per misurare la particella concentrazione del numero, mentre un OPC può anche misurare la distribuzione delle dimensioni delle particelle. </li><li> SampLe particelle rilasciate utilizzando un campionatore di particelle contenenti materiali filtranti o una griglia TEM. NOTA: Le particelle rilasciate da nanocompositi per abrasione passaggio alla uscita della camera seguendo la corrente d&#39;aria. All&#39;uscita della camera, le particelle rilasciate possono essere campionati utilizzando un campionatore di particelle. Le particelle rilasciate raccolti su supporti filtro o una griglia TEM possono poi essere analizzati utilizzando TEM o SEM (microscopia elettronica a scansione). </li><li> Arrestare la misura e campionamento quando la concentrazione del numero di particelle raggiunge inferiore allo 0,1% del picco di particelle concentrazione del numero. </li><li> Salvare i tutti i dati (CPC, OPC) e rimuovere tutti i campioni (provini). </li><li> Utilizzare un nuovo campione e nuove ruote abrasione per ogni prova, e lavare la camera e abrasore con Kimwipes e IPA (alcool isopropilico) dopo ogni prova di abrasione per confermare la ripetibilità. </li></ol>

<ol>
	<li>Froggett, S. J., Clancy, S. F., Boverhof, D. R., Canady, 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=A+review+and+perspectives+of+existing+research+on+the+release+of+nanomaterials+from+solid+nanocomposites.">A review and perspectives of existing research on the release of nanomaterials from solid nanocomposites.</a> Part Fibre Toxicol. 11, (2014).</li><li>Kingston, C., Zepp, R., Andrady, A., Boverhof, D., Fehir, R., Hawkins, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Release+characteristics+of+selected+carbon+nanotube+polymer+composites.">Release characteristics of selected carbon nanotube polymer composites.</a> Carbon. 68, 33-57 (2014).</li><li>Kaiser, D., Stefaniak, A., Scott, K., Nguyen, T., Schutz, 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> Methods for the Measurement of Release of MWCNTs from MWCNT-Polymer Composites, NIST. , (2014).</li><li>Nowack, B., David, R. M., Fissan, H., Morris, H., Shatkin, J. A., Stintz, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Potential+release+scenarios+for+carbon+nanotubes+used+in+composites.">Potential release scenarios for carbon nanotubes used in composites.</a> Environ. Int. 59, 1-11 (2013).</li><li>Kim, E., Lee, J. H., Kim, J. K., Lee, G. H., Ahn, K., Park, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Case+Study+on+Risk+Evaluation+of+Silver+Nanoparticle+Exposure+from+Antibacterial+Sprays+Containing+Silver+Nanoparticles.">Case Study on Risk Evaluation of Silver Nanoparticle Exposure from Antibacterial Sprays Containing Silver Nanoparticles.</a> J of Nanomaterial. , 346586 (2015).</li><li>Kim, E., Lee, J. H., Kim, J. K., Lee, G. H., Ahn, K., Park, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Case+study+on+risk+evaluation+of+printed+electronics+using+nanosilver+ink.">Case study on risk evaluation of printed electronics using nanosilver ink.</a> Nano Convergence. , (2016).</li><li>Vorbau, M., Hillemann, L., Stintz, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Method+for+the+characterization+of+the+abrasion+induced+nanoparticle+release+into+air+from+surface+coatings.">Method for the characterization of the abrasion induced nanoparticle release into air from surface coatings.</a> J. Aerosol Sci. 40, 209-217 (2009).</li><li>Golanski, L., Gaborieau, A., Guiot, A., Uzu, G., Chatenet, J., Tardif, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+abrasion-induced+nanoparticle+release+from+paints+into+liquids+and+air.">Characterization of abrasion-induced nanoparticle release from paints into liquids and air.</a> J. Phys. Conf. Ser. 304, 012062 (2011).</li><li>Wohlleben, W., Brill, S., Meier, M. W., Mertler, M., Cox, G., Hirth, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+lifecycle+of+nanocomposites:+Comparing+released+fragments+and+their+in-vivo+hazards+from+three+release+mechanisms+and+four+nanocomposites.">On the lifecycle of nanocomposites: Comparing released fragments and their in-vivo hazards from three release mechanisms and four nanocomposites.</a> Small. 7, 2384-2395 (2011).</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> ISO 7784-1, Paints and varnishes -- Determination of resistance to abrasion -- Part 1: Rotating abrasive-paper-covered wheel method. , (1997).</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> ISO 5470-1, Rubber- or plastics-coated fabrics -- Determination of abrasion resistance -- Part 1: Taber abrader. , (1999).</li><li>Schlagenhauf, L., Chu, B. T. T., Buha, J., N&#252;sch, F., Wang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Release+of+carbon+nanotubes+from+an+epoxy-based+nanocomposites+during+an+abrasion+process.">Release of carbon nanotubes from an epoxy-based nanocomposites during an abrasion process.</a> Enviorn. Sci. Tech. 46, 7366-7372 (2012).</li><li>Bello, D., Wardle, B. L., Yamamoto, N., deVilloria, R. G., Garcia, E. J., Hart, A. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Exposure+to+nanoscale+particles+and+fibers+during+machining+of+hybrid+advanced+composites+containing+carbon+nanotubes.">Exposure to nanoscale particles and fibers during machining of hybrid advanced composites containing carbon nanotubes.</a> J. Nanopart. Res. 11, 231-249 (2009).</li><li>Cena, L. G., Peters, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+and+control+of+airborne+particles+emitted+during+production+of+epoxy/carbon+nanotube+nanocomposites.">Characterization and control of airborne particles emitted during production of epoxy/carbon nanotube nanocomposites.</a> J. Occup. Environ. Hyg. 8, 86-92 (2011).</li></ol>

