内皮微粒作为内皮细胞通过出芽方式分泌的富含生物活性分子的膜性囊泡已被证实具有重要生物学功能。本项目前期研究发现内皮微粒对肿瘤血管生成的调控作用可能与其选择性包裹并靶向传递miRNA有关，然而限于动态研究平台的缺乏，关于该过程中更精细的调控机制，目前还无法进一步阐明。本项目组近期首次实现对细胞源性微粒稳定可靠的量子点标记，并将其用于内皮微粒的活体成像和动态示踪。基于上述工作基础，本项目拟进一步利用量子点实现对内皮微粒及其内部miRNA的多重标记，结合单颗粒示踪技术实时研究内皮微粒靶向传递miRNA的动态过程，以揭示该过程中的关键分子事件及受体细胞的变化规律。同时，利用活体成像技术，研究内皮微粒在荷瘤小鼠体内的分布特点及其miRNA靶向传递作用。本项目首次发展针对细胞源性微粒的动态研究平台，有望揭示内皮微粒通过靶向传递miRNA调控肿瘤血管生成的作用和机制，为肿瘤及相关疾病的治疗提供新的思路。

As bioactive membrane vesicles secreted by endothelial cells, endothelial microparticles (EMPs) have been shown to have important biological functions. We have previously revealed that the regulation of tumor angiogenesis by EMPs might be tightly associated with their selective packaging and targeted delivery of microRNAs (miRNAs). However, due to lack of efficient dynamic research platforms, clarification of the intricate regulatory mechanism during EMP-mediated miRNA delivery remains to be a great challenge. Our recent studies have, for the first time, realized reliable and efficient fluorescent labeling of cell-derived microparticles using quantum dots (QDs), which have been demonstrated to be applicable to both in vivo imaging and dynamic tracking of EMPs. Our present project is proposed to further realize the simultaneous labeling of EMPs and their miRNA cargoes using QDs. Then, QD-based single-particle tracking will be established to monitor and investigate the dynamic process of miRNA-delivery mediated by EMPs. Meanwhile, the in vivo distribution rule and miRNA-delivery function of EMPs in animal tumor models will be studied by employing multimodality imaging techniques. Our study, which will develop the first dynamic research platform for cell-derived microparticles, may help elucidate the miRNA-delivering function of EMPs during the process of tumor angiogenesis, shed new light on development of novel targets or treatments for tumors and other related diseases.