skip to main content


Title: Label-free inertial-ferrohydrodynamic cell separation with high throughput and resolution
Rapid and label-free separation of target cells from biological samples provided unique opportunity for disease diagnostics and treatment. However, even with advanced technologies for cell separation, the limited throughput, high cost and low separation resolution still prevented their utility in separating cells with well-defined physical features from a large volume of biological samples. Here we described an ultrahigh-throughput microfluidic technology, termed as inertial-ferrohydrodynamic cell separation (inertial-FCS), that rapidly sorted through over 60 milliliters of samples at a throughput of 100 000 cells per second in a label-free manner, differentiating the cells based on their physical diameter difference with ∼1–2 μm separation resolution. Through the integration of inertial focusing and ferrohydrodynamic separation, we demonstrated that the resulting inertial-FCS devices could separate viable and expandable circulating tumor cells from cancer patients' blood with a high recovery rate and high purity. We also showed that the devices could enrich lymphocytes directly from white blood cells based on their physical morphology without any labeling steps. This label-free method could address the needs of high throughput and high resolution cell separation in circulating tumor cell research and adoptive cell transfer immunotherapy.  more » « less
Award ID(s):
1648035
NSF-PAR ID:
10311300
Author(s) / Creator(s):
; ; ; ; ; ; ; ;
Date Published:
Journal Name:
Lab on a Chip
Volume:
21
Issue:
14
ISSN:
1473-0197
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. Profiling circulating tumour cells (CTCs) in cancer patients' blood samples is critical to understand the complex and dynamic nature of metastasis. This task is challenged by the fact that CTCs are not only extremely rare in circulation but also highly heterogeneous in their molecular programs and cellular functions. Here we report a combinational approach for the simultaneous biochemical and functional phenotyping of patient-derived CTCs, using an integrated inertial ferrohydrodynamic cell separation (i 2 FCS) method and a single-cell microfluidic migration assay. This combinatorial approach offers unique capability to profile CTCs on the basis of their surface expression and migratory characteristics. We achieve this using the i 2 FCS method that successfully processes whole blood samples in a tumor cell marker and size agnostic manner. The i 2 FCS method enables an ultrahigh blood sample processing throughput of up to 2 × 10 5 cells s −1 with a blood sample flow rate of 60 mL h −1 . Its short processing time (10 minutes for a 10 mL sample), together with a close-to-complete CTC recovery (99.70% recovery rate) and a low WBC contamination (4.07-log depletion rate by removing 99.992% of leukocytes), results in adequate and functional CTCs for subsequent studies in the single-cell migration device. For the first time, we employ this new approach to query CTCs with single-cell resolution in accordance with their expression of phenotypic surface markers and migration properties, revealing the dynamic phenotypes and the existence of a high-motility subpopulation of CTCs in blood samples from metastatic lung cancer patients. This method could be adopted to study the biological and clinical value of invasive CTC phenotypes. 
    more » « less
  2. Abstract The efficient isolation of viable and intact circulating tumor cells (CTCs) from blood is critical for the genetic analysis of cancer cells, prediction of cancer progression, development of drugs, and evaluation of therapeutic treatments. While conventional cell separation devices utilize the size difference between CTCs and other blood cells, they fail to separate CTCs from white blood cells (WBCs) due to significant size overlap. To overcome this issue, we present a novel approach that combines curved contraction–expansion (CE) channels with dielectrophoresis (DEP) and inertial microfluidics to isolate CTCs from WBCs regardless of size overlap. This label‐free and continuous separation method utilizes dielectric properties and size variation of cells for the separation of CTCs from WBCs. The results demonstrate that the proposed hybrid microfluidic channel can effectively isolate A549 CTCs from WBCs regardless of their size with a throughput of 300 μL/min, achieving a high separation distance of 233.4 μm at an applied voltage of 50 V p–p . The proposed method allows for the modification of cell migration characteristics by controlling the number of CE sections of the channel, applied voltage, applied frequency, and flow rate. With its unique features of a single‐stage separation, simple design, and tunability, the proposed method provides a promising alternative to the existing label‐free cell separation techniques and may have a wide range of applications in biomedicine. 
    more » « less
  3. Abstract

