Este trabalho foi apoiado em parte pelas bolsas do Ministério da Ciência e Tecnologia de Taiwan (a maioria 104-2628-E-007-001-MY3 (CMC)) e Taichung Veterans Hospital Geral <span style="color: rgb(34, 34, 34); font-family: arial, sans-serif; font-size: 12.8px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 1; word-spacing: 0px; -webkit-text-stroke-width: 0px; display: inline !important; float: none; background-color: rgb(255, 255, 255);">(TCVGH-1056904C (MYH)).

CUIDADO: A prática correta higiene laboratório é necessária. Luvas e precauções universais são necessárias ao usar este dispositivo POC. A contaminação de resultados ou infecção pode ocorrer se os procedimentos de esterilização adequadas não forem realizados corretamente. 1. Prepare tiras de teste Devices <ol><li> Determinar a hidrofobicidade da camada exterior do algodão purificação por medição do ângulo de contacto 8 (Figura 3). </li><li> Fabricar o dispositivo analítico em algodão através do corte de algodão de limpeza em 5,5 cm x 1 cm pedaços com um cortador de papel (Figura 2A). </li><li> Faça furos (Ø = 0,5 cm) em uma folha padrão de filme de laminação em fileiras de três; a distância entre dois furos subsequentes é de 1 cm. NOTA: Como muitos como 36 tiras de teste individuais com três áreas de teste cada um pode ser feito usando uma folha padrão de filme de laminação (5,5 cm x 2 cm) (Figura 2B). </li><li> Sanduíche do algodão de limpeza (characterized pela hidrofobicidade e hidrofilicidade exterior interior) entre dois pedaços de película de laminação, ou seja, a folha perfurados buracos de filme de laminação, de um lado, e uma folha de película não perfuradas de laminação (não há furos), por outro lado. Coloque o conjunto em um laminador para empacotar o dispositivo. Isto aumenta a resistência mecânica do dispositivo, e proporciona uma camada exterior, impermeável. NOTA: Os diâmetros de furos vai encolher de 0,5 cm para ~ 0,47 cm após a laminação. Algumas pequenas aberturas permanecerá entre o algodão de limpeza e a película de laminação em torno do perímetro de cada orifício. Estas pequenas aberturas facilitar a colocação da almofada de teste círculos feito num passo subsequente. </li><li> Utilizar um par de tesoura para cortar dispositivos de tiras de teste de 5,5 cm x 1 cm individuais do conjunto, ou seja, a folha de laminação perfurado / almofada de algodão / folha de laminação não perfuradas &quot;sanduíche&quot; (Figura 2C). Adicione 48 total de dispositivos para criar curvas padrão como descrito mais tarde (18 dispositivospara o ensaio de nitritos, 15 dispositivos para o ensaio de BSA, 15 e dispositivos para o ensaio de urobilinogénio). </li><li> Utilize uma faca afiada ou lâmina para cortar uma fenda (como um pequeno canal fluídico) a partir do centro de cada zona de ensaio (não cobertos pela película de laminação), do outro lado e através da camada hidrofóbica de área de teste para a camada hidrófila do dispositivo longitudinal, sendo cauteloso para cortar a meio da profundidade do dispositivo ensanduichada (Figura 2D). </li><li> Aplicar compressas de teste de papel (Ø = 0,5 cm), deslizando-as para as lacunas no perímetro de cada orifício na laminação (Figura 2E). </li></ol> 2. Prepare Padrões e Indicadores Soluções para Urinalysis <ol><li> Prepare a 10,0 mm da solução de nitrito por dissolução de 69,0 mg de nitrito de sódio em 100 ml de água desionizada (Dl). Dilui-se a solução stock de nitrito em água DI para criar uma série de soluções padrão de nitrito (concentração de 2.500, 1.250, 625, 312, 156, e 78 ^ M) (Figura4A). </li><li> Preparar a solução de albumina de soro (BSA) 60 uM da bovina por dissolução de 415 mg de BSA, em 100 ml de solução de PBS (tampão de fosfato 10 M, 0,0027 M de cloreto de potássio e cloreto de sódio 0,137 M; pH 7,0). Dilui-se a solução de reserva de BSA em água DI para criar uma série de soluções padrão de concentração de BSA (30, 15, 7,5, 3,75, e 1,875 uM) (Figura 4B). </li><li> Prepare 25 g / L solução de urobilinogênio dissolvendo 2,5 g urobilinogénio em 100 ml de água DI. Diluir solução estoque urobilinogénio em água DI para criar uma série de soluções padrão de concentração urobilinogénio (7,8, 15,6, 31,2, 62,5, e 125 mg / L) (Figura 4C). </li><li> Preparar a solução de indicador de nitrito de sulfanilamida contendo 50 mM, ácido cítrico 330 mM, e 10 mM de N- (1-naftil) etilenodiamina dicloridrato. </li><li> Preparar a solução de indicador de BSA