Este material está basado en trabajo apoyado por el Departamento de Energía de EE.UU., Ciencias de los Materiales e Ingeniería de la División (N º Premio DEFG-02-07ER46471) y el Departamento de Energía de Energía Centro de Investigación en Materiales Light-Interacciones en Conversión de Energía (Laudo No. DE-SC0001293 ), y se benefició de acceso al Centro de Microanálisis de Materiales en el Frederick Seitz Laboratorio de Investigación de Materiales (FSMRL).

1. Introducción <ol><li> Este trabajo demuestra la 1D, 2D, 3D e impresión de microelectrodos conductor a través de escritura directa de montaje. </li><li> Escritura directa de la Asamblea es un método de construcción de 1D a 3D estructuras impresas por el depósito de tintas concentradas a través de boquillas finas. </li><li> Nuestro sistema consiste en un ordenador controlado por la etapa de traducción de 3 ejes, un depósito de tinta y la punta, y 10x para imágenes telescópicas (Figura 1). </li><li> Escritura directa de la Asamblea es un método de impresión filamentosas en el que las tintas concentradas son expulsados ​​a través de boquillas cilíndricas, cuyos diámetros oscilan desde 0,1 hasta 250 m (Figura 2). Cabe destacar que, debido a las características viscoelásticas de tinta, escritura directa de montaje permite el auto-apoyo que abarca características (Figura 3). Hasta la fecha, una amplia gama de tintas, incluidos los compuestos de cerámica de 6,7, 8-10 orgánicos, metálicos 11-15, 16,17 poliméricos y materiales sol-gel 18,19 han sidodesarrollado para este método de impresión (Figura 4). </li></ol> 2. Preparación de las tintas de nanopartículas de plata de alta concentración <ol><li> Tintas de nanopartículas de plata se prepara disolviendo en primer lugar una mezcla de 5.000 y 50.000 de peso molecular (ácido acrílico) poli en una mezcla de 50 g de agua y 40 g de dietanolamina (Video 2.1). </li><li> El polímero actúa como un agente de recubrimiento para controlar el tamaño de las nanopartículas de plata. </li><li> A continuación, una solución acuosa de nitrato de plata se inyecta en la solución de polímero. Después de la adición, una luz de solución transparente amarillo se obtiene (Video 2.2). </li><li> Después de agitar durante 24 horas a temperatura ambiente, la solución se desarrolla un color rojizo-marrón (Video 2.3), que coincide con la formación de nanopartículas de plata con un diámetro de 5 nm, según lo determinado por microscopía electrónica de transmisión. </li><li> A continuación, la solución se somete a sonicación a 65 ° C en un baño de agua durante 2 horas para el crecimiento de partículas aún más (Video 2.4). </li><li> After sonicación, la solución se transfiere a un vaso de 500 ml y se enfrió a temperatura ambiente. Entonces, 300 ml de etanol se valora a razón de 30 ml / min. Dado que el etanol es un mal disolvente para el poli (ácido acrílico) limitación de agente, las partículas rápidamente coagulan y precipitan de la solución (Video 2.5). </li><li> Después de decantar el sobrenadante, el precipitado se recoge en un tubo de centrífuga y se centrifuga a 9000 rpm durante 20 minutos (Video 2.6). </li><li> Después de este paso, una tinta de nanopartículas de plata de alta concentración con una carga de sólidos de ~ 85% en peso, se obtiene (Video 2.7). </li><li> Un mayor control de viscosidad de la tinta y el módulo de elasticidad se puede lograr mediante la dilución, seguido por la homogeneización. Por ejemplo, una solución humectante, tales como el etilenglicol, se puede agregar a la tinta y luego homogeneizada a 2000 rpm durante 3 minutos usando un mezclador de homogeneización Thinky. Después de este proceso, una tinta uniforme de azul a color magenta se obtiene (Video 2.8). </li><li> La imagen TEM muestrananopartículas de plata obtenidas por este procedimiento de síntesis (Figura 5_left). Las partículas tienen un diámetro medio de 20 nm con una distribución de tamaño de 50-50 nm. Estructuras impresas requieren post-recocido para mejorar su conductividad. Después del recocido a 250 ° C durante menos de 30 minutos, la forma de las nanopartículas de plata microelectrodos conductor con una resistencia eléctrica se acerca a 10 -5 Ω • cm (figura de la derecha 5_bottom). La evolución microestructural de los microelectrodos de plata impresas en función de la temperatura de recocido se muestra en la figura de la derecha 5_top. A medida que la temperatura aumenta de 150 ° a 550 ° C, los microelectrodos someterse a la densificación con una contracción volumétrica total de ~ 30% 11. </li><li> La reología de tinta, que depende fuertemente de su carga de sólidos, determina su capacidad de impresión. El aumento de viscosidad de la tinta con la carga cada vez mayor de sólidos (Figura 6). Debido a diluir las tintas con resultado de baja viscosidad en una importante difusión lateral, Concentrtintas cuencia a un carga de sólidos de 70 a 85% en peso son necesarias para la impresión de los filamentos de tinta plana y de expansión. </li><li> La tinta módulo de elasticidad se incrementa con el aumento de carga de sólidos (Figura 7). En la región viscoelástica lineal, el módulo elástico se eleva casi tres órdenes de magnitud que la carga de sólidos aumentos de 60 a 75% en peso. Un módulo elástico mínimo de 2.000 Pa es necesaria para producir la auto-apoyo o que abarca características. </li></ol> 3. Escritura directa de la Asamblea <ol><li> Escritura directa de montaje se lleva a cabo por primera carga de la tinta en una jeringa. Después de fijar una boquilla de deposición, la tinta cargada jeringa está montado en la fase de impresión de 3 ejes (Video 3.1). </li><li> Mediante un programa informático, los diseños arbitrarios, incluso lineal, plana, y el complejo de estructuras tridimensionales se pueden generar fácilmente (Video 3.2). </li><li> A continuación, la altura de la boquilla se ajusta con la ayuda de la lente del telescopio, con un zoom de 10x (Video 3.3). </li&gt; <li> Después de aplicar la presión con un aire de propulsión de líquido del sistema de distribución, la tinta se deposita sobre el sustrato con una velocidad de impresión controlada (Video 3.4). La presión requerida depende de la reología de tinta, diámetro de la boquilla y la velocidad de impresión, pero los valores típicos de rango 10 a 100 psi a 20-500 m / s. Esta impresión se realiza en el aire a temperatura ambiente. El uso de este procedimiento de impresión, la impresión de microelectrodos de plata en diferentes formatos y escalas de tamaño se demuestra. </li><li> Por ejemplo, la impresión de las redes conductoras de plata con un espaciado entre líneas de centro a centro de 100 micras, modelado por una boquilla de 5 micras sobre un sustrato de oblea de silicio se demuestra (Video 3.5). </li><li> Además, este video se muestra cómo crear una estructura de relación de aspecto cilíndrico de alta por una boquilla de 30 micras utilizando un método de impresión capa a capa (Video 3.6). </li><li> Además, la impresión omnidireccional de microelectrodos de plata entre dos sustratos de cristal compensado por una altura de 1 mm de diferenc se demuestra mediante una boquilla de 30 micras (Video 3.7). </li><li> Totalmente independiente, vertical impresa microspikes de plata puede ser creada por una boquilla de 30 micras sobre un sustrato de la oblea de Si (Video 3.8). </li><li> Finalmente, este video muestra la escritura directa de un microelectrodo de plata que abarca el uso de una boquilla de 10 micras (Video 3.9). La función de impresión pueden abarcar distancias de hasta un centímetro con un mínimo de caída o el pandeo. </li></ol> 4. Los resultados representativos: Hemos preparado una tinta de plata de alta concentración de nanopartículas y demostró las características conductoras impresas con motivos planas y 3D para aplicaciones electrónicas y optoelectrónicas con una resolución de impresión de ~ 2 a 30 micras. Por ejemplo, la figura 8 muestra la resolución de impresión de esta técnica. Características impresas con un ancho mínimo de electrodos de ~ 2 m (1,4 m de espesor) se obtienen en un solo paso utilizando una boquilla de 1 m 11. Figura 9 muestras transparentes las redes conductoras de plata, modelado por una boquilla de 5 micras en una película de poliamida flexible de 12. Los textos impresos debajo de las rejillas son claramente visibles. Estas rejillas de plata transparente podría ser una alternativa atractiva para la realización de óxido transparente (TCO) de materiales. Impresión de conformación a una sustratos no planos también se ha habilitado con este método. La figura 10 muestra la impresión de conformación de una antena en 3D eléctricamente pequeñas. Una boquilla de 100 micras de metal se utiliza para imprimir los patrones de línea serpenteante en la superficie de un vaso hemisferio 13. Este enfoque puede encontrar varias aplicaciones, incluidas las antenas