scholarly journals Micromagnet arrays for on-chip focusing, switching, and separation of superparamagnetic beads and single cells

Lab on a Chip ◽  
2015 ◽  
Vol 15 (16) ◽  
pp. 3370-3379 ◽  
Author(s):  
S. Rampini ◽  
D. Kilinc ◽  
P. Li ◽  
C. Monteil ◽  
D. Gandhi ◽  
...  

We present novel micromagnet array designs for on-chip focusing, programmable transport, and size-selective sorting of superparamagnetic beads. Controlled transport of cancer cells immunolabelled with beads is provided as proof-of-concept.

2003 ◽  
Vol 773 ◽  
Author(s):  
Xiaohu Gao ◽  
Shuming Nie ◽  
Wallace H. Coulter

AbstractLuminescent quantum dots (QDs) are emerging as a new class of biological labels with unique properties and applications that are not available from traditional organic dyes and fluorescent proteins. Here we report new developments in using semiconductor quantum dots for quantitative imaging and spectroscopy of single cancer cells. We show that both live and fixed cells can be labeled with multicolor QDs, and that single cells can be analyzed by fluorescence imaging and wavelength-resolved spectroscopy. These results raise new possibilities in cancer imaging, molecular profiling, and disease staging.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kanako Saito ◽  
Yuri Ota ◽  
Dieter M. Tourlousse ◽  
Satoko Matsukura ◽  
Hirotsugu Fujitani ◽  
...  

AbstractDroplet microfluidics has emerged as a powerful technology for improving the culturing efficiency of environmental microorganisms. However, its widespread adoption has been limited due to considerable technical challenges, especially related to identification and manipulation of individual growth-positive droplets. Here, we combined microfluidic droplet technology with on-chip “fluorescent nucleic acid probe in droplets for bacterial sorting” (FNAP-sort) for recovery of growth-positive droplets and droplet microdispensing to establish an end-to-end workflow for isolation and culturing of environmental microbes. As a proof-of-concept, we demonstrate the ability of our technique to yield high-purity cultures of rare microorganisms from a representative complex environmental microbiome. As our system employs off-the-shelf commercially available equipment, we believe that it can be readily adopted by others and may thus find widespread use toward culturing the high proportion of as-of-yet uncultured microorganisms in different biomes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Haoran Wang ◽  
Anton Enders ◽  
John-Alexander Preuss ◽  
Janina Bahnemann ◽  
Alexander Heisterkamp ◽  
...  

Abstract3D printing of microfluidic lab-on-a-chip devices enables rapid prototyping of robust and complex structures. In this work, we designed and fabricated a 3D printed lab-on-a-chip device for fiber-based dual beam optical manipulation. The final 3D printed chip offers three key features, such as (1) an optimized fiber channel design for precise alignment of optical fibers, (2) an optically clear window to visualize the trapping region, and (3) a sample channel which facilitates hydrodynamic focusing of samples. A square zig–zag structure incorporated in the sample channel increases the number of particles at the trapping site and focuses the cells and particles during experiments when operating the chip at low Reynolds number. To evaluate the performance of the device for optical manipulation, we implemented on-chip, fiber-based optical trapping of different-sized microscopic particles and performed trap stiffness measurements. In addition, optical stretching of MCF-7 cells was successfully accomplished for the purpose of studying the effects of a cytochalasin metabolite, pyrichalasin H, on cell elasticity. We observed distinct changes in the deformability of single cells treated with pyrichalasin H compared to untreated cells. These results demonstrate that 3D printed microfluidic lab-on-a-chip devices offer a cost-effective and customizable platform for applications in optical manipulation.


2021 ◽  
Vol 22 (10) ◽  
pp. 5073
Author(s):  
Nazanin Nahrjou ◽  
Avik Ghosh ◽  
Marina Tanasova

Specific link between high fructose uptake and cancer development and progression highlighted fructose transporters as potential means to achieve GLUT-mediated discrimination between normal and cancer cells. The gained expression of fructose-specific transporter GLUT5 in various cancers offers a possibility for developing cancer-specific imaging and bioactive agents. Herein, we explore the feasibility of delivering a bioactive agent through cancer-relevant fructose-specific transporter GLUT5. We employed specific targeting of GLUT5 by 2,5-anhydro-D-mannitol and investigated several drug conjugates for their ability to induce cancer-specific cytotoxicity. The proof-of-concept analysis was carried out for conjugates of chlorambucil (CLB) in GLUT5-positive breast cancer cells and normal breast cells. The cytotoxicity of conjugates was assessed over 24 h and 48 h, and significant dependence between cancer-selectivity and conjugate size was observed. The differences were found to relate to the loss of GLUT5-mediated uptake upon increased conjugate size and hydrophobicity. The findings provide information on the substrate tolerance of GLUT5 and highlight the importance of maintaining appropriate hydrophilicity for GLUT-mediated delivery.