contendo 250 mM de solução tampão de citrato (pH 1,8) e uma solução 3,3 mM de tetrabromophenol azul em 95% de etanol. </li><li>Preparar a solução indicador urobilinogénio contendo 0,1 M de 4 Dimethylamine benzaldeído. </li></ol> 3. Prepare Pads indicadoras <ol><li> Corte três almofadas em forma circulares ou discos (o = 0,5 cm) de papel de cromatografia e inserir cada um deles (um para cada ensaio na tira de ensaio de três) para cada dispositivo de tira de teste para criar uma curva padrão solução (secção 4). </li><li> Em cada um dos três furos de filmes de laminação da montagem, observar um pequeno espaço entre o filme de laminação e a almofada de teste de algodão nas próprias bordas do furo do corte. Note-se, o orifício no filme de laminação é ligeiramente menor em diâmetro que a almofada de ensaio de papel. NOTA: Em conjunto, estas características permitem que o tampão de teste de papel para ser aplicada contra a parte da almofada de teste de algodão do dispositivo, de modo que as bordas da almofada de deslizamento de ensaio de papel para o intervalo fino mencionado, isto é, sob as bordas do orifício de filme de laminação. Esta detém as almofadas de teste papel no lugar. </li><li> Prepare o Nitrito Assay porção do dispositivo. <ol><li> Brasão da almofada ensaio de nitritos com 4 ml de solução de nitrito de indicador (preparada no passo 2.4) e deixe-a secar completamente à temperatura ambiente. </li></ol></li><li> Preparar a percentagem do total de ensaio de proteína do dispositivo de detecção. <ol><li> Revestir a almofada de ensaio total de proteína com 4 ul de solução de BSA indicador (preparado no passo 2.5) e deixar secar completamente à temperatura ambiente. </li></ol></li><li> Prepara-se o Porção Uroblinogen Ensaio do dispositivo de detecção. <ol><li> Brasão da almofada de ensaio uroblinogen com 4 ul de indicador uroblinogen (preparado no passo 2.6) e deixe-a secar completamente à temperatura ambiente. </li></ol></li></ol> 4. criar curvas padrão para o dispositivo analítico à base de algodão <ol><li> Para cada padrão preparada, mergulhe o fim de absorção de um dispositivo preparado (pré-carregado com indicadores de ensaio (ver secção 3.4)) para a solução padrão para 10 segundos (o volume de absorção ~200 - 300 ul) (Figura 2F). </li><li> Coloque o dispositivo à base de algodão num ambiente ambiente durante 10 min para completar as reacções colorimétricas (Figura 2F). Repita cada experimento em triplicado. </li><li> Digitalizar o dispositivo para analisar a alteração colorimétrica ocorrendo em cada almofada de ensaio (Figura 2G). Lugar resultando compressas de teste no vidro de um scanner de mesa e almofadas de teste de verificação no modo RGB com 600 dpi de resolução de imagem. Salvar cada imagem em formato jpeg. </li><li> Analisar a imagem digitalizada em um computador utilizando o software de análise para determinar respectivas intensidades de cor (Figura 2H). <ol><li> Baixar software ImageJ na http://imagej.nih.gov/ij/. Abra os arquivos de imagens digitalizadas. Selecione a imagem nos comandos de menu e selecione &quot;Type&quot; para converter imagens RGB para 8 bits em tons de cinza. </li><li> Use a ferramenta &quot;Oval&quot; na barra de ferramentas para selecionar a área de análise do teste pad. Selecione &quot;Analisar&quot; no menu de commands, e selecione &quot;Measure&quot; para analisar a intensidade da cor. Grave significa resultados intensidade. </li></ol></li><li> Estabelecer as curvas padrão de nitrito, proteína total, e ensaios urobilinogênio (Figura 2I). <ol><li> Indicar diferentes concentrações de nitrito padrão, proteína total, e soluções urobilinogênio e correlacionados os resultados médios de intensidade num sistema de coordenadas bidimensional utilizando software stastical. </li><li> Ajustar a curva padrão para um ensaio de nitritos por um modelo quadrático e as curvas padrão para o total de ensaios de proteína e urobilinogênio por modelos de regressão linear. </li></ol></li></ol> 5. determinar as concentrações de amostra desconhecida Usando estabelecia valores curva padrão <ol><li> Para determinar nitrito, proteína total, e as concentrações de urobilinogênio em soluções desconhecidos, usar o dispositivo como descrito para a medição das concentrações de soluções padrão e substitutos medido resultados intensidade para nitrito, proteína total, e urobiensaios linogen nas equações dos modelos construídos no passo 2. </li></ol>

