Este trabalho é apoiado pelo programa Rowland Júnior Fellow. Os autores gostariam de expressar gratidão aos cientistas e funcionários do Instituto Rowland em Harvard: Chris Stokes a sua ajuda para o desenvolvimento da, configuração de controle de pressão assistida por computador custom-built, Diane Schaak, Ph.D. por sua entrada para a manipulação de amostra biológica, Winfield Hill para o desenvolvimento da instalação elétrica, Alavaro Sanchez, Ph.D. para a concessão de acesso ao citômetro de fluxo, Scott Bevis, Kenny Spencer e Don Rogers para a usinagem de componentes hidráulicos mecânicos necessários para a configuração de pressão. Mestres microfluídicos foram fabricados no Centro de Sistemas em nanoescala (CNS) na Universidade de Harvard.

1. celular Preparação <ol><li> Placa 1 × 10 5 células / ml de linha celular de cancro da mama metastático MDA-MB-231 em um volume de 10 ml por frasco de cultura T75 tecido em meio L-15 de Leibovitz suplementado com 10% (v / v) de soro fetal bovino e 1 % de penicilina-estreptomicina. </li><li> Incubar MDA-MB-231 numa incubadora humidificada a 37 ° C, com 0% de CO 2 ambiente. </li><li> Células colheita para experiências 2 dias após a sementeira por tratamento de células com 0,25% de tripsina-EDTA durante 2 min e inactivar a actividade enzimática da tripsina por adição de 8 mL de meio de crescimento. </li><li> Células de pelotas por centrifugação durante 5 min a 200 x g e ressuspender em tampão fosfato salino de Dulbecco (DPBS, 1x, sem Ca 2 + e Mg 2 +) para uma concentração final de 5 x 10 5 células / ml. </li></ol> 2 Dispositivo de projeto e fabricação NOTA: A máscara, fabricações molde mestre eoprocesso de inclusão de microcanais devem ser conduzidas dentro de uma sala limpa, enquanto o polidimetilsiloxano (PDMS) processo de fundição de microcanais pode ser realizada em uma bancada de laboratório regular. <ol><li> Conceber um dispositivo de microfluidos, tal como ilustrado na Figura 1 com o AutoCAD. O dispositivo deverá ser composto por uma entrada com múltiplos orifícios de injecção, e dois filtros grossos inerciais concentrando canais rectangulares rectas paralelas (L = 7 mm, W = 40 pm, e H = 70 mm). Canal linear individual consiste de 5 secções de electroporação, os quais são colocados 800 um aparte (W C = 400 um), com dois furos através de eléctrodos de alumínio. Duas câmaras de eletroporação transversalmente adjacentes compartilhar o buraco para o eletrodo negativo. Dois canais rectos fundir a uma tomada no jusante da região de electroporação. </li><li> Converter o arquivo CAD com micro-padrões para um arquivo GDSII usando LinkCAD. Escreva os micro-padrões em um 5 &quot;x 5&quot; photomask em brancousando um gravador de revestimento de laser. Desenvolver a máscara, seguindo o protocolo do fabricante. NOTA: O processo de desenvolvimento máscara inclui o desenvolvimento photoresist, cromo corrosão e resistem à remoção. Alternativamente, as micro-padrões impressos sobre uma transparência elevada resolução (&gt; 20.000 dpi) pode ser adquirido a partir de um terceiro fabricante e utilizado como um foto-mascara. Microescala características finais de uma fotomáscara deve ser transparente para coincidir com a polaridade negativa de uma foto-resistente. </li><li> Fabricar o molde de fundição de concepção do dispositivo, utilizando técnicas de litografia suave padrão 23 com um revestimento foto-resistente negativo fiado sobre uma bolacha de silício de 4 polegadas a 2.000 rpm para ter a espessura final de 70 mM. </li><li> Prebake a bolacha com fotorresistente negativo durante 20 min a 95 ° C. </li><li> Em contato com a máscara com a bolacha e expor a uma fonte de UV (17,4 mJ / cm 2) durante 80 segundos usando um alinhador de máscara. </li><li> Desenvolver a bolacha exposta durante 4 minutos num revelador SU-8. </li><li> Medir oespessura photoresist desenvolvido utilizando um perfilômetro de superfície. </li><li> Rigorosamente misturar uma proporção de 10: 1 de elastômero para agente (kit elastômero de silicone) cura e despeje a mistura no molde de fundição para gerar réplicas de PDMS. Desgasificar o elastómero de fundição, durante 30 min e curar o molde de fundição com elastómero desgasificada num forno a 70 ° C durante 2 horas. </li><li> Delaminate curado réplica PDMS com padrões de microcanais dos orifícios do molde e perfurados para entradas, saída e eletrodos inserções utilizando um torno pinos. NOTA: O diâmetro normal de ponta da viseira pino deve ser 0,76 milímetros, adequada para segurando firmemente tubagem de PEEK (OD de 1/32 &quot;) e os eléctrodos de alumínio (OD de 0,029&quot;) no lugar. </li><li> Criar fechados canais microfluídicos por ligação PDMS réplicas para uma lâmina de vidro tratado em um limpador de plasma de oxigênio para 7 segundos a uma potência e pressão parcial de oxigênio de freqüência de rádio de 75 W e 500 