The authors have nothing to disclose.

Le fasi più critiche quando effettuano il test nanorelease da materiali nanocompositi utilizzando una prova di abrasione erano: 1) usando un sistema a camera in acciaio inossidabile con un neutralizzatore per rimuovere la carica elettrostatica generata da abrasione e ridurre la deposizione delle particelle sulle pareti della camera; 2) la fornitura di aria supplementare per fornire una migliore sospensione di particelle; e 3) il campionamento delle particelle rilasciate e il monitoraggio on-line utilizzando un CPC e OP...

esposizione nanomateriale è stato per lo più studiata in relazione ai lavoratori nei luoghi di lavoro di produzione, la manipolazione, la fabbricazione, il confezionamento e nanomateriali, mentre l&#39;esposizione del consumatore non è stata ampiamente studiata. Una recente analisi della banca dati ambientali e la letteratura di salute creato dal Consiglio Internazionale del Nanotechnology (ICON) ha inoltre indicato che la maggior parte ricerca sulla sicurezza dei nanomateriali è concentrata sui rischi (83%) e l&#39;esposizione potenziale (16%), con il rilascio di nanocompositi, che rappresenta esposizione dei consumatori, che rappresenta solo lo 0,8% 1. Così, molto poco si sa circa l&#39;esposizione dei consumatori ai nanomateriali. Rilascio delle nanoparticelle è stato utilizzato per stimare l&#39;esposizione dei consumatori in studi di simulazione, tra cui la all&#39;abrasione e agli agenti atmosferici di nanocompositi, tessuti di lavaggio, o metodi polverosità test, come ad esempio il metodo di tamburo rotante, metodo vortice agitazione, e altri metodi shaker 2-3. In più, molti internazionaletentativi, come il nanorelease ILSI (International Life Science Institute) e NanoReg UE, sono stati fatti per sviluppare la tecnologia per comprendere il rilascio di nanomateriali utilizzati nei prodotti di consumo. Il prodotto nanorelease consumo ILSI lanciato nel 2011 rappresenta un approccio del ciclo di vita per il rilascio nanomateriale dai prodotti di consumo, in cui la fase 1 comporta la selezione nanomateriale, la fase 2 riguarda i metodi di valutazione, e la fase 3 implementa studi interlaboratorio. Diverse monografie e pubblicazioni sulla sicurezza dei nanomateriali nei prodotti di consumo sono stati pubblicati 4-6. Nel frattempo, NanoReg rappresenta un approccio comune europeo per il collaudo normativo di nanomateriali fabbricati e fornisce un programma di metodi per l&#39;uso nella simulazione si avvicina a nanorelease dai prodotti di consumo 2. ISO TC 229 sta anche cercando di sviluppare norme rilevanti per la sicurezza dei consumatori e presentare una nuova proposta oggetto di lavoro per la sicurezza dei consumatori. L&#39;OCSE WPMN (working partito sui nanomateriali), in particolare SG8 (gruppo direttivo sulla valutazione dell&#39;esposizione e la mitigazione di esposizione), ha recentemente condotto un sondaggio sulla direzione dei lavori futuri, in particolare dei consumatori e valutazione dell&#39;esposizione ambientale. Pertanto, alla luce di queste attività internazionali, i Ministeri coreani del commercio, dell&#39;industria e dell&#39;energia ha lanciato un progetto a più livelli nel 2013 si è concentrato sulla &quot;Sviluppo di tecnologie per la valutazione della sicurezza e standardizzazione dei nanomateriali e nanoprodotti&quot;. Inoltre, diversi studi rilevanti per la sicurezza dei consumatori per standardizzare il rilascio nanomateriale dai prodotti di consumo sono stati anche pubblicati 7-8. Una prova di abrasione è uno degli approcci di simulazione inclusi nel nanorelease ILSI e NanoReg 2-3 per determinare il livello di potenziale di emissione di nanoparticelle di diversi prodotti composti commerciali. La perdita di peso massa viene dedotta basa sulla differenza di peso del campione prima e dopo abrasionico usando una abrasore. Il campione nanocomposito viene abrasa a velocità costante, un campionatore aspira l&#39;aerosol e le particelle vengono quindi analizzati utilizzando dispositivi di conteggio delle particelle, ad esempio un contatore di condensa particelle (CPC) o contatore ottico di particelle (OPC), e raccolto su un TEM (microscopia elettronica a trasmissione) griglia o membrana per ulteriori analisi visiva. Tuttavia, eseguendo un test di abrasione per materiali nanocompositi richiede una versione nanoparticella coerente, che è difficile a causa di particelle di carica a seguito di abrasione e quando il campionamento delle particelle è condotto in prossimità del punto di emissione 2-3, 9-11. Di conseguenza, questo documento presenta un sistema di camere come nuovo metodo per valutare il rilascio nanomateriale nel caso di abrasione di materiali nanocompositi. Quando confrontato con altri test di abrasione e di simulazione, il sistema camerale proposto fornisce i dati di rilascio di nanoparticelle consistenti nel caso di abrasione. Inoltre, questo nuovo metodo di provaè stato utilizzato ampiamente nel campo della qualità dell&#39;aria interna e l&#39;industria semi-condotta come numero totale di particelle metodo di conteggio 12, 13. Pertanto, si prevede che il metodo proposto può essere sviluppato in un metodo standardizzato per il rilascio test nanoparticelle da prodotti di consumo contenenti nanomateriali.