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The authors declare that they have no competing financial interests. S.C.L., C.M.K., F.G.T., and C.M.C. are inventors of a patent (patent No.: US 8691162 B1) owned by National Tsing Hua University on the basis of the work reported in this manuscript. S.C.L., C.M.K., F.G.T., and C.M.C.have patents pending in Taiwan and China based on the work reported in this manuscript. M.Y.H. declares no potential conflict of interest.

passos críticos neste protocolo incluiu a determinação da combinação adequada de material de algodão (com diferentes hidrofobicidade / hidrofilicidade) e filtro de papel (papel de filtro cromatografia ou papel de filtro quantitativo). Um projeto dispositivo bem planejado e executado torna atribui o melhor desempenho para ensaios colorimétricos. A partir dos nossos resultados ensaio colorimétrico, o dispositivo analítico em algodão aqui apresentado demonstra grande potencial como uma plataforma para a detecçã...

O desenvolvimento de point-of-care (POC) dispositivos de diagnóstico que são acessíveis, robusto e de fácil utilização é imperativo para a melhoria 1,2 a saúde global. Em particular, os dispositivos composta de substratos de celulose (por exemplo, papel, linha, e algodão) fornecem plataformas analíticas promissoras para a análise de baixo custo por causa de sua onipresença, acessibilidade, facilidade de uso, robustez e capacidade de fornecer resultados rápidos 3-7. Aqui, nós desvendar o desenvolvimento de um dispositivo analítico em algodão que usa um formato de fluxo lateral com base em urina. Este dispositivo analítico baseado em algodão fornece uma abordagem de detecção alternativo com várias vantagens importantes: i) a fabricação com o esforço humano mínimo; ii) baixo custo; iii) a capacidade de ser usado para conduzir múltiplos ensaios diferentes, sem preocupações de contaminação cruzada; . iv) independência do dispositivo, ou seja, a capacidade de ser executado sem equipamento e / ou eletricidade adicional; e, v) Velocidade (ensaios colorimétricos pode ser concluída dentro de 10 min). A estrutura deste dispositivo analítico em algodão pode ser dividido em quatro partes: i) de algodão, que é naturalmente hidrofóbico na sua camada externa hidrofóbica; ii) de algodão hidrófilo que é internamente e serve como um canal de transporte para que a absorção de líquido; iii) película de laminação que se liga e comprime o algodão a ser utilizado, mas contém orifícios perfurados para fora para a colocação de pastilhas de reacção / ensaio; e, iv) compressas de teste de papel de cromatografia, os quais são revestidos / incorporados com reagentes reactivos, colocados sobre a superfície exterior do algodão (especificamente, no espaço perfurado para fora da película de laminação) como zonas de reacção para os ensaios colorimétricos (isto é, nitrito, proteína total, pH, e ensaios urobilinogênio) e exibir os resultados. O mecanismo subjacente do teste é como se segue. O dispositivo analítico baseado em algodão é marcado com linhas que penetram a meio do depth do material de algodão para criar um canal de fluxo que permite que o fluido de amostra para atingir as almofadas reactivos a ser utilizado. A borda de absorção do dispositivo de análise é imerso na amostra alvo, após o que a solução é mau ao longo do canal de fluidos a partir do extremo de absorção às almofadas de teste (Figura 1). Uma vez que a força de absorção da almofada de teste é maior do que a de algodão, soluções de absorvidos pelas almofadas de teste são firmemente contido no interior do papel de teste do rato de modo que não existe qualquer refluxo de volta para dentro do canal de fluidos, e os resultados colorimétricos tornar-se subsequentemente fixado sobre o material de almofada de teste. No final da reacção, colorimétricos resultados são registados por meio de um digitalizador de mesa, e analisados ​​por meio de software de análise de imagem.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>bovine serum albumin</td>