mTorr, respectivamente. </li></ol> 3. experimentos em fluxo <ol><li> Inserireléctrodos de alumínio (0,029 &quot;OD) e um tubo de saída de PEEK (1/32&quot; OD) em locais designados via furos nos microcanais (ver Figura 3B). </li><li> Conecte o equipamento eléctrico 18 responsáveis ​​pela geração de alta tensão pulsos de onda quadrada curto para os eletrodos de alumínio (ver Figura 3C), que estão em contato com soluções de fluxo no molde PDMS. NOTA: O equipamento deve ser constituído por um gerador de pulso e um amplificador de alta tensão em-casa construída 18. </li><li> Preparar 50 ml de quatro tubos de centrífuga contendo individualmente DPBS, soluções com as células e biomoléculas, e atribuem cada tubo para o seu respectivo suporte de frasco ligado ao sistema de controlo de fluxo pneumático (ver Figura 3A) 18. </li><li> Conecte tubulação PEEK entrada dos detentores dos frascos nos respectivos orifícios de entrada no dispositivo micro. </li><li> Definir a magnitude dos impulsos de onda quadrada, V, 100 V, a fim de ter o fie eléctricoforça ld, E = V / L e, do outro lado da câmara de electroporação ser equivalente a 0,7 kV / cm. NOTA: Aqui, L e é a distância entre dois pontos em que os eléctrodos positivo e negativo se encontram em contacto com a solução de fluxo (ver Figura 1). </li><li> Ajuste o regulador de pressão para 40 psi. NOTA:. Uma única fonte de azoto manualmente ajustável é usado para pressurizar uniformemente todos os frascos de amostra e de um colector de alta velocidade é utilizada para activar portas oportuna solução individuais usando o software LabVIEW construído sob encomenda 18 </li><li> Para o controle de válvula, abra o software LabVIEW custom-built rotulado Válvula Runner e clique em Executar no menu suspenso o direito operar. </li><li> Ligue válvulas, clicando no ícone de cada válvula correspondente. Nota: O ícone da válvula deve ficar verde quando é ativado. Clicando no ícone ativo irá desativar e fechar a válvula. O ícone da válvula fechada deve virar cinza. </li><li> Abrir a válvula para o reservatório de DPBS (ie., solução de lavagem) para preparar a velocidade do fluxo necessário para a geração de vórtice de células-trapping estável por 1,5 min. </li><li> Alternar a porta solução activa a partir da solução de lavagem para a solução de células para células de armadilha na câmara de electroporação de 30 segundos (ou seja, o passo de captura de células). </li><li> Fluxo de ambas as soluções de lavagem e de célula através do dispositivo ao mesmo tempo durante 10 segundos, antes da etapa de captura de célula para garantir um fluxo ininterrupto durante a etapa de comutação de solução. NOTA: Este breve passo co-fluxo deve ser repetido a cada passo de mudança de solução. </li><li> Ligue o porto de lavar e limpar o aparelho durante 20 segundos, a fim de remover as células contaminantes não aprisionadas. </li><li> Injectar a solução que contém a primeira molécula de interesse (0,2 mg / ml de moléculas de dextrano 3000 Da neutro e aniónico ou 1,5 mg / ml de dextrano 70.000 Da molécula neutra) para o dispositivo. </li><li> Aplicar cinco pulsos curtos (AT = 30 ms com intervalos de 2 seg) imediatamente após a injeção dosolução molecular e monitorar a magnitude e duração dos pulsos elétricos aplicados em tempo real usando um osciloscópio. </li><li> Repetir o passo 3.10 tantas vezes quanto o número de moléculas adicionais a serem entregues. Para cada entrega molecular, as células incubar durante 100 s na solução molecular, em seguida, o dispositivo de descarga com a solução de lavagem de 100 s para remover o excesso de moléculas. </li><li> Libertar as células em uma placa de 96 poços para análise a jusante através da diminuição da pressão de operação inferior a 5 psi. NOTA: Cerca de 100 ml de solução com 100 células são coletadas de cada lançamento. </li><li> Execute o experimental passos 3.9 através de 3.16 três vezes para coletar células suficientes para citometria de fluxo. </li><li> Centrifuga-se a placa de 96 poços contendo células transformadas por 5 min a 228 x g. </li><li> Retirar o sobrenadante que contém o excesso de moléculas fluorescentes. </li><li> Ressuspender as células em DPBS para análise de citometria de fluxo. </li><li> As células de carga no citômetro de fluxo para u molecularptake análise de eficiência. </li></ol>

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Com a nova plataforma eletroporação paralelizado, o aumento de 10 vezes na produtividade e eficiência da prestação de multi-molécula foi alcançado, além de todas as vantagens que o sistema de câmara única previamente desenvolvido proporciona. 18 méritos Anteriormente disponíveis incluem: (i) pré-purificação de as células alvo e com distribuição uniforme de tamanho de reforço viabilidade, (ii) o controlo de dosagem molecular preciso e individual, e (iii) a partir de corrente eléctrica opera...

