这项研究得到 greenpac 公司聚合物应用中心的支持, 作为项目140413的一部分: "3D 印刷生产"。我们要感谢哈特曼, 科琳面包车 Noordenne, Rens 面包车 Leeuwen, Anniek 熊, Femke Tamminga, 范本面包车 Dijken 和阿尔伯特 Woortman, 以促进视频拍摄。

警告: 使用前请查阅所有相关的材料安全数据表 (MSDS)。
1. 光敏树脂的制备
注: 请在以下程序中使用个人防护设备 (安全眼镜、手套、实验室大衣)。有关本节的详细信息, 请参阅我们以前的工作12 。
<ol><li>将50克 110-decanediol 丙烯酸酯 (SA5201) 倒入500毫升锥形瓶中。</li>
	<li>将1.0 克 (24, 6-trimethylbenzoyl) 氢氧化膦 (TPO) 和0.40 克的 25-双(5-叔丁基 benzoxazol-2 基) 噻吩 (BBOT) 添加到烧瓶中。</li>
	<li>用机械搅拌器将烧瓶装上, 在室温下搅拌200转5分钟的混合物, 以溶解丙烯酸酯单体中的 TPO 和 BBOT。</li>
	<li>添加100克季戊四醇丙烯酸酯和100克多功能环氧丙烯酸酯 (见材料表) 的混合物。</li>
	<li>搅拌的混合物在 200 rpm 30 分钟在50摄氏度, 以确保均匀树脂。</li>
	<li>拆卸机械搅拌器, 用塞子装瓶。该烧瓶包裹在铝箔, 以保护生物基丙烯酸酯光敏树脂 (BAPR) 从光。 注意: 协议可以在这里暂停。</li>
	<li>用 photoresin 覆盖带有平行板几何的流变仪的底板。</li>
	<li>设置在1毫米的板块之间的差距, 并涵盖了流变仪与防紫外线罩。</li>
	<li>以0.1 至 100s-1的剪切速率测定室温下的树脂粘度;例如,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 和 100s15.8。</li>
</ol>2. 生物基丙烯酸酯 Stereolithographic 3D 印花
注: 有关本节的详细信息, 请参阅我们以前的工作12 。
<ol><li>打开 SLA 3D 打印机, 然后选择 "打开模式"。</li>
	<li>在计算机上启动模型准备软件。选择所需的打印设置: 材质 (清除)、版本 (V4) 和层厚度 (50 µm)。</li>
	<li>打开复杂形状原型的数字模型, 一个标准的镶嵌语言 (. stl) 文件 (请参阅补充编码文件), 并选择生成平台上的位置和方向。 将打印作业从模型准备软件上载到 SLA 3D 打印机。 注意: 根据产品的体系结构, 支持结构可以集成在3D 模型中, 以在制造过程中稳定构造。如果在这里演示的是复杂形状的原型, 则在打印正常到生成方向时不需要支持结构。</li>
	<li>将200毫升的生物基 photoresin 倒入树脂罐中。打开3D 打印机, 正确安装树脂罐。</li>
	<li>装入生成平台并关闭3D 打印机。</li>
	<li>启动打印作业。</li>
	<li>允许3D 打印机制造复杂形状的原型。 在打印作业完成之前, 请勿打开打印机。 注意: 打印前, 请确保3D 打印机已被调配。对于演示的协议, 紫外线激光器的波长是 405 nm。对象的打印时间为2.5 小时。</li>
</ol>3. 3D 打印对象的后处理
注: 请在以下程序中使用个人防护设备 (安全眼镜、手套)。
<ol><li>打印作业完成后, 打开打印机。卸下生成平台, 并连接已生成的部件, 然后关闭打印机。</li>
	<li>打开洗涤站, 填充异丙醇, 并插入生成平台。启动过程, 冲洗20分钟, 以去除任何反应树脂。</li>
	<li>冲洗过程完成后, 从洗涤站中取出生成平台, 并将原型从生成平台中分离出来。</li>
	<li>让原型空气干燥30分钟。同时, 将 UV 烤箱预热60摄氏度。 注: 预热至少要15分钟。烤箱的紫外线波长是405毫微米, 与 SLA 激光器的波长相同。</li>
	<li>打开 UV 烤箱, 快速将原型放在旋转平台上。关闭 UV 烤箱和治疗60分钟在60摄氏度, 以确保完全转换。</li>
	<li>固化后的工序完成后, 打开 UV 烤箱, 取出原型。</li>
</ol>4. 复杂形状原型的表面形貌表征
注: 有关本节的详细信息, 请参阅我们以前的工作12 。
<ol><li>用剃刀刀片从复杂形状的原型中切割出约1厘米的内部螺旋线。</li>
	<li>将样品附着在带双面碳导电胶带的样品架上。</li>
	<li>在成像之前, 在溅射系统上涂上30纳米 Pt/Pd (80:20) 的样品。</li>
	<li>将样品插入扫描电子显微镜中, 以5伏的加速电压运行。以30X 和120X 放大倍数获取样本的多个图像。</li>
</ol>

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作者没有什么可透露的。

添加剂制造是应用于制造的量身定做的原型和小系列, 当较高的生产成本, 每部分可以与常规工艺竞争, 因为不需要生产模具和工具。在过去十年中, 与添加剂制造业有关的服务和产品的收入增长了13。材料销售的最大部分来自 photopolymers。这一增长引起了人们的关注, 并发起了主要工业的投资,例如航空航天、汽车、医疗。因此, 3D 印刷领域有望在未来几年内进一步扩大。
...

