Skoltech Center for Photonic Science and Engineering, Skolkovo Institute of Science and Technology Skolkovo Innovation Center, 121205 Moscow, Russia.
National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov, 117997 Moscow, Russia.
J Mater Chem B. 2024 Jul 10;12(27):6678-6689. doi: 10.1039/d4tb00127c.
The isolation of small extracellular vesicles (sEVs), including those secreted by pathological cells, with high efficiency and purity is highly demanded for research studies and practical applications. Conventional sEV isolation methods suffer from low yield, presence of contaminants, long-term operation and high costs. Bead-assisted platforms are considered to be effective for trapping sEVs with high recovery yield and sufficient purity for further molecular profiling. In this study, magnetically responsive beads made of calcium carbonate (CaCO) particles impregnated with iron oxide (FeO) nanoparticles are fabricated using a freezing-induced loading (FIL) method. The developed magnetic beads demonstrate sufficient magnetization and can be collected by a permanent magnet, ensuring their rapid and gentle capture from an aqueous solution. The tannic acid on the surface of magnetic beads is formed by a layer-by-layer (LbL) method and is used to induce coupling of sEVs with the surface of magnetic beads. These tannic acid coated magnetic beads (TAMB) were applied to capture sEVs derived from MCF7 and HCT116 cell lines. Quantitative data derived from nanoparticle tracking analysis (NTA) and BCA methods revealed the capture efficiency and recovery yield of about 60%. High-resolution transmission electron microscopy (HRTEM) imaging of sEVs on the surface of TAMBs indicated their structural integrity. Compared with the size exclusion chromatography (SEC) method, the proposed approach demonstrated comparable efficiency in terms of recovery yield and purity, while offering a relatively short operation time. These results highlight the high potential of the TAMB approach for the enrichment of sEVs from biological fluids, such as cell culture media.
高效且高纯度地分离包括病理细胞分泌的小细胞外囊泡（sEV）对于研究和实际应用具有极高的需求。传统的 sEV 分离方法存在产量低、存在污染物、操作时间长和成本高等问题。基于珠粒的平台被认为是有效捕获 sEV 的方法，具有高回收率和足够的纯度，可用于进一步的分子分析。在本研究中，使用冷冻加载（FIL）方法制备了由碳酸钙（CaCO）颗粒负载氧化铁（FeO）纳米颗粒的磁性响应珠粒。所开发的磁性珠粒具有足够的磁化强度，可以通过永磁体收集，确保其能够快速、温和地从水溶液中捕获。磁性珠粒表面的单宁酸通过层层（LbL）方法形成，用于诱导 sEV 与磁性珠粒表面的偶联。这些涂覆有单宁酸的磁性珠粒（TAMB）被用于捕获 MCF7 和 HCT116 细胞系衍生的 sEV。纳米颗粒跟踪分析（NTA）和 BCA 方法得出的定量数据显示，捕获效率和回收率约为 60%。TAMB 上 sEV 的高分辨率透射电子显微镜（HRTEM）成像表明其结构完整。与尺寸排阻色谱（SEC）方法相比，该方法在回收率和纯度方面具有相当的效率，同时操作时间相对较短。这些结果突出了 TAMB 方法在从细胞培养介质等生物流体中富集 sEV 方面的巨大潜力。
