This work was supported by the EC within the framework of the STIFF-FLOP FP7-ICT-2011.2.1 European Project (#287728).

Nota: Este protocolo describe las fases de fabricación de un solo módulo, que incluye las cámaras de fluidos, de rigidización de canales, tuberías de accionamiento y la vaina externa. El siguiente procedimiento debe ser ejecutado bajo una campana de humos y con bata de laboratorio y guantes por razones de seguridad. Como se mencionó anteriormente, el proceso de fabricación de la unidad elastomérico se basa en el uso secuencial de moldes diseñados con el software de CAD. Se componen de las 13 piezas que se muestran en la Figura 2 y en la Tabla 1 se enumeran. 1. Preparación de la silicona <ol><li> Pesar 12 g de la parte A y 12 g de la parte B en el mismo vaso de plástico o caja de Petri y mezclarlos entre sí, revolviendo. Nota: proporciones de materiales pueden variar dependiendo de la silicona específico utilizado, en este caso se compone de dos partes: Parte A (la base) y la parte B (el catalizador). Se utilizan en proporción 1A: 1B en peso. </li><li> Colocar el vaso que contiene la mezclamateriales de silicona ed en una máquina desgasificador de presión de vacío de 1 bar. Mantenga el vidrio bajo vacío hasta que todas las burbujas se eliminan del material de silicona. Para la silicona empleado el proceso de desgasificación tarda unos 10 min. Una vez que los materiales están completamente libres de la presencia de burbujas, restablecer la presión atmosférica en la máquina y utilizar la silicona. </li></ol> 2. La fabricación del módulo de silicona <ol><li> Asamblea del molde. <ol><li> Inserte el cilindro de refuerzo y la parte superior de las cámaras en cap_A (Figura 3a). </li><li> Cierre las cáscaras alrededor de la segunda capa de cap_A. </li></ol></li><li> En primer lugar la fundición de silicona. <ol><li> Verter la silicona dentro del molde hasta ensamblado hasta el borde de las conchas (Figura 3B). </li><li> Colocar el molde en un horno a 60 ° C durante aproximadamente 30 min. </li></ol></li><li> Reordenamiento del molde. <ol><li> Retire las cáscaras externas e cap_A (Figura 3c). </li><li> Inserte los cilindros de las bases de las cámaras y el cilindro de refuerzo dentro cap_B (Figura 3d). </li><li> Cierre las conchas de nuevo alrededor del módulo, deslizándolos de 10 mm hacia arriba con el fin de tener un espacio de 10 mm entre la superficie superior del módulo y los bordes de las conchas (Figura 3E). </li></ol></li><li> En segundo lugar colada de silicona. <ol><li> Verter la silicona dentro del molde hasta reordenado hasta el borde de las conchas en la parte superior (es decir, también hasta el cilindro de refuerzo) (Figura 3f). </li><li> Poner el molde en un horno a 60 ° C durante aproximadamente 30 min. </li><li> Retire las cáscaras externas, cap_B y las cámaras (excepto el cilindro de refuerzo) (Figura 3g). </li></ol></li></ol> 3. La inserción de los tubos <ol><li> Corte 3 tubos a la misma longitud deseada (300 mm por ejemplo). </li><li> Ponga pegamento de silicona alrededor de un extremo de cada tubo de 10 mm, sin obtrucción de los tubos. </li><li> Inserte los tubos dentro de los 2 mm de canales en la unidad de silicona (Figura 