基于声流体及DNA四面体分子镊子的外泌体circRNA富集、检测技术及在肝癌中的应用

外泌体circRNA是液体活检的新型生物标志物，对肝癌早期诊断具有重要意义。现有技术均无法实现外泌体circRNA富集、检测一体化。本项目拟在前期声表面波传感器研究基础上，建立一种基于声流体及DNA四面体分子镊子的外泌体circRNA富集、检测技术。通过构建基于筛分微孔阵列-聚焦型声表面波（FSAW）平行集成结构的声流体技术，实现外泌体非标记式富集，明确FSAW作用下外泌体声学响应特征，阐明FSAW与外泌体相互关系的理论模型，再将DNA四面体纳米结构与DNA分子镊子有机结合实现外泌体circRNA原位检测，以DNA分子镊子触发的滚环扩增反应实现检测信号的级联放大，并利用锁核酸修饰DNA分子镊子提高circRNA识别的特异性。项目的实施将为声流体技术在生物学微纳操控领域中的应用奠定坚实的理论基础，并最终创建一种全新的外泌体circRNA富集、检测一体化技术，为肝癌早期诊断提供技术支撑。

As a novel biomarker of liquid biopsy, the exosomal circRNA plays an important role in the early diagnosis of hepatocellular carcinoma. However, the existing technologies cannot integrate the processes of exosomal circRNA enrichment and detection. Under the previous study of the surface acoustic wave sensor, we want to establish a novel technique of exosomal circRNA enrichment and detection based on acoustofluidics and DNA tetrahedron tweezer. In this study, acoustofluidics would be established to achieve label-free enrichment of exosomes by combining the focusing surface acoustic wave (FSAW) with microporous array. Subsequently, the acoustic response characterictics of exosomes under FSAW will be identified. And theoretical model of the association between FSAW and exosomes will be built. Furthermore, the tetrahedral DNA nanostructures and DNA tweezer are combined to ensure the detection in situ for exosomal circRNA. Rolling circle amplification is triggered by DNA tetrahedron tweezer, which is used to improve the detection sensitivity of exosomal circRNA by the biological signaling cascade. Meanwhile, the DNA tetrahedron tweezer was modified with locked nucleic acid which is used to enhance the specific identification of exosomal circRNA. A solid theoretic basement will be established with the employment of this item, which can apply the acoustofluidics technique to the biological micro-nano manipulation field. Finally, a novel technique is established by combining acoustofluidics and DNA tetrahedron tweezer for the integration of enrichment and detection of exosomal circRNA. The present study aims to provide a new method for early diagnosis of the hepatocellular carcinoma.