高效分离外泌体的微流控介电泳系统的构建

Cancer is one of the major threats to human health. Early diagnosis could highly increase the survival rate and improve the quality of life for cancer patients. However, early diagnosis of cancer can be difficult and face a lot of challenges. Exosomes are nanovesicles secreted by most types of cells, exist in virtually all bodily fluids. Their rich nucleic acid and protein content make them potentially valuable biomarkers for noninvasive molecular diagnosis. They also show promise to serve as a drug delivery system. Unfortunately, existing exosome separation technologies are time-consuming, laborious and separate only exosomes of low purity. Dielectrophoresis is an ideal tool for exosome separation, since they enable non-invasive, fast, cost-efficient, continue and tunable processing of nanoparticles and small volumes of liquid samples. In this project, we plan to investigate the dielectrophoresis of exosomes and develop a microfluidic platform for high purity exosome separation. We will firstly investigate the dielectrophoretic mechanism of exosomes; and then design and fabricate microfluidic chips; finally, we will separate high purity exosomes from cell culture supernatant and blood sample. This research will provide a powerful tool for exosome related biology and clinical research, and further lay the foundation for cancer early diagnosis.

癌症是人类健康的重大威胁之一，早期诊断能够显著提高癌症病人的生存率和生活质量。然而，癌症的早期诊断一直是医学领域试图攻克的难题。外泌体（Exosome）作为来源肿瘤细胞遗传物质和蛋白质的稳定载体，广泛存在于体液之中，其内容物是潜在的癌症早期诊断生物标志物，外泌体本身则是潜在的给药载体。快速、高纯度的外泌体分离，是对外泌体进行深入研究的基础。然而目前的外泌体分离方法面临着耗时长、操作复杂、分离纯度低等挑战。介电泳生物颗粒分离方法具有非侵入，分离效率高，分离过程连续、可控、可调整等优点。本项目拟利用介电泳现象在微流控系统中对高纯度外泌体的分离方法进行研究，阐明外泌体在非均匀电场中介电泳现象的原理和机制；设计研制出用于分离外泌体的微流控芯片；实现对细胞培养上清液和血液样本中外泌体的高纯度快速分离，为外泌体相关的生物医学研究提供重要的技术支撑，为深入研究基于外泌体的癌症早期诊断方法奠定基础。

外泌体是多数类型细胞都会分泌的纳米囊泡，大量存在于体液之中。外泌体包含其来源细胞丰富的核酸和蛋白质，可作为疾病早期诊断的重要生物标志物。同时外泌体的双层膜结构和良好的生物相容性使其成为具有潜力的给药载体。然而目前现有的外泌体分离技术，仍面临着耗时长、操作复杂、分离纯度低等局限性和挑战。本项目利用介电泳（Dielectrophoresis, DEP）对外泌体在微流控系统中的分离方法进行了研究。首先在微流控芯片中研究了外泌体在非均匀电场中介电泳现象的原理和机制，获得了外泌体在不同电场条件下的DEP谱。在此基础上，成功构建了利用介电力分离外泌体的微流控系统，设计并研制出了用于分离外泌体的微流控芯片。进而利用介电泳在微流控芯片中成功实现了对乳腺癌细胞MCF-7的细胞培养上清液中的外泌体的分离。最终成功实现了血液样本中外泌体在微流通道中的分步介电力分离，各项鉴定分析结果显示获得了纯度较高的外泌体。这一系统的研究和构建，为外泌体分离及相关研究开辟了新途径，能够促进对外泌体的生理功能和外泌体病理学的深入研究，为癌症等疾病的临床早期诊断及治疗提供有力的技术支撑，具有重要的科学意义和临床应用价值。