3h) dedicados. </li><li> Permitir un tiempo de curado de 12 min a temperatura ambiente o poner el módulo dentro de un horno a una temperatura más alta (50 ° - 60 °) para acelerar el proceso de secado. </li></ol> 4. La fabricación del prensado trenzado vaina <ol><li> Cortar 700 mm de una funda trenzada expandible (aproximadamente 15 veces la altura del módulo). </li><li> Insertar un cilindro metálico de 30 mm de diámetro y 250 mm de longitud dentro de la vaina. </li><li> Empuje hacia abajo y obligar a la vaina por deslizamiento sobre el cilindro, con el fin de crear ondulaciones. </li><li> Fijar mecánicamente la vaina en su lugar con una abrazadera y el calor con una pistola de calentamiento a 350 ° C durante 2-3 min hasta que se obtiene una deformación permanente. </li><li> Deje que la vaina se enfríe y retire el cilindro interno. </li></ol> 5. Integración de la vaina externa <ol><li> Pasa eltubos a través de los agujeros de cap_C. </li><li> Vierta 3 g de silicona en cap_C. </li><li> Abrazadera cap_C a un soporte que es más alto que el plano de trabajo. </li><li> Insertar el lado inferior del módulo previamente fabricado en cap_C. </li><li> Deslice la cubierta ondulada alrededor del módulo. </li><li> Empuje las primeras ondulaciones de la vaina dentro cap_C y sumergirlos en la silicona recién vertida (Figura 3i). </li><li> Poner el molde en un horno a 60 ° C durante aproximadamente 20 min. </li><li> Repita el mismo procedimiento desde el punto 5.1 a 5.6 para fijar la cubierta en la parte superior, utilizando cap_D (figura 3j). </li><li> Retire cap_C y cap_D. </li><li> Retire el cilindro central (Figura 3k). </li></ol> 6. La fabricación del granulado Jamming Membrana <ol><li> Verter 5 g de látex líquido en un vaso de plástico. </li><li> Sumergir el cilindro para la membrana (última pieza muestra en la Figura 2) en el interior del látex líquido hasta que la superficieestá completamente cubierto. </li><li> Dejar secar bajo una campana de 20 min. </li><li> Repetir los puntos 6.2 y 6.3. </li><li> Retire la membrana del molde. </li></ol> 7. Inserción del Granular Jamming Membrana <ol><li> Cortar un tubo (2 mm de diámetro) a la longitud deseada (300 mm por ejemplo). </li><li> Cortar una pieza cuadrada de aproximadamente 100 mm 2 de tejido de nylon y cerrar un extremo del tubo con este tejido usando una película de plástico o de parafina superglue. </li><li> Pesar 4 g de polvo de café y llenar la membrana. </li><li> Introducir el tubo (el extremo con el filtro) dentro de la membrana llena y fijarlo alrededor del tubo usando una película de parafina plástico. </li><li> Aplicar un vacío en el otro lado del tubo (la membrana se vuelve más rígido). </li><li> Inserte la membrana en el interior del canal central vacía del módulo de silicona (figura 3l). </li><li> Pegue los extremos de la membrana de refuerzo al módulo de silicona. </li><li> Cierre los anillos alrededor de la parte superiorlado del módulo (Figura 3M). </li><li> Vierta 2 g de silicona en los anillos con el fin de nivelar la superficie. </li><li> Deje que la silicona seca bajo el capó o en un horno a 60 °. </li><li> Retire los anillos. </li><li> Repita desde los puntos 7.8 a 7.11 de la parte inferior (Figura 3n). </li></ol>