Nos últimos anos, a utilização de impulsos eléctricos para facilitar a entrega de moléculas extracelulares citosólica tornou-se um meio atractivo de manipulação de células de mamífero. Uma Este processo, também conhecido como electroporação, reversivelmente, permeabiliza a membrana celular, permitindo que as moléculas de membrana inerentemente impermeáveis ​​para aceder ao meio intracelular das células. Como virtualmente qualquer molécula pode ser introduzida no citossol através de poros criados temporárias na membrana de qualquer tipo de células, utilizando a electroporação, a técnica tem sido relatada como sendo mais reprodutível, de aplicação universal, e mais eficiente do que outros métodos, incluindo mediada por vírus, química e abordagens ópticos 2-3. Esta técnica tem sido utilizada para introduzir moléculas fluorescentes, 4 drogas 5 e ácidos nucleicos de 6-7, mantendo as células viáveis ​​e intacta. Dadas essas vantagens, eletroporação foi adotado como um trabalho comumtória técnica para a transfecção de ADN, a terapia de genes in vivo e 8 estudos de vacinação celular. É, no entanto, continua a ser difícil para os sistemas convencionais de electroporação para conseguir simultaneamente a eficiência prática e viabilidade para as amostras com grande heterogeneidade no tamanho, porque a intensidade do campo eléctrico necessário para electroporação bem sucedida se correlaciona intimamente com o diâmetro da célula. Além disso, esses sistemas não permitem um controle preciso das quantidades moleculares múltiplas sendo entregues devido à dependência do processo de entrega molecular estocástico granel. 9 A fim de abordar estas questões, muitos grupos desenvolveram plataformas eletroporação microfluídicos, oferecendo a vantagem de tensões formadores de poros menores, melhor eficiência de transfecção, uma grande redução na mortalidade celular e capacidade de oferecer várias moléculas. foram possíveis devido às pequenas pegadas de sistemas de eletroporação em microescala cujo eletrodo passo 10-13 Estas vantagenscomprimentos são sub-milímetros, diminuindo drasticamente as tensões necessárias para entrega bem sucedida. Além disso, esses sistemas de eletroporação em microescala pode alcançar distribuição de campo elétrico uniforme e rapidamente dissipa o calor gerado, produzindo mortalidade celular reduzida, reforçando simultaneamente a eficiência de entrega. A utilização de materiais transparentes para estas micropastilhas permite ainda na observação in situ do processo de modificações dos parâmetros de electroporação rápidas. 2,12 Contudo, o controlo de dosagem precisa e controlo do parâmetro molecular-celular e dependente, necessária para a pesquisa e aplicações terapêuticas, 6 emergente, 14-16 continuam por resolver. Este trabalho apresenta um sistema de eletroporação microfluídica assistida por vórtice, capaz de oferecer múltiplas moléculas sequencialmente em uma população idêntica pré-selecionado de células-alvo. As células com a distribuição de tamanho uniforme são isolados antes de electroporação utilizando si previamente relatadomecanismo de ze-seletiva trapping. 17-18 Por ter uma distribuição uniforme tamanho, menor variação na eficiência eletroporação e maior viabilidade por determinado intensidade do campo elétrico foram atingidos. 19 Além disso, continuamente agitando células presos usando vórtices microescala permitido para entrega uniforme de moléculas através da citosol inteiro, de acordo com os resultados relatados anteriormente usando uma outra plataforma electroporação assistida por vórtice. 20 Para demonstrar que este sistema pode ser aplicado a uma ampla gama de moléculas comumente utilizados em aplicações biológicas, macromoléculas com uma ampla gama de pesos moleculares foram entregues aos células de câncer de mama metastático. Além disso, com a ajuda de monitoramento de processos em tempo real, este trabalho fornece mais evidências para pôr fim ao debate de longa data sobre o mecanismo de entrega molecular durante electrporation, sendo predominantemente eletroforese mediada versus 14 mediada por difusão. </sup&gt; Ao contrário de outros sistemas de electroporação, esta plataforma fornece exclusivamente as vantagens combinadas de precisão de entrega multi-molécula, de alta eficiência de entrega molecular, a mortalidade celular mínimo, um período largo de tamanho e taxas de moléculas entregues, bem como a visualização em tempo real da electroporação processo. Dadas estas capacidades, o sistema de eletroporação desenvolvido tem potencial prático como uma ferramenta versátil para estudos de reprogramação celular, aplicativos de entrega de drogas 6,14,21-22 10,19 e aplicações que requerem para a compreensão em profundidade dos mecanismos moleculares de entrega eletroporação.