implantable y portátiles, dispositivos electrónicos y sensores. Aplicaciones de micro-electrodos de plata de expansión en tres dimensiones la energía fotovoltaica y los diodos emisores de luz se muestran (Figura 11-14). En primer lugar, la Figura 11 es un ejemplo de silicio cubierta esférica. Esta película tenue con una t de 2 micrashickness puede ser de alambre unido a un circuito externo mediante la impresión de omnidireccional 14. Este método utiliza la presión de contacto mínimo, lo cual es muy ventajoso para dispositivos delicados. A continuación, figura 12 muestra un ejemplo de la impresión de una interconexión de expansión de una serie de microcélulas solares de silicio en el que los elementos de silicio microribbon están separados por 33 m distancia 15. A continuación, figura 13 muestra las interconexiones de plata para el arseniuro de galio con sede matriz de LED de 4 por 4 píxeles, donde cada píxel (500 x 500 x 2,5 m 3) está separada 200 micras aparte 11. La imagen inferior muestra la matriz de LED, que emiten luz de color rojo uniforme bajo una polarización aplicada de 6 V de un solo píxel. La posibilidad de imprimir los electrodos que abarca permite la interconexión de múltiples capas sin el uso de capas de soporte o de sacrificios (imágenes superiores). Como una demostración final, figura 14 muestra las imágenes SEM para el complejo de micro 3Dred roperiodic plata impreso por una boquilla de 5μm. <img alt="Figura 1" src="/files/ftp_upload/3189/3189fig1.jpg" /> Figura 1. Óptico de la imagen de los aparatos de la escritura directa de tinta. <img alt="Figura 2" src="/files/ftp_upload/3189/3189fig2.jpg" /> Figura 2. Escritura de tinta directa de una característica de filamento. <img alt="Figura 3" src="/files/ftp_upload/3189/3189fig3.jpg" /> Figura 3. Escritura de tinta directa de auto-apoyo a las características de expansión. <img alt="Figura 4" src="/files/ftp_upload/3189/3189fig4.jpg" /> Figura 4. Diseños de tinta para la escritura de tinta directa. Una amplia gama de tintas viscoelástico concentrados se han desarrollado para la escritura directa de las estructuras 3D de planos y complejos con las características de la microescala. <img alt="Figura 5" src="/files/ftp_upload/3189/3189fig5.jpg" /> Figura 5. (Izquierda) microscopía electrónica de transmisión (TEM) la imagen de nanopartículas de plata. (Arriba a la derecha) SEM imágenes de microelectrodos patrón de plata con una boquilla de 15 micras en función de la temperatura de recocido. (Abajo a la derecha) la resistividad eléctrica de microelectrodos de plata en función de la temperatura de recocido y el tiempo. <img alt="Figura 6" src="/files/ftp_upload/3189/3189fig6.jpg" /> Figura 6. Viscosidad aparente (η) de las tintas de nanopartículas de plata en función de la carga de sólidos. <img alt="Figura 7" src="/files/ftp_upload/3189/3189fig7.jpg" /> Figura 7. Shear módulo elástico (G &#39;) en función del esfuerzo de corte para las tintas de nanopartículas de plata de diferentes carga de sólidos. <img alt="Figura 8" src="/files/ftp_upload/3189/3189fig8.jpg" /> Figura 8. SEM imágenes de matrices planas de microelectrodos de plata con dibujosen una oblea de silicio con una boquilla de 1-m. <img alt="Figura 9" src="/files/ftp_upload/3189/3189fig9.jpg" /> Figura 9. Óptico de la imagen de las redes de plata conductora transparente (izquierda) y las imágenes SEM de las redes de impresión en función de la densidad de líneas (derecha). <img alt="Figura 10" src="/files/ftp_upload/3189/3189fig10.jpg" /> Figura 10. Óptico de la imagen capturada durante la impresión de conformación de las antenas eléctricamente pequeñas sobre un sustrato de vidrio hemisférico. <img alt="Figura 11" src="/files/ftp_upload/3189/3189fig11.jpg" /> Figura 11. Óptico de la imagen obtenida durante la impresión de que abarca microelectrodos de plata sobre una delgada (2-m) cáscara de silicio esférico. <img alt="Figura 12" src="/files/ftp_upload/3189/3189fig12.jpg" /> Figura 12. Imagen de SEM de un microelectrodo de plata que abarca impresa en una de silicio paralar microcelular matriz. <img alt="Figura 13" src="/files/ftp_upload/3189/3189fig13.jpg" /> Figura 13. SEM imágenes (arriba) y óptica de la imagen (abajo) de un 4-por-4 matriz de chips LED conectados entre sí por microelectrodos de plata. <img alt="Figura 14" src="/files/ftp_upload/3189/3189fig14.jpg" /> Figura 14. Imagen SEM de la red 3D de plata microperiodic.

