Abstract：
Bacterial extracellular vesicles (BEVs) are nano-size vesicles containing a cargo of bioactive molecules that can play key roles in microbe-microbe and microbe-host interactions. In tracking their biodistribution in vivo, BEVs can cross several physical host barriers including the intestinal epithelium, vascular endothelium, and blood-brain-barrier (BBB) to ultimately accumulate in tissues such as the liver, lungs, spleen, and the brain. This tissue-specific dissemination has been exploited for the delivery of biomolecules such as vaccines for mucosal delivery. Although numerous strategies for labeling and tracking BEVs have been described, most have constraints that impact on interpreting in vivo bioimaging patterns. Here, we describe a general method for labeling BEVs using lipophilic fluorescent membrane stains which can be adopted by non-expert users. We also describe how the procedure can be used to overcome potential limitations. Furthermore, we outline methods of quantitative ex vivo tissue imaging that can be used to evaluate BEV organ trafficking.
摘要：
细菌细胞外囊泡（BEV）是纳米大小的囊泡，包含生物活性分子的货物，可以在微生物-微生物和微生物-宿主相互作用中发挥关键作用。在追踪它们在体内的生物分布时，BEV可以跨越几个物理宿主屏障，包括肠上皮，血管内皮,血脑屏障（BBB）最终积聚在肝脏等组织中，肺,脾,脾还有大脑.这种组织特异性播散已被用于递送生物分子,例如用于粘膜递送的疫苗。尽管已经描述了许多标记和跟踪BEV的策略，大多数都有限制，影响体内生物成像模式的解释。这里,我们描述了一种使用亲脂性荧光膜染色剂标记BEV的一般方法，该方法可被非专业用户采用。我们还描述了如何使用该程序来克服潜在的限制。此外，我们概述了可用于评估BEV器官运输的定量离体组织成像方法。