    Circulating Tumor Cells (CTCs), which migrate from original sites in a body to distant organs through blood, are a key factor in cancer detection. Emerging Label-free techniques owing to their inherent advantage to preserve characteristics of sorted cells and low consumption of samples can be promising to the prediction of cancer progression and metastasis research. Deterministic Lateral Displacement (DLD) is one of the label-free separation techniques employing a specific arrangement of micro-posts for continuous separation of suspended cells in a buffer based on the size of cells. Separation based solely on size is challenging since the size distributions of CTCs might overlap with those of normal blood cells. To address this problem, DLD can be combined with dielectrophoresis (DEP) technique which is the phenomenon of particle movement in a non-uniform electric field owing to the polarization effect. Although, DLD devices employ the laminar flow in low Reynolds number (Re) fluid flow due to predictability of such flow regimes, they should be improved to work in higher Re flow regime so as to attain high throughput devices. In this paper, a particle tracing simulation is developed to study the effects of different post shapes, shift fraction of micropost arrays, and dielectrophoresis forces on separation of CTCs from peripheral blood cells. Our numerical model and results provide a groundwork for design and fabrication of high-throughput DLD-DEP devices for improvement of CTC separation.

     
    more » « less
  4. Abstract

    Circulating tumor cells (CTCs) are shed from primary tumors, circulate in the bloodstream and are capable of initiating metastasis at distant anatomical sites. The detection and molecular characterization of CTCs are pivotal for early-stage cancer diagnosis and prognosis. Recently, microfluidic technology has achieved significant progress in the separation of cells from complex and heterogeneous mixtures for many biomedical applications. Conventional microfluidic platforms exploit the difference in size between the particles to achieve separation, which makes them ineffective for sorting overlapping-sized CTCs. To address this issue, we propose a method using a spiral channel for label-free, and high throughput separation of CTCs coupling Dielectrophoresis (DEP) with inertial microfluidics. A numerical model has been developed to investigate the separation effectiveness of the device over a range of electrical voltage and flow rates. The presented channel is shown to effectively isolate similar-sized CTCs from the white blood cells (WBCs) in a single-stage separation process. Subsequently, optimum working parameters to enhance separation efficiency have been proposed. The hybrid microfluidic device can provide valuable insight into the development of a robust, inexpensive, and efficient platform for cell separation with reduced analysis time for future cancer research and treatment.

     
    more » « less
  5. Abstract

    Circulating tumor cells (CTCs) have been proven to have significant prognostic, diagnostic, and clinical values in early‐stage cancer detection and treatment. The efficient separation of CTCs from peripheral blood can ensure intact and viable CTCs and can, thus, give proper genetic characterization and drug innovation. In this study, continuous and high‐throughput separation of MDA‐231 CTCs from overlapping sized white blood cells (WBCs) is achieved by modifying inertial cell focusing with dielectrophoresis (DEP) in a single‐stage microfluidic platform by numeric simulation. The DEP is enabled by embedding interdigitated electrodes with alternating field control on a serpentine microchannel to avoid creating two‐stage separation. Rather than using the electrokinetic migration of cells which slows down the throughput, the system leverages the inertial microfluidic flow to achieve high‐speed continuous separation. The cell migration and cell positioning characteristics are quantified through coupled physics analyses to evaluate the effects of the applied voltages and Reynolds numbers (Re) on the separation performance. The results indicate that the introduction of DEP successfully migrates WBCs away from CTCs and that separation of MDA‐231 CTCs from similar sized WBCs at a highReof 100 can be achieved with a low voltage of magnitude 4 ×106 V/m. Additionally, the viability of MDA‐231 CTCs is expected to be sustained after separation due to the short‐term DEP exposure. The developed technique could be exploited to design active microchips for high‐throughput separation of mixed cell beads despite their significant size overlap, using DEP‐modified inertial focusing controlled simply by adjusting the applied external field.

     
    more » « less