<table border="0" cellpadding="0" cellspacing="0" width="1056">
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			<td height="20" style="height:21px;width:475px;">MDA-MB-231 cancer cell line</td>
			<td style="width:297px;">American Type Culture Collection (ATCC)</td>
			<td style="width:119px;">HTB-26</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">Leibovitz&#8217;s L-15 Medium</td>
			<td style="width:297px;">Cellgro, Mediatech, Inc.</td>
			<td style="width:119px;">10-045-CV</td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:475px;">fetal bovine serum (FBS)</td>
			<td style="width:297px;">Gibco, Life Technologies</td>
			<td style="width:119px;">16000-044</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">penicillin-streptomycin</td>
			<td style="width:297px;">Sigma-Aldrich</td>
			<td style="width:119px;">P4333</td>
			<td></td>
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		<tr height="20">
			<td height="20" style="height:20px;width:475px;">Dulbecco&#39;s phosphate buffered saline (DPBS)</td>
			<td style="width:297px;">Cellgro, Mediatech, Inc.</td>
			<td style="width:119px;">21-030</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">Trypsin</td>
			<td style="width:297px;">Gibco, Life Technologies</td>
			<td style="width:119px;">25200-056</td>
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			<td height="21" style="height:21px;width:475px;">Flow Cytometer easyCyte HT</td>
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			<td style="width:119px;">0500-4008</td>
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			<td height="21" style="height:21px;width:475px;">Oxygen Plasma Cleaner</td>
			<td style="width:297px;">Technics Micro-RIE</td>
			<td style="width:119px;"></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:475px;">Dektak 6M surface profiler</td>
			<td style="width:297px;">Veeco</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">KMPR 1050</td>
			<td style="width:297px;">Microchem</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">SYLGARD 184 SILICONE ELASTOMER KIT</td>
			<td style="width:297px;">Dow Corning</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">Compressed Nitrogen gas</td>
			<td style="width:297px;">Airgas</td>
			<td style="width:119px;">NI 300</td>
			<td></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:475px;">High Pressure Regulator</td>
			<td style="width:297px;">McMaster-Carr</td>
			<td>6162K22</td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:475px;">Downstream regulator</td>
			<td style="width:297px;">McMaster-Carr</td>
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			<td height="21" style="height:21px;width:475px;">high-speed 3/2way-8 valve manifold</td>
			<td style="width:297px;">Festo</td>
			<td style="width:119px;"></td>
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			<td height="21" style="height:21px;width:475px;">Inline Check Valve</td>
			<td style="width:297px;">Idex Health and Science</td>
			<td style="width:119px;">CV3320</td>
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		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:475px;">5/32&#34; OD x 3/32&#34;ID Polyurethan tubes</td>
			<td style="width:297px;">Pneumadyne</td>
			<td>PU-156F-0</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">1/4&#34; OD X 0.17&#34; ID Polyurethan tubes</td>
			<td style="width:297px;">Pneumadyne</td>
			<td style="width:119px;">PU-250PB-4</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:475px;">1/16&#34; PEEK tubings</td>
			<td style="width:297px;">Festo</td>
			<td style="width:119px;">P1533</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">1/32&#34; PEEK tubings</td>
			<td style="width:297px;">Idex Health and Science</td>
			<td style="width:119px;">P1569</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">PEEK tubing unions</td>
			<td style="width:297px;">Idex Health and Science</td>
			<td style="width:119px;">P881</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">Pulse Generator</td>
			<td style="width:297px;">HP</td>
			<td style="width:119px;">8110A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">Aluiminum Wire</td>
			<td style="width:297px;">Bob Martin Company</td>
			<td style="width:119px;">6061 ALUM</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">oscilloscope</td>
			<td style="width:297px;">Agilent</td>
			<td style="width:119px;">DSO3062A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">50 mL centrifuge tubes</td>
			<td style="width:297px;">VWR</td>
			<td style="width:119px;">21008-178</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">15 mL centrifuge tube</td>
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			<td style="width:119px;">21008-216</td>
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			<td height="21" style="height:21px;width:475px;">T75 culture flask</td>
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			<td height="21" style="height:21px;width:475px;">Dextran, Tetramethylrhodamine, 3000 MW, Anionic</td>
			<td style="width:297px;">Gibco, Life Technologies</td>
			<td style="width:119px;">D3307</td>
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			<td height="21" style="height:21px;width:475px;">Dextran, Tetramethylrhodamine, 70,000 MW, Neutral&#160;</td>
			<td style="width:297px;">Gibco, Life Technologies</td>
			<td style="width:119px;">D1819</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:475px;">Dextran, Texas Red, 3000 MW, Neutral</td>
			<td style="width:297px;">Gibco, Life Technologies</td>
			<td style="width:119px;">D3329</td>
			<td></td>
		</tr>
	</tbody>
</table>