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Mater. 21, 47-54 (2011).</li><li>Wu, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct-write+assembly+of+biomimetic+microvascular+networks+for+efficient+fluid+transport.">Direct-write assembly of biomimetic microvascular networks for efficient fluid transport.</a> Soft. Matter. 6, 739-742 (2010).</li><li>Wu, W., DeConinck, A., Lewis, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Omnidirectional+Printing+of+3D+Microvascular+Networks.">Omnidirectional Printing of 3D Microvascular Networks.</a> Adv. Mater. 23, H178-H183 (2011).</li></ol>

No hay conflictos de interés declarado.

Convencionales gota enfoques basados ​​en la impresión, como la impresión de inyección de tinta, se limitan a la fabricación de electrodos plana con relación de aspecto baja debido a la naturaleza diluir y de baja viscosidad de las tintas utilizadas. Recientemente, el dip-pen nanolitografía (DPN) y 20-22 e 23-25 ​​por chorro de tinta se han utilizado a las funciones de patrón de conducción. Estas rutas también emplean tintas diluidas, de baja viscosidad. Pearton y compañeros de trabajo utilizados DPN para depositar una tinta de nanopartículas de plata comercialmente disponible en velocidades de escritura de hasta 1600 m s-1 anchos y una línea de aproximadamente 0,5 m 22. Sin embargo, la fabricación de patrones reproducibles en grandes áreas aún no se ha demostrado por este método. Tintas de nanopartículas de plata también se han depositado mediante la impresión de e-jet para formar trazas conductoras con anchos de línea de ~ 1,5 m 25. Sin embargo, como con la impresión de inyección de tinta, no homogénea las características impresas pueden surgir debido a la formación de gotas de satélite y no uniforme caída drying 24,25. Como se demostró anteriormente, escritura directa asamblea de nanopartículas de plata se concentró tintas supera estas limitaciones a través de un método de impresión basado en filamentos. Esta técnica permite la fabricación de micro-electrodos conductores con una alta relación de aspecto (H / W ≈ 1,0) en un único pase que permite la creación de 1D, 2D, 3D y arquitecturas. El tamaño de las características de impresión depende de diámetro de la boquilla, la carga de tinta sólidos, la presión aplicada, y la velocidad de impresión. Hasta la fecha, los rastros conductores tan pequeño como ~ 2 micras se han modelado con una boquilla de 1 m a una velocidad moderada (&lt;2 mm s -1). Mediante la adaptación de la composición de la tinta y la geometría de la boquilla, la velocidad máxima de impresión de más de 10 cm s -1 son posibles. Sin embargo, la alta velocidad de impresión de la utilización de boquillas finas (&lt;5 micras) sigue siendo un reto importante. Para demostrar las aplicaciones de la escritura directa de la Asamblea, que fabrica redes de conducción, ELectrically antenas pequeñas, células solares y diodos emisores de luz con electrodos impresos plana y que abarca (Figura 8-14). En particular, nuestro enfoque no se limita a la creación de estructuras metálicas. El uso de diseños de tinta, como los basados ​​en la fibroína de seda, de hidrogel y fugitivo tintas orgánicas, hemos construido andamios 3D y redes microvasculares de la ingeniería de tejidos y cultivos celulares a través de escritura directa de montaje 26-30. Mirando hacia el futuro, hay muchas oportunidades y desafíos. Nuevos avances requieren nuevos diseños de tinta, un mejor modelado de la dinámica de flujo de tinta y mejora de los sistemas robóticos y de control. Gran área de fabricación de estructuras 1D a 3D con un alto rendimiento y resolución nanométrica (&lt;100 nm) sigue siendo un reto importante.

<table border="1"><tr><td> Nombre del reactivo </td><td> Empresa </td><td> Número de catálogo </td><td> Comentarios </td></tr><tr><td> Poli (ácido acrílico) </td><td> Polysciences, Inc. </td><td> 06519 </td><td> mw 5000 g / mol </td></tr><tr><td> Poli (ácido acrílico) </td><td> Polysciences, Inc. </td><td> 00627 </td><td> mw 50.000 g / mol </td></tr><tr><td> Nitrato de plata </td><td> Sigma-Aldrich </td><td> 209139 </td><td> Fuente de plata </td></tr><tr><td> Dietanolamina </td><td> Sigma-Aldrich </td><td> D8885 </td><td> Disolvente / Agente reductor </td></tr><tr><td> Etilenglicol </td><td> Sigma-Aldrich </td><td> 102466 </td><td> Humectante </td></tr><tr><td> Sonicater </td><td> Fisher Scientific </td><td> FS30H </td><td> - </td></tr><tr><td> Centrífugo </td><td> Beckman Coulter </td><td> Avanti TM J-25 I </td><td> - </td></tr><tr><td> Etapa robótica </td><td> Aerotech Inc. </td><td> ABL 900010 </td><td> Movimiento de 3 ejes </td></tr><tr><td>Jeringa barril </td><td> EFD Inc. </td><td> 5109LBP-B </td><td> 3 ml </td></tr><tr><td> Boquilla </td><td> EFD Inc. </td><td> - </td><td> id = 0,1 a 250 micras </td></tr><tr><td> Dispensador </td><td> EFD Inc. </td><td> 800 </td><td> Neumático </td></tr><tr><td> Diseño de software </td><td> Diseñado </td><td> - </td><td> Mingjie Xu </td></tr></table>

planar and three-dimensional printing of conductive inks

Electrónica impresa se ​​basan en el bajo coste, rutas de fabricación de gran superficie para crear flexibles o multidimensional electrónicos, optoelectrónicos y dispositivos biomédicos 1-3. En este trabajo, nos centramos en un (1D), dos (2D) y tridimensional (3D) de impresión de tintas conductoras metálicas en forma de microelectrodos flexible, extensible y de expansión. Escritura directa de montaje 4,5 es una técnica de impresión de 1-a-3D que permite la fabricación de características que van desde líneas simples a estructuras complejas por la deposición de tintas concentradas a través de boquillas finas (~ 0,1 a 250 micras). Este método de impresión consta de una etapa de traducción controlado por ordenador en 3 ejes, un depósito de tinta y la punta, y la lente de 10x telescópica para la visualización. A diferencia de la impresión de inyección de tinta, un proceso basado en gotas, de escritura directa de montaje consiste en la extrusión de filamentos de tinta ya sea dentro o fuera del plano. Los filamentos impresos suelen ajustarse al tamaño de la boquilla. Hence, características micro (&lt;1 m) se pueden modelar y montados en grandes arreglos y las arquitecturas multidimensionales. En este trabajo, lo primero que sintetizar una tinta de nanopartículas de plata de alta concentración para la impresión de planos y 3D a través de escritura directa de montaje. A continuación, un protocolo estándar para la impresión de microelectrodos en motivos multidimensional se demuestra. Por último, las aplicaciones de micro-electrodos impresos para las antenas eléctricamente pequeñas, células solares y diodos emisores de luz se destacan.

