Photoabsorbing bioinks for expanding 3D printed human liver in situ

用于原位扩展 3D 打印人类肝脏的光吸收生物墨水

• 批准号: 10490395
• 负责人: Kelly R Stevens
• 金额: $ 72.05万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-21 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10490395
• 关键词: 3D Print; Address; Architecture; Artificial Liver; Artificial tissue; Biocompatible Materials; Biological; Biomedical Engineering; Bioreactors; Blood Vessels; Blood capillaries; Caliber; Cellular biology; Cessation of life; Clinical; Collaborations; Data; Disease; Donor person; Engineering; Engraftment; Formulation; Generations; Goals; Growth; Heart Diseases; Hepatic; Hepatocyte; Hepatology; Human; In Situ; Ink; Kidney Diseases; Lead; Libraries; Life; Liver; Liver Failure; Liver diseases; Lobule; Measures; Medical; Methods; Mus; Natural regeneration; Operative Surgical Procedures; Organ; Organ Transplantation; Osteogenesis; Pancreatic Diseases; Patients; Pattern; Physiology; Protein Biosynthesis; Public Health; Research; Resolution; Role; Route; Testing; Therapeutic; Tissue Engineering; Tissues; Transplantation; Work; base; bioink; bioprinting; density; drug metabolism; falls; hepatocyte engraftment; implantation; improved; in vivo; in vivo engraftment; injured; innovation; interstitial; liver injury; liver metabolism; liver transplantation; multidisciplinary; novel strategies; novel therapeutics; regenerative growth; scale up; self assembly; support network; vascular tissue engineering

Project Summary/Abstract Liver disease is a pressing public health challenge, because unlike most other major killers deaths due to liver disease are rapidly rising rather than falling. Although liver transplantation prolongs survival, there is a growing number of patients in need of transplant, but donor supply has remained stagnant. To address this major medical problem, we are working to build artificial liver tissue that could serve as a bridge or alterative to organ transplant. A crucial remaining hurdle for developing artificial liver tissue is building the multiscale vasculature needed to support billions of densely packed hepatocytes. Novel approaches that address this challenge would transform liver research and therapy. Our recent work pushed the field closer to addressing this hurdle by introducing a breakthrough method for 3D printing volumetric vascular networks in artificial tissues. This advance was made possible by addition of photoabsorbers to stereolithography bioinks, which enabled millions of voxels to be patterned over many tissue layers. Yet, tissues produced with stereolithography remain incompletely vascularized and sparsely cellularized, with functional levels that still fall short of those needed for therapy. We have recently gained important clues towards addressing this challenge. First, we identified new photoabsorber formulations that substantively improve print resolution, providing a new route to volumetrically scaling a denser vasculature. Furthermore, we found that adding biological matrices to bioinks allows us “expand” vasculature and hepatocytes within printed tissues after implantation in the body to produce tissues with native density. These data lead us to hypothesize that dual-role bioinks that support both technical and biological modes of scale-up will facilitate generation of human liver tissue with volumetric vasculature that expands in vivo. Further, such tissue will have hepatic functional levels sufficient to therapeutically treat liver disease. To test these hypotheses, we established a team with synergistic expertise in liver and vascular tissue engineering, biomaterials and bioprinting, clinical liver surgery, clinical hepatology, liver cell biology, and liver metabolism. We will employ our expertise to develop vascularized bioprinted liver tissue that grows in the body. We will first formulate a new library of bioinks for projection stereolithography with improved print resolution and bioactivity, to facilitate both 3D printing and in vivo tissue engineering (Aim 1). We will then 3D print scaled vascular topologies that mimic liver vasculature and support hepatocyte engraftment (Aim 2). Finally, we will trigger hepatocyte expansion in the tissues to achieve hepatocyte density and functional levels sufficient to rescue mice with liver injury (Aim 3). The real power of this proposal lies in conflating bioprinting and biological modes of tissue scale-up, which will transform tissue engineering and generate bioprinted liver tissue as a new therapy for liver disease. The new material bioinks and 3D printing innovations developed in proposal would also be broadly useful across diverse fields of translational biomedicine, such as heart and kidney disease.

项目摘要/摘要 肝病是一个紧迫的公共卫生挑战，因为与大多数其他主要杀手不同的是， 患肝病的人数迅速上升，而不是下降。虽然肝移植可以延长存活期，但也有 越来越多的患者需要移植，但捐赠者的供应仍然停滞不前。要解决这一重大问题 医学问题，我们正在努力建造人工肝组织，可以作为器官的桥梁或替代品 移植。发展人工肝组织的一个关键障碍是建立多尺度血管系统 需要支持数十亿密集排列的肝细胞。应对这一挑战的新方法将 转变肝脏研究和治疗。 我们最近的工作通过引入一种突破性的方法将该领域推向了解决这一障碍的更近一步 用于3D打印人造组织中的体积血管网络。这一进步是由于增加了 光吸收剂到立体平版印刷生物墨水，这使得数百万个体素能够在许多组织上图案化 层次感。然而，用立体光固化技术生产的组织仍然不完全血运，细胞稀少， 功能水平仍达不到治疗所需的水平。我们最近得到了一些重要线索 以应对这一挑战。首先，我们确定了新的光吸收剂配方， 提高打印分辨率，为体积测量更密集的血管系统提供了一条新的途径。此外，我们 发现将生物基质添加到生物墨水中可以使打印出来的血管和肝细胞“扩张” 组织植入体内后，产生具有天然密度的组织。这些数据让我们得出了假设 同时支持技术和生物放大模式的双重角色生物墨水将促进 人体肝组织，具有在体内扩张的体积血管。此外，这样的组织会有肝脏 足以治疗肝病的功能水平。为了检验这些假设，我们成立了一个团队 在肝脏和血管组织工程、生物材料和生物打印、临床肝脏 外科、临床肝病、肝细胞生物学和肝脏代谢。我们将利用我们的专业知识来开发 血管化的生物打印的肝组织，在体内生长。我们将首先制定一个新的生物墨水库 具有改进的打印分辨率和生物活性的投影立体光刻术，以促进3D打印和 活体组织工程(目标1)。然后我们将3D打印模拟肝脏血管的比例血管拓扑结构和 支持肝细胞植入(目标2)。最后，我们将触发肝细胞在组织中的扩张，以实现 肝细胞密度和功能水平足以挽救肝损伤小鼠(目标3)。 这一提议的真正力量在于将生物打印和组织放大的生物学模式结合在一起， 这将改变组织工程，产生生物打印的肝组织，作为肝病的一种新疗法。 提案中开发的新材料生物墨水和3D打印创新也将在 翻译生物医学的不同领域，如心脏和肾脏疾病。