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The authors have nothing to disclose.

The technique described in this protocol enables the fabrication of a pneumatically actuated soft unit usable for modular compliant structures. Thanks to the design of the molds and their simple assembly, it is possible to fabricate one complete module in about 4 hours with 7 main steps. The process of fabrication involves specific materials, which are easily available, and work should be carried out under a fume hood. An external set up including air valves, air compressor and vacuum pump is necessary to activate the mo...

Las tendencias recientes en el campo de la medicina están presionando para una reducción de la capacidad de invasión de las operaciones quirúrgicas. Cirugía mínimamente invasiva (MIS) se ha mejorado con éxito en los últimos años para las operaciones abdominales. Procedimientos de MIS se basan en el uso de herramientas introducidos a través de cuatro o cinco puntos de acceso (trocares) colocados en la pared abdominal. Con el fin de reducir el número de trócares, los instrumentos pueden ser insertados por un solo puerto Laparoscopia (SPL) o la cirugía por orificios naturales Endoscópica Transluminal (NOTAS) 1. Estos procedimientos evitan cicatrices visibles externos, pero aumentan la dificultad para los clínicos en la ejecución de la cirugía. Esta limitación se debe principalmente a los puntos reducidos de acceso y de la naturaleza rígida y semi-rígida de los instrumentos, que no son capaces de evitar o pasar alrededor de los órganos 2, 3. Destreza y la motilidad se pueden mejorar usando articulado e hiper-redundante robots que pueden cubrir un área de trabajo más amplia y compleja, THnos permite un objetivo específico en el cuerpo para llegar más fácilmente 4, 5, 6 y trabajar como sistemas cuando sea necesario 7 de retracción. Un manipulador flexible puede mejorar el cumplimiento de los tejidos, con lo que el contacto más seguro que las herramientas tradicionales. Sin embargo, estos manipuladores a menudo carecen de la estabilidad cuando se alcanza el objetivo y por lo general no pueden controlar el contacto con los tejidos circundantes 8, 9. Estudios sobre las estructuras biológicas, tales como el brazo de pulpo 10 y la trompa de elefante 11, han inspirado recientemente el diseño de manipuladores flexibles, deformables y que cumplen con una serie redundante de grados de libertad (DoFs) y rigidez controlable 12. Este tipo de dispositivos utilizan resortes pasivos, materiales inteligentes, elementos neumáticos, o tendones 13, 14, 15. En general, manipuladores fabricados con materiales blandos y flexibles no garantizan la generación de elevadas fuerzas. Tque TIESO-FLOP (rigidez controlable manipulador flexible y se puede aprender en operaciones quirúrgicas) manipulador ha sido recientemente presentado como un dispositivo quirúrgico novedoso para las notas y SPL inspirados en las capacidades de los pulpos. Con el fin de superar las limitaciones de manipuladores suaves anteriores, que tiene un cuerpo blando así como una alta destreza, alta fuerza y rigidez controlable 16. La arquitectura del manipulador se basa en un enfoque modular: unidades múltiples, con la misma estructura y funcionalidades, están integrados juntos. La sola unidad se muestra en la Figura 1. Se basa en un cilindro de elastómero obtenida por una fabricación multifásica. Los pasos de montaje de los componentes del molde y de los procesos de fundición permiten tres cámaras vacías (para el accionamiento fluídico) y un canal central hueco 17 (para alojar un mecanismo basado en el jamming granular 18) para ser embebidos. Las cámaras se colocan en 120 °, de modo que lainflación combinada IR produce un movimiento omnidireccional y elongación. Además una funda trenzada externa se coloca externamente para limitar la expansión radial hacia fuera de las cámaras de fluidos cuando se presuriza, optimizando así el efecto de la cámara de accionamiento en el movimiento del módulo (flexión y el alargamiento). El canal central alberga un dispositivo cilíndrico compuesto de una membrana externa lleno de material granular. Cuando se aplica una presión de vacío, que cambia sus propiedades elásticas causando una rigidez que afecta a las propiedades de todo el módulo. Actuaciones de movimiento y rigidez son controlados por una configuración externa que incluye un compresor de aire y tres válvulas de presión para accionar las cámaras y una bomba de vacío para activar el vacío en el canal de refuerzo. Una interfaz de usuario intuitiva permite el control de la actuación y de vacío presiones en el interior del módulo. Este documento detalla el fabrication proceso de la solo módulo de este manipulador y los informes de los resultados más significativos sobre las capacidades básicas del movimiento. Teniendo en cuenta la naturaleza modular del dispositivo, la evaluación de la fabricación y el rendimiento de un solo módulo que también permite que los resultados sean extendidos y para predecir el comportamiento básico de un manipulador multi-módulo de la integración de dos o más módulos.