Watch this Scientific Journal Video about Planar and Three-Dimensional Printing of Conductive Inks at JoVE.com

Planar and Three-Dimensional Printing of Conductive Inks

Impresión de planos y tridimensionales de los conductores tintas metálicas se describe. Nuestro enfoque ofrece nuevas vías para la fabricación de impresos electrónicos, optoelectrónicos y dispositivos biomédicos en los diseños inusuales en la microescala.

Impresión plana y tridimensional de tintas conductoras

Printed electronics rely on low-cost, large-area fabrication routes to create flexible or multidimensional electronic, optoelectronic, and biomedical ...

planar-and-three-dimensional-printing-of-conductive-inks

Research

JoVE Journal

Bioengineering

37.0K vistas.  University of Illinois at Urbana-Champaign. Impresión de planos y tridimensionales de los conductores tintas metálicas se describe. Nuestro enfoque ofrece nuevas vías para la fabricación de impresos electrónicos, optoelectrónicos y dispositivos biomédicos en los diseños inusuales en la microescala.

Video: Planar and Three-Dimensional Printing of Conductive Inks

Three-dimensional Optical-resolution Photoacoustic Microscopy

Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As the mainstays of in vivo three-dimensional (3-D) optical microscopy, single-/multi-photon fluorescence microscopy and optical coherence tomography (OCT) have demonstrated their extraordinary sensitivities to fluorescence and optical scattering contrasts, respectively. However, the optical absorption contrast of biological tissues, which encodes essential physiological/pathological information, has not yet been assessable. 
The emergence of biomedical photoacoustics has led to a new branch of optical microscopy optical-resolution photoacoustic microscopy (OR-PAM)1, where the optical irradiation is focused to the diffraction limit to achieve cellular1 or even subcellular2 level lateral resolution. As a valuable complement to existing optical microscopy technologies, OR-PAM brings in at least two novelties. First and most importantly, OR-PAM detects optical absorption contrasts with extraordinary sensitivity (i.e., 100%). Combining OR-PAM with fluorescence microscopy3 or with optical-scattering-based OCT4 (or with both) provides comprehensive optical properties of biological tissues. Second, OR-PAM encodes optical absorption into acoustic waves, in contrast to the pure optical processes in fluorescence microscopy and OCT, and provides background-free detection. The acoustic detection in OR-PAM mitigates the impacts of optical scattering on signal degradation and naturally eliminates possible interferences (i.e., crosstalks) between excitation and detection, which is a common problem in fluorescence microscopy due to the overlap between the excitation and fluorescence spectra. 
Unique for optical absorption imaging, OR-PAM has demonstrated broad biomedical applications since its invention, including, but not limited to, neurology5, 6, ophthalmology7, 8, vascular biology9, and dermatology10. In this video, we teach the system configuration and alignment of OR-PAM as well as the experimental procedures for in vivo functional microvascular imaging.

Optical-resolution photoacoustic microscopy (OR-PAM) is an emerging technology capable of imaging optical absorption contrasts in vivo with cellular resolution and sensitivity. Here, we provide a visualized instruction on the experimental protocols of OR-PAM, including system configuration, system alignment, typical in vivo experimental procedures, and functional imaging schemes.

Tridimensional óptico resolución microscopía fotoacústica

Optical microscopy, providing valuable insights at the cellular and organelle levels, has been widely recognized as an enabling biomedical technology. As ...

