School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong , Wollongong, NSW 2522, Australia.
Queensland Micro- and Nanotechnology Centre, Griffith University , Brisbane, QLD 4111, Australia.
Anal Chem. 2017 Sep 5;89(17):9574-9582. doi: 10.1021/acs.analchem.7b02671. Epub 2017 Aug 17.
This work investigates the on-chip washing process of microparticles and cells using coflow configuration of viscoelastic fluid and Newtonian fluid in a straight microchannel. By adding a small amount of biocompatible polymers into the particle medium or cell culture medium, the induced viscoelasticity can push particles and cells laterally from their original medium to the coflow Newtonian medium. This behavior can be used for particle or cell washing. First, we demonstrated on-chip particle washing by the size-dependent migration speed using coflow of viscoelastic fluid and Newtonian fluid. The critical particle size for efficient particle washing was determined. Second, we demonstrated continuous on-chip washing of Jurkat cells using coflow of viscoelastic fluid and Newtonian fluid. The lateral migration process of Jurkat cells along the channel length was investigated. In addition, the cell washing quality was verified by hemocytometry and flow cytometry with a recovery rate as high as 92.8%. Scanning spectrophotometric measurements of the media from the two inlets and the two outlets demonstrated that diffusion of the coflow was negligible, indicating efficient cell washing from culture medium to phosphate-buffered saline medium. This technique may be a safer, simpler, cheaper, and more efficient alternative to the tedious conventional centrifugation methods and may open up a wide range of biomedical applications.
本工作研究了在直微通道中使用粘性流体和牛顿流体的共流配置对微颗粒和细胞的片上洗涤过程。通过向颗粒介质或细胞培养基中添加少量生物相容性聚合物，可以将颗粒和细胞从其原始介质横向推动到共流牛顿介质中。这种行为可用于颗粒或细胞洗涤。首先，我们使用粘性流体和牛顿流体的共流来证明了基于尺寸的迁移速度的片上颗粒洗涤。确定了有效颗粒洗涤的临界颗粒尺寸。其次，我们使用粘性流体和牛顿流体的共流来证明了 Jurkat 细胞的连续片上洗涤。研究了 Jurkat 细胞沿着通道长度的横向迁移过程。此外，通过血细胞计数和流式细胞术验证了细胞洗涤质量，回收率高达 92.8%。对两个入口和两个出口的介质进行扫描分光光度测量表明，共流的扩散可以忽略不计，表明从培养基到磷酸盐缓冲盐水培养基的细胞洗涤效率很高。与繁琐的传统离心方法相比，该技术可能是一种更安全、更简单、更便宜、更高效的替代方法，并可能开辟广泛的生物医学应用。