<table><tbody><tr><td>Foamex</td><td>Taeyoung, R. of Korea</td><td></td><td></td></tr><tr><td>MWCNT (multiwalled carbon nanotube) composite</td><td>Hanwha, Incheon, R. of Korea</td><td></td><td>2% MWCNTs in low density polyethylene</td></tr><tr><td>Abrasion Paper</td><td>Derfos, R. of Korea</td><td>#100</td><td>100 grit sand paper</td></tr><tr><td>Condensation Particle Counter (CPC)</td><td>TSI Inc, Shoreview, MN</td><td>UCPC 3775</td><td></td></tr><tr><td>Optical Paritcle Counter (OPC)</td><td>Grimm, Ainring, Germany</td><td>1.109</td><td></td></tr><tr><td>Mini Particle Sampler</td><td>Ecomesure, Saclay, France</td><td></td><td></td></tr><tr><td>Quantifoil Holey Carbon Film</td><td>TED PELLA Inc. USA</td><td>1.2/1.3</td><td></td></tr><tr><td>Filter Holder</td><td></td><td></td><td>custom made</td></tr><tr><td>Polycarbonate Filter&amp;nbsp;</td><td>Millipore, USA</td><td>CAT No. GTTP02500</td><td></td></tr><tr><td>Soft X-ray Ionizer (Neutralizer)</td><td>SUNJE, R. of Korea</td><td>SXN-05U</td><td></td></tr><tr><td>Field Emission-Scanning Electron Microscope (FE-SEM)</td><td>Hitachi</td><td>S-4300</td><td></td></tr></tbody></table>

testing of nanoparticle release from a composite containing nanomaterial using a chamber system