Investigación

Bioingeniería

Alginate Hydrogels for Three-Dimensional Organ Culture of Ovaries and Oviducts

Ovarian cancer is the fifth leading cause of cancer deaths in women and has a 63% mortality rate in the United States1. The cell type of origin for ovarian cancers is still in question and might be either the ovarian surface epithelium (OSE) or the distal epithelium of the fallopian tube fimbriae2,3. Culturing the normal cells as a primary culture in vitro will enable scientists to model specific changes that might lead to ovarian cancer in the distinct epithelium, thereby definitively determining the cell type of origin. This will allow development of more accurate biomarkers, animal models with tissue-specific gene changes, and better prevention strategies targeted to this disease.
Maintaining normal cells in alginate hydrogels promotes short term in vitro culture of cells in their three-dimensional context and permits introduction of plasmid DNA, siRNA, and small molecules. By culturing organs in pieces that are derived from strategic cuts using a scalpel, several cultures from a single organ can be generated, increasing the number of experiments from a single animal. These cuts model aspects of ovulation leading to proliferation of the OSE, which is associated with ovarian cancer formation. Cell types such as the OSE that do not grow well on plastic surfaces can be cultured using this method and facilitate investigation into normal cellular processes or the earliest events in cancer formation4.
Alginate hydrogels can be used to support the growth of many types of tissues5. Alginate is a linear polysaccharide composed of repeating units of &beta;-D-mannuronic acid and &alpha;-L-guluronic acid that can be crosslinked with calcium ions, resulting in a gentle gelling action that does not damage tissues6,7. Like other three-dimensional cell culture matrices such as Matrigel, alginate provides mechanical support for tissues; however, proteins are not reactive with the alginate matrix, and therefore alginate functions as a synthetic extracellular matrix that does not initiate cell signaling5. The alginate hydrogel floats in standard cell culture medium and supports the architecture of the tissue growth in vitro.
A method is presented for the preparation, separation, and embedding of ovarian and oviductal organ pieces into alginate hydrogels, which can be maintained in culture for up to two weeks. The enzymatic release of cells for analysis of proteins and RNA samples from the organ culture is also described. Finally, the growth of primary cell types is possible without genetic immortalization from mice and permits investigators to use knockout and transgenic mice.

Culture of normal cells in their three-dimensional context represents an alternative method to study early events required for cellular transformation and tumorigenesis. This method is used to grow normal ovarian and oviductal cells to study early events in ovarian cancer formation.

Los hidrogeles de alginato para la cultura del órgano en tres dimensiones de los ovarios y oviductos

Ovarian cancer is the fifth leading cause of cancer deaths in women and has a 63% mortality rate in the United States1. The cell type of origin for ...

Investigating the Three-dimensional Flow Separation Induced by a Model Vocal Fold Polyp

The fluid-structure energy exchange process for normal speech has been studied extensively, but it is not well understood for pathological conditions. Polyps and nodules, which are geometric abnormalities that form on the medial surface of the vocal folds, can disrupt vocal fold dynamics and thus can have devastating consequences on a patient&#39;s ability to communicate. Our laboratory has reported particle image velocimetry (PIV) measurements, within an investigation of a model polyp located on the medial surface of an in&#160;vitro driven vocal fold model, which show that such a geometric abnormality considerably disrupts the glottal jet behavior. This flow field adjustment is a likely reason for the severe degradation of the vocal quality in patients with polyps. A more complete understanding of the formation and propagation of vortical structures from a geometric protuberance, such as a vocal fold polyp, and the resulting influence on the aerodynamic loadings that drive the vocal fold dynamics, is necessary for advancing the treatment of this pathological condition. The present investigation concerns the three-dimensional flow separation induced by a wall-mounted prolate hemispheroid with a 2:1 aspect ratio in cross flow, i.e. a model vocal fold polyp, using an oil-film visualization technique. Unsteady, three-dimensional flow separation and its impact of the wall pressure loading are examined using skin friction line visualization and wall pressure measurements.

Vocal fold polyps can disrupt vocal fold dynamics and thus can have devastating consequences on a patient&#39;s ability to communicate. Three-dimensional flow separation induced by a wall-mounted model polyp and its impact on the wall pressure loading are examined using particle image velocimetry, skin friction line visualization, and wall pressure measurements.

Investigación De La Separación De Flujo Tridimensional Inducida Por Un Pólipo Modelo De Pliegue Vocal

The fluid-structure energy exchange process for normal speech has been studied extensively, but it is not well understood for pathological conditions. ...

Human Cartilage Tissue Fabrication Using Three-dimensional Inkjet Printing Technology

Bioprinting, which is based on thermal inkjet printing, is one of the most attractive enabling technologies in the field of tissue engineering and regenerative medicine. With digital control&#160;cells, scaffolds, and growth factors can be precisely deposited to the desired two-dimensional (2D) and three-dimensional (3D) locations rapidly. Therefore, this technology is an ideal approach to fabricate tissues mimicking their native anatomic structures. In order to engineer cartilage with native zonal organization, extracellular matrix composition (ECM), and mechanical properties, we developed a bioprinting platform using a commercial inkjet printer with simultaneous photopolymerization capable for 3D cartilage tissue engineering. Human chondrocytes suspended in poly(ethylene glycol) diacrylate (PEGDA) were printed for 3D neocartilage construction via layer-by-layer assembly. The printed cells were fixed at their original deposited positions, supported by the surrounding scaffold in simultaneous photopolymerization. The mechanical properties of the printed tissue were similar to the native cartilage. Compared to conventional tissue fabrication, which requires longer UV exposure, the viability of the printed cells with simultaneous photopolymerization was significantly higher. Printed neocartilage demonstrated excellent glycosaminoglycan (GAG) and collagen type II production, which was consistent with gene expression. Therefore, this platform is ideal for accurate cell distribution and arrangement for anatomic tissue engineering.

The methods described in this paper show how to convert a commercial inkjet printer into a bioprinter with simultaneous UV polymerization. The printer is capable of constructing 3D tissue structure with cells and biomaterials. The study demonstrated here constructed a 3D neocartilage.