			<td>Sigma-Aldrich, US</td>
			<td>No. 9048468</td>
			<td>&#8805; 99%</td>
		</tr>
		<tr>
			<td>nitrite&#160;</td>
			<td>Sigma-Aldrich, US</td>
			<td>No. 7632000</td>
			<td>&#8805; 99%</td>
		</tr>
		<tr>
			<td>urobilinogen&#160;</td>
			<td>Santa Cruz Bio, US</td>
			<td>No. SC-296690</td>
			<td></td>
		</tr>
		<tr>
			<td>citrate</td>
			<td>Sigma-Aldrich U.S</td>
			<td>No. 6132043</td>
			<td>&#8805; 99%</td>
		</tr>
		<tr>
			<td>tetrabromophenol blue</td>
			<td>Sigma-Aldrich U.S</td>
			<td>No. 4430255</td>
			<td>&#8805; 99%</td>
		</tr>
		<tr>
			<td>sulfanilamide</td>
			<td>Sigma-Aldrich U.S</td>
			<td>No. 63741</td>
			<td>&#8805; 99%</td>
		</tr>
		<tr>
			<td>citric acid&#160;</td>
			<td>Sigma-Aldrich U.S</td>
			<td>No. 77929</td>
			<td>&#8805; 99.5%</td>
		</tr>
		<tr>
			<td>&#160;N-(1-naphthyl) ethylenediamine dihydrochloride</td>
			<td>Sigma-Aldrich U.S</td>
			<td>No. 1465254</td>
			<td>&#8805; 98%</td>
		</tr>
		<tr>
			<td>4-(Dimethylamine)benzaldehyde</td>
			<td>AlfaAesar, U.S</td>
			<td>No. A11712</td>
			<td>&#8805; 98%</td>
		</tr>
		<tr>
			<td>Methyl Red sodium salt</td>
			<td>sigma, U.S</td>
			<td>No. 114502</td>
			<td>&#8805;95%</td>
		</tr>
		<tr>
			<td>Bromothyle blue</td>
			<td>sigma, U.S</td>
			<td>No. 114413</td>
			<td>&#8805;95%</td>
		</tr>
		<tr>
			<td>Shiseido Cleansing Cotton</td>
			<td>Shiseido, Japan</td>
			<td>No. 79014</td>
			<td></td>
		</tr>
		<tr>
			<td>chromatography paper</td>
			<td>GE Healthcare Whatman, Springfield Mill, UK</td>
			<td>No. 30306132</td>
			<td></td>
		</tr>
		<tr>
			<td>plastic substrate</td>
			<td>lamination film, MAS</td>
			<td>A4</td>
			<td>216 mm &#215; 303 mm</td>
		</tr>
		<tr>
			<td>scanner</td>
			<td>microtek scanmaker</td>
			<td>&#160;i2400</td>
			<td></td>
		</tr>
		<tr>
			<td>paper cutter</td>
			<td>Life paper cutter</td>
			<td>No.306</td>
			<td></td>
		</tr>
		<tr>
			<td>laminator</td>
			<td>AURORA&#160;</td>
			<td>LM4231H</td>
			<td></td>
		</tr>
		<tr>
			<td>laminator film</td>
			<td>UNI LAMI&#160;</td>
			<td>4A</td>
			<td></td>
		</tr>
	</tbody>
</table>

fabricating cotton analytical devices

Um dispositivo analítico robusto e de baixo custo deve ser de fácil utilização, rápida e acessível. Tais dispositivos também deve ser capaz de operar com amostras escassos e fornecer informações para acompanhamento do tratamento. Aqui, demonstramos o desenvolvimento de uma análise de urina à base de algodão (ou seja, nitrito, proteína total, e urobilinogênio ensaios) do dispositivo de análise que emprega um formato baseado em fluxo lateral, e é barato, facilmente fabricado, rápido, e pode ser usado para conduzir vários testes sem preocupações contaminação cruzada. O algodão é composto por fibras de celulose com as propriedades de absorção naturais que podem ser aproveitados para a análise baseada em fluxo. O processo de fabricação simples mas elegante do nosso dispositivo analítico baseado em algodão é descrito neste estudo. O arranjo da estrutura de algodão e a almofada de ensaio tira vantagem da hidrofobicidade e a força de absorção de cada material. Devido a estas características físicas, os resultados colorimétricos persistentemente podem aderir ao testealmofada. Este dispositivo permite aos médicos para receber informação clínica em tempo hábil e mostra grande potencial como ferramenta de intervenção precoce.

