Tao Jinsong, Wei Zhengjie, He Yuan, Yan Xingyang, Ming-Yuen Lee Simon, Wang Xueqing, Ge Wei, Zheng Ying
State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, China.
Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System, School of Pharmaceutical Sciences, Peking University, Beijing, 100191, China.
Biomaterials. 2020 Oct;256:120180. doi: 10.1016/j.biomaterials.2020.120180. Epub 2020 Jun 25.
Understanding the behaviors of nanomedicines in vivo is one of the most important prerequisites for the design and optimization of nanomedicines. However, the in vivo tracking of nanomedicines in rodents is severely limited by the restricted imaging possibilities within these animals. To meet these needs, the FRET (fluorescence or Förster resonance energy transfer) imaging combined with visual zebrafish larvae model (7 dpf) was used to study the behaviors of polymeric micelles in vivo at high spatiotemporal resolution. Firstly, the FRET ordinary Pluronic micelles (OPMs) and disulfide bond crosslinked Pluronic micelles (CPMs) were synthesized to quantify their integrity in vitro and in vivo by FRET ratio. The behaviors and integrity of OPMs and CPMs in vivo were visually investigated in zebrafish larvae across the entire living organism and at cellular molecular level after intravenous microinjection. Results showed that OPMs were rapidly disassociated in circulation, then largely sequestrated by the endothelial cells (ECs) of caudal vein (CV) and liver in zebrafish larvae, which resulted in quick elimination from blood circulation. While the CPMs were more stable and escaped the sequestration by ECs of CV and liver, which prolonged their circulation in blood. Moreover, we pioneered to use the zebrafish model to reveal that polymeric micelles were eliminated through hepatobiliary pathway after disassociation. While the intact micelles were relatively difficult to eliminate. We further verified that the scavenger receptors of ECs but not the macrophages mainly mediated the elimination of polymeric micelles in CV and liver of zebrafish larvae. These finding on behaviors and elimination mechanisms of polymeric micelles in zebrafish model could contribute to the rational design and optimization of nanomedicines, further guide their studies in rodents.
了解纳米药物在体内的行为是纳米药物设计和优化的最重要前提之一。然而，啮齿动物体内纳米药物的追踪受到这些动物有限成像可能性的严重限制。为满足这些需求，将荧光共振能量转移（FRET）成像与可视化斑马鱼幼体模型（7日龄）相结合，以高时空分辨率研究聚合物胶束在体内的行为。首先，合成了FRET普通普朗尼克胶束（OPM）和二硫键交联普朗尼克胶束（CPM），通过FRET比率在体外和体内对其完整性进行定量。静脉微量注射后，在整个生物体以及细胞分子水平上，对斑马鱼幼体体内OPM和CPM的行为及完整性进行了可视化研究。结果表明，OPM在循环中迅速解离，然后在斑马鱼幼体中主要被尾静脉（CV）和肝脏的内皮细胞（EC）截留，导致其从血液循环中快速清除。而CPM更稳定，避免了被CV和肝脏的EC截留，从而延长了它们在血液中的循环时间。此外，我们率先利用斑马鱼模型揭示聚合物胶束在解离后通过肝胆途径被清除。而完整的胶束相对难以清除。我们进一步证实，EC的清道夫受体而非巨噬细胞主要介导了斑马鱼幼体CV和肝脏中聚合物胶束的清除。这些关于聚合物胶束在斑马鱼模型中的行为和清除机制的发现有助于纳米药物的合理设计和优化，进一步指导它们在啮齿动物中的研究。