El cartílago humano Tissue Fabrication Usando tridimensional Tecnología de impresión inyección de tinta

Bioprinting, which is based on thermal inkjet printing, is one of the most attractive enabling technologies in the field of tissue engineering and ...

Analysis of Cell Migration within a Three-dimensional Collagen Matrix

The ability to migrate is a hallmark of various cell types and plays a crucial role in several physiological processes, including&#160;embryonic development, wound healing, and immune responses. However, cell migration is also a key mechanism in cancer enabling these cancer cells to detach from the primary tumor to start metastatic spreading. Within the past years various cell migration assays have been developed to analyze the migratory behavior of different cell types. Because the locomotory behavior of cells markedly differs between a two-dimensional (2D) and three-dimensional (3D) environment it can be assumed that the analysis of the migration of cells that are embedded within a 3D environment would yield in more significant cell migration data. The advantage of the described 3D collagen matrix migration assay is that cells are embedded within a physiological 3D network of collagen fibers representing the major component of the extracellular matrix. Due to time-lapse video microscopy real cell migration is measured allowing the determination of several migration parameters as well as their alterations in response to pro-migratory factors or inhibitors. Various cell types could be analyzed using this technique, including lymphocytes/leukocytes, stem cells, and tumor cells. Likewise, also cell clusters or spheroids could be embedded within the collagen matrix concomitant with analysis of the emigration of single cells from the cell cluster/ spheroid into the collagen lattice. We conclude that the 3D collagen matrix migration assay is a versatile method to analyze the migration of cells within a physiological-like 3D environment.

Cell migration is a biological phenomenon that is involved in a plethora of physiological, such as wound healing and immune responses, and pathophysiological processes, like cancer. The 3D-collagen matrix migration assay is a versatile tool to analyze the migratory properties of different cell types within in a 3D physiological-like environment.

Análisis de la migración de células dentro de una matriz de colágeno tridimensional

The ability to migrate is a hallmark of various cell types and plays a crucial role in several physiological processes, including&#160;embryonic ...

Generation of a Three-dimensional Full Thickness Skin Equivalent and Automated Wounding

In vitro models are a cost effective and ethical alternative to study cutaneous wound healing processes. Moreover, by using human cells, these models reflect the human wound situation better than animal models. Although two-dimensional models are widely used to investigate processes such as cellular migration and proliferation, models that are more complex are required to gain a deeper knowledge about wound healing. Besides a suitable model system, the generation of precise and reproducible wounds is crucial to ensure comparable results between different test runs. In this study, the generation of a three-dimensional full thickness skin equivalent to study wound healing is shown. The dermal part of the models is comprised of human dermal fibroblast embedded in a rat-tail collagen type I hydrogel. Following the inoculation with human epidermal keratinocytes and consequent culture at the air-liquid interface, a multilayered epidermis is formed on top of the models. To study the wound healing process, we additionally developed an automated wounding device, which generates standardized wounds in a sterile atmosphere.

The goal of this protocol is to build up a three-dimensional full thickness skin equivalent, which resembles natural skin. With a specifically constructed automated wounding device, precise and reproducible wounds can be generated under maintenance of sterility.

Generación de una tridimensional grosor de la piel completa y automatizada Equivalente Heridas

In vitro models are a cost effective and ethical alternative to study cutaneous wound healing processes. Moreover, by using human cells, these models ...

Preparation and Analysis of In Vitro Three Dimensional Breast Carcinoma Surrogates

Three dimensional (3D) culture is a more physiologically relevant method to model cell behavior in vitro than two dimensional culture. Carcinomas, including breast carcinomas, are complex 3D tissues composed of cancer epithelial cells and stromal components, including fibroblasts and extracellular matrix (ECM). Yet most in vitro models of breast carcinoma consist only of cancer epithelial cells, omitting the stroma and, therefore, the 3D architecture of a tumor in vivo. Appropriate 3D modeling of carcinoma is important for accurate understanding of tumor biology, behavior, and response to therapy. However, the duration of culture and volume of 3D models is limited by the availability of oxygen and nutrients within the culture. Herein, we demonstrate a method in which breast carcinoma epithelial cells and stromal fibroblasts are incorporated into ECM to generate a 3D breast cancer surrogate that includes stroma and can be cultured as a solid 3D structure or by using a perfusion bioreactor system to deliver oxygen and nutrients. Following setup and an initial growth period, surrogates can be used for preclinical drug testing. Alternatively, the cellular and matrix components of the surrogate can be modified to address a variety of biological questions. After culture, surrogates are fixed and processed to paraffin, in a manner similar to the handling of clinical breast carcinoma specimens, for evaluation of parameters of interest. The evaluation of one such parameter, the density of cells present, is explained, where ImageJ and CellProfiler image analysis software systems are applied to photomicrographs of histologic sections of surrogates to quantify the number of nucleated cells per area. This can be used as an indicator of the change in cell number over time or the change in cell number resulting from varying growth conditions and treatments.