<table border="0">
	<tbody>
		<tr>
			<td>Ecoflex 00-50 Trial Kit</td>
			<td>SmoothOn</td>
			<td></td>
			<td>Used for the fabrication of the soft unit, combining equal amounts of liquid parts A (the base) and B (the catalyst)</td>
		</tr>
		<tr>
			<td>Latex</td>
			<td>Antichit&#224; Belsito</td>
			<td></td>
			<td>Used for the fabrication of the granular jamming membrane</td>
		</tr>
		<tr>
			<td>Peroxide-Cured Silicone Tubing</td>
			<td>Cole Parmer</td>
			<td>T-06411-59</td>
			<td>Used for actuating the chambers and applying vacuum</td>
		</tr>
		<tr>
			<td>PET expandable braided sleeving</td>
			<td>RS</td>
			<td>408-249</td>
			<td>Used for the fabrication of the external braided sheath</td>
		</tr>
		<tr>
			<td>Silicone Rubber</td>
			<td>Momentive</td>
			<td>127374</td>
			<td>Used to fix the actuation tubes to the module</td>
		</tr>
		<tr>
			<td>Parafilm</td>
			<td>Cole Parmer</td>
			<td>EW-06720-40</td>
			<td>Used to fix the latex membrane to the vacuum tube</td>
		</tr>
		<tr>
			<td>Fume hood Secuflow</td>
			<td>Groupe Waldner</td>
			<td></td>
			<td>Working space</td>
		</tr>
		<tr>
			<td>Precision scale</td>
			<td>KERN EW</td>
			<td></td>
			<td>Used to weight silicone, latex and coffee powder</td>
		</tr>
		<tr>
			<td>Oven/degasser</td>
			<td>Heraeus</td>
			<td></td>
			<td>Used to degass the silicone and reduce its cure time</td>
		</tr>
		<tr>
			<td>Vacuum pump</td>
			<td>DVP Vacuum Technology</td>
			<td></td>
			<td>Used to apply vacuum to the latex membrane</td>
		</tr>
	</tbody>
</table>

design and fabrication of an elastomeric unit for soft modular robots in minimally invasive surgery

En los últimos años, las tecnologías de robótica blandos han despertado un creciente interés en el campo de la medicina debido a su interacción intrínsecamente seguro en entornos no estructurados. Al mismo tiempo, los nuevos procedimientos y técnicas se han desarrollado para reducir la invasividad de las operaciones quirúrgicas. Cirugía mínimamente invasiva (MIS) se ha empleado con éxito para las intervenciones abdominales, los procedimientos de embargo estándar MIS se basan principalmente en herramientas rígidas o semi-rígidas que limitan la habilidad del clínico. Este trabajo presenta un manipulador diestro suave y alto para MIS. El manipulador se inspiró en las capacidades biológicas del brazo de pulpo, y está diseñado con un enfoque modular. Cada módulo presenta las mismas características funcionales, logrando así la máxima destreza y versatilidad a la hora más módulos están integrados. El documento detalla el diseño, la fabricación y el proceso de los materiales necesarios para el desarrollo de una sola unidad, que se fabrica por casting de silicona interior moldes específicos. El resultado consiste en un cilindro elastomérico incluyendo tres actuadores neumáticos flexibles que permiten el alargamiento y la flexión omnidireccional de la unidad. Una funda trenzada externa mejora el movimiento del módulo. En el centro de cada módulo de un mecanismo basado-jamming granular varía la rigidez de la estructura durante las tareas. Las pruebas demuestran que el módulo es capaz de doblar hasta 120 ° y para alargar hasta 66% de la longitud inicial. El módulo genera una fuerza máxima de 47 N, y su rigidez puede aumentar hasta 36%.

Las diversas fases de la fabricación, que se describe en el Protocolo, se ilustran en la Figura 3. Con el fin de evaluar la efectividad de la técnica y los resultados de la prototipo final, el módulo se probó en diferentes condiciones de trabajo. Una configuración externa permite el control tanto de la actuación y la rigidez del módulo. Incluye un compresor de aire que activa tres válvulas. Están conectados a los tubos silicónicos integrados en las...

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Design and Fabrication of an Elastomeric Unit for Soft Modular Robots in Minimally Invasive Surgery

This paper describes the design and fabrication of a soft unit for surgical manipulators. The base module includes three flexible fluidic actuators to achieve omnidirectional bending and elongation, and a granular jamming-based mechanism to enable stiffness control. A complete mechanical characterization is also reported.

Diseño y fabricación de una Unidad de elastómero de suaves modulares Robots en Cirugía Mínimamente Invasiva

In recent years, soft robotics technologies have aroused increasing interest in the medical field due to their intrinsically safe interaction in ...

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8.9K vistas.  Scuola Superiore Sant'Anna. This paper describes the design and fabrication of a soft unit for surgical manipulators. The base module includes three flexible fluidic actuators to achieve omnidirectional bending and elongation, and a granular jamming-based mechanism to enable stiffness control. A complete mechanical characterization is also reported. 

