3D Freeform Ice Printing to Create Tissues with Biomimetic Vasculature

项目总结 三十多年来，科学家们一直渴望创造出模仿非凡生物的工程化组织 天然组织的生理和功能特性。这种组织和器官不仅可以用于 移植以拯救生命，也用于体外芯片上组织方法来测试药物 对病原体的反应。然而，我们仍然缺乏创造具有三维组织模拟的组织的能力 脉管系统。没有3D、光滑的分支和多尺度的血管网络，这有助于营养/氧气 由于细胞死亡受到扩散的限制，工程化的全层组织将不能完全发挥功能。AS 这样的仿生血管网络对于可行的和临床相关的组织结构非常重要。 我们提出了一种创新的方法来解决用仿生技术制造组织结构的挑战 脉管系统。我们的方法涉及牺牲血管模板的3D自由形式冰打印并使用它们 制作用于创建仿生血管组织构造物的支架。我们新颖的3D自由形式(与之相反 到逐层)冰打印工艺独特地能够制造模仿几何形状的冰模板 实际的血管系统，包括复杂的形状、圆形的横截面、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冰块打印技术使 创建具有仿生3D血管网络的组织支架。在这个R21项目中，我们的目标是开发我们的 基于3D冰块打印的血管组织构建平台及其可行性 具有3D仿生血管系统的人体皮肤芯片上组织系统，在未来也可以用于 组织植入。我们的初步结果表明，我们通常有能力打印多尺度的冰结构，制造 具有血管导管的多孔支架，并在可溶解的多孔上生长内皮细胞和成纤维细胞 脚手架。拟议的研究旨在显示我们的方法的可行性，以创造血管 纸巾。根据我们的初步数据和公布的经验，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冰打印技术的开发，以重现定义的仿生技术 多孔组织支架内的血管构筑。目标2将演示我们创建3D血管化的方法 芯片上的组织构建使用制造的支架和多个细胞系统。 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， 直接涉及提议的项目。私人投资机构有长达十年的强大合作历史，包括 共同为博士生提供建议，并出版了多本合著的出版物。我们期待这项工作的结果将带来 能够创建具有3D仿生血管的组织支架，以创建许多不同的血管化 未来的组织和器官。这将对组织工程领域产生深远的影响，影响组织- 芯片上、患者特定的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.