Preparation and Analysis of In Vitro Three Dimensional Breast Carcinoma Surrogates

We demonstrate a method to generate 3D breast cancer surrogates, which can be cultured using a perfusion bioreactor system to deliver oxygen and nutrients. Following growth, surrogates are fixed and processed to paraffin for evaluation of parameters of interest. The evaluation of one such parameter, cell density, is explained.

Preparación y análisis de<em&gt; In Vitro</em&gt; Tres de mama Carcinoma de dimensiones Surrogates

Three dimensional (3D) culture is a more physiologically relevant method to model cell behavior in vitro than two dimensional culture. Carcinomas, ...

Engineering Three-dimensional Epithelial Tissues Embedded within Extracellular Matrix

The architecture of branched organs such as the lungs, kidneys, and mammary glands arises through the developmental process of branching morphogenesis, which is regulated by a variety of soluble and physical signals in the microenvironment. Described here is a method created to study the process of branching morphogenesis by forming engineered three-dimensional (3D) epithelial tissues of defined shape and size that are completely embedded within an extracellular matrix (ECM). This method enables the formation of arrays of identical tissues and enables the control of a variety of environmental factors, including tissue geometry, spacing, and ECM composition. This method can also be combined with widely used techniques such as traction force microscopy (TFM) to gain more information about the interactions between cells and their surrounding ECM. The protocol can be used to investigate a variety of cell and tissue processes beyond branching morphogenesis, including cancer invasion.

This manuscript describes a soft lithography-based technique to engineer uniform arrays of three-dimensional (3D) epithelial tissues of defined geometry surrounded by extracellular matrix. This method is amenable to a wide variety of cell types and experimental contexts and allows for high-throughput screening of identical replicates.

Ingeniería tridimensionales epiteliales tejidos embebidos dentro de la matriz extracelular

The architecture of branched organs such as the lungs, kidneys, and mammary glands arises through the developmental process of branching morphogenesis, ...

Culturing Mammalian Cells in Three-dimensional Peptide Scaffolds

A useful technique for culturing cells in a self-assembling nanofiber three-dimensional (3D) scaffold is described. This culture system recreates an environment that closely mimics the structural features of non-polarized tissue. Furthermore, the particular intrinsic nanofiber structure of the scaffold makes it transparent to visual light, which allows for easy visualization of the sample under microscopy. This advantage was largely used to study cell migration, organization, proliferation, and differentiation and thus any development of their particular cellular function by staining with specific dyes or probes. Furthermore, in this work, we describe the good performance of this system to easily study the redifferentiation of expanded human articular chondrocytes into cartilaginous tissue. Cells were encapsulated into self-assembling peptide scaffolds and cultured under specific conditions to promote chondrogenesis. Three-dimensional cultures showed good viability during the 4 weeks of the experiment. As expected, samples cultured with chondrogenic inducers (compared to non-induced controls) stained strongly positive for toluidine blue (which stains glycosaminoglycans (GAGs) that are highly present in cartilage extracellular matrix) and expressed specific molecular markers, including collagen type I, II and X, according to Western Blot analysis. This protocol is easy to perform and can be used at research laboratories, industries and for educational purposes in laboratory courses.

Here, we present a protocol to obtain 3D-culture systems in self-assembling peptide scaffolds to promote the differentiation of dedifferentiated human articular chondrocytes into cartilage-like tissue.

Cultivo de células de mamífero en andamios tridimensionales péptido

A useful technique for culturing cells in a self-assembling nanofiber three-dimensional (3D) scaffold is described. This culture system recreates an ...

Three-dimensional Printing of Thermoplastic Materials to Create Automated Syringe Pumps with Feedback Control for Microfluidic Applications

Microfluidics has become a critical tool in research across the biological, chemical, and physical sciences. One important component of microfluidic experimentation is a stable fluid handling system capable of accurately providing an inlet flow rate or inlet pressure. Here, we have developed a syringe pump system capable of controlling and regulating the inlet fluid pressure delivered to a microfluidic device. This system was designed using low-cost materials and additive manufacturing principles, leveraging three-dimensional (3D) printing of thermoplastic materials and off-the-shelf components whenever possible. This system is composed of three main components: a syringe pump, a pressure transducer, and a programmable microcontroller. Within this paper, we detail a set of protocols for fabricating, assembling, and programming this syringe pump system. Furthermore, we have included representative results that demonstrate high-fidelity, feedback control of inlet pressure using this system. We expect this protocol will allow researchers to fabricate low-cost syringe pump systems, lowering the entry barrier for the use of microfluidics in biomedical, chemical, and materials research.

Here we present a protocol to construct a pressure-controlled syringe pump to be used in microfluidic applications. This syringe pump is made from an&#160;additively manufactured body, off-the-shelf hardware, and open-source electronics. The resulting system is low-cost, straightforward to build, and delivers well-regulated fluid flow to enable rapid microfluidic research.

Tridimensional de la impresión de materiales termoplásticos para crear automatizado de bombas de la jeringuilla con retroalimentación de Control para aplicaciones de microfluídica

Microfluidics has become a critical tool in research across the biological, chemical, and physical sciences. One important component of microfluidic ...

Methods Article

Impresión plana y tridimensional de tintas conductoras