Foi demonstrado com êxito do desenvolvimento de dispositivos de análise à base de algodão usando disponível comercialmente de algodão hidrófilo de limpeza caracteriza-se por (porção interna) e propriedades hidrofóbicas (parte exterior) (Figura 1A). A Figura 3 mostra os resultados da medição do ângulo de contacto. A interface de algodão hidrófobo exterior era 127,35 ° ± 4,73 °. De uma perspectiva de user-friendly, ensaios colorimétricos...

Watch this Scientific Journal Video about Fabricating Cotton Analytical Devices at JoVE.com

Fabricating Cotton Analytical Devices

To investigate simple fabrication approaches for multiple assay needs, we created a fluid-absorbing channel system made of cotton material. This device was used to establish a multiple detection platform, and solve contamination issues that commonly affect lateral flow-based biomedical devices, for clinical urinalysis of nitrite, total protein, and urobilinogen.

Fabricação de algodão dispositivos analíticos

A robust, low-cost analytical device should be user-friendly, rapid, and affordable. Such devices should also be able to operate with scarce samples and ...

Research

JoVE Journal

Bioengineering

6.6K visualizações.  National Tsing Hua University. To investigate simple fabrication approaches for multiple assay needs, we created a fluid-absorbing channel system made of cotton material. This device was used to establish a multiple detection platform, and solve contamination issues that commonly affect lateral flow-based biomedical devices, for clinical urinalysis of nitrite, total protein, and urobilinogen.

Vídeo: Fabricating Cotton Analytical Devices

Manufacturing Devices and Instruments for Easier Rat Liver Transplantation

Orthotopic rat liver transplantation is a popular model, which has been shown in a recent JoVE paper with the use of the "quick-linker" device. This technique allows for easier venous cuff-anatomoses after a reasonable learning curve. The device is composed of two handles, which are carved out from scalpel blades, one approximator, which is obtained by modifying Kocher's forceps, and cuffs designed from fine-bore polyethylene tubing. The whole process can be performed at a low-cost using common laboratory material. The present report provides a step-by-step protocol for the design of the required pieces and includes stencils.

We describe the design of the &#x201C;quick-linker&#x201D; device for easier orthotopic rat liver transplantation.

Dispositivos de fabricação e instrumentos para facilitar a Rat Liver Transplantation

Orthotopic rat liver transplantation is a popular model, which has been shown in a recent JoVE paper with the use of the "quick-linker" device. This ...

Bioengenharia

Fabricating Complex Culture Substrates Using Robotic Microcontact Printing (R-&#181;CP) and Sequential Nucleophilic Substitution

In tissue engineering, it is desirable to exhibit spatial control of tissue morphology and cell fate in culture on the micron scale. Culture substrates presenting grafted poly(ethylene glycol) (PEG) brushes can be used to achieve this task by creating microscale, non-fouling and cell adhesion resistant regions as well as regions where cells participate in biospecific interactions with covalently tethered ligands. To engineer complex tissues using such substrates, it will be necessary to sequentially pattern multiple PEG brushes functionalized to confer differential bioactivities and aligned in microscale orientations that mimic in vivo niches. Microcontact printing (&#956;CP) is a versatile technique to pattern such grafted PEG brushes, but manual &#956;CP cannot be performed with microscale precision. Thus, we combined advanced robotics with soft-lithography techniques and emerging surface chemistry reactions to develop a robotic microcontact printing (R-&#956;CP)-assisted method for fabricating culture substrates with complex, microscale, and highly ordered patterns of PEG brushes presenting orthogonal &#8216;click&#8217; chemistries. Here, we describe in detail the workflow to manufacture such substrates.

Fabricating Complex Culture Substrates Using Robotic Microcontact Printing R- &#181;CP and Sequential Nucleophilic Substitution

Cell culture substrates functionalized with microscale patterns of biological ligands have immense utility in the field of tissue engineering. Here, we demonstrate the versatile and automated manufacture of tissue culture substrates with multiple, micropatterned poly(ethylene glycol) brushes presenting orthogonal chemistries that enable spatially precise and site-specific immobilization of biological ligands.