Con il rapido sviluppo delle nanotecnologie, come una delle tecnologie più importanti del 21 ° secolo, l&#39;interesse per la sicurezza dei prodotti di consumo contenenti nanomateriali è in aumento. Valutare il rilascio nanomateriale da prodotti contenenti nanomateriali è un passo cruciale nella valutazione della sicurezza di questi prodotti, e ha portato a numerosi sforzi internazionali per sviluppare tecnologie coerenti e affidabili per uniformare la valutazione del rilascio di nanomateriali. In questo studio, il rilascio di nanomateriali da prodotti contenenti nanomateriali viene valutata utilizzando un sistema di camere che comprende un contatore di particelle di condensazione, contatore ottico di particelle, e il campionamento porte per raccogliere campioni di filtro per l&#39;analisi al microscopio elettronico. Il sistema camerale proposto è stato testato utilizzando un abrasore e il disco di tipo campioni di materiali nanocompositi per determinare se il rilascio nanomateriale è ripetibile e coerente all&#39;interno di un range accettabile.I risultati del test indicano che il numero totale di particelle in ciascuna prova è entro il 20% dalla media dopo diverse prove. Le tendenze di rilascio sono simili e mostrano molto buona ripetibilità. Pertanto, il sistema camerale proposto può essere utilizzato in modo efficace per il controllo del rilascio nanomateriale di prodotti contenenti nanomateriali.

Abrasione test di ripetibilità Utilizzando Sistema Camerale Il numero totale di particelle erano coerenti per 8 test di abrasione, come mostrato nella Tabella 3. Il CPC misurato una media di 3,67 x 10 9 particelle, mentre l&#39;OPC contato una media di 1,98 x 10 9 particelle (&gt; 0,3 micron). Le deviazioni erano meno di 20%, corrispondente ad un rilascio uniforme di particelle durante l&#3...

Watch this Scientific Journal Video about Testing of Nanoparticle Release from a Composite Containing Nanomaterial Using a Chamber System at JoVE.com

Testing of Nanoparticle Release from a Composite Containing Nanomaterial Using a Chamber System

Nanoparticle release is tested using a chamber system that includes a condensation particle counter, an optical particle counter and sampling ports to collect filter samples for microscopy analysis. The proposed chamber system can be effectively used for nanomaterial release testing with a repeatable and consistent data range.

Prove di nanoparticelle di uscita da un composto contenente Nanomateriale Utilizzo di un Sistema Camerale

With the rapid development of nanotechnology as one of the most important technologies in the 21st century, interest in the safety of consumer products ...

testing-nanoparticle-release-from-composite-containing-nanomaterial

Universidad San Sebastian

Research

JoVE Journal

Engineering

6.7K Views.  Hanyang University. Nanoparticle release is tested using a chamber system that includes a condensation particle counter, an optical particle counter and sampling ports to collect filter samples for microscopy analysis. The proposed chamber system can be effectively used for nanomaterial release testing with a repeatable and consistent data range.

Video: Testing of Nanoparticle Release from a Composite Containing Nanomaterial Using a Chamber System

Optical Trapping of Nanoparticles

Optical trapping is a technique for immobilizing and manipulating small objects in a gentle way using light, and it has been widely applied in trapping and manipulating small biological particles. Ashkin and co-workers first demonstrated optical tweezers using a single focused beam1. The single beam trap can be described accurately using the perturbative gradient force formulation in the case of small Rayleigh regime particles1. In the perturbative regime, the optical power required for trapping a particle scales as the inverse fourth power of the particle size. High optical powers can damage dielectric particles and cause heating. For instance, trapped latex spheres of 109 nm in diameter were destroyed by a 15 mW beam in 25 sec1, which has serious implications for biological matter2,3.
A self-induced back-action (SIBA) optical trapping was proposed to trap 50 nm polystyrene spheres in the non-perturbative regime4. In a non-perturbative regime, even a small particle with little permittivity contrast to the background can influence significantly the ambient electromagnetic field and induce a large optical force. As a particle enters an illuminated aperture, light transmission increases dramatically because of dielectric loading. If the particle attempts to leave the aperture, decreased transmission causes a change in momentum outwards from the hole and, by Newton's Third Law, results in a force on the particle inwards into the hole, trapping the particle. The light transmission can be monitored; hence, the trap can become a sensor. The SIBA trapping technique can be further improved by using a double-nanohole structure.
The double-nanohole structure has been shown to give a strong local field enhancement5,6. Between the two sharp tips of the double-nanohole, a small particle can cause a large change in optical transmission, thereby inducing a large optical force. As a result, smaller nanoparticles can be trapped, such as 12 nm silicate spheres7 and 3.4 nm hydrodynamic radius bovine serum albumin proteins8. In this work, the experimental configuration used for nanoparticle trapping is outlined. First, we detail the assembly of the trapping setup which is based on a Thorlabs Optical Tweezer Kit. Next, we explain the nanofabrication procedure of the double-nanohole in a metal film, the fabrication of the microfluidic chamber and the sample preparation. Finally, we detail the data acquisition procedure and provide typical results for trapping 20 nm polystyrene nanospheres.

The following setup approach details low power optical trapping of dielectric nanoparticles using a double-nanohole in metal film.

Trapping ottica di nanoparticelle

Optical trapping is a technique for immobilizing and manipulating small objects in a gentle way using light, and it has been widely applied in trapping ...

Ricerca

Ingegneria

Combinatorial Synthesis of and High-throughput Protein Release from Polymer Film and Nanoparticle Libraries

Polyanhydrides are a class of biomaterials with excellent biocompatibility and drug delivery capabilities. While they have been studied extensively with conventional one-sample-at-a-time synthesis techniques, a more recent high-throughput approach has been developed enabling the synthesis and testing of large libraries of polyanhydrides1. This will facilitate more efficient optimization and design process of these biomaterials for drug and vaccine delivery applications. The method in this work describes the combinatorial synthesis of biodegradable polyanhydride film and nanoparticle libraries and the high-throughput detection of protein release from these libraries. In this robotically operated method (Figure 1), linear actuators and syringe pumps are controlled by LabVIEW, which enables a hands-free automated protocol, eliminating user error. Furthermore, this method enables the rapid fabrication of micro-scale polymer libraries, reducing the batch size while resulting in the creation of multivariant polymer systems. This combinatorial approach to polymer synthesis facilitates the synthesis of up to 15 different polymers in an equivalent amount of time it would take to synthesize one polymer conventionally. In addition, the combinatorial polymer library can be fabricated into blank or protein-loaded geometries including films or nanoparticles upon dissolution of the polymer library in a solvent and precipitation into a non-solvent (for nanoparticles) or by vacuum drying (for films). Upon loading a fluorochrome-conjugated protein into the polymer libraries, protein release kinetics can be assessed at high-throughput using a fluorescence-based detection method (Figures 2 and 3) as described previously1. This combinatorial platform has been validated with conventional methods2 and the polyanhydride film and nanoparticle libraries have been characterized with 1H NMR and FTIR. The libraries have been screened for protein release kinetics, stability and antigenicity; in vitro cellular toxicity, cytokine production, surface marker expression, adhesion, proliferation and differentiation; and in vivo biodistribution and mucoadhesion1-11. The combinatorial method developed herein enables high-throughput polymer synthesis and fabrication of protein-loaded nanoparticle and film libraries, which can, in turn, be screened in vitro and in vivo for optimization of biomaterial performance.

This method describes the combinatorial synthesis of biodegradable polyanhydride film and nanoparticle libraries and the high-throughput detection of protein release from these libraries.

Sintesi combinatoria di e High-throughput di rilascio di proteine ​​da film polimerico e Biblioteche nanoparticelle

Polyanhydrides are a class of biomaterials with excellent biocompatibility and drug delivery capabilities. While they have been studied extensively with ...

Bioingegneria

Experimental Protocol to Investigate Particle Aerosolization of a Product Under Abrasion and Under Environmental Weathering

The present article presents an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental weathering, which is a fundamental element to the approach of nanosafety-by-design of nanostructured products for their durable development. This approach is basically a preemptive one in which the focus is put on minimizing the emission of engineered nanomaterials' aerosols during the usage phase of the product's life cycle. This can be attained by altering its material properties during its design phase without compromising with any of its added benefits. In this article, an experimental protocol is presented to investigate the nanosafety-by-design of three commercial nanostructured products with respect to their mechanical solicitation and environmental weathering. The means chosen for applying the mechanical solicitation is an abrasion process and for the environmental weathering, it is an accelerated UV exposure in the presence of humidity and heat. The eventual emission of engineered nanomaterials is studied in terms of their number concentration, size distribution, morphology and chemical composition. The purpose of the protocol is to study the emission for test samples and experimental conditions which are corresponding to real life situations. It was found that the application of the mechanical stresses alone emits the engineered nanomaterials' aerosols in which the engineered nanomaterial is always embedded inside the product matrix, thus, a representative product element. In such a case, the emitted aerosols comprise of both nanoparticles as well as microparticles. But if the mechanical stresses are coupled with the environmental weathering, the experimental protocol reveals then the eventual deterioration of the product, after a certain weathering duration, may lead to the emission of the free engineered nanomaterial aerosols too.

In this article, an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental weathering is presented. Results on the emission of engineered nanomaterials, in the form of aerosols are presented. The specific experimental set-up is described in detail.

Protocollo sperimentale per Indagare particelle aerosol di un prodotto in base alle abrasioni e Under atmosferici ambientale

The present article presents an experimental protocol to investigate particle aerosolization of a product under abrasion and under environmental ...

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 ...

Advanced Compositional Analysis of Nanoparticle-polymer Composites Using Direct Fluorescence Imaging

The fabrication of polymer-nanoparticle composites is extremely important in the development of many functional materials. Identifying the precise composition of these materials is essential, especially in the design of surface catalysts, where the surface concentration of the active component determines the activity of the material. Antimicrobial materials which utilize nanoparticles are a particular focus of this technology. Recently swell encapsulation has emerged as a technique for inserting antimicrobial nanoparticles into a host polymer matrix. Swell encapsulation provides the advantage of localizing the incorporation to the external surfaces of materials, which act as the active sites of these materials. However, quantification of this nanoparticle uptake is challenging. Previous studies explore the link between antimicrobial activity and surface concentration of the active component, but this is not directly visualized. Here we show a reliable method to monitor the incorporation of nanoparticles into a polymer host matrix via swell encapsulation. We show that the surface concentration of CdSe/ZnS nanoparticles can be accurately visualized through cross-sectional fluorescence imaging. Using this method, we can quantify the uptake of nanoparticles via swell encapsulation and measure the surface concentration of encapsulated particles, which is key in optimizing the activity of functional materials.

Here we present a reliable method to monitor the incorporation of nanoparticles into a polymer host matrix via swell encapsulation. We show that the surface concentration of cadmium selenide quantum dots can be accurately visualized through cross-sectional fluorescence imaging.

Avanzate analisi composizionale di Compositi nanoparticelle-polimero Uso diretto imaging di fluorescenza

The fabrication of polymer-nanoparticle composites is extremely important in the development of many functional materials. Identifying the precise ...

A System to Create Stable Nanoparticle Aerosols from Nanopowders

Nanoparticle aerosols released from nanopowders in workplaces are associated with human exposure and health risks. We developed a novel system, requiring minimal amounts of test materials (min. 200 mg), for studying powder aerosolization behavior and aerosol properties. The aerosolization procedure follows the concept of the fluidized-bed process, but occurs in the modified volume of a V-shaped aerosol generator. The airborne particle number concentration is adjustable by controlling the air flow rate. The system supplied stable aerosol generation rates and particle size distributions over long periods (0.5-2 hr and possibly longer), which are important, for example, to study aerosol behavior, but also for toxicological studies. Strict adherence to the operating procedures during the aerosolization experiments ensures the generation of reproducible test results. The critical steps in the standard protocol are the preparation of the material and setup, and the aerosolization operations themselves. The system can be used for experiments requiring stable aerosol concentrations and may also be an alternative method for testing dustiness. The controlled aerosolization made possible with this setup occurs using energy inputs (may be characterized by aerosolization air velocity) that are within the ranges commonly found in occupational environments where nanomaterial powders are handled. This setup and its operating protocol are thus helpful for human exposure and risk assessment.

We designed and developed an effective nanopowder aerosolization setup and operating protocol. The system generated nanoparticle aerosols with stable number concentrations and size distributions for long durations, requiring only small quantities of test material (min. 200 mg).

Un sistema per creare aerosol nanoparticelle stabili da Nanopolveri

Nanoparticle aerosols released from nanopowders in workplaces are associated with human exposure and health risks. We developed a novel system, requiring ...

A Continuous-flow Photocatalytic Reactor for the Precisely Controlled Deposition of Metallic Nanoparticles

In this work, a novel photocatalytic reactor for the pulsed and controlled excitation of the photocatalyst and the precise deposition of metallic nanoparticles is developed. Guidelines for the replication of the reactor and its operation are provided in detail. Three different composite systems (Pt/graphene, Pt/TiO2, and Au/TiO2) with monodisperse and uniformly distributed particles are produced by this reactor, and the photodeposition mechanism, as well as the synthesis optimization strategy, are discussed. The synthesis methods and their technical aspects are described comprehensively. The role of the ultraviolet (UV) dose (in each excitation pulse) on the photodeposition process is investigated and the optimum values for each composite system are provided.

For a continuous and scalable synthesis of noble-metal-based nanocomposites, a novel photocatalytic reactor is developed and its structure, operation principles, and product quality optimization strategies are described.

Un reattore di flusso continuo fotocatalitica di precisamente controllato deposizione di nanoparticelle metalliche

In this work, a novel photocatalytic reactor for the pulsed and controlled excitation of the photocatalyst and the precise deposition of metallic ...

Chimica

Development of a Nose-only Inhalation Toxicity Test Chamber That Provides Four Exposure Concentrations of Nano-sized Particles

Using a numerical analysis based on computerized fluid dynamics, a nose-only inhalation toxicity chamber with four different exposure concentrations is designed and validated for flow field uniformity and cross-contamination among the exposure ports for each concentration. The designed flow field values are compared with the measured values from exposure ports located horizontally and vertically. For this purpose, nanoscale sodium chloride particles are generated as test particles and introduced to the inhalation chamber to evaluate the cross-contamination and concentration maintenance among the chambers, for each concentration group. The results indicate that the designed multiconcentration inhalation chamber can be used in animal inhalation toxicity testing without cross-contamination among concentration groups. Moreover, the designed multiconcentration inhalation toxicity chamber can also be converted to a single-concentration inhalation chamber. Further testing with gas, organic vapor, or non-nanoscale particles will ensure the use of the chamber in the inhalation testing of other test articles.

A nose-only inhalation toxicity chamber capable of testing inhalation toxicity at four different exposure concentrations was designed and validated for flow field uniformity and cross-contamination between the exposure ports for each concentration. Here, we present a protocol to confirm that the designed chamber is effective for inhalation toxicity testing.

Sviluppo di una camera di prova di tossicità per inalazione solo naso che fornisce quattro concentrazioni di esposizione di particelle nanometriche

Using a numerical analysis based on computerized fluid dynamics, a nose-only inhalation toxicity chamber with four different exposure concentrations is ...

Whole-Body Nanoparticle Aerosol Inhalation Exposures

Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle inhalation toxicology studies, the aerosols in a chamber housing the experimental animals must have: 1) a steady concentration maintained at a desired level for the entire exposure period; 2) a homogenous composition free of contaminants; and 3) a stable size distribution with a geometric mean diameter &lt; 200 nm and a geometric standard deviation &sigma;g &lt; 2.5 5. The generation of aerosols containing nanoparticles is quite challenging because nanoparticles easily agglomerate. This is largely due to very strong inter-particle forces and the formation of large fractal structures in tens or hundreds of microns in size 6, which are difficult to be broken up. Several common aerosol generators, including nebulizers, fluidized beds, Venturi aspirators and the Wright dust feed, were tested; however, none were able to produce nanoparticle aerosols which satisfy all criteria 5.
A whole-body nanoparticle aerosol inhalation exposure system was fabricated, validated and utilized for nano-TiO2 inhalation toxicology studies. Critical components: 1) novel nano-TiO2 aerosol generator; 2) 0.5 m3 whole-body inhalation exposure chamber; and 3) monitor and control system. Nano-TiO2 aerosols generated from bulk dry nano-TiO2 powders (primary diameter of 21 nm, bulk density of 3.8 g/cm3) were delivered into the exposure chamber at a flow rate of 90 LPM (10.8 air changes/hr). Particle size distribution and mass concentration profiles were measured continuously with a scanning mobility particle sizer (SMPS), and an electric low pressure impactor (ELPI). The aerosol mass concentration (C) was verified gravimetrically (mg/m3). The mass (M) of the collected particles was determined as M = (Mpost-Mpre), where Mpre and Mpost are masses of the filter before and after sampling (mg). The mass concentration was calculated as C = M/(Q*t), where Q is sampling flowrate (m3/min), and t is the sampling time (minute). The chamber pressure, temperature, relative humidity (RH), O2 and CO2 concentrations were monitored and controlled continuously. Nano-TiO2 aerosols collected on Nuclepore filters were analyzed with a scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis.
In summary, we report that the nano-particle aerosols generated and delivered to our exposure chamber have: 1) steady mass concentration; 2) homogenous composition free of contaminants; 3) stable particle size distributions with a count-median aerodynamic diameter of 157 nm during aerosol generation. This system reliably and repeatedly creates test atmospheres that simulate occupational, environmental or domestic ENM aerosol exposures.

A whole-body nanoparticle aerosol inhalation exposure facility was constructed for nano-sized titanium dioxide (TiO2) inhalation toxicology studies. This system provides nano-TiO2 aerosol test atmospheres that have: 1) a steady mass concentration; 2) a homogenous composition free of contaminants; and 3) a stable particle size distribution during aerosol generation.

