مقالات پذیرفته شده در سومین کنگره بین المللی زیست پزشکی
Microfluidic Blood Cell Sorting: Review
Microfluidic Blood Cell Sorting: Review
Hamide Ehtesabi,1,*
1. Faculty of Life Sciences and Biotechnology, ShahidBeheshti University G.C., Tehran, Iran
Introduction: Microfluidics, New Approach to Process Samples
Therapeutic development often relies heavily upon model systems (Biglari et al. 2019) and Microfluidics as a new trend in science and technology of systems is able to process or manipulate small (10–9 to 10–18litres) amounts of fluids, using channels with dimensions of tens to hundreds of micrometres that use very small quantities of samples and reagents, and to carry out separations and detections with high resolution and sensitivity (Whitesides 2006). A microfluidic, chip-based assay device has been developed for measuring physical properties of an analyte (particularly, whole blood or whole blood derivatives (Bakhru et al. 2018) (Duncombe et al. 2015)(Kand and Lee 2015) and these properties of microfluidic technologies, such as rapid sample processing and the precise control of fluids in an assay, have made them attractive candidates to replace traditional experimental approaches (Sackmann et al.2014).
Methods: Recent advances in microfluidics have brought forth new tools for studying flow-induced effects on mammalian cells like shear stress(Zheng et al.2012), mechanical properties (Ye et al. 2019) and sorting particles based in miscellaneous features(Zhao et al. 2016) with important applications in cardiovascular, bone and cancer biology (H. Chen et al. 2013). Cell sorters have been a key tool in several ground-breaking medical discoveries. Their ability to sort based on different parameters simultaneously has made them valuable tools used to study the Immune System, cancers, and other complex biology (Winkler 2019). In this review, recent advances made in the field by microfluidics, devices have been reviewed.
Results: Tumor-derived circulating exosomes, enriched with a group of tumor antigens, have been recognized as a promising biomarker source for cancer diagnosis via a less invasive procedure. Zhao et al havedesigned a simple microfluidic approach (ExoSearch) which provides enriched preparation of blood plasma exosomes for in situ, multiplexed detection using immunomagnetic beads. They employed the ExoSearch chip for blood-based diagnosis of ovarian cancer by multiplexed measurement of three exosomal tumor markers (CA-125, EpCAM, CD24) using a training set of ovarian cancer patient plasma, which showed significant diagnostic power (a.u.c. = 1.0, p = 0.001) and was comparable with the standard Bradford assay. This work provides an essentially needed platform for utilization of exosomes in clinical cancer diagnosis, as well as fundamental exosome research (Zhao et al. 2016).
Conclusion: In another study, a microfluidic system that combines membraneless microfluidic dialysis and dielectrophoresis to achieve label-free isolation and concentration of bacteria from whole blood is presented. Target bacteria and undesired blood cells are discriminated on the basis of their differential susceptibility to permeabilizing agents that alter the dielectrophoretic behavior of blood cells but not bacteria. The combined membranelessmicrodialysis and dielectrophoresis system isolated 79 ± 3% of Escherichia coli and 78 ± 2% of Staphylococcus aureus spiked into whole blood at a processing rate of 0.6 mL h−1. These data proved feasibility for an instrument to accelerate the detection and analysis of bacteria in blood by first isolating and concentrating them in a microchamber (D'Amico et al. 2017).
A new approach measures the levitation of RBCs in a magnetic medium, commonly applied as a contrast agent in magnetic resonance imaging, to assess cell deformability. RBCs are immersed in a gadolinium solution and injected into a microcapillary sandwiched between two rare earth magnets (Felton et al. 2016, Tasoglu et al. 2015). The magnetic force decreases vertically from the capillary bottom to the top, and the resulting equilibrium position of the RBC is therefore defined by the cell density. This method allows for differentiation between anemic and healthy RBCs (Felton et al. 2016) and could find further use in passive sorting of blood cells. The medical potential for the detection of diseases such as malaria, iron deficiency, or sickle cell disease (SCD) inspired the authors to develop a smartphone-based setup (Sebastian and Dittrich 2018).