Name: stereolithographic 3d printing with renewable acrylates
Uploaded: 2018-09-12T15:00:00.000+00:00
Duration: 8 min 28 s
Description: Watch this Scientific Journal Video about Stereolithographic 3D Printing with Renewable Acrylates at JoVE.com

Este estudio fue apoyado por el centro de solicitud de polímero GreenPAC como parte del proyecto 140413: "impresión 3D en producción". Nos gustaría reconocer Albert Hartman, Corinne van Noordenne, Rens van Leeuwen, Anniek Bruins, Femke Tamminga, Jur van Dijken y Albert Woortman para facilitar el rodaje del video.

PRECAUCIÓN: Consulte todas las hojas de datos de seguridad del material (MSDS) antes de su uso.
1. preparación de resina fotocurables
Nota: Utilice equipo de protección personal (gafas, guantes, bata de laboratorio) durante el siguiente procedimiento. Ver nuestro trabajo anterior12 para más detalles en esta sección.
<ol><li>Verter 50 g de 1, 10-Decanodiol diacrylate (SA5201) en un erlenmeyer de 500 mL.</li>
	<li>Agregar 1,0 g de diphenyl(2,4,6-trimethylbenzoyl) óxido de fosfina (TPO) y 0,40 g de 2, 5 -bis(5 -terc-butil-benzoxazol-2-yl) tiofeno (BBOT) al matraz.</li>
	<li>Equipar el matraz con un agitador mecánico y revolver la mezcla a 200 rpm por 5 min a temperatura ambiente con el fin de disolver el TPO y el BBOT en el monómero de acrilato.</li>
	<li>Añadir 100 g de tetraacrylate de pentaeritritol y 100 g de acrilato epoxy multifuncional (véase Tabla de materiales) a la mezcla.</li>
	<li>Revolver la mezcla a 200 rpm por 30 min a 50 ° C para una resina homogénea.</li>
	<li>Quite el agitador mecánico y coloque el matraz con un tapón. El frasco se envuelve en papel aluminio para proteger la resina de polímetro acrilato de base biológica (BAPR) de la luz. Nota: El protocolo se puede detener aquí.</li>
	<li>Cubrir la placa inferior de un reómetro con geometría de placas paralelas con la photoresin.</li>
	<li>Ajustar el espacio entre las placas a 1 mm y cubrir el Reómetro con capucha resistente a UV.</li>
	<li>Medir la viscosidad de la resina a temperatura ambiente a velocidades de corte de 0,1 a 100 s-1; por ejemplo,0.100, 0.126, 0.158, 0.200, 0,251, 0,316, 0.398, 0.501, 0.631, 0.794, 1.00, 1.26, 1,58, 2.00, 2.51, 3.16, 3.98, 5.01, 6.31, 7.94, 10.0, 12.6, 15.8, 20.0, 25.1, 31.6, 39.8, 50.1, 63.1, 79.4 y 100 s-1.</li>
</ol>2. Stereolithographic impresión 3D con biobásicos Acrylates
Nota: Vea nuestro trabajo anterior12 para más detalles en esta sección.
<ol><li>Encienda la impresora 3D de SLA y selecciona modo abierto.</li>
	<li>Inicie el software de preparación de la modelo en una computadora. Elija la configuración de impresión: material (claro), versión (V4) y espesor de la capa (50 μm).</li>
	<li>Abra el modelo digital del prototipo en forma de complejo, un archivo de lenguaje (.stl) mosaico estándar (véase Archivo de codificación complementaria) y elija la ubicación y orientación en la plataforma de la construcción.  Subir el trabajo de impresión desde el software de preparación de la modelo a la impresora 3D de SLA. Nota: Dependiendo de la arquitectura del producto, una estructura de soporte puede integrarse en el modelo 3D para estabilizar la construcción durante la fabricación. En el caso del prototipo en forma de complejo demostrado aquí, una estructura de apoyo no es necesaria si impreso normal a la dirección de construcción.</li>
	<li>Verter 200 mL de la base biológica photoresin en un tanque de resina. Abrir la impresora 3D y Monte bien el tanque de resina.</li>
	<li>Montaje de la plataforma de construcción y cierre la impresora 3D.</li>
	<li>Iniciar el trabajo de impresión.</li>
	<li>Permita que la impresora 3D fabricar prototipos en forma complejas.  No abra la impresora hasta que haya terminado el trabajo de impresión. Nota: Antes de imprimir, asegúrese de que esté nivelada la impresora 3D. Para el protocolo demostrado, la longitud de onda del láser UV es 405 nm. El tiempo de impresión del objeto es h 2,5.</li>
</ol>3. después del tratamiento de 3D imprimir objetos
Nota: Utilice equipo de protección personal (gafas, guantes) durante el siguiente procedimiento.
<ol><li>Una vez terminado el trabajo de impresión, abra la impresora. Retire la plataforma de la construcción, con las piezas producidas adjuntadas y cierre la impresora.</li>
	<li>La estación de lavado, llenada de alcohol isopropílico e inserte la plataforma de la construcción. Iniciar el procedimiento y enjuague durante 20 min eliminar cualquier resina sin reaccionar.</li>
	<li>Una vez finalizado el procedimiento de lavado, retire la plataforma de la construcción de la estación de lavado y separe los prototipos de la plataforma de la construcción.</li>
	<li>Seque los prototipos a aire durante 30 minutos. Mientras tanto, precalentar el horno UV a 60 ° C. Nota: Precalentamiento tendrá por lo menos 15 minutos. La longitud de onda de UV del horno es 405 nm, idéntica a la longitud de onda del laser de SLA.</li>
	<li>Abrir el horno UV y colocar rápidamente los prototipos de la plataforma giratoria. Cierre el horno UV y curación durante 60 min a 60 ° C para asegurar la conversión completa.</li>
	<li>Cuando termine el procedimiento post curado, abrir el horno UV y quitar los prototipos.</li>
</ol>4. Caracterización de la morfología superficial de prototipos en forma de complejo
Nota: Vea nuestro trabajo anterior12 para más detalles en esta sección.
<ol><li>Cortar aprox. 1 cm de hélice interna del prototipo en forma complejo utilizando una hoja de afeitar.</li>
	<li>Coloque la muestra en el portamuestras con la cinta conductiva de carbón de doble cara.</li>
	<li>Antes de la proyección de imagen, capa de la muestra con 30 nm Pt/Pd (80: 20) en un sistema de pulverización catódica.</li>
	<li>Inserte la muestra en un microscopio electrónico de barrido operando a un voltaje de aceleración de 5 kV. Adquirir varias imágenes de la muestra a 30 X y 120 aumentos.</li>
</ol>