Video: Design and Fabrication of an Elastomeric Unit for Soft Modular Robots in Minimally Invasive Surgery

Elastomeric PGS Scaffolds in Arterial Tissue Engineering

Cardiovascular disease is one of the leading cause of mortality in the US and especially, coronary artery disease increases with an aging population and increasing obesity1. Currently, bypass surgery using autologous vessels, allografts, and synthetic grafts are known as a commonly used for arterial substitutes2. However, these grafts have limited applications when an inner diameter of arteries is less than 6 mm due to low availability, thrombotic complications, compliance mismatch, and late intimal hyperplasia3,4. To overcome these limitations, tissue engineering has been successfully applied as a promising alternative to develop small-diameter arterial constructs that are nonthrombogenic, robust, and compliant. Several previous studies have developed small-diameter arterial constructs with tri-lamellar structure, excellent mechanical properties and burst pressure comparable to native arteries5,6. While high tensile strength and burst pressure by increasing collagen production from a rigid material or cell sheet scaffold, these constructs still had low elastin production and compliance, which is a major problem to cause graft failure after implantation. Considering these issues, we hypothesized that an elastometric biomaterial combined with mechanical conditioning would provide elasticity and conduct mechanical signals more efficiently to vascular cells, which increase extracellular matrix production and support cellular orientation.
The objective of this report is to introduce a fabrication technique of porous tubular scaffolds and a dynamic mechanical conditioning for applying them to arterial tissue engineering. We used a biodegradable elastomer, poly (glycerol sebacate) (PGS)7 for fabricating porous tubular scaffolds from the salt fusion method. Adult primary baboon smooth muscle cells (SMCs) were seeded on the lumen of scaffolds, which cultured in our designed pulsatile flow bioreactor for 3 weeks. PGS scaffolds had consistent thickness and randomly distributed macro- and micro-pores. Mechanical conditioning from pulsatile flow bioreactor supported SMC orientation and enhanced ECM production in scaffolds. These results suggest that elastomeric scaffolds and mechanical conditioning of bioreactor culture may be a promising method for arterial tissue engineering.

Elastomeric PGS scaffolds with vascular smooth muscle cells cultured in a pulsatile flow bioreactor may lead to promising small-diameter arterial constructs with native ECM production in a relatively short culture period.

PGS elastomérico andamios en ingeniería de tejidos arteriales

Cardiovascular disease is one of the leading cause of mortality in the US and especially, coronary artery disease increases with an aging population and ...

Investigación

Bioingeniería

Polymeric Microneedle Array Fabrication by Photolithography

This manuscript describes the fabrication of polymeric microneedle (MN) arrays by photolithography. It involves a simple mold-free process by using a photomask consisting of embedded micro-lenses. Embedded micro-lenses were found to influence MN geometry (sharpness). Robust MN arrays with tip diameters ranging between 41.5 &#181;m &#177; 8.4 &#181;m and 71.6 &#181;m &#177; 13.7 &#181;m, with two different lengths (1,336 &#181;m &#177; 193 &#181;m and 957 &#181;m &#177; 171 &#181;m) were fabricated. These MN arrays may provide potential applications in delivery of low molecular and macromolecular therapeutic agents through skin.

Here, we present a protocol describing a mold-free fabrication process of the polymeric microneedles by photolithography.

Fabrication polimérico matriz de microagujas por fotolitografía

This manuscript describes the fabrication of polymeric microneedle (MN) arrays by photolithography. It involves a simple mold-free process by using a ...

Rod-based Fabrication of Customizable Soft Robotic Pneumatic Gripper Devices for Delicate Tissue Manipulation