快速原型实现了按需生产和设计自由, 并允许以逐层方式有效地制造3D 结构1。因此, 3D 印刷作为一种制造技术, 近年来发展迅速,2。各种技术都是可用的, 都依赖于将虚拟模型转换为物理对象, 并应用挤压、直接能量沉积、粉末凝固、薄板层压和聚合等过程。后者涉及逐步 UV 固化液体光敏树脂。在 1986年, 赫尔和同事们开发了光固化成形设备 (SLA), 一种 UV 激光3D 打印机。最近, 一个类似的过程称为数字光处理 (DLP) 已经成为可用, 其中聚合是由一个轻型投影机启动。DLP 和 SLA 一起称为光固化成形3D 打印3。
SLA 应用于高分辨率的生物医学器件的原型制作和制造4,5。该技术在精度、表面处理和分辨率6方面优于广泛应用的熔融沉积模型。根据产品的体系结构, 在3D 模型中集成了一个支持结构, 以在制造过程中稳定构造。此外, 印刷后处理的制造零件是需要7,8。通常, 打印的对象被洗涤在酒精浴溶化反应树脂, 并且后续固化在一个 UV 烤箱被执行保证9聚合的完全转换。
一般而言, 基于光刻的添加剂制造的树脂依赖于含有多功能丙烯酸酯或环氧化合物10的光敏系统。目前商业市场上的光敏树脂是基于化石和昂贵的, 而低成本再生树脂的供应是需要的, 以促进生物基经济的可持续3D 产品的无废料和本地制造1,6. 最近, 以可再生丙烯酸酯为基础的光敏树脂被开发并成功应用于光固化成形3D 印刷11,12。在这个详细的协议中, 我们展示了生物基树脂在商用光固化成形设备上的快速原型。特别注意程序中的关键步骤,即树脂配方和印后处理, 以帮助在添加剂制造领域的新从业者。

<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

具有成本竞争性的可再生材料的可获得性及其在添加剂制造中的应用是有效生物基经济的关键。我们展示了可持续树脂的快速原型使用 stereolithographic 3D 打印机。树脂配方是通过直接混合生物基丙烯酸酯单体和寡聚物与 photoinitiatior 和光吸收器。树脂粘度受单体对低聚比的控制, 由平行板几何流变仪确定为剪切速率函数。用生物基树脂充电的 stereolithographic 装置, 用于生产复杂形状的原型, 精度高。该产品需要后处理, 包括酒精冲洗和紫外线照射, 以确保完全固化。通过扫描电镜, 揭示了原型的高特征分辨率和良好的表面整理。

表 1显示了四种代表性树脂组合物, 以及它们的平均生物基碳含量 (bc), 这些成分来自于该组件的单个 BC。树脂粘度 (图 1) 受丙烯酸酯单体和寡聚物比例的影响, 典型表现为牛顿行为。用应力-应变分析法测定了不同树脂制造的零件的力学性能。图 2显示了在通用测试机上以电子模量和抗拉强度计算的代表性结果。打印?...

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

Stereolithographic 3D Printing with Renewable Acrylates

介绍了一种可再生光敏树脂在光固化成形装置上的添加剂制造协议。

Stereolithographic 3D 印刷用可再生丙烯酸酯

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 次观看.  NHL Stenden University of Applied Sciences. 介绍了一种可再生光敏树脂在光固化成形装置上的添加剂制造协议。

视频: 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.

平面和立体印刷的导电油墨

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

科研

生物工程

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.

生物分子模型的3D打印技术的研究与教学

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

工程学

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.

打印温敏反向模具图案创作的双组分水凝胶的三维细胞培养

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

免疫与感染

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.

聚合物薄膜在多孔基板上的转移程序,具有最小化的缺陷

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.

三维仿生技术:新型Biorubber创建自定义微观和宏观尺度架构的胶原凝胶

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.

幻影的多模态3D打印模拟生物组织

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.

带 3D 打印的交互式分子模型组件

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

化学

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.

通过I型光引发可逆加成-碎片链转移聚合进行3D打印和原位表面改性

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.

一种新的三维打印解光矩阵处理方法

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

光调谐生物打印水凝胶，用于探测细胞对 ECM 硬化的反应

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.

作者聚焦：使用 3D 打印光可调谐水凝胶了解慢性肺病 

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

3D生物打印光可调水凝胶研究成纤维细胞活化

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