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C., Schwentenwein, M., Gorsche, C., Stampfl, J., Liska, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toughening+of+photo-curable+polymer+networks:+A+review.">Toughening of photo-curable polymer networks: A review.</a> Polymer Chemistry. 7, 257-286 (2016).</li><li>Miao, S., Zhu, W., Castro, N. J., Nowicki, M., Zhou, X., Cui, H., Fisher, J. P., Zhang, L. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=4D+printing+smart+biomedical+scaffolds+with+novel+soybean+oil+epoxidized+acrylate.">4D printing smart biomedical scaffolds with novel soybean oil epoxidized acrylate.</a> Scientific Reports. 6, 27226 (2016).</li><li>Voet, V. S. D., Strating, T., Schnelting, G. H. M., Dijkstra, P., Tietema, M., Xu, J., Woortman, A. J. 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Los autores no tienen nada que revelar.

Fabricación aditiva se aplica en la fabricación de prototipos a medida y pequeñas series, cuando los mayores costos de producción por parte pueden competir con los procesos convencionales ya no es necesario para la producción de moldes y herramientas. En la última década, los ingresos de servicios y productos relacionados con la fabricación aditiva han crecido de manera exponencial13. La fracción más grande de las ventas de material es de fotopolímeros. El crecimiento atrajo atención e...