Soft compliant gripping is essential in delicate surgical manipulation for minimizing the risk of tissue grip damage caused by high stress concentrations at the point of contact. It can be achieved by complementing traditional rigid grippers with soft robotic pneumatic gripper devices. This manuscript describes a rod-based approach that combined both 3D-printing and a modified soft lithography technique to fabricate the soft pneumatic gripper. In brief, the pneumatic featureless mold with chamber component is 3D-printed and the rods were used to create the pneumatic channels that connect to the chamber. This protocol eliminates the risk of channels occluding during the sealing process and the need for external air source or related control circuit. The soft gripper consists of a chamber filled with air, and one or more gripper arms with a pneumatic channel in each arm connected to the chamber. The pneumatic channel is positioned close to the outer wall to create different stiffness in the gripper arm. Upon compression of the chamber which generates pressure on the pneumatic channel, the gripper arm will bend inward to form a close grip posture because the outer wall area is more compliant. The soft gripper can be inserted into a 3D-printed handling tool with two different control modes for chamber compression: manual gripper mode with a movable piston, and robotic gripper mode with a linear actuator. The double-arm gripper with two actuatable arms was able to pick up objects of sizes up to 2 mm and yet generate lower compressive forces as compared to elastomer-coated and non-coated rigid grippers. The feasibility of having other designs, such as single-arm or hook gripper, was also demonstrated, which further highlighted the customizability of the soft gripper device, and it's potential to be used in delicate surgical manipulation to reduce the risk of tissue grip damage.

This protocol describes a rod-based approach, combining 3D-printing and soft lithography techniques for fabricating the soft gripper devices. This approach eliminates the need for an external air source by incorporating a chamber component and reduces the chance of occlusion during the sealing process, particularly for miniaturized pneumatic channels.

a base de varilla de fabricación de dispositivos robóticos adaptables pinza neumática suaves para la manipulación del tejido delicado

Soft compliant gripping is essential in delicate surgical manipulation for minimizing the risk of tissue grip damage caused by high stress concentrations ...

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.

Automatizado de montaje robotizada manipulación líquido de dispositivos modulares de la DNA

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

Biomechanical Characterization of Human Soft Tissues Using Indentation and Tensile Testing

Regenerative medicine aims to engineer materials to replace or restore damaged or diseased organs. The mechanical properties of such materials should mimic the human tissues they are aiming to replace; to provide the required anatomical shape, the materials must be able to sustain the mechanical forces they will experience when implanted at the defect site. Although the mechanical properties of tissue-engineered scaffolds are of great importance, many human tissues that undergo restoration with engineered materials have not been fully biomechanically characterized. Several compressive and tensile protocols are reported for evaluating materials, but with large variability it is difficult to compare results between studies. Further complicating the studies is the often destructive nature of mechanical testing. Whilst an understanding of tissue failure is important, it is also important to have knowledge of the elastic and viscoelastic properties under more physiological loading conditions.
This report aims to provide a minimally destructive protocol to evaluate the compressive and tensile properties of human soft tissues. As examples of this technique, the tensile testing of skin and the compressive testing of cartilage are described. These protocols can also be directly applied to synthetic materials to ensure that the mechanical properties are similar to the native tissue. Protocols to assess the mechanical properties of human native tissue will allow a benchmark by which to create suitable tissue-engineered substitutes.

Tissue biomechanics is important for maintaining cell shape and function and for determining phenotype. This report demonstrates non-destructive mechanical protocols for characterizing elastic and viscoelastic properties of human soft tissues, which can be directly applied to tissue-engineered substrates to allow a close matching of engineered materials to native tissue.

Caracterización biomecánica de los tejidos blandos humanos utilizando sangría y Ensayo de tracción

Regenerative medicine aims to engineer materials to replace or restore damaged or diseased organs. The mechanical properties of such materials should ...

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and dampen loads in the spine. The IVD consists of a proteoglycan-rich nucleus pulposus (NP) and a collagen-rich annulus fibrosis (AF) sandwiched by cartilaginous end-plates. Together with the adjacent vertebrae, the vertebrae-IVD structure forms a functional spine unit (FSU). These microstructures contain unique cell types as well as unique extracellular matrices. Whole organ culture of the FSU preserves the native extracellular matrix, cell differentiation phenotypes, and cellular-matrix interactions. Thus, organ culture techniques are particularly useful for investigating the complex biological mechanisms of the IVD. Here, we describe a high-throughput approach for culturing whole lumbar mouse FSUs that provides an ideal platform for studying disease mechanisms and therapies for the IVD. Furthermore, we describe several applications that utilize this organ culture method to conduct further studies including contrast-enhanced microCT imaging and three-dimensional high-resolution finite element modeling of the IVD.

