3D Freeform Ice Printing to Create Tissues with Biomimetic Vasculature

项目摘要 三十多年来，科学家们一直渴望创造出能够模仿人类非凡的 天然组织的生理和功能特性。这些组织和器官不仅可以用于 移植来挽救生命，而且还用于体外组织芯片方法来测试药物， 对病原体的反应。然而，我们仍然缺乏利用三维组织模拟技术来创建组织的能力， 脉管系统没有3D、光滑的分支和多尺度血管网络，这有助于营养/氧气 由于细胞死亡受到扩散的限制，工程化的全厚度组织将不能完全发挥功能。作为 这样的仿生脉管系统网络对于有活力的和临床相关的组织构建体是非常重要的。 我们提出了一种创新的方法来解决仿生组织构建的挑战， 脉管系统我们的方法涉及牺牲脉管系统模板的3D自由形式冰打印，并使用它们 来制造用于创建仿生血管化组织构造的支架。我们新颖的3D自由形式（相对于 到逐层）冰打印过程独特地使得能够制造模仿冰模板的几何形状的冰模板。 实际的脉管系统，包括复杂的形状，圆形横截面，以及不同的直径和分支 具有平滑过渡的结构。我们的基本假设是，我们的3D冰打印技术能够实现 创建具有仿生3D脉管系统网络的组织支架。在这个R21项目中，我们的目标是开发我们的 基于3D冰打印的血管化组织制造平台，并通过创建 具有3D仿生脉管系统的人类皮肤组织芯片系统，在未来也可用于 组织移植我们的初步结果显示了我们打印多尺度冰结构的一般能力， 多孔支架与血管管道，并生长内皮细胞和成纤维细胞在多孔可溶性 脚手架拟议的研究旨在显示我们的方法对建立血管化的可行性 组织中根据我们的初步数据和已发表的经验，我们的方法将涉及两个具体目标： 目标1将专注于我们的3D冰打印技术的发展，以可重复地创建定义的仿生 多孔组织支架内的脉管系统。目的2将展示我们的方法，创造3D血管化 使用制造的支架和多细胞系统的芯片上组织构建体。 我们的跨学科项目团队结合了互补的专业知识和研究基础设施， 直接针对拟议的项目。PI拥有长达十年的强大合作历史，包括 共同建议博士生和多个共同撰写的出版物。我们希望这项工作的结果将带来 能够创建具有3D仿生血管系统的组织支架，以创建许多不同的血管化 组织和器官。这将对组织工程领域产生深远的影响，影响组织- 芯片、患者特异性器官移植和再生医学领域。

PROJECT SUMMARY For more than three decades, scientists have aspired to create engineered tissues that mimic the remarkable physiological and functional properties of natural tissues. Such tissues and organs can be used not only for transplantation to save lives but also for ex vivo tissue-on-a-chip approaches to test pharmaceuticals the response to pathogens. However, we still lack the ability to create tissues with three-dimensional tissue-mimetic vasculature. Without 3D, smooth branched, and multi-scale vascular networks, which facilitate nutrient/oxygen transport, engineered full-thickness tissues will not be fully functional due to cell death limited by diffusion. As such, biomimetic vasculature networks are very important for viable and clinically relevant tissue constructs. We propose an innovative approach to address the challenge of fabricating tissue constructs with biomimetic vasculature. Our approach involves 3D freeform ice printing of sacrificial vasculature templates and uses them to fabricate scaffolds for creating biomimetic vascularized tissue constructs. Our novel 3D freeform (as opposed to layer-by-layer) ice printing process uniquely enables fabricating ice templates that mimic the geometry of the actual vasculature, including complex shapes, circular cross-sections, and varying diameters and branched structures with smooth transitions. Our fundamental hypothesis is that our 3D ice printing technique enables the creation of tissue scaffolds with biomimetic 3D vasculature networks. In this R21 project, we aim to develop our 3D ice printing-based vascularized tissue fabrication platform and to demonstrate its feasibility by creating human-skin tissue-on-a-chip systems with 3D biomimetic vasculature that also in the future can be used for tissue implantation. Our preliminary results show our general ability to print multi-scale ice structures, fabricate porous scaffolds with vasculature conduits, and grow endothelial and fibroblasts cells on porous dissolvable scaffolds. The proposed studies aim to show the feasibility of our approach towards creating vascularized tissues. Our approach, based on our preliminary data and published experience, will involve two Specific Aims: Aim 1 will focus on the development of our 3D ice printing technique to reproducibly create defined biomimetic vasculature within porous tissue scaffolds. Aim 2 will demonstrate our approach for creating 3D vascularized tissue-on-a-chip constructs using the fabricated scaffolds and multiple cell systems. Our interdisciplinary project team combines complementary expertise and research infrastructure that directly addresses the proposed project. The PIs have a decade-long history of strong collaboration, including co-advised PhD students and multiple co-authored publications. We expect the results of this work will bring the ability to create tissue scaffolds with 3D biomimetic vasculature toward creating many different vascularized tissues and organs in the future. This will have a profound effect on the tissue engineering field, impacting tissue- on-a-chip, patient-specific organ transplantation, and regenerative medicine areas.