Prototipado rápido permite libertad de diseño y producción bajo demanda y que la fabricación eficiente de 3D construye en forma de capa por capa1. Como resultado, la impresión 3D como una técnica de fabricación ha desarrollado rápidamente en últimos años2. Varias tecnologías están disponibles, todo depende de la traducción de modelos virtuales en objetos físicos y la aplicación de procesos como extrusión, deposición de energía directa, solidificación de polvo, laminación de hoja y fotopolimerización. Este último consiste en paso a paso UV curado de resinas de fotopolímero líquido. En 1986, casco y sus colaboradores desarrollaron el aparato de la estereolitografía (SLA), una impresora 3D basada en láser UV. Más recientemente, un proceso similar llamado luz digital (DLP) de procesamiento ha estado disponible, en que photopolymerization es iniciado por un proyector de luz. Juntos, DLP y SLA se denominan estereolitografía 3D impresión3.
SLA aplica en alta resolución de prototipos y fabricación de dispositivos biomédicos4,5. Esta tecnología es superior a la deposición fundida ampliamente utilizada modeling (FDM) en términos de precisión, acabado superficial y resolución6. Dependiendo de la arquitectura del producto, una estructura de apoyo está integrada en el modelo 3D para estabilizar la construcción durante la fabricación. Además, un tratamiento post-impresión de piezas fabricadas es necesario7,8. Por lo general, objetos impresos son lavados en un baño de alcohol para disolver resina sin reaccionar y posterior curado en horno UV se realiza para garantizar la completa conversión de la polimerización9.
En general, resinas para la fabricación aditiva basada en litografía dependen de sistemas fotocurables que contiene acrilatos o epóxidos multifuncional10. Resinas de fotopolímeros actuales en el mercado comercial son fósil y caros, mientras que la disponibilidad de resinas renovables de bajo costo es necesario para facilitar la fabricación local y libre de residuos de productos 3D sostenibles para una economía de base biológica1 , 6. recientemente, fotopolímero resinas a base de acrilatos renovables desarrolladas y aplicadas con éxito en estereolitografía 3D impresión11,12. En este protocolo detallado, demostramos la creación rápida de prototipos con resinas de base biológica sobre un aparato comercial de estereolitografía. Se presta especial atención a los pasos críticos en el procedimiento, es decir, resina de formulación y posterior impresión de tratamientos, para ayudar a los nuevos profesionales en el campo de la fabricación aditiva.

<table><tbody><tr><td>Isobornyl acrylate&amp;nbsp;</td><td>Sartomer</td><td>SA5102</td><td>Acrylate monomer</td></tr><tr><td>1,10-decanediol diacrylate</td><td>Sartomer</td><td>SA5201</td><td>Acrylate monomer</td></tr><tr><td>Pentaerythritol tetraacrylate</td><td>Sartomer</td><td>SA5400</td><td>Acrylate monomer</td></tr><tr><td>Multifunctional epoxy acrylate</td><td>Sartomer</td><td>SA7101</td><td>Acrylate oligomer</td></tr><tr><td>Diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO), 97%</td><td>Sigma Aldrich</td><td>415952</td><td>Photoinitiator</td></tr><tr><td>2,5-bis(5-&lt;em&gt;tert&lt;/em&gt;-butyl-benzoxazol-2-yl)thiophene (BBOT), 99%</td><td>Sigma Aldrich</td><td>223999</td><td>Optical absorber</td></tr><tr><td>Isopropyl alcohol (IPA), 99%</td><td>Bleko</td><td>1010500</td><td>For alcohol bath (applied in Form Wash)</td></tr><tr><td>Paar Physica MCR300&amp;nbsp;</td><td>Anton Paar</td><td>-</td><td>Rheometer with parallel plate geometry</td></tr><tr><td>Form 2 Printer</td><td>Formlabs</td><td>-</td><td>Desktop SLA 3D printer</td></tr><tr><td>Form Wash&amp;nbsp;</td><td>Formlabs</td><td>-</td><td>Washing station</td></tr><tr><td>Form Cure</td><td>Formlabs</td><td>-</td><td>UV oven</td></tr><tr><td>Instron 4301 1KN Series IX</td><td>Instron</td><td>-</td><td>Universal testing machine</td></tr><tr><td>Philips XL30 ESEM-FEG&amp;nbsp;</td><td>Philips</td><td>-</td><td>Scanning electron microscope</td></tr></tbody></table>

