Laboratory of Biomedical Microsystems and Nano Devices, Bionic Sensing and Intelligence Center, Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, 518055 Shenzhen, China.
Marine Engineering College, Dalian Maritime University, 116026 Dalian, China.
Lab Chip. 2022 Jun 28;22(13):2476-2488. doi: 10.1039/d2lc00217e.
Small vesicles (sEVs) are closely related to many diseases as they carry various bio-markers. Efficient separation of sEVs from complex biological samples is essential and prerequisite for the following treatment and further disease diagnosis. Here we propose a label-free and biocompatible on-chip magnetic separation system for efficient extraction of sEVs from cell culture supernatant. Through an on-chip ultra-high gradient magnetic field module, a magnetic field gradient close to 100 000 T m is generated inside the separation microchannel. By using fluorescent particles of 200 nm and 1000 nm to simulate sEVs and other bioparticles in a complex sample, the system design and the experimental parameters are optimized. Flow cytometry and a proposed fluorescence intensity analysis method both verify that the recovery rate and purity of 200 nm particles can reach 84.91% and 98.02%, respectively. Then, a biocompatible ferrofluid is utilized in the separation system to separate sEVs from the cell culture supernatant. The results tested by nanoparticle tracking analysis show that the recovery rate and purity of sEVs are 85.80% and 80.45%, superiorly exceeding the performance that the ultracentrifugation method can provide.
小泡 (sEVs) 与许多疾病密切相关，因为它们携带各种生物标志物。高效地从复杂的生物样本中分离 sEVs 是后续处理和进一步疾病诊断的必要前提。在这里，我们提出了一种无标记且生物兼容的片上磁分离系统，用于从细胞培养上清液中高效提取 sEVs。通过片上超陡梯度磁场模块，在分离微通道内产生接近 100000 T m 的磁场梯度。通过使用 200nm 和 1000nm 的荧光颗粒来模拟复杂样品中的 sEVs 和其他生物颗粒，对系统设计和实验参数进行了优化。流式细胞术和提出的荧光强度分析方法均验证了 200nm 颗粒的回收率和纯度分别达到 84.91%和 98.02%。然后，在分离系统中使用生物兼容的铁磁流体来分离 sEVs 从细胞培养上清液中。通过纳米颗粒跟踪分析测试的结果表明，sEVs 的回收率和纯度分别为 85.80%和 80.45%，大大超过了超速离心法所能提供的性能。