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Whole organ culture of the intervertebral disc (IVD) preserves the native extracellular matrix, cell phenotypes, and cellular-matrix interactions. Here we describe an IVD culture system using mouse lumbar and caudal IVDs in their functional spinal units and several applications utilizing this system.

Un<em&gt; In Vitro</em&gt; Órgano Cultura Modelo Murino del disco intervertebral

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and ...

A Novel Surgical Technique As a Foundation for In Vivo Partial Liver Engineering in Rat

Organ engineering is a novel strategy to generate liver organ substitutes that can potentially be used in transplantation. Recently, in vivo liver engineering, including in vivo organ decellularization followed by repopulation, has emerged as a promising approach over ex vivo liver engineering. However, postoperative survival was not achieved. The aim of this study is to develop a novel surgical technique of in vivo selective liver lobe perfusion in rats as a prerequisite for in vivo liver engineering. We generate a circuit bypass only through the left lateral lobe. Then, the left lateral lobe is perfused with heparinized saline. The experiment is performed with 4 groups (n = 3 rats per group) based on different perfusion times of 20 min, 2 h, 3 h, and 4 h. Survival, as well as the macroscopically visible change of color and the histologically determined absence of blood cells in the portal triad and the sinusoids, is taken as an indicator for a successful model establishment. After selective perfusion of the left lateral lobe, we observe that the left lateral lobe, indeed, turned from red to faint yellow. In a histological assessment, no blood cells are visible in the branch of the portal vein, the central vein, and the sinusoids. The left lateral lobe turns red after reopening the blocked vessels. 12/12 rats survived the procedure for more than one week. We are the first to report a surgical model for in vivo single liver lobe perfusion with a long survival period of more than one week. In contrast to the previously published report, the most important advantage of the technique presented here is that perfusion of 70% of the liver is maintained throughout the whole procedure. The establishment of this technique provides a foundation for in vivo partial liver engineering in rats, including decellularization and recellularization.

A Novel Surgical Technique As a Foundation for In Vivo Partial Liver Engineering in Rat

We establish a novel surgical technique for an in vivo single liver lobe perfusion model in rat as a prerequisite for further studying in vivo partial liver engineering in the future.

Una novedosa técnica quirúrgica como base para In Vivo parcial ingeniería hígado de rata

Organ engineering is a novel strategy to generate liver organ substitutes that can potentially be used in transplantation. Recently, in vivo liver ...

Bioinspired Soft Robot with Incorporated Microelectrodes

Bioinspired soft robotic systems that mimic living organisms using engineered muscle tissue and biomaterials are revolutionizing the current biorobotics paradigm, especially in biomedical research. Recreating artificial life-like actuation dynamics is crucial for a soft-robotic system. However, the precise control and tuning of actuation behavior still represents one of the main challenges of modern soft robotic systems. This method describes a low-cost, highly scalable, and easy-to-use procedure to fabricate an electrically controllable soft robot with life-like movements that is activated and controlled by the contraction of cardiac muscle tissue on a micropatterned sting ray-like hydrogel scaffold. The use of soft photolithography methods makes it possible to successfully integrate multiple components in the soft robotic system, including micropatterned hydrogel-based scaffolds with carbon nanotubes (CNTs) embedded gelatin methacryloyl (CNT-GelMA), poly(ethylene glycol) diacrylate (PEGDA), flexible gold (Au) microelectrodes, and cardiac muscle tissue. In particular, the hydrogels alignment and micropattern are designed to mimic the muscle and cartilage structure of the sting ray. The electrically conductive CNT-GelMA hydrogel acts as a cell scaffold that improves the maturation and contraction behavior of cardiomyocytes, while the mechanically robust PEGDA hydrogel provides structural cartilage-like support to the whole soft robot. To overcome the hard and brittle nature of metal-based microelectrodes, we designed a serpentine pattern that has high flexibility and can avoid hampering the beating dynamics of cardiomyocytes. The incorporated flexible Au microelectrodes provide electrical stimulation across the soft robot, making it easier to control the contraction behavior of cardiac tissue.

