State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710054, Shaanxi, China.
Xi'an Key Laboratory of Biomedical Testing and High-End Equipment, Xi'an 710049, Shaanxi, China.
Anal Chem. 2023 Feb 21;95(7):3569-3576. doi: 10.1021/acs.analchem.2c03470. Epub 2023 Jan 20.
Exosomes are important participants in numerous pathophysiological processes and hold promising application value in cancer diagnosis, monitoring, and prognosis. However, the small size (40-160 nm) and high heterogeneity of exosomes make it still challenging to enrich exosomes efficiently from the complex biological fluid microenvironment, which has largely restricted their downstream analysis and clinical application. In this work, we introduced a novel method for rapid isolation and mild release of exosomes from the cell culture supernatant. A Strep-tag II-based immunomagnetic isolation (SIMI) system was constructed by modifying the capture antibodies onto magnetic nanoparticles through specific and reversible recognition between Strep-Tactin and Strep-tag II. Due to their high affinity and binding selectivity, exosomes could be isolated within 38 min with an isolation efficiency of 82.5% and a release efficiency of 62%. Compared with the gold-standard ultracentrifugation, the SIMI system could harvest nearly 59% more exosomes from the 293 T cell culture medium with shorter isolation time and higher purity. In addition, cellular uptake assay indicated that exosomes released from magnetic nanoparticles could maintain their high biological activity. These superior characteristics show that this novel method is a fast, efficient, and nondestructive exosome isolation tool and thus could potentially be further utilized in various exosome-related applications, e.g., disease diagnosis and drug delivery.
外泌体是众多病理生理过程中的重要参与者，在癌症诊断、监测和预后方面具有有前景的应用价值。然而，外泌体的小尺寸（40-160nm）和高度异质性使得其从复杂的生物流体微环境中高效富集仍然具有挑战性，这在很大程度上限制了它们的下游分析和临床应用。在这项工作中，我们介绍了一种从细胞培养上清液中快速分离和温和释放外泌体的新方法。通过特异性和可逆识别链霉亲和素和 Strep-tag II，将捕获抗体修饰到磁性纳米颗粒上，构建了基于 Strep-tag II 的免疫磁分离（SIMI）系统。由于其高亲和力和结合选择性，外泌体可以在 38 分钟内分离，分离效率为 82.5%，释放效率为 62%。与黄金标准的超速离心相比，SIMI 系统可以从 293T 细胞培养基中收获近 59%的更多外泌体，分离时间更短，纯度更高。此外，细胞摄取实验表明，从磁性纳米颗粒中释放的外泌体可以保持其高生物活性。这些优越的特性表明，这种新方法是一种快速、高效且无损的外泌体分离工具，因此可能进一步应用于各种外泌体相关应用，例如疾病诊断和药物传递。
