scholarly journals Modular operation of microfluidic chips for highly parallelized cell culture and liquid dosing via a fluidic circuit board

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
A. R. Vollertsen ◽  
D. de Boer ◽  
S. Dekker ◽  
B. A. M. Wesselink ◽  
R. Haverkate ◽  
...  
Keyword(s):  
Cell Culture ◽  
Large Scale ◽  
Dynamic Range ◽  
Umbilical Vein ◽  
Building Blocks ◽  
High Dynamic Range ◽  
Microfluidic System ◽  
Circuit Board ◽  
Microfluidic Chips ◽  
Umbilical Vein Endothelial Cells

AbstractMicrofluidic systems enable automated and highly parallelized cell culture with low volumes and defined liquid dosing. To achieve this, systems typically integrate all functions into a single, monolithic device as a “one size fits all” solution. However, this approach limits the end users’ (re)design flexibility and complicates the addition of new functions to the system. To address this challenge, we propose and demonstrate a modular and standardized plug-and-play fluidic circuit board (FCB) for operating microfluidic building blocks (MFBBs), whereby both the FCB and the MFBBs contain integrated valves. A single FCB can parallelize up to three MFBBs of the same design or operate MFBBs with entirely different architectures. The operation of the MFBBs through the FCB is fully automated and does not incur the cost of an extra external footprint. We use this modular platform to control three microfluidic large-scale integration (mLSI) MFBBs, each of which features 64 microchambers suitable for cell culturing with high spatiotemporal control. We show as a proof of principle that we can culture human umbilical vein endothelial cells (HUVECs) for multiple days in the chambers of this MFBB. Moreover, we also use the same FCB to control an MFBB for liquid dosing with a high dynamic range. Our results demonstrate that MFBBs with different designs can be controlled and combined on a single FCB. Our novel modular approach to operating an automated microfluidic system for parallelized cell culture will enable greater experimental flexibility and facilitate the cooperation of different chips from different labs.

EFFECTS OF SUBSTRATE DEFORMABILITY ON CELL BEHAVIORS: ELASTIC MODULUS VERSUS THICKNESS

2017 ◽  
Vol 17 (05) ◽  
pp. 1750088 ◽  
Author(s):  
ZAHRA GOLI-MALEKABADI ◽  
MOHAMMAD TAFAZZOLI-SHADPOUR ◽  
EHSAN SEYEDJAFARI
Keyword(s):  
Cell Proliferation ◽  
Elastic Modulus ◽  
Umbilical Vein ◽  
Cell Behavior ◽  
Substrate Thickness ◽  
Microfluidic Chips ◽  
Cell Behaviors ◽  
Varying Thickness ◽  
Wide Range ◽  
Umbilical Vein Endothelial Cells

The deformability of the substrate stimulating cell mechanotransduction depends not only on elastic modulus but also on the thickness. Polydimethylsiloxane (PDMS) which is widely used in microfluidic chips and platforms can be fabricated in a wide range of elastic modulus and thickness. In this study, we cultured human umbilical vein endothelial cells (HUVECs) on four groups of PDMS substrates of varying thickness and elastic modulus to examine effects of these parameters on morphology, viability and proliferation of cells. Both elastic modulus and thickness affected cell behavior. In general, the thickness of substrates had relatively higher impact on endothelial morphology than elastic modulus. Elongation of HUVECs on thick substrates was more intense compared to those on thin substrates. Both lowering thickness and reducing elastic modulus of PDMS decreased the viability of HUVECs, although thickness was more influential. Decrease in substrate thickness reduced cell proliferation regardless of substrate elastic modulus. In conclusion, our results suggest that endothelial behavior depends on substrate deformability, but cells react differently to the elastic modulus and thickness of PDMS by morphology, viability and growth. Results can improve the comprehension of cell mechanotransduction.

scholarly journals Parallel Isolation and Characterization of Porcine Smooth Muscle, Endothelial and Mesenchymal Stromal Cells for Bioengineering Applications

2021 ◽  
Author(s):  
Sara Morini ◽  
Iris Pla-Palacín ◽  
Pilar Sainz-Arnal ◽  
Natalia Sánchez-Romero ◽  
Maria Falceto ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Cultured Cells ◽  
Umbilical Vein ◽  
Building Blocks ◽  
Cell Types ◽  
Aortic Smooth Muscle ◽  
Isolation And Characterization ◽  
Umbilical Vein Endothelial Cells

Abstract There is significant interest in the pig as the animal model of choice for organ transplantation and the study of tissue engineering (TE) products and applications. Currently, efforts are being taken to bioengineer solid organs to reduce donor shortages for transplantation. For complex organs such as the lung, heart, and liver, the vasculature represents a fundamental feature. Thus, to generate organs with a functional vascular network, the different cells constituting the building blocks of the blood vessels should be procured. However, due to species' specificities, porcine cell isolation, expansion, and characterization are not entirely straightforward compared to human cell procurement. Here, we report the establishment of simple and suitable methods for the isolation and characterization of distinct porcine cells for bioengineering purposes.We successfully isolated, expanded and characterized porcine bone marrow-derived mesenchymal stromal (pBM-MSC), aortic smooth muscle (pASMC), and umbilical vein endothelial cells (pUVEC). We demonstrated that the three cell types showed specific immunophenotypical features. Moreover, we demonstrated that pBM-MSC could preserve their multipotency in vitro, and pUVEC were capable of maintaining their functionality in vitro.These cultured cells could be further expanded and represent a useful cellular tool for TE purposes (i.e., for recellularization approaches of vascularized organs or in vitro angiogenