Department of Biomedical Engineering, School of Life Sciences, Ulsan National Institute of Science and Technology (UNIST), UNIST gil 50, Ulsan, 44919, Republic of Korea.
Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, Republic of Korea.
Small. 2018 Aug;14(34):e1801731. doi: 10.1002/smll.201801731. Epub 2018 Jul 25.
A major challenge to scale up a microfluidic magnetic separator for extracorporeal blood cleansing applications is to overcome low magnetic drag velocity caused by viscous blood components interfering with magnetophoresis. Therefore, there is an unmet need to develop an effective method to position magnetic particles to the area of augmented magnetic flux density gradients while retaining clinically applicable throughput. Here, a magnetophoretic cell separation device, integrated with slanted ridge-arrays in a microfluidic channel, is reported. The slanted ridges patterned in the microfluidic channels generate spiral flows along the microfluidic channel. The cells bound with magnetic particles follow trajectories of the spiral streamlines and are repeatedly transferred in a transverse direction toward the area adjacent to a ferromagnetic nickel structure, where they are exposed to a highly augmented magnetic force of 7.68 µN that is much greater than the force (0.35 pN) at the side of the channel furthest from the nickel structure. With this approach, 91.68% ± 2.18% of Escherichia coli (E. coli) bound with magnetic nanoparticles are successfully separated from undiluted whole blood at a flow rate of 0.6 mL h in a single microfluidic channel, whereas only 23.98% ± 6.59% of E. coli are depleted in the conventional microfluidic device.
将微流控磁分离器扩大规模用于体外血液净化应用的主要挑战是克服由于粘性血液成分干扰磁泳而导致的低磁拉力速度。因此，需要开发一种有效的方法，将磁性颗粒定位到增强的磁通密度梯度区域，同时保持临床适用的吞吐量。在这里，报告了一种与微流道中的倾斜脊阵列集成的磁泳细胞分离装置。微流道中图案化的倾斜脊产生沿微流道的螺旋流。与磁性颗粒结合的细胞遵循螺旋流线的轨迹，并在横向方向上被反复转移到靠近铁磁镍结构的区域，在该区域它们暴露于 7.68 µN 的强磁场力，远大于通道最远离镍结构一侧的力（0.35 pN）。通过这种方法，在 0.6 mL h 的流速下，成功地从未稀释的全血中分离出与磁性纳米颗粒结合的 91.68%±2.18%的大肠杆菌（E. coli），而在传统的微流控装置中仅去除了 23.98%±6.59%的大肠杆菌。