Tutto il corpo Nanoparticelle Aerosol esposizioni inalatorie

Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle ...

Biologia

An Air-liquid Interface Bronchial Epithelial Model for Realistic, Repeated Inhalation Exposure to Airborne Particles for Toxicity Testing

For toxicity testing of airborne particles, air-liquid interface (ALI) exposure systems have been developed for in vitro tests in order to mimic realistic exposure conditions. This puts specific demands on the cell culture models. Many cell types are negatively affected by exposure to air (e.g., drying out) and only remain viable for a few days. This limits the exposure conditions that can be used in these models: usually relatively high concentrations are applied as a cloud (i.e., droplets containing particles, which settle down rapidly) within a short period of time. Such experimental conditions do not reflect realistic long-term exposure to low concentrations of particles. To overcome these limitations the use of a human bronchial epithelial cell line, Calu-3 was investigated. These cells can be cultured at ALI conditions for several weeks while retaining a healthy morphology and a stable monolayer with tight junctions. In addition, this bronchial model is suitable for testing the effects of repeated exposures to low, realistic concentrations of airborne particles using an ALI exposure system. This system uses a continuous airflow in contrast to other ALI exposure systems that use a single nebulization producing a cloud. Therefore, the continuous flow system is suitable for repeated and prolonged exposure to airborne particles while continuously monitoring the particle characteristics, exposure concentration, and delivered dose. Taken together, this bronchial model, in combination with the continuous flow exposure system, is able to mimic realistic, repeated inhalation exposure conditions that can be used for toxicity testing.

Described is the cell culture and exposure method of an in vitro bronchial model for realistic, repeated inhalation exposure to particles for toxicity testing.

Un modello epiteliale bronchiale interfaccia aria-liquido per un'esposizione realistica e ripetuta all'inalazione alle particelle trasportate dall'aria per i test di tossicità

For toxicity testing of airborne particles, air-liquid interface (ALI) exposure systems have been developed for in vitro tests in order to mimic realistic ...

Prove di nanoparticelle di uscita da un composto contenente Nanomateriale Utilizzo di un Sistema Camerale

Riepilogo

Esplora Altri Video

Capitoli in questo video

Trapping ottica di nanoparticelle

Sintesi combinatoria di e High-throughput di rilascio di proteine da film polimerico e Biblioteche nanoparticelle

Protocollo sperimentale per Indagare particelle aerosol di un prodotto in base alle abrasioni e Under atmosferici ambientale

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

Avanzate analisi composizionale di Compositi nanoparticelle-polimero Uso diretto imaging di fluorescenza

Un sistema per creare aerosol nanoparticelle stabili da Nanopolveri

Un reattore di flusso continuo fotocatalitica di precisamente controllato deposizione di nanoparticelle metalliche

Sviluppo di una camera di prova di tossicità per inalazione solo naso che fornisce quattro concentrazioni di esposizione di particelle nanometriche

Tutto il corpo Nanoparticelle Aerosol esposizioni inalatorie

Un modello epiteliale bronchiale interfaccia aria-liquido per un'esposizione realistica e ripetuta all'inalazione alle particelle trasportate dall'aria per i test di tossicità

Prove di nanoparticelle di uscita da un composto contenente Nanomateriale Utilizzo di un Sistema Camerale

Riepilogo

Esplora Altri Video

Capitoli in questo video

Trapping ottica di nanoparticelle

Sintesi combinatoria di e High-throughput di rilascio di proteine ​​da film polimerico e Biblioteche nanoparticelle

Protocollo sperimentale per Indagare particelle aerosol di un prodotto in base alle abrasioni e Under atmosferici ambientale

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

Avanzate analisi composizionale di Compositi nanoparticelle-polimero Uso diretto imaging di fluorescenza

Un sistema per creare aerosol nanoparticelle stabili da Nanopolveri

Un reattore di flusso continuo fotocatalitica di precisamente controllato deposizione di nanoparticelle metalliche

Sviluppo di una camera di prova di tossicità per inalazione solo naso che fornisce quattro concentrazioni di esposizione di particelle nanometriche

Tutto il corpo Nanoparticelle Aerosol esposizioni inalatorie

Un modello epiteliale bronchiale interfaccia aria-liquido per un'esposizione realistica e ripetuta all'inalazione alle particelle trasportate dall'aria per i test di tossicità

Sintesi combinatoria di e High-throughput di rilascio di proteine da film polimerico e Biblioteche nanoparticelle