Fabricando substratos de cultura complexos usando Robotic microcontact Printing (R-μCP) e substituição nucleofílica Sequential

In tissue engineering, it is desirable to exhibit spatial control of tissue morphology and cell fate in culture on the micron scale. Culture substrates ...

Generation of Scalable, Metallic High-Aspect Ratio Nanocomposites in a Biological Liquid Medium

The goal of this protocol is to describe the synthesis of two novel biocomposites with high-aspect ratio structures. The biocomposites consist of copper and cystine, with either copper nanoparticles (CNPs) or copper sulfate contributing the metallic component. Synthesis is carried out in liquid under biological conditions (37 &#176;C) and the self-assembled composites form after 24 hr. Once formed, these composites are highly stable in both liquid media and in a dried form. The composites scale from the nano- to micro- range in length, and from a few microns to 25 nm in diameter. Field emission scanning electron microscopy with energy dispersive X-ray spectroscopy (EDX) demonstrated that sulfur was present in the NP-derived linear structures, while it was absent from the starting CNP material, thus confirming cystine as the source of sulfur in the final nanocomposites. During synthesis of these linear nano- and micro-composites, a diverse range of lengths of structures is formed in the synthesis vessel. Sonication of the liquid mixture after synthesis was demonstrated to assist in controlling average size of the structures by diminishing the average length with increased time of sonication. Since the formed structures are highly stable, do not agglomerate, and are formed in liquid phase, centrifugation may also be used to assist in concentrating and segregating formed composites.

Here we present a protocol to synthesize novel, high-aspect ratio biocomposites under biological conditions and in liquid media. The biocomposites scale from nanometers to micrometers in diameter and length, respectively. Copper nanoparticles (CNPs) and copper sulfate combined with cystine are the key components for the synthesis.

Geração de escalável e de alto-Aspect Metallic nanocompósitos índices, em um Biológico Líquido Médio

The goal of this protocol is to describe the synthesis of two novel biocomposites with high-aspect ratio structures. The biocomposites consist of copper ...

Fabricating Superhydrophobic Polymeric Materials for Biomedical Applications

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial applications. Here we describe how electrospinning or electrospraying a polymer mixture containing a biodegradable, biocompatible aliphatic polyester (e.g., polycaprolactone and poly(lactide-co-glycolide)), as the major component, doped with a hydrophobic copolymer composed of the polyester and a stearate-modified poly(glycerol carbonate) affords a superhydrophobic biomaterial. The fabrication techniques of electrospinning or electrospraying provide the enhanced surface roughness and porosity on and within the fibers or the particles, respectively. The use of a low surface energy copolymer dopant that blends with the polyester and can be stably electrospun or electrosprayed affords these superhydrophobic materials. Important parameters such as fiber size, copolymer dopant composition and/or concentration, and their effects on wettability are discussed. This combination of polymer chemistry and process engineering affords a versatile approach to develop application-specific materials using scalable techniques, which are likely generalizable to a wider class of polymers for a variety of applications.

Two- and three-dimensional superhydrophobic polymeric materials are prepared by electrospinning or electrospraying biodegradable polymers blended with a lower surface energy polymer of similar composition.

Fabricação de super-hidrofóbicas Materiais Poliméricos para aplicações biomédicas

Superhydrophobic materials, with surfaces possessing permanent or metastable non-wetted states, are of interest for a number of biomedical and industrial ...

Using Adhesive Patterning to Construct 3D Paper Microfluidic Devices

We demonstrate the use of patterned aerosol adhesives to construct both planar and nonplanar 3D paper microfluidic devices. By spraying an aerosol adhesive through a metal stencil, the overall amount of adhesive used in assembling paper microfluidic devices can be significantly reduced. We show on a simple 4-layer planar paper microfluidic device that the optimal adhesive application technique and device construction style depends heavily on desired performance characteristics. By moderately increasing the overall area of a device, it is possible to dramatically decrease the wicking time and increase device success rates while also reducing the amount of adhesive required to keep the device together. Such adhesive application also causes the adhesive to form semi-permanent bonds instead of permanent bonds between paper layers, enabling single-use devices to be non-destructively disassembled after use. Nonplanar 3D origami devices also benefit from the semi-permanent bonds during folding, as it reduces the likelihood that unrelated faces may accidently stick together. Like planar devices, nonplanar structures see reduced wicking times with patterned adhesive application vs uniformly applied adhesive.

