仿生肝芯片用于癌细胞入侵肝脏的研究

Liver is a common site of cancer cell metastasis. It is of great significance to investigate the invasiveness of cancer cells to liver for prevention, diagnosis and treatment of liver metastasis. In existing studies, animal models are often used to study the invasiveness of various cancer cells to liver; however, due to their limitations, little is known about the mechanism of cancer cell invasion to liver at the cellular level. With the rapid development of microfluidic and soft lithography techniques, the exploitation of liver chips to replace animal models has broad prospects. So far, the study of cancer cell invasion to liver by biochips has not been reported, mostly resulting from these chips different from a biological liver. This project intends to develop a bionic liver chip and then uses it to study the invasiveness of cancer cells to liver. The research topics include: 1. To design and fabricate a highly bionic liver chip; 2. To study the invasion process of melanoma cells B16 to liver and thus observe the influence of microenvironment factors such as oxygen, flow, stellate cells and Kupffer cells on the invasion, and discover the changes of liver microstructures such as bile canaliculi and fenestrated endothelia, and the variations of liver functions such as albumin synthesis, urea production, biliary excretion, and cytochrome P450 activity; 3. To develop an oxygen transport model, and thus deeply analyze the effect of oxygen on the invasion and show the change of the liver zonation during the invasion process. This project aims to contribute to discover the mechanism of cancer cell invasion to liver and has important academic significance as well as practical value.

肝是癌细胞转移的常见部位，研究癌细胞入侵肝的过程对转移性肝癌的预防、诊断和治疗具有重要意义。现有研究多采用动物模型，但存在多方面局限，且无法在细胞水平上揭示入侵机制。随着微流控和软刻蚀等技术的迅速发展，研制生物芯片替代动物模型具有广阔前景，但迄今为止利用肝芯片研究癌细胞入侵还未见报道，主要困难在于当前肝芯片离仿生有较大差距。本项目拟研制仿生肝芯片用于研究癌细胞入侵肝脏。主要内容为：1.研制高度仿生的肝芯片；2.以黑色素瘤细胞B16为例研究癌细胞入侵肝的过程，考察肝微环境（氧气、流动、星形细胞和枯否细胞）对入侵的影响，揭示入侵过程中肝微结构（胆小管和内皮孔窗）及肝细胞功能（白蛋白合成、尿素生成、胆汁分泌和P450酶活性）的变化；3.建立氧输运理论模型，深入分析氧分布对入侵的影响，研究入侵过程中肝功能分区的变化。本项目的开展将有助于揭示癌细胞转移侵入肝脏的机制，具有重要的学术意义和实用价值。

癌细胞肝转移一直是研究的焦点。当前，癌细胞肝转移研究主要基于动物模型，但存在多方面的局限。近年来，随着器官芯片技术的发展，肝芯片作为动物模型替代虽然已被广泛应用于药物测试，但是当前报道的肝芯片仿生程度依然较低，这导致其无法应用于癌细胞入侵肝脏研究。因此，研制更仿生的肝芯片以研究癌细胞肝转移过程具有十分重要的意义。本项目根据肝脏的构造特点，研制了四种类型的肝芯片，从结构、尺度和功能上多角度仿生肝脏；根据肝组织结构（比如血管网络、胆小管、狄氏腔、肝细胞板、内皮孔窗等）和肝细胞功能（比如白蛋白合成、尿素代谢、胆汁分泌、P450酶活性等），确认了研制的肝芯片的仿生性并分析了微环境（比如氧、流动等）对片上组织自组装的影响；基于研制的仿生肝芯片，可视化了癌细胞（比如黑色素瘤B16细胞、乳腺癌细胞、结肠癌细胞等）入侵肝脏的过程，揭示了微环境对入侵的影响以及入侵导致的肝组织结构和肝细胞功能的变化。同时，本项目建立了氧输运理论模型，通过COMSOL软件，模拟了肝芯片内的氧分布以及癌细胞迁移引起的氧分布变化。此外，本项目还设计了氧供给芯片以提供肝芯片生理相似的氧浓度、建立了基于肝芯片的脂肪肝疾病模型、测试了多种药物的肝毒性及脂肪肝治疗药物的有效性并构建了肝组织相似性分析模型等。本项目不但为转移性肝癌研究提供了重要参考，也为药物测试和疾病建模提供了更为有效的平台。