stereolithographic 3d printing with renewable acrylates

La accesibilidad de materiales renovables competitivos en costo y su aplicación en la fabricación aditiva es esencial para una economía de base biológica eficiente. Demostramos la creación rápida de prototipos de resinas sostenibles mediante una impresora 3D de stereolithographic. Formulación de resina ocurre por simple mezcla de base biológica acrilato monómeros y oligómeros con photoinitiatior y amortiguador de óptico. Viscosidad de la resina es controlado por el monómero al cociente de oligómero y se determina en función de la tarifa del esquileo de un reómetro con geometría de placas paralelas. Un aparato de stereolithographic cargado con las resinas de base biológica se emplea para producir prototipos forma complejos con gran precisión. Los productos requieren un tratamiento posterior, como enjuague de alcohol y la irradiación UV, para asegurar un curado completo. La resolución de la característica alto y excelente superficie de acabado de los prototipos es revelado por microscopía electrónica de barrido.

Cuatro composiciones de resina representativos se muestran en la tabla 1, junto con su contenido de carbono promedio de base biológica (A.C.) derivada de el BC individual de los componentes. La viscosidad de la resina (figura 1) está influenciada por la proporción de monómeros de acrilato y oligómeros y típicamente demuestra comportamiento newtoniano. Las propiedades mecánicas de piezas fabricadas de varias resinas fueron determinadas ...

Watch this Scientific Journal Video about Stereolithographic 3D Printing with Renewable Acrylates at JoVE.com

Stereolithographic 3D Printing with Renewable Acrylates

Se presenta un protocolo para la fabricación aditiva con resinas renovables fotopolímero en un aparato de estereolitografía.

Impresión 3D stereolithographic con acrilatos renovables

The accessibility of cost-competitive renewable materials and their application in additive manufacturing is essential for an efficient biobased economy. ...

stereolithographic-3d-printing-with-renewable-acrylates

Universidad de Cartagena UDEC

Research

JoVE Journal

Chemistry

9.4K vistas.  NHL Stenden University of Applied Sciences. Se presenta un protocolo para la fabricación aditiva con resinas renovables fotopolímero en un aparato de estereolitografía.

Video: Stereolithographic 3D Printing with Renewable Acrylates

Planar and Three-Dimensional Printing of Conductive Inks

Printed electronics rely on low-cost, large-area fabrication routes to create flexible or multidimensional electronic, optoelectronic, and biomedical devices1-3. In this paper, we focus on one- (1D), two- (2D), and three-dimensional (3D) printing of conductive metallic inks in the form of flexible, stretchable, and spanning microelectrodes.
Direct-write assembly4,5 is a 1-to-3D printing technique that enables the fabrication of features ranging from simple lines to complex structures by the deposition of concentrated inks through fine nozzles (~0.1 - 250 &mu;m). This printing method consists of a computer-controlled 3-axis translation stage, an ink reservoir and nozzle, and 10x telescopic lens for visualization. Unlike inkjet printing, a droplet-based process, direct-write assembly involves the extrusion of ink filaments either in- or out-of-plane. The printed filaments typically conform to the nozzle size. Hence, microscale features (&lt; 1 &mu;m) can be patterned and assembled into larger arrays and multidimensional architectures.
In this paper, we first synthesize a highly concentrated silver nanoparticle ink for planar and 3D printing via direct-write assembly. Next, a standard protocol for printing microelectrodes in multidimensional motifs is demonstrated. Finally, applications of printed microelectrodes for electrically small antennas, solar cells, and light-emitting diodes are highlighted.