microscale vortex-assisted electroporator for sequential molecular delivery

A electroporação tem recebido crescente atenção nos últimos anos, porque é uma técnica muito potente para a introdução de sondas moleculares exógenas fisicamente não permeantes em células. Este trabalho apresenta uma plataforma microfluídica eletroporação capaz de realizar múltiplas entrega molécula para células de mamíferos com controle de parâmetro preciso e molecular dependente. A capacidade do sistema para isolar células com distribuição de tamanho uniforme permite menos variação na eficiência eletroporação per dada intensidade do campo elétrico; por conseguinte, melhorada a viabilidade da amostra. Além disso, o recurso de visualização do processo permite a observação do processo molecular fluorescente captação em tempo real, que permite ajustes de parâmetros entrega moleculares rápidas in situ para aumento de eficiência. Para mostrar as vastas capacidades da plataforma relatado, macromoléculas com diferentes tamanhos e cargas elétricas (por exemplo, dextrano com MW de 3.000 e 70.000 Da) foramentregues para as células do câncer de mama metastático com alta eficiência de entrega (&gt; 70%) para todas as moléculas testadas. A plataforma desenvolvida provou o seu potencial para uso na expansão de campos de pesquisa onde on-chip técnicas de eletroporação pode ser benéfico.

O electroporator microfluídica paralelo desenvolvido entregues macromoléculas com tamanhos variados e cargas elétricas em células de câncer de mama metastático vivo. Entrega bem sucedida molecular foi qualitativamente determinado monitorizando alterações na intensidade de fluorescência de células electroporadas em órbita in situ e confirmado por medidas quantitativas por meio de análise de citometria de fluxo. Figura 4A mostra que 90% das células tratadas com a absorção de 70.000...

Watch this Scientific Journal Video about Microscale Vortex-assisted Electroporator for Sequential Molecular Delivery at JoVE.com

Microscale Vortex-assisted Electroporator for Sequential Molecular Delivery

Um vórtice microfluídico plataforma eletroporação assistida foi desenvolvido para entrega seqüencial de múltiplas moléculas em populações de células idênticas, com controle de dosagem precisa e independente. Tamanho com base etapa de purificação de células alvo eletroporação anterior do sistema auxiliado para aumentar a eficiência de entrega molecular e viabilidade celular processado.

Microescala Electroporator para entrega Sequential Molecular assistida por Vortex

Electroporation has received increasing attention in the past years, because it is a very powerful technique for physically introducing non-permeant ...

microscale-vortex-assisted-electroporator-for-sequential-molecular

Research

JoVE Journal

Bioengineering

8.4K visualizações.  Harvard University.  Um vórtice microfluídico plataforma eletroporação assistida foi desenvolvido para entrega seqüencial de múltiplas moléculas em populações de células idênticas, com controle de dosagem precisa e independente. Tamanho com base etapa de purificação de células alvo eletroporação anterior do sistema auxiliado para aumentar a eficiência de entrega molecular e viabilidade celular processado. 

Vídeo: Microscale Vortex-assisted Electroporator for Sequential Molecular Delivery

Low Molecular Weight Protein Enrichment on Mesoporous Silica Thin Films for Biomarker Discovery

The identification of circulating biomarkers holds great potential for non invasive approaches in early diagnosis and prognosis, as well as for the monitoring of therapeutic efficiency.1-3 The circulating low molecular weight proteome (LMWP) composed of small proteins shed from tissues and cells or peptide fragments derived from the proteolytic degradation of larger proteins, has been associated with the pathological condition in patients and likely reflects the state of disease.4,5 Despite these potential clinical applications, the use of Mass Spectrometry (MS) to profile the LMWP from biological fluids has proven to be very challenging due to the large dynamic range of protein and peptide concentrations in serum.6 Without sample pre-treatment, some of the more highly abundant proteins obscure the detection of low-abundance species in serum/plasma. Current proteomic-based approaches, such as two-dimensional polyacrylamide gel-electrophoresis (2D-PAGE) and shotgun proteomics methods are labor-intensive, low throughput and offer limited suitability for clinical applications.7-9 Therefore, a more effective strategy is needed to isolate LMWP from blood and allow the high throughput screening of clinical samples. 
Here, we present a fast, efficient and reliable multi-fractionation system based on mesoporous silica chips to specifically target and enrich LMWP.10,11 Mesoporous silica (MPS) thin films with tunable features at the nanoscale were fabricated using the triblock copolymer template pathway. Using different polymer templates and polymer concentrations in the precursor solution, various pore size distributions, pore structures, connectivity and surface properties were determined and applied for selective recovery of low mass proteins. The selective parsing of the enriched peptides into different subclasses according to their physicochemical properties will enhance the efficiency of recovery and detection of low abundance species. In combination with mass spectrometry and statistic analysis, we demonstrated the correlation between the nanophase characteristics of the mesoporous silica thin films and the specificity and efficacy of low mass proteome harvesting. The results presented herein reveal the potential of the nanotechnology-based technology to provide a powerful alternative to conventional methods for LMWP harvesting from complex biological fluids. Because of the ability to tune the material properties, the capability for low-cost production, the simplicity and rapidity of sample collection, and the greatly reduced sample requirements for analysis, this novel nanotechnology will substantially impact the field of proteomic biomarker research and clinical proteomic assessment.

We developed a technology based on mesoporous silica thin film for the selective recovery of low molecular weight proteins and peptides from human serum. The physico-chemical properties of our mesoporous chips were finely tuned to provide substantial control in peptide enrichment and consequently profile the serum proteome for diagnostic purposes.

Enriquecimento protéico de baixo peso molecular em filmes finos de sílica mesoporosa para a descoberta de biomarcadores

The identification of circulating biomarkers holds great potential for non invasive approaches in early diagnosis and prognosis, as well as for the ...

Bioengenharia

Skin Tattooing As A Novel Approach For DNA Vaccine Delivery

Nucleic acid-based vaccination is a topic of growing interest, especially plasmid DNA (pDNA) encoding immunologically important antigens. After the engineered pDNA is administered to the vaccines, it is transcribed and translated into immunogen proteins that can elicit responses from the immune system. Many ways of delivering DNA vaccines have been investigated; however each delivery route has its own advantages and pitfalls. Skin tattooing is a novel technique that is safe, cost-effective, and convenient. In addition, the punctures inflicted by the needle could also serve as a potent adjuvant. Here, we a) demonstrate the intradermal delivery of plasmid DNA encoding enhanced green fluorescent protein (pCX-EGFP) in a mouse model using a tattooing device and b) confirm the effective expression of EGFP in the skin cells using confocal microscopy.

Skin tattooing is a potent and safe way to delivery DNA vaccine intradermally. Here, a DNA plasmid encoding EGFP is delivered by tattooing to the skin of a laboratory mouse, and the expression of EGFP in the skin cells is then inspected by confocal microscopy.

Pele a tatuagem como uma nova abordagem para a Campanha de Vacinação de DNA

Nucleic acid-based vaccination is a topic of growing interest, especially plasmid DNA (pDNA) encoding immunologically important antigens. After the ...

Self-reporting Scaffolds for 3-Dimensional Cell Culture

Culturing cells in 3D on appropriate scaffolds is thought to better mimic the in vivo microenvironment and increase cell-cell interactions. The resulting 3D cellular construct can often be more relevant to studying the molecular events and cell-cell interactions than similar experiments studied in 2D. To create effective 3D cultures with high cell viability throughout the scaffold the culture conditions such as oxygen and pH need to be carefully controlled as gradients in analyte concentration can exist throughout the 3D construct. Here we describe the methods of preparing biocompatible pH responsive sol-gel nanosensors and their incorporation into poly(lactic-co-glycolic acid) (PLGA) electrospun scaffolds along with their subsequent preparation for the culture of mammalian cells. The pH responsive scaffolds can be used as tools to determine microenvironmental pH within a 3D cellular construct. Furthermore, we detail the delivery of pH responsive nanosensors to the intracellular environment of mammalian cells whose growth was supported by electrospun PLGA scaffolds. The cytoplasmic location of the pH responsive nanosensors can be utilized to monitor intracellular pH (pHi) during ongoing experimentation.

Biocompatible pH responsive sol-gel nanosensors can be incorporated into poly(lactic-co-glycolic acid) (PLGA) electrospun scaffolds. The produced self-reporting scaffolds can be used for in&#160;situ monitoring of microenvironmental conditions whilst culturing cells upon the scaffold. This is beneficial as the 3D cellular construct can be monitored in real-time without disturbing the experiment.

Andaimes auto-relato para cultura de células 3-Dimensional

Culturing cells in 3D on appropriate scaffolds is thought to better mimic the in vivo microenvironment and increase cell-cell interactions. The resulting ...

Cell Squeezing as a Robust, Microfluidic Intracellular Delivery Platform

Rapid mechanical deformation of cells has emerged as a promising, vector-free method for intracellular delivery of macromolecules and nanomaterials. This technology has shown potential in addressing previously challenging applications; including, delivery to primary immune cells, cell reprogramming, carbon nanotube, and quantum dot delivery. This vector-free microfluidic platform relies on mechanical disruption of the cell membrane to facilitate cytosolic delivery of the target material. Herein, we describe the detailed method of use for these microfluidic devices including, device assembly, cell preparation, and system operation. This delivery approach requires a brief optimization of device type and operating conditions for previously unreported applications. The provided instructions are generalizable to most cell types and delivery materials as this system does not require specialized buffers or chemical modification/conjugation steps. This work also provides recommendations on how to improve device performance and trouble-shoot potential issues related to clogging, low delivery efficiencies, and cell viability.

Rapid mechanical deformation of cells has emerged as a promising, vector-free method for intracellular delivery of macromolecules and nanomaterials. This protocol provides detailed steps on how to use the system for a broad range of applications.

Espremendo celular como uma plataforma de entrega intracelular Robust Microfluidic

Rapid mechanical deformation of cells has emerged as a promising, vector-free method for intracellular delivery of macromolecules and nanomaterials. This ...

