Lasting Impacts: Dynamic, Fully Natural Bioprinted 3D Human Neurovascular Biomimetic Model to Study Traumatic Brain Injury Pathophysiology

摘要 持久的影响：动态，完全自然的生物打印3D人类神经血管仿生学研究创伤 脑损伤病理生理学 据估计，每年有250万人遭受创伤性脑损伤（TBI），许多幸存者经历 随后的长期认知缺陷、感觉运动障碍和神经精神残疾，导致 对受影响的个人造成了深刻的心理社会和经济后果。急性和慢性影响 神经创伤是美国和世界各地死亡率、发病率和长期残疾的主要原因。 世界虽然TBI在神经病理学上有明确的定义，但最初的TBI与TBI之间的关系不太明确。 创伤相关的神经血管病理学的影响和由此产生的进展。这种多学科的多PI 该提案是对跨机构血脑接口计划（RFA-HL-20-021，R61/R33）的响应，并且 建立在劳伦斯利弗莫尔国家实验室，波士顿大学 医学院和NIH/NIA资助的波士顿大学阿尔茨海默病中心， 神经创伤急性和慢性效应的基本机制，包括创伤引起的 与慢性创伤相关的微血管损伤和潜伏性tau蛋白神经退行性病变 脑病（CTE）。本项目将开发和表征人体体外灌注神经血管单位 (NVU)模型的首要目标是确定生物力学触发和分子细胞反应， 脑损伤决定了创伤性微血管损伤（TMI）的位置、严重程度和进展， 脑屏障（BBB）破坏和磷酸化tau蛋白病。为了实现这一目标，这项工作将 利用现有的BBB平台生物制造3D多细胞动态人类NVU仿生， 可灌注的内皮化脉管系统。由此产生的光学透明NVU平台将使系统 通过时空控制询问人血管系统，包括所有人NVU细胞类型 和结构功能的实时测量。在R61阶段，我们将修改现有的3D打印BBB 模型包括人诱导多能干细胞（iPSC）衍生的内皮细胞，周细胞，星形胶质细胞， 和神经元。细胞组成、结构-功能关系、流体流动动力学（血管内， 间质）和培养孵育条件对iPSC成熟的影响。在R61阶段， 开发一种平台兼容的损伤仪器，通过计算模拟提供信息， 体内动物研究。3D打印模型中的嵌入式标记将实现直接测量， 可视化冲击过程中随时间变化的应变，作为血管、神经胶质和神经元病理学的函数， 功能受损（R33阶段）。此外，我们将研究分子，细胞和功能的影响， TBI损伤后的继发性损伤。结果将由实验动物的伴随研究得出， 与独特人脑标本的临床病理学相关性。该项目将有助于基础 了解脑损伤生物力学以及与神经创伤急性和慢性效应的关系， 人脑

ABSTRACT Lasting impacts: dynamic, fully natural bioprinted 3d human neurovascular biomimetic to study traumatic brain injury pathophysiology Every year an estimated 2.5 million people sustain a traumatic brain injury (TBI), and many survivors experience subsequent long-term cognitive deficits, sensorimotor impairments, and neuropsychiatric disability that result in profound psychosocial and economic consequences for affected individuals. Acute and chronic effects of neurotrauma represent leading causes of mortality, morbidity, and long-term disability in the US and around the world. Although TBI is clearly defined neuropathologically, less well-defined is the relationship between the initial impact and the resulting progression of trauma-related neurovascular pathology. This multidisciplinary multi-PI proposal is responsive to the Trans-Agency Blood-Brain Interface Program (RFA-HL-20-021, R61/R33) and builds on a longstanding collaboration between Lawrence Livermore National Laboratory, Boston University School of Medicine, and the NIH/NIA-funded Boston University Alzheimer’s Disease Center to address fundamental mechanisms underpinning acute and chronic effects of neurotrauma, including trauma-induced microvascular injury and latent tau protein neurodegenerative pathologies associated with chronic traumatic encephalopathy (CTE). This project will develop and characterize a human in vitro perfusable neurovascular unit (NVU) model with the overarching goal of identifying biomechanical triggers and molecular-cellular responses to brain injury that determine the location, severity, and progression of traumatic microvascular injury (TMI), blood- brain barrier (BBB) disruption, and phosphorylated tau proteinopathy. To accomplish this objective, this work will leverage an existing BBB platform to biofabricate a 3D multi-cellular dynamic human NVU biomimetic with perfusable endothelialized vasculature. The resulting optically clear NVU platform will enable systematic interrogation of the human cerebrovasculature, including all human NVU cell types, with spatiotemporal control and structure-function measurements in real-time. In the R61 phase, we will modify our existing 3D-printed BBB model to include culture of human induced pluripotent stem cell (iPSC)-derived endothelia, pericytes, astrocytes, and neurons. Effects of cellular composition, structure-function relations, fluid flow dynamics (intravascular, interstitial), and culture incubation conditions on iPSC maturation will be investigated. In the R61 phase, we will develop a platform-compatible injury instrument informed by computational simulations to match loads used in in vivo animal studies. Embedded markers in the 3D-printed model will enable direct measurement and visualization of time-varying strain during impact as a function of vascular, glial, and neuronal pathology and compromised function (R33 phase). In addition, we will investigate molecular, cellular, and functional effects of secondary damage post-TBI injury. Results will be informed by companion studies in experimental animals and clinicopathological correlation with unique human brain specimens. This project will contribute to fundamental understanding of brain injury biomechanics and relationship to acute and chronic effects of neurotrauma in the human brain.