2021 ◽  
Author(s):  
Jeff Darabi ◽  
Joseph Schober

Abstract Studies have shown that primary tumor sites begin shedding cancerous cells into peripheral blood at early stages of cancer, and the presence and frequency of circulating tumor cells (CTCs) in blood is directly proportional to disease progression. The challenge is that the concentration of the CTCs in peripheral blood may be extremely low. In the past few years, several microfluidic-based concepts have been investigated to isolate CTCs from whole blood. However, these devices are generally hampered by complex fabrication processes and very low volumetric throughputs, which may not be practical for rapid clinical applications. This paper presents a high-performance yet simple magnetophoretic microfluidic chip for the enrichment and on-chip analysis of rare CTCs from blood. Microscopic and flow cytometric assays developed for selection of cancer cell lines, selection of monoclonal antibodies, and optimization of bead coupling are discussed. Additionally, on-chip characterization of rare cancer cells using high resolution immunofluorescence microscopy and modeling results for prediction of CTC capture length are presented. The device has the ability to interface directly with on-chip pre and post processing modules such as mixing, incubation, and automated image analysis systems. These features will enable us to isolate rare cancer cells from whole blood and detect them on the chip with subcellular resolution.


The Analyst ◽  
2020 ◽  
Vol 145 (17) ◽  
pp. 5878-5888
Author(s):  
Julia Gala de Pablo ◽  
David R. Chisholm ◽  
Carrie A. Ambler ◽  
Sally A. Peyman ◽  
Andrew Whiting ◽  
...  

Tracking of the accumulation, activation, degradation of a photosensitiser and cell response in live colorectal cancer single-cells using Raman spectroscopy.


Author(s):  
Jinfen Wei ◽  
Zixi Chen ◽  
Meiling Hu ◽  
Ziqing He ◽  
Dawei Jiang ◽  
...  

Hypoxia is a characteristic of tumor microenvironment (TME) and is a major contributor to tumor progression. Yet, subtype identification of tumor-associated non-malignant cells at single-cell resolution and how they influence cancer progression under hypoxia TME remain largely unexplored. Here, we used RNA-seq data of 424,194 single cells from 108 patients to identify the subtypes of cancer cells, stromal cells, and immune cells; to evaluate their hypoxia score; and also to uncover potential interaction signals between these cells in vivo across six cancer types. We identified SPP1+ tumor-associated macrophage (TAM) subpopulation potentially enhanced epithelial–mesenchymal transition (EMT) by interaction with cancer cells through paracrine pattern. We prioritized SPP1 as a TAM-secreted factor to act on cancer cells and found a significant enhanced migration phenotype and invasion ability in A549 lung cancer cells induced by recombinant protein SPP1. Besides, prognostic analysis indicated that a higher expression of SPP1 was found to be related to worse clinical outcome in six cancer types. SPP1 expression was higher in hypoxia-high macrophages based on single-cell data, which was further validated by an in vitro experiment that SPP1 was upregulated in macrophages under hypoxia-cultured compared with normoxic conditions. Additionally, a differential analysis demonstrated that hypoxia potentially influences extracellular matrix remodeling, glycolysis, and interleukin-10 signal activation in various cancer types. Our work illuminates the clearer underlying mechanism in the intricate interaction between different cell subtypes within hypoxia TME and proposes the guidelines for the development of therapeutic targets specifically for patients with high proportion of SPP1+ TAMs in hypoxic lesions.


Author(s):  
Wenwei Xu ◽  
Roman Mezencev ◽  
Byungkyu Kim ◽  
Lijuan Wang ◽  
John McDonald ◽  
...  

Cancer cells undergo a variety of biochemical and biophysical transformations when compared to identical cells displaying a healthy phenotypic state, cancer cells show a drastic reduction of stiffness upon malignancy[1, 2] and change of stiffness of single cells can indicate the presence of disease [3–6]. Besides, metastatic cancer has a higher deformability than their benign counterparts[7, 8]. Using atomic force microscopy, we demonstrated that cancerous ovarian cells (OVCAR3, OVCAR4, HEY and HEYA8) are substantially softer than the healthy immortalized ovarian surface epithelium (IOSE) cells. In addition, within the different types of cancerous ovarian cells, increased invasiveness and migration are directly correlated with increased cell deformability. These results indicate that stiffness of individual cells can distinguish not only ovarian cancer cells from healthy cells types, but also invasive cancer types from less invasive types. Stiffness may provide an alternative and convenient biomarker to grade the metastasis potential of cancer cells.


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