A bioinspired scaffold is fabricated by a soft photolithography technique using mechanically robust and electrically conductive hydrogels. The micropatterned hydrogels provide directional cardiomyocyte cell alignment, resulting in a tailored direction of actuation. Flexible microelectrodes are also integrated into the scaffold to bring electrical controllability for a self-actuating cardiac tissue.

Robot suave bioinspirado con microelectrodos incorporados

Bioinspired soft robotic systems that mimic living organisms using engineered muscle tissue and biomaterials are revolutionizing the current biorobotics ...

Simple, Affordable, and Modular Patterning of Cells using DNA

The relative positioning of cells is a key feature of the microenvironment that organizes cell-cell interactions. To study the interactions between cells of the same or different type, micropatterning techniques have proved useful. DNA Programmed Assembly of Cells (DPAC) is a micropatterning technique that targets the adhesion of cells to a substrate or other cells using DNA hybridization. The most basic operations in DPAC begin with decorating cell membranes with lipid-modified oligonucleotides, then flowing them over a substrate that has been patterned with complementary DNA sequences. Cells adhere selectively to the substrate only where they find a complementary DNA sequence. Non-adherent cells are washed away, revealing a pattern of adherent cells. Additional operations include further rounds of cell-substrate or cell-cell adhesion, as well as transferring the patterns formed by DPAC to an embedding hydrogel for long-term culture. Previously, methods for patterning oligonucleotides on surfaces and decorating cells with DNA sequences required specialized equipment and custom DNA synthesis, respectively. We report an updated version of the protocol, utilizing an inexpensive benchtop photolithography setup and commercially available cholesterol modified oligonucleotides (CMOs) deployed using a modular format. CMO-labeled cells adhere with high efficiency to DNA-patterned substrates. This approach can be used to pattern multiple cell types at once with high precision and to create arrays of microtissues embedded within an extracellular matrix. Advantages of this method include its high resolution, ability to embed cells into a three-dimensional microenvironment without disrupting the micropattern, and flexibility in patterning any cell type.

Here we present a protocol to micropattern cells at single-cell resolution using DNA-programmed adhesion. This protocol uses a benchtop photolithography platform to create patterns of DNA oligonucleotides on a glass slide and then labels cell membranes with commercially available complementary oligonucleotides. Hybridization of the oligos results in programmed cell adhesion.

Patrones simples, asequibles y modulares de células utilizando ADN

The relative positioning of cells is a key feature of the microenvironment that organizes cell-cell interactions. To study the interactions between cells ...

Voxel Printing Anatomy: Design and Fabrication of Realistic, Presurgical Planning Models through Bitmap Printing

Most applications of 3-dimensional (3D) printing for presurgical planning have been limited to bony structures and simple morphological descriptions of complex organs due to the fundamental limitations in accuracy, quality, and efficiency of the current modeling paradigm. This has largely ignored the soft tissue critical to most surgical specialties where the interior of an object matters and anatomical boundaries transition gradually. Therefore, the needs of the biomedical industry to replicate human tissue, which displays multiple scales of organization and varying material distributions, necessitate new forms of representation. 
Presented here is a novel technique to create 3D models directly from medical images, which are superior in spatial and contrast resolution to current 3D modeling methods and contain previously unachievable spatial fidelity and soft tissue differentiation. Also presented are empirical measurements of novel, additively manufactured composites that span the gamut of material stiffnesses seen in soft biological tissues from MRI and CT. These unique volumetric design and printing methods allow for deterministic and continuous adjustment of material stiffness and color. This capability enables an entirely new application of additive manufacturing to presurgical planning: mechanical realism. As a natural complement to existing models that provide appearance matching, these new models also allow medical professionals to "feel" the spatially varying material properties of a tissue simulant-a critical addition to a field in which tactile sensation plays a key role.

This method demonstrates a voxel-based 3D printing workflow, which prints directly from medical images with exact spatial fidelity and spatial/contrast resolution. This enables the precise, graduated control of material distributions through morphologically complex, graduated materials correlated to radiodensity without loss or alteration of data.

Voxel Printing Anatomy: Diseño y fabricación de modelos de planificación realistas y prequirúrgicos a través de la impresión de mapas de bits

Most applications of 3-dimensional (3D) printing for presurgical planning have been limited to bony structures and simple morphological descriptions of ...