scholarly journals Microfluidic device for the evaluation of biofilm removal under shear stress

2015 ◽  
Author(s):  
Bowen Huo
Keyword(s):  
Shear Stress ◽  
Microfluidic Device ◽  
Biofilm Removal

Membranes under shear stress: visualization of non-equilibrium domain patterns and domain fusion in a microfluidic device

Soft Matter ◽  
2016 ◽  
Vol 12 (23) ◽  
pp. 5072-5076 ◽  
Author(s):  
Flurin Sturzenegger ◽  
Tom Robinson ◽  
David Hess ◽  
Petra S. Dittrich
Keyword(s):  
Shear Stress ◽  
Microfluidic Device ◽  
Domain Fusion ◽  
Non Equilibrium

scholarly journals A tapered channel microfluidic device for comprehensive cell adhesion analysis, using measurements of detachment kinetics and shear stress-dependent motion

2012 ◽  
Vol 6 (1) ◽  
pp. 014107 ◽  
Author(s):  
Peter Rupprecht ◽  
Laurent Golé ◽  
Jean-Paul Rieu ◽  
Cyrille Vézy ◽  
Rosaria Ferrigno ◽  
...  
Keyword(s):  
Shear Stress ◽  
Cell Adhesion ◽  
Microfluidic Device ◽  
Tapered Channel ◽  
Stress Dependent

scholarly journals Endothelial cell polarization and orientation to flow in a novel microfluidic multimodal shear stress generator

Lab on a Chip ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 4373-4390
Author(s):  
Utku M. Sonmez ◽  
Ya-Wen Cheng ◽  
Simon C. Watkins ◽  
Beth L. Roman ◽  
Lance A. Davidson
Keyword(s):  
Shear Stress ◽  
Endothelial Cell ◽  
Microfluidic Device ◽  
Cell Polarization ◽  
Orientation Analysis ◽  
Stress Gradients ◽  
Multiple Levels

Endothelial cell polarization and orientation analysis using a novel microfluidic device that can simultaneously generate multiple levels of shear stress and shear stress gradients for systematic mechanobiology studies under flow.

Study of Long Term Viability of Endothelial Cells on Biochip for Rapid and Reliable Water Toxicity Measurements

2013 ◽  
Author(s):  
Fei Liu ◽  
Tingting Chen ◽  
Xudong Zhang ◽  
Fang Li ◽  
Ioana Voiculescu
Keyword(s):  
Shear Stress ◽  
Microfluidic Device ◽  
Cell Attachment ◽  
Good Health ◽  
Low Flow ◽  
Live Cells ◽  
Toxicity Tests ◽  
Bovine Aortic Endothelial Cell ◽  
Microfluidic Channels ◽  
Water Toxicity

Measuring water toxicity is a lengthy process, and rapid analytical methods are limited. A complementary approach is to measure water toxicity on live cells via electric cell-substrate impedance sensing (ECIS) using a field portable device. This paper presents a study of the longevity of bovine aortic endothelial cell (BAECs VEC Technologies, Rensselaer, NY) by integrating a microfluidic device onto the ECIS sensors. This microfluidic chamber with a network of tree-like perfusion microfluidic channels for cell media delivery to the culturing chamber was fabricated from a biocompatible polymer and tested for longevity studies. This perfusion microchannels were designed as a symmetric arbor with binary splitting to provide equal flow in all the perfusion channels. The microdimensions of the perfusion channels provide high flow resistance, thus carrying low flow rates for a given head pressure and generating low shear stress to the cells during the long-time cell attachment and proliferation period. With such a microfluidic device, cell media can be automatically and evenly perfused into the culturing chamber and no significant shear stress produced by media perfusion was observed. During the longevity study, the BAECs were able to survive in good health for longer than one month. Toxicity tests to study the BAECs responsiveness to health-threatening concentrations of ammonia using the microfluidic ECIS sensor will be also presented. Using impedance spectroscopy technique we demonstrated the BAECs can rapidly respond to ammonia concentrations between the military exposure guideline of 2mM and human lethal concentration of 55mM. The BAECs monolayer represent the most important component of a biosensor for testing water toxicity in the field. This research concluded that the BAECs could resist at least 34 days on the microfluidic chip and demonstrate high values of cell membrane impedance during long period of time.

scholarly journals A microfluidic device towards shear stress analysis of clonal expanded endothelial cells

2014 ◽  
Vol 9 (1) ◽  
pp. JBSE0006-JBSE0006
Author(s):  
Emilie WEIBULL ◽  
Shunsuke MATSUI ◽  
Helene ANDERSSON SVAHN ◽  
Toshiro OHASHI
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Stress Analysis ◽  
Microfluidic Device

scholarly journals High blood flow shear stress values are associated with circulating tumor cells cluster disaggregation in a multi-channel microfluidic device

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245536
Author(s):  
Alessandra Marrella ◽  
Arianna Fedi ◽  
Gabriele Varani ◽  
Ivan Vaccari ◽  
Marco Fato ◽  
...  
Keyword(s):  
Blood Flow ◽  
Shear Stress ◽  
Tumor Cells ◽  
Circulating Tumor Cells ◽  
Microfluidic Device ◽  
Single Cells ◽  
Biological Significance ◽  
Circulatory System ◽  
Cfd Modeling