Utilization of Microscale Silicon Cantilevers to Assess Cellular Contractile Function In Vitro

The development of more predictive and biologically relevant in vitro assays is predicated on the advancement of versatile cell culture systems which facilitate the functional assessment of the seeded cells. To that end, microscale cantilever technology offers a platform with which to measure the contractile functionality of a range of cell types, including skeletal, cardiac, and smooth muscle cells, through assessment of contraction induced substrate bending. Application of multiplexed cantilever arrays provides the means to develop moderate to high-throughput protocols for assessing drug efficacy and toxicity, disease phenotype and progression, as well as neuromuscular and other cell-cell interactions. This manuscript provides the details for fabricating reliable cantilever arrays for this purpose, and the methods required to successfully culture cells on these surfaces. Further description is provided on the steps necessary to perform functional analysis of contractile cell types maintained on such arrays using a novel laser and photo-detector system. The representative data provided highlights the precision and reproducible nature of the analysis of contractile function possible using this system, as well as the wide range of studies to which such technology can be applied. Successful widespread adoption of this system could provide investigators with the means to perform rapid, low cost functional studies in vitro, leading to more accurate predictions of tissue performance, disease development and response to novel therapeutic treatment.

Utilization of Microscale Silicon Cantilevers to Assess Cellular Contractile Function In Vitro

This protocol describes the use of microscale silicon cantilevers as pliable culture surfaces for measuring the contractility of muscle cells in vitro. Cellular contraction causes cantilever bending, which can be measured, recorded, and converted into readouts of force, providing a non-invasive and scalable system for measuring contractile function in vitro.

Utilização de microscópicos de silício Cantilevers para avaliar a função celular contrátil<em&gt; In Vitro</em

The development of more predictive and biologically relevant in vitro assays is predicated on the advancement of versatile cell culture systems which ...

Porous Silicon Microparticles for Delivery of siRNA Therapeutics

Small interfering RNA (siRNA) can be used to suppress gene expression, thereby providing a new avenue for the treatment of various diseases. However, the successful implementation of siRNA therapy requires the use of delivery platforms that can overcome the major challenges of siRNA delivery, such as enzymatic degradation, low intracellular uptake and lysosomal entrapment. Here, a protocol for the preparation and use of a biocompatible and effective siRNA delivery system is presented. This platform consists of polyethylenimine (PEI) and arginine (Arg)-grafted porous silicon microparticles, which can be loaded with siRNA by performing a simple mixing step. The silicon particles are gradually degraded over time, thereby triggering the formation of Arg-PEI/siRNA nanoparticles. This delivery vehicle provides a means for protecting and internalizing siRNA, without causing cytotoxicity. The major steps of polycation functionalization, particle characterization, and siRNA loading are outlined in detail. In addition, the procedures for determining particle uptake, cytotoxicity, and transfection efficacy are also described.

Delivery remains the main challenge for the therapeutic implementation of small interfering RNA (siRNA). This protocol involves the use of a multifunctional and biocompatible siRNA delivery platform, consisting of arginine and polyethylenimine grafted porous silicon microparticles.

Porous Silicon micropartículas para entrega de siRNA Therapeutics

Small interfering RNA (siRNA) can be used to suppress gene expression, thereby providing a new avenue for the treatment of various diseases. However, the ...

Biofunctionalized Prussian Blue Nanoparticles for Multimodal Molecular Imaging Applications

Multimodal, molecular imaging allows the visualization of biological processes at cellular, subcellular, and molecular-level resolutions using multiple, complementary imaging techniques. These imaging agents facilitate the real-time assessment of pathways and mechanisms in vivo, which enhance both diagnostic and therapeutic efficacy. This article presents the protocol for the synthesis of biofunctionalized Prussian blue nanoparticles (PB NPs) - a novel class of agents for use in multimodal, molecular imaging applications. The imaging modalities incorporated in the nanoparticles, fluorescence imaging and magnetic resonance imaging (MRI), have complementary features. The PB NPs possess a core-shell design where gadolinium and manganese ions incorporated within the interstitial spaces of the PB lattice generate MRI contrast, both in T1 and T2-weighted sequences. The PB NPs are coated with fluorescent avidin using electrostatic self-assembly, which enables fluorescence imaging. The avidin-coated nanoparticles are modified with biotinylated ligands that confer molecular targeting capabilities to the nanoparticles. The stability and toxicity of the nanoparticles are measured, as well as their MRI relaxivities. The multimodal, molecular imaging capabilities of these biofunctionalized PB NPs are then demonstrated by using them for fluorescence imaging and molecular MRI in vitro.

This protocol describes the synthesis of biofunctionalized Prussian blue nanoparticles and their use as multimodal, molecular imaging agents. The nanoparticles have a core-shell design where gadolinium or manganese ions within the nanoparticle core generate MRI contrast. The biofunctional shell contains fluorophores for fluorescence imaging and targeting ligands for molecular targeting.

Bioativa de Prussian Blue Nanopartículas para Multimodal Imagem Molecular Applications

Multimodal, molecular imaging allows the visualization of biological processes at cellular, subcellular, and molecular-level resolutions using multiple, ...