Planar and three-dimensional printing of conductive metallic inks is described. Our approach provides new avenues for fabricating printed electronic, optoelectronic, and biomedical devices in unusual layouts at the microscale.

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 ...

Investigación

Bioingeniería

3D Printing of Biomolecular Models for Research and Pedagogy

The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D structures are most often perceived using the two-dimensional and exclusively visual medium of the computer screen. Converting digital 3D molecular data into real objects enables information to be perceived through an expanded range of human senses, including direct stereoscopic vision, touch, and interaction. Such tangible models facilitate new insights, enable hypothesis testing, and serve as psychological or sensory anchors for conceptual information about the functions of biomolecules. Recent advances in consumer 3D printing technology enable, for the first time, the cost-effective fabrication of high-quality and scientifically accurate models of biomolecules in a variety of molecular representations. However, the optimization of the virtual model and its printing parameters is difficult and time consuming without detailed guidance. Here, we provide a guide on the digital design and physical fabrication of biomolecule models for research and pedagogy using open source or low-cost software and low-cost 3D printers that use fused filament fabrication technology.

Physical models of biomolecules can facilitate an understanding of their structure-function for the researcher, aid in communication between researchers, and serve as an educational tool in pedagogical endeavors. Here, we provide detailed guidance for the 3D printing of accurate models of biomolecules using fused filament fabrication desktop 3D printers.

La impresión 3D de Modelos de Investigación Biomolecular y Pedagogía

The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D ...

Ingeniería

Printing Thermoresponsive Reverse Molds for the Creation of Patterned Two-component Hydrogels for 3D Cell Culture

Bioprinting is an emerging technology that has its origins in the rapid prototyping industry. The different printing processes can be divided into contact bioprinting1-4 (extrusion, dip pen and soft lithography), contactless bioprinting5-7 (laser forward transfer, ink-jet deposition) and laser based techniques such as two photon photopolymerization8. It can be used for many applications such as tissue engineering9-13, biosensor microfabrication14-16 and as a tool to answer basic biological questions such as influences of co-culturing of different cell types17. Unlike common photolithographic or soft-lithographic methods, extrusion bioprinting has the advantage that it does not require a separate mask or stamp. Using CAD software, the design of the structure can quickly be changed and adjusted according to the requirements of the operator. This makes bioprinting more flexible than lithography-based approaches.
Here we demonstrate the printing of a sacrificial mold to create a multi-material 3D structure using an array of pillars within a hydrogel as an example. These pillars could represent hollow structures for a vascular network or the tubes within a nerve guide conduit. The material chosen for the sacrificial mold was poloxamer 407, a thermoresponsive polymer with excellent printing properties which is liquid at 4 &deg;C and a solid above its gelation temperature ~20 &deg;C for 24.5% w/v solutions18. This property allows the poloxamer-based sacrificial mold to be eluted on demand and has advantages over the slow dissolution of a solid material especially for narrow geometries. Poloxamer was printed on microscope glass slides to create the sacrificial mold. Agarose was pipetted into the mold and cooled until gelation. After elution of the poloxamer in ice cold water, the voids in the agarose mold were filled with alginate methacrylate spiked with FITC labeled fibrinogen. The filled voids were then cross-linked with UV and the construct was imaged with an epi-fluorescence microscope.

A bioprinter was used to create patterned hydrogels based on a sacrificial mold. The poloxamer mold was backfilled with a second hydrogel and then eluted, leaving voids which were filled with a third hydrogel. This method uses fast elution and good printability of poloxamer to generate complex architectures from biopolymers.

Impresión Moldes inversa termosensible para la Creación de modelado hidrogeles de dos componentes para el 3D de cultivo celular

Bioprinting is an emerging technology that has its origins in the rapid prototyping industry. The different printing processes can be divided into contact ...

Inmunología e Infección

Procedure for the Transfer of Polymer Films Onto Porous Substrates with Minimized Defects

The fabrication of devices containing thin film composite membranes necessitates the transfer of these films onto the surfaces of arbitrary support substrates. Accomplishing this transfer in a highly controlled, mechanized, and reproducible manner can eliminate the creation of macroscale defect structures (e.g., tears, cracks, and wrinkles) within the thin film that compromise device performance and the usable area per sample. Here, we describe a general protocol for the highly controlled and mechanized transfer of a polymeric thin film onto an arbitrary porous support substrate for eventual use as a water filtration membrane device. Specifically, we fabricate a block copolymer (BCP) thin film on top of a sacrificial, water-soluble poly(acrylic acid) (PAA) layer and silicon wafer substrate. We then utilize a custom-designed, 3D-printed transfer tool and drain chamber system to deposit, lift-off, and transfer the BCP thin film onto the center of a porous anodized aluminum oxide (AAO) support disc. The transferred BCP thin film is shown to be consistently placed onto the center of the support surface due to the guidance of the meniscus formed between the water and the 3D-printed plastic drain chamber. We also compare our mechanized transfer-processed thin films to those that have been transferred by hand with the use of tweezers. Optical inspection and image analysis of the transferred thin films from the mechanized process confirm that little-to-no macroscale inhomogeneities or plastic deformations are produced, as compared to the multitude of tears and wrinkles produced from manual transfer by hand. Our results suggest that the proposed strategy for thin film transfer can reduce defects when compared to other methods across many systems and applications.

We present a procedure for highly controlled and wrinkle-free transfer of block copolymer thin films onto porous support substrates using a 3D-printed drain chamber. The drain chamber design is of general relevance to all procedures involving transfer of macromolecular films onto porous substrates, which is normally done by hand in an irreproducible fashion.

Procedimiento para la transferencia de películas de polímeros a sustratos porosos con defectos minimizados

The fabrication of devices containing thin film composite membranes necessitates the transfer of these films onto the surfaces of arbitrary support ...

Three-dimensional Biomimetic Technology: Novel Biorubber Creates Defined Micro- and Macro-scale Architectures in Collagen Hydrogels

Tissue scaffolds play a crucial role in the tissue regeneration process. The ideal scaffold must fulfill several requirements such as having proper composition, targeted modulus, and well-defined architectural features. Biomaterials that recapitulate the intrinsic architecture of in vivo tissue are vital for studying diseases as well as to facilitate the regeneration of lost and malformed soft tissue. A novel biofabrication technique was developed which combines state of the art imaging, three-dimensional (3D) printing, and selective enzymatic activity to create a new generation of biomaterials for research and clinical application. The developed material, Bovine Serum Albumin rubber, is reaction injected into a mold that upholds specific geometrical features. This sacrificial material allows the adequate transfer of architectural features to a natural scaffold material. The prototype consists of a 3D collagen scaffold with 4 and 3 mm channels that represent a branched architecture. This paper emphasizes the use of this biofabrication technique for the generation of natural constructs. This protocol utilizes a computer-aided software (CAD) to manufacture a solid mold which will be reaction injected with BSA rubber followed by the enzymatic digestion of the rubber, leaving its architectural features within the scaffold material.

An innovative biofabrication technique was developed to engineer three-dimensional constructs that resemble the architectural features, components, and mechanical properties of in vivo tissue. This technique features a newly developed sacrificial material, BSA rubber, which transfers detailed spatial features, reproducing the in vivo architectures of a wide variety of tissues.

Tridimensional Tecnología Biomimética: Novel biorubber Crea Definido micro y macro escala Arquitecturas de colágeno hidrogeles

Tissue scaffolds play a crucial role in the tissue regeneration process. The ideal scaffold must fulfill several requirements such as having proper ...

Multimodal 3D Printing of Phantoms to Simulate Biological Tissue

Biomedical optical imaging is playing an important role in diagnosis and treatment of various diseases. However, the accuracy and the reproducibility of an optical imaging device are greatly affected by the performance characteristics of its components, the test environment, and the operations. Therefore, it is necessary to calibrate these devices by traceable phantom standards. However, most of the currently available phantoms are homogeneous phantoms that cannot simulate multimodal and dynamic characteristics of biological tissue. Here, we show the fabrication of heterogeneous tissue-simulating phantoms using a production line integrating a spin coating module, a polyjet module, a fused deposition modeling (FDM) module, and an automatic control framework. The structural information and the optical parameters of a &#34;digital optical phantom&#34; are defined in a prototype file, imported to the production line, and fabricated layer-by-layer with sequential switch between different printing modalities. Technical capability of such a production line is exemplified by the automatic printing of skin-simulating phantoms that comprise the epidermis, dermis, subcutaneous tissue, and an embedded tumor.

Spin coating, polyjet printing, and fused deposition modeling are integrated to produce multilayered heterogeneous phantoms that simulate structural and functional properties of biological tissue.

Impresión 3D multimodal de fantasmas para simular tejido biológico

Biomedical optical imaging is playing an important role in diagnosis and treatment of various diseases. However, the accuracy and the reproducibility of ...

Interactive Molecular Model Assembly with 3D Printing

With the growth in accessibility of 3D printing, there has been a growing application of and interest in additive manufacturing processes in chemical laboratories and chemical education. Building on the long and successful history of physical modeling of molecular systems, we present select models along with a protocol to facilitate 3D printing of molecular structures that are able to do more than represent shape and connectivity. Models assembled as described incorporate dynamic aspects and degrees of freedom into saturated hydrocarbon structures. As a representative example, cyclohexane was assembled from parts printed and finished using different thermoplastics, and the resulting models retain their functionality at a variety of scales. The resulting structures show configurational space accessibility consistent with calculations and literature, and versions of these structures can be used as aids to illustrate concepts that are difficult to convey in other ways. This exercise enables us to evaluate successful printing protocols, make practical recommendations for assembly, and outline design principles for physical modeling of molecular systems. The provided structures, procedures, and results provide a foundation for individual manufacture and exploration of molecular structure and dynamics with 3D printing.

Physical modeling of microscopic systems helps obtain insights that are difficult to gain by other means. To facilitate the construction of physical molecular models, we demonstrate how 3D printing can be used to assemble functional macroscopic models that capture qualities of molecular systems in a tactile way.

Ensamblaje de modelo molecular interactivo con impresión 3D

With the growth in accessibility of 3D printing, there has been a growing application of and interest in additive manufacturing processes in chemical ...

Química

3D Printing and In Situ Surface Modification via Type I Photoinitiated Reversible Addition-Fragmentation Chain Transfer Polymerization

3D printing provides facile access to geometrically complex materials. However, these materials have intrinsically linked bulk and interfacial properties dependent on the chemical composition of the resin. In the current work, 3D printed materials are post-functionalized using the 3D printer hardware via a secondary surface-initiated polymerization process, thus providing independent control over the bulk and interfacial material properties. This process begins with preparing liquid resins, which contain a monofunctional monomer, a crosslinking multifunctional monomer, a photochemically labile species that enables initiation of polymerization, and critically, a thiocarbonylthio compound which facilitates reversible addition-fragmentation chain transfer (RAFT) polymerization. The thiocarbonylthio compound, known commonly as a RAFT agent, mediates the chain growth polymerization process and provides polymeric materials with more homogeneous network structures. The liquid resin is cured in a layer-by-layer fashion using a commercially available digital light processing 3D printer to give three-dimensional materials having spatially controlled geometries. The initial resin is removed and replaced with a new mixture containing functional monomers and photoinitiating species. The 3D printed material is then exposed to light from the 3D printer in the presence of the new functional monomer mixture. This allows photoinduced surface-initiated polymerization to occur from the latent RAFT agent groups on the surface of the 3D printed material. Given the chemical flexibility of both resins, this process allows a wide range of 3D printed materials to be produced with tailorable bulk and interfacial properties.

3D Printing and In Situ Surface Modification via Type I Photoinitiated Reversible Addition-Fragmentation Chain Transfer Polymerization

The present protocol describes the digital light processing-based 3D printing of polymeric materials using type I photoinitiated reversible addition-fragmentation chain transfer polymerization and the subsequent in situ material post-functionalization via surface-mediated polymerization. Photoinduced 3D printing provides materials with independently tailored and spatially controlled bulk and interfacial properties.

Impresión 3D y modificación de superficies in situ mediante polimerización de transferencia de cadena de adición reversible-fragmentación fotoiniciada tipo I

3D printing provides facile access to geometrically complex materials. However, these materials have intrinsically linked bulk and interfacial properties ...

Novel Process for 3D Printing Decellularized Matrices

3D bioprinting aims to create custom scaffolds that are biologically active and accommodate the desired size and geometry. A thermoplastic backbone can provide mechanical stability similar to native tissue while biologic agents offer compositional cues to progenitor cells, leading to their migration, proliferation, and differentiation to reconstitute the original tissues/organs1,2. Unfortunately, many 3D printing compatible, bioresorbable polymers (such as polylactic acid, PLA) are printed at temperatures of 210 &#176;C or higher - temperatures that are detrimental to biologics. On the other hand, polycaprolactone (PCL), a different type of polyester, is a bioresorbable, 3D printable material that has a gentler printing temperature of 65 &#176;C. Therefore, it was hypothesized that decellularized extracellular matrix (DM) contained within a thermally protective PLA barrier could be printed within PCL filament and remain in its functional conformation. In this work, osteochondral repair was the application for which the hypothesis was tested. As such, porcine cartilage was decellularized and encapsulated in polylactic acid (PLA) microspheres which were then extruded with polycaprolactone (PCL) into filament to produce 3D constructs via fused deposition modeling. The constructs with or without the microspheres (PLA-DM/PCL and PCL(-), respectively) were evaluated for differences in surface features.

This protocol describes the production of polycaprolactone (PCL) filament with embedded polylactic acid (PLA) microspheres which contain decellularized matrices (DM) for 3D printing of structural tissue engineering constructs.

Novedoso proceso para la impresión 3D Decellularized Matrices

3D bioprinting aims to create custom scaffolds that are biologically active and accommodate the desired size and geometry. A thermoplastic backbone can ...

Hidrogeles bioimpresos fotoajustables para sondear las respuestas celulares al endurecimiento de la MEC

3D Bioprinting Phototunable Hydrogels to Study Fibroblast Activation

Phototunable hydrogels can transform spatially and temporally in response to light exposure. Incorporating these types of biomaterials in cell-culture platforms and dynamically triggering changes, such as increasing microenvironmental stiffness, enables researchers to model changes in the extracellular matrix (ECM) that occur during fibrotic disease progression. Herein, a method is presented for 3D bioprinting a phototunable hydrogel biomaterial capable of two sequential polymerization reactions within a gelatin support bath. The technique of Freeform Reversible Embedding of Suspended Hydrogels (FRESH) bioprinting was adapted by adjusting the pH of the support bath to facilitate a Michael addition reaction. First, the bioink containing poly(ethylene glycol)-alpha methacrylate (PEG&#945;MA) was reacted off-stoichiometry with a cell-degradable crosslinker to form soft hydrogels. These soft hydrogels were later exposed to photoinitator and light to induce the homopolymerization of unreacted groups and stiffen the hydrogel. This protocol covers hydrogel synthesis, 3D bioprinting, photostiffening, and endpoint characterizations to assess fibroblast activation within 3D structures. The method presented here enables researchers to 3D bioprint a variety of materials that undergo pH-catalyzed polymerization reactions and could be implemented to engineer various models of tissue homeostasis, disease, and repair.

Autor destacado: Comprensión de las enfermedades pulmonares crónicas mediante hidrogeles fotoajustables impresos en 3D 

This article describes how to 3D bioprint phototunable hydrogels to study extracellular matrix stiffening and fibroblast activation.

Bioimpresión 3D de hidrogeles fotoajustables para estudiar la activación de fibroblastos

Phototunable hydrogels can transform spatially and temporally in response to light exposure. Incorporating these types of biomaterials in cell-culture ...