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: 10631804
• 负责人: Kelly R Stevens
• 金额: $ 8.3万
• 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/10631804
• 关键词: 3D Print; Address; Artificial Liver; Artificial tissue; Biocompatible Materials; Biological; Blood Vessels; Cellular biology; Cessation of life; Clinical; Data; Donor person; Formulation; Generations; Heart Diseases; Hepatic; Hepatocyte; Hepatology; Human; In Situ; Kidney Diseases; Lead; Libraries; Liver; Liver diseases; Medical; Methods; Mus; Operative Surgical Procedures; Organ Transplantation; Patients; Pattern; Public Health; Research; Resolution; Role; Route; Testing; Therapeutic; Tissue Engineering; Tissues; Transplantation; Work; bioink; bioprinting; density; falls; hepatocyte engraftment; implantation; improved; in vivo; innovation; liver injury; liver metabolism; liver transplantation; novel strategies; novel therapeutics; scale up; 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.

项目总结/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， 肝脏疾病的发病率正在迅速上升而不是下降。虽然肝移植提高了存活率，但 越来越多的病人需要移植，但捐赠者的供应仍然停滞不前。为了解决这一重大问题， 医学问题，我们正在努力建立人工肝组织，可以作为一个桥梁或替代器官 移植开发人工肝组织的一个关键障碍是建立多尺度血管系统 需要支持数十亿个密集的肝细胞。应对这一挑战的新方法将 转化肝脏研究和治疗。 我们最近的工作通过引入一种突破性的方法使该领域更接近于解决这一障碍 用于在人造组织中3D打印体积血管网络。这一进步是通过增加 光吸收剂到立体光刻生物墨水，这使得数百万的体素能够在许多组织上形成图案 层次。然而，用立体平版印刷术产生的组织保持不完全血管化和稀疏细胞化， 其功能水平仍然达不到治疗所需的水平。我们最近获得了重要线索 来应对这一挑战。首先，我们确定了新的光吸收剂配方， 提高打印分辨率，提供了一种新的途径来体积缩放更密集的脉管系统。而且我们 研究人员发现，将生物基质添加到生物墨水中可以使我们在打印的血管和肝细胞中“扩展”血管和肝细胞， 在植入体内后，组织被植入体内以产生具有天然密度的组织。这些数据让我们假设 支持技术和生物放大模式的双重作用生物墨水将促进 具有在体内膨胀的体积脉管系统的人类肝脏组织。此外，这样的组织将具有肝 足以治疗肝病的功能水平。为了验证这些假设，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 外科学、临床肝病学、肝细胞生物学和肝代谢。我们将利用我们的专业知识， 在体内生长的血管化生物打印肝脏组织。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，以促进3D打印和 体内组织工程（Aim 1）。然后，我们将3D打印模拟肝脏血管系统的缩放血管拓扑结构， 支持肝细胞移植（目标2）。最后，我们将在组织中触发肝细胞扩增， 肝细胞密度和功能水平足以挽救肝损伤小鼠（目的3）。 这个提议的真实的力量在于将生物打印和组织放大的生物模式混为一谈， 这将改变组织工程并产生生物打印的肝脏组织作为肝病的新疗法。 在提案中开发的新材料生物墨水和3D打印创新也将广泛适用于 转化生物医学的不同领域，如心脏和肾脏疾病。