High-Throughput Volumetric Photoacoustic Imaging of Living Vascularized Organoids

摘要 在过去的十年里，正在开发的治疗化合物的数量增加了62% 用于癌症、糖尿病、神经退行性疾病和心血管疾病，总支出为 几乎翻了一番。尽管投入了大量资金，但美国食品和药物管理局批准的新药平均数量 药品监督管理局(FDA)自20世纪90年代以来一直在下降，主要原因是人类临床成功率很低 试验以及与候选药物相关的疗效不足和/或过度的不良(毒性)反应。 用于药物测试的平面细胞培养和动物模型往往不能准确地反映人类的生理和 病理学。基于三维(3D)人体细胞的芯片上器官模型，结合先进的 血管形成和微流控技术越来越多地被用于改善药物测试，通过 重述了他们在活体人类同行的重要生理参数。然而， 用纯光学成像方法表征3D血管化类器官培养是具有挑战性的， 只有很小的深度(~1毫米)和/或缺乏功能成像能力。有机化合物的总直径可达2-3毫米 维度，以及不同位置的细胞对药物治疗的反应可能会因以下原因而显著不同 组织特性不均匀，分子扩散受限，血管分枝不均匀。致信地址 针对这些问题，我们提出开发一种新型的集成成像-生物反应器平台，该平台结合了小型化的 光声断层扫描(mini-PAT)系统(AIM 1)和人体血管器官芯片生物反应器 (目标2)。迷你PAT可以直接集成到生物反应器上，并提供关键的解剖和功能 关于3D器官的发育、血管功能和新陈代谢的信息。作为概念的证明， 我们将应用集成平台进行芯片上、纵向和体积成像 肝细胞癌有机类化合物及其多尺度血管化及其对抗肿瘤药物的反应 血管生成药物(目标3)。最重要的是，微型PAT和生物反应器都是高度紧凑和低成本的 (每台约200美元)，因此可以很容易地对它们进行多路复用，以并行监测大量有机化合物。这个 因此，高度不均匀的药物-有机化合物相互作用可以同时在具有统计学意义的 举止。最终，该提案将为各种应用提供平台技术，这些应用需要 对人体组织模型进行高通量病理测试。更令人兴奋的是，这将为 使用一系列患者衍生疾病模型进行个性化药物筛选。

Abstract Over the last decade, there has been a 62% rise in the number of therapeutic compounds under development for cancers, diabetes, neurodegenerative diseases, and cardiovascular diseases, and the total expenditure has nearly doubled. Despite the significant investment, the average number of new drugs approved by the Food and Drug Administration (FDA) has declined since the 1990s, mainly due to the low success rate of human clinical trials and the insufficient efficacy and/or excessive adverse (toxic) reactions associated with the candidate drugs. Planar cell cultures and animal models used in drug testing often fail to accurately reflect human physiology and pathology. Three-dimensional (3D) human cell-based organ-on-a-chip models, combined with advanced vascularization and microfluidics technologies, have been increasingly used to improve drug testing, by recapitulating important physiological parameters of their in vivo human counterparts. However, the characterization of 3D vascularized organoid cultures is challenging with pure optical imaging methods that reach only small depths (~1 mm) and/or lacks functional imaging capability. The organoids can reach 2–3 mm in all dimensions, and the response to the drug treatment by cells at different locations may significantly vary due to non-uniform tissue properties, limited molecular diffusion, and heterogeneous vascular arborization. To address these issues, we propose to develop a novel integrated imaging-bioreactor platform that combines a miniaturized photoacoustic tomography (mini-PAT) system (Aim 1) and a human vascularized organ-on-a-chip bioreactor (Aim 2). Mini-PAT can be directly integrated onto the bioreactor and provide critical anatomical and functional information about the 3D organoid’s development, vasculature function and metabolism. As proof of concept, we will apply the integrated platform for on-chip, longitudinal, and volumetric imaging of the progression of hepatocellular carcinoma (HCC) organoids, their multiscale vascularization, and their response to anti- angiogenic drugs (Aim 3). Most importantly, both the mini-PAT and bioreactor are highly compact and low-cost (~$200 per unit), so they can be readily multiplexed for monitoring a large array of organoids in parallel. The highly heterogeneous drug-organoid interactions can thus be simultaneously studied in a statistically meaningful manner. Ultimately, this proposal will provide a platform technology for a variety of applications that require high-throughput pathological testing on human tissue models. More excitingly, it would pave the way for personalized medicine screening using an array of patient-derived disease models.