Extracellular vesicles (EVs) are nanosized lipid bilayer-bound vesicles that are naturally secreted from most cell types as a communication mechanism to deliver proteins, lipids, and genetic material. Despite the therapeutic potential of EVs, there is limited information on EV uptake kinetics and specificity. Here, we optimized an imaging flow cytometry (IFC)-based platform to quantitatively assess dose, time, and recipient cell specificity effects on human embryonic kidney cell (HEK293T) EV internalization in a high-throughput manner. We found that HEK293T EV uptake is an active process that is dose and time dependent. Further, the selectivity of EV uptake was quantified in vitro, and we found that HEK293T EVs were internalized at higher quantities by cells of the same origin. Lastly, neural stem cells internalized significantly more HEK293T EVs relative to mature neurons, suggesting that stem cells or progenitors, which are more metabolically active than terminally differentiated cells, may have higher rates of active EV internalization. The characterization of EV uptake, notably specificity, dose and time dependence, and kinetic assays will help inform and develop targeted and efficient EV-based therapeutics.

细胞外囊泡（EVs）是纳米脂质双层结合的囊泡，可从大多数细胞类型自然分泌，作为传递蛋白质，脂质和遗传物质的通讯机制。尽管电动汽车具有治疗潜力，但有关电动汽车摄取动力学和特异性的信息有限。在这里，我们优化了基于成像流式细胞仪（IFC）的平台，以高通量方式定量评估了剂量，时间和受体细胞特异性对人胚肾细胞（HEK293T）EV内在化的影响。我们发现，HEK293T EV摄取是一个活跃的过程，与剂量和时间有关。此外，在体外对EV摄取的选择性进行了定量，并且我们发现，HEK293T EV被相同来源的细胞内化了。最后，相对于成熟的神经元，神经干细胞内化了更多的HEK293T EV，这表明与终末分化细胞相比代谢活性更高的干细胞或祖细胞可能具有更高的活性EV内化率。电动汽车摄取的特征，尤其是特异性，剂量和时间依赖性以及动力学测定，将有助于指导和开发针对性且有效的基于电动汽车的疗法。