Analyzing Mixing Inhomogeneity in a Microfluidic Device by Microscale Schlieren Technique

In this paper, we introduce the use of microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. The microscale schlieren system is constructed from a Hoffman modulation contrast microscope, which provides easy access to the rear focal plane of the objective lens, by removing the slit plate and replacing the modulator with a knife-edge. The working principle of microscale schlieren technique relies on detecting light deflection caused by variation of refractive index1-3. The deflected light either escapes or is obstructed by the knife-edge to produce a bright or a dark band, respectively. If the refractive index of the mixture varies linearly with its composition, the local change in light intensity in the image plane is proportional to the concentration gradient normal to the optical axis. The micro-schlieren image gives a two-dimensional projection of the disturbed light produced by three-dimensional inhomogeneity.
To accomplish quantitative analysis, we describe a calibration procedure that mixes two fluids in a T-microchannel. We carry out a numerical simulation to obtain the concentration gradient in the T-microchannel that correlates closely with the corresponding micro-schlieren image. By comparison, a relationship between the grayscale readouts of the micro-schlieren image and the concentration gradients presented in a microfluidic device is established. Using this relationship, we are able to analyze the mixing inhomogeneity from associate micro-schlieren image and demonstrate the capability of microscale schlieren technique with measurements in a microfluidic oscillator4. For optically transparent fluids, microscale schlieren technique is an attractive diagnostic tool to provide instantaneous full-field information that retains the three-dimensional features of the mixing process.

Herein, we describe a procedure that employs microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. Through calibration, distribution of concentration gradient can be derived from the micro-schlieren image.

Analisando falta de homogeneidade de mistura em um dispositivo micro, pela técnica Microscale Schlieren

In this paper, we introduce the use of microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. The microscale schlieren ...

Mesenchymal Stromal Cell Culture and Delivery in Autologous Conditions: A Smart Approach for Orthopedic Applications

Human Mesenchymal Stromal Cells (hMSCs) are cultured in vitro with different media. Limits on their use in clinical settings, however, mainly depend on potential biohazard and inflammation risks exerted by xenogeneic nutrients for their culture. Human derivatives or recombinant materials are the first choice candidates to reduce these reactions. Therefore, culture supplements and materials of autologous origin represent the best nutrients and the safest products.
Here, we describe a new protocol for the isolation and culture of bone marrow hMSCs in autologous conditions &#8212;&#160;namely,&#160;patient-derived serum as a supplement for the culture medium and fibrin as a scaffold for hMSC administration. Indeed, hMSC/fibrin clot constructs could be extremely useful for several clinical applications. In particular, we focus on their use in orthopedic surgery, where the fibrin clot derived from the donor&#39;s own blood allowed effective cell delivery and nutrient/waste exchanges. To ensure optimal safety conditions, it is of the utmost importance to avoid the risks of hMSC transformation and tissue overgrowth. For these reasons, the approach described in this paper also indicates a minimally ex vivo hMSC expansion, to reduce cell senescence and morphologic changes, and short-term osteo-differentiation before implantation, to induce osteogenic lineage specification, thus decreasing the risk of subsequent uncontrolled proliferation.

Culturing human Mesenchymal Stromal Cells (hMSCs) with autologous serum, reduces the risks of rejection by xenogeneic material and other negative effects. It also allows for the recovery of a subset of mesodermal progenitors, which can deliver fresh hMSCs. Embedding hMSCs in an autologous fibrin clot enables easy handling and effective surgical implantation.

Estromais mesenquimais cultura de células e Entrega em condições autólogas: Uma abordagem inteligente para aplicações ortopédicas

Human Mesenchymal Stromal Cells (hMSCs) are cultured in vitro with different media. Limits on their use in clinical settings, however, mainly depend on ...

Four-Dimensional CT Analysis Using Sequential 3D-3D Registration

Four-dimensional computed tomography (4DCT) provides a series of volume data and visualizes joint motions. However, numerical analysis of 4DCT data remains difficult because segmentation in all volumetric frames is time-consuming. We aimed to analyze joint kinematics using a sequential 3D-3D registration technique to provide the kinematics of the moving bone with respect to the fixed bone semiautomatically using 4DCT DICOM data and existing software. Surface data of the source bones are reconstructed from 3DCT. The trimmed surface data are respectively matched with surface data from the first frame in 4DCT. These trimmed surfaces are sequentially matched until the last frame. These processes provide positional information for target bones in all frames of the 4DCT. Once the coordinate systems of the target bones are decided, translation and rotation angles between any two bones can be calculated. This 4DCT analysis offers advantages in kinematic analyses of complex structures such as carpal or tarsal bones. However, fast or large-scale motions cannot be traced because of motion artifacts.

We analyzed joint kinematics from four-dimensional computed tomography data. The sequential 3D-3D registration method semiautomatically provides the kinematics of the moving bone with respect to the subject bone from four-dimensional computed tomography data.

Análise de TC quadridimensional usando registro 3D-3D sequencial

Four-dimensional computed tomography (4DCT) provides a series of volume data and visualizes joint motions. However, numerical analysis of 4DCT data ...