Metastasis represents a dynamic succession of events involving tumor cells which disseminate through the organism via the bloodstream. Circulating tumor cells (CTCs) can flow the bloodstream as single cells or as multicellular aggregates (clusters), which present a different potential to metastasize. The effects of the bloodstream-related physical constraints, such as hemodynamic wall shear stress (WSS), on CTC clusters are still unclear. Therefore, we developed, upon theoretical and CFD modeling, a new multichannel microfluidic device able to simultaneously reproduce different WSS characterizing the human circulatory system, where to analyze the correlation between SS and CTC clusters behavior. Three physiological WSS levels (i.e. 2, 5, 20 dyn/cm2) were generated, reproducing values typical of capillaries, veins and arteries. As first validation, triple-negative breast cancer cells (MDA-MB-231) were injected as single CTCs showing that higher values of WSS are correlated with a decreased viability. Next, the SS-mediated disaggregation of CTC clusters was computationally investigated in a vessels-mimicking domain. Finally, CTC clusters were injected within the three different circuits and subjected to the three different WSS, revealing that increasing WSS levels are associated with a raising clusters disaggregation after 6 hours of circulation. These results suggest that our device may represent a valid in vitro tool to carry out systematic studies on the biological significance of blood flow mechanical forces and eventually to promote new strategies for anticancer therapy.

P–171 Automated oocyte and zygote denudation using a novel microfluidic device supervised by a computer vision algorithm

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
J Guerrer. Sánchez ◽  
Y Cabello ◽  
G Fernánde. Blanco ◽  
J Fidalgo ◽  
I Hernánde. Montilla ◽  
...  
Keyword(s):  
Computer Vision ◽  
Shear Stress ◽  
Microfluidic Device ◽  
False Negative ◽  
Fluid Motion ◽  
Cumulus Cells ◽  
Automated System ◽  
Microfluidic Channels ◽  
Dna Contamination ◽  
Metabolomics Analysis

Abstract Study question Is it possible to remove cumulus cells using a 16-well microfluidic device with automated flows to facilitate vitrification, ICSI, NI-PGT or non-invasive metabolomics analysis? Summary answer The designed automated system and protocol efficiently denude 16 samples simultaneously with a x10 lower shear stress than the manual process and without human intervention. What is known already Most processes involved in IVF such as insemination, washing, denudation, embryo culture and selection are still manually performed, labor-intensive and require highly skilled professionals. This leads to a significant variability in the clinical outcomes achieved by different embryologists and labs. The automation of these processes is a promising approach to reduce costs and improve the accessibility to assisted reproductive therapies. Although a simple procedure, standardization of cumulus oocyte complex (COCs) and zygotes denudation is key to facilitate ICSI, vitrification and to avoid DNA contamination for NI-embryo testing (PGT or metabolomics), while avoiding damage to the oocyte by excessive shear stress. Study design, size, duration A total of 160 cow COCs were used due to their size similarity with human COCs. Half were denuded 16–20 hours post-insemination and half pre-insemination for 5–10 minutes. COCs were classified as partially denuded if fertilization assessment, ICSI or vitrification was possible, and completely denuded if no cumulus cells remained. COCs controls were manually denuded (Stripper® capillary 145μm ID) to compare shear stress between procedures. This study was conducted during 2020 – 2021. Participants/materials, setting, methods We developed a customized microfluidic biochip that exerts a particular fluid motion while avoiding egg entrapment within microfluidic channels. The denudation efficacy was established by subjectively scoring images of bovine oocytes after generating a continuous “Push & Pull” fluid motion inside the biochip wells. A Computer Vision model was developed in parallel in order to optically assess denudation completion. The model used was a Pytorch implementation of Faster-RCNN with ImageNet pretrained weights Main results and the role of chance 96 bovine COCs were microfuidically handled post insemination achieving complete (56/96) or partial (40/96) removal of the cumulus cells on day 1, while for day 3 double denudation group, 89/96 (92.7%) were completely denuded while the rest remained partially denuded. In comparison, 80/80 (100%) of manually denuded cow COCs, achieved complete denudation (50% post-insemination group and 50% pre-insemination group). In addition, 48/64 (75%) cow COCs treated pre-insemination were partially denuded, enough to carry out ICSI after 5–10 min of treatment. The results here obtained indicate that media needs to flow through the device at a rate that can generate enough shear to strip off the cumulus-corona cells while avoiding emptying of the reservoirs containing the fertilization or culture medium. The shear stress of our design was calculated to be smaller than 4.4 Pa, about ten times lower than the one applied by the manual process (∼44Pa). The deep learning algorithm was tested on 20 unseen human oocytes on day 1, with 10 true positives 9 true negatives, and 1 false negative (95% accuracy). Limitations, reasons for caution The success of the denudation procedure was dependent on the design of the biochip wells and the microfluidic protocol used. The accuracy of our findings is still limited because of the difficulty in manufacturing prototype biochips. Wider implications of the findings: Complete denudation is key to avoid DNA contamination for NI-PGT or metabolomics analysis, while avoiding damage to the oocyte by excessive shear stress. Our device, which has the potential of scaling up and treat each oocyte individually, can improve automation and increase efficiency of current ART procedures Trial registration number NA

Sign in / Sign up

Export Citation Format

Share Document