We demonstrate the use of patterned aerosol adhesives to construct 3D paper microfluidic devices. This method of adhesive application forms semi-permanent bonds between layers, enabling single-use devices to be non-destructively disassembled after use and to ease folding complex nonplanar structures.

Usando Adhesive Padronização Construir 3D de papel microfluídicos

We demonstrate the use of patterned aerosol adhesives to construct both planar and nonplanar 3D paper microfluidic devices. By spraying an aerosol ...

High-throughput Identification of Bacteria Repellent Polymers for Medical Devices

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as contributing to antimicrobial resistance. One possible avenue for the reduction of device-associated infections is the identification of bacteria-repellent polymer coatings for these devices, which would prevent bacterial binding at the initial attachment step. A method for the identification of such repellent polymers, based on the parallel screening of hundreds of polymers using a microarray, is described here. This high-throughput method resulted in the identification of a range of promising polymers that resisted binding of various clinically relevant bacterial species individually and also as multi-species communities. One polymer, PA13 (poly(methylmethacrylate-co-dimethylacrylamide)), demonstrated significant reduction in attachment of a number of hospital isolates when coated onto two commercially available central venous catheters. The method described could be applied to identify polymers for a wide range of applications in which modification of bacterial attachment is important.

A high-throughput microarray method for the identification of polymers which reduce bacterial surface binding on medical devices is described.

High-throughput identificação de bactérias Polymers Repelente para dispositivos médicos

Medical devices are often associated with hospital-acquired infections, which place enormous strain on patients and the healthcare system as well as ...

Automated Robotic Liquid Handling Assembly of Modular DNA Devices

Recent advances in modular DNA assembly techniques have enabled synthetic biologists to test significantly more of the available &#34;design space&#34; represented by &#34;devices&#34; created as combinations of individual genetic components. However, manual assembly of such large numbers of devices is time-intensive, error-prone, and costly. The increasing sophistication and scale of synthetic biology research necessitates an efficient, reproducible way to accommodate large-scale, complex, and high throughput device construction.
Here, a DNA assembly protocol using the Type-IIS restriction endonuclease based Modular Cloning (MoClo) technique is automated on two liquid-handling robotic platforms. Automated liquid-handling robots require careful, often times tedious optimization of pipetting parameters for liquids of different viscosities (e.g. enzymes, DNA, water, buffers), as well as explicit programming to ensure correct aspiration and dispensing of DNA parts and reagents. This makes manual script writing for complex assemblies just as problematic as manual DNA assembly, and necessitates a software tool that can automate script generation. To this end, we have developed a web-based software tool, http://mocloassembly.com, for generating combinatorial DNA device libraries from basic DNA parts uploaded as Genbank files. We provide access to the tool, and an export file from our liquid handler software which includes optimized liquid classes, labware parameters, and deck layout. All DNA parts used are available through Addgene, and their digital maps can be accessed via the Boston University BDC ICE Registry. Together, these elements provide a foundation for other organizations to automate modular cloning experiments and similar protocols.
The automated DNA assembly workflow presented here enables the repeatable, automated, high-throughput production of DNA devices, and reduces the risk of human error arising from repetitive manual pipetting. Sequencing data show the automated DNA assembly reactions generated from this workflow are ~95% correct and require as little as 4% as much hands-on time, compared to manual reaction preparation.

Here, an automated workflow to perform modular DNA &#34;device&#34; assembly using a modular cloning DNA assembly method on liquid-handling robots is presented. The protocol uses an intuitive software tool for generating liquid handler picklists for combinatorial DNA device library generation, which we demonstrate using two liquid handling platforms.

Robótico líquido manipulação montagem de dispositivos modulares DNA automática

Recent advances in modular DNA assembly techniques have enabled synthetic biologists to test significantly more of the available &#34;design space&#34; ...

