National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, P. R. China.
J Mater Chem B. 2022 Jun 1;10(21):4059-4069. doi: 10.1039/d2tb00226d.
Exosomes are small extracellular vesicles secreted by cells. They play an important regulatory role in the physiological and pathological processes of the body, and participate in the occurrence and development of many diseases. Although tumor-derived exosomes have been used as biomarkers for cancer detection, it is still a huge challenge to efficiently capture and release functionally complete exosomes. In our research, inspired by the structure of hedgehog burrs, we proposed immunomagnetic hedgehog particles (IMHPs) to efficiently capture and release exosomes. In general, after the assembly of one-dimensional nanostructural TiO bundles into hedgehog TiO particles with 356.12 ± 38.32 nm spikes, magnetic responsive nanoparticles (FeO, ∼20 nm), an antifouling polyethylene glycol (PEG) component containing a redox responsive disulfide linkage and anti-CD63 antibody were introduced stepwise to functionalize hedgehog particles and generate IMHPs (1.23 ± 0.18 μm). Due to their unique topological structures, exosomes were positively selected with an exosomal marker (CD63) and negatively selected by depleting environmental pollutants (protein precipitates, cell debris) with the nano-spikes. These prepared IMHPs were successfully applied to capture exosomes from MCF-7 cells, with a capture efficiency of 91.70%. Then, tris (2-carboxyethyl) phosphine hydrochloride (TCEP) was used to reduce the disulfide bond to release exosomes, and the release efficiency was up to 82.45%. The exosomes that experienced successive immunomagnetic separation and release well maintained their structural integrity and good bioactivity to promote MCF-7 cell migration, as compared with those exosomes separated by the classic ultracentrifugation approach. These results also indicated that IMHPs would have broad prospects in biomedicine and clinical applications, where highly efficient and non-destructive separation of bio-substances (cells, extracellular vesicles, ) is critically required.
外泌体是细胞分泌的小细胞外囊泡。它们在机体的生理和病理过程中发挥着重要的调节作用，并参与许多疾病的发生和发展。虽然肿瘤来源的外泌体已被用作癌症检测的生物标志物，但有效地捕获和释放功能完整的外泌体仍然是一个巨大的挑战。在我们的研究中，受刺猬刺毛结构的启发，我们提出了免疫磁性刺猬颗粒（IMHP）来高效捕获和释放外泌体。一般来说，一维纳米结构的 TiO 束组装成具有 356.12 ± 38.32nm 刺的刺猬 TiO 颗粒后，依次引入磁响应纳米颗粒（FeO，约 20nm）、含有氧化还原响应二硫键和抗 CD63 抗体的抗污聚乙烯乙二醇（PEG）成分，以功能化刺猬颗粒并生成 IMHP（1.23 ± 0.18μm）。由于其独特的拓扑结构，外泌体被外泌体标志物（CD63）正向选择，而被纳米刺去除环境污染物（蛋白沉淀、细胞碎片）负向选择。这些制备的 IMHP 成功地从 MCF-7 细胞中捕获外泌体，捕获效率为 91.70%。然后，用三（2-羧乙基）膦盐酸盐（TCEP）还原二硫键以释放外泌体，释放效率高达 82.45%。与经典的超速离心分离方法分离的外泌体相比，经历连续免疫磁分离和释放的外泌体很好地保持了其结构完整性和良好的生物活性，以促进 MCF-7 细胞迁移。这些结果还表明，IMHP 在生物医学和临床应用中具有广阔的前景，在这些领域中，高效、非破坏性地分离生物物质（细胞、细胞外囊泡等）是至关重要的。