Multi-step Variable Height Photolithography for Valved Multilayer Microfluidic Devices

Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to entry for non-specialists who would benefit greatly from the ability to develop their own microfluidic devices to address research questions. Particularly lacking has been the open dissemination of protocols related to photolithography, a key step in the development of a replica mold for the manufacture of polydimethylsiloxane (PDMS) devices. While the fabrication of single height silicon masters has been explored extensively in literature, fabrication steps for more complicated photolithography features necessary for many interesting device functionalities (such as feature rounding to make valve structures, multi-height single-mold patterning, or high aspect ratio definition) are often not explicitly outlined. 
Here, we provide a complete protocol for making multilayer microfluidic devices with valves and complex multi-height geometries, tunable for any application. These fabrication procedures are presented in the context of a microfluidic hydrogel bead synthesizer and demonstrate the production of droplets containing polyethylene glycol (PEG diacrylate) and a photoinitiator that can be polymerized into solid beads. This protocol and accompanying discussion provide a foundation of design principles and fabrication methods that enables development of a wide variety of microfluidic devices. The details included here should allow non-specialists to design and fabricate novel devices, thereby bringing a host of recently developed technologies to their most exciting applications in biological laboratories.

Multilayer microfluidic devices often involve the fabrication of master molds with complex geometries for functionality. This article presents a complete protocol for multi-step photolithography with valves and variable height features tunable to any application. As a demonstration, we fabricate a microfluidic droplet generator capable of producing hydrogel beads.

Multi-passo fotolitografia Variável Altura para Valved multicamada microfluídicos Devices

Microfluidic systems have enabled powerful new approaches to high-throughput biochemical and biological analysis. However, there remains a barrier to ...

High-resolution Patterning Using Two Modes of Electrohydrodynamic Jet: Drop on Demand and Near-field Electrospinning

Electrohydrodynamic (EHD) jet printing has drawn attention in various fields because it can be used as a high-resolution and low-cost direct patterning tool. EHD printing uses a fluidic supplier to maintain the extruded meniscus by pushing the ink out of the nozzle tip. The electric field is then used to pull the meniscus down to the substrate to produce high-resolution patterns. Two modes of EHD printing have been used for fine patterning: continuous near-field electrospinning (NFES) and dot-based drop-on-demand (DOD) EHD printing. According to the printing modes, the requirements for the printing equipment and ink viscosity will differ. Even though two different modes can be implemented with a single EHD printer, the realization methods significantly differ in terms of ink, fluidic system, and driving voltage. Consequently, without a proper understanding of the jetting requirements and limitations, it is difficult to obtain the desired results. The purpose of this paper is to present a guideline so that inexperienced researchers can reduce the trial and error efforts to use the EHD jet for their specific research and development purposes. To demonstrate the fine-patterning implementation, we use Ag nanoparticle ink for the conductive patterning in the protocol. In addition, we also present the generalized printing guidelines that can be used for other types of ink for various fine-patterning applications.

Here, we present a protocol to produce high-resolution conductive patterns using electrohydrodynamic (EHD) jet printing. The protocol includes two modes of EHD jet printing: the continuous near-field electrospinning (NFES) and the dot-based drop-on-demand (DOD) EHD printing.

De alta resolução padronização usando dois modos de Jet Electrohydrodynamic: queda na demanda e campo próximo eletrofiação

Electrohydrodynamic (EHD) jet printing has drawn attention in various fields because it can be used as a high-resolution and low-cost direct patterning ...

Fabricating a Kidney Cortex Extracellular Matrix-Derived Hydrogel

Extracellular matrix (ECM) provides important biophysical and biochemical cues to maintain tissue homeostasis. Current synthetic hydrogels offer robust mechanical support for in vitro cell culture but lack the necessary protein and ligand composition to elicit physiological behavior from cells. This manuscript describes a fabrication method for a kidney cortex ECM-derived hydrogel with proper mechanical robustness and supportive biochemical composition. The hydrogel is fabricated by mechanically homogenizing and solubilizing decellularized human kidney cortex ECM. The matrix preserves native kidney cortex ECM protein ratios while also enabling gelation to physiological mechanical stiffnesses. The hydrogel serves as a substrate upon which kidney cortex-derived cells can be maintained under physiological conditions. Furthermore, the hydrogel composition can be manipulated to model a diseased environment which enables the future study of kidney diseases.

Here we present a protocol to fabricate a kidney cortex extracellular matrix-derived hydrogel to retain the native kidney extracellular matrix (ECM) structural and biochemical composition. The fabrication process and its applications are described. Finally, a perspective on using this hydrogel to support kidney-specific cellular and tissue regeneration and bioengineering is discussed.

Fabricando um rim córtex Extracellular Matrix-derivado hidrogel

Extracellular matrix (ECM) provides important biophysical and biochemical cues to maintain tissue homeostasis. Current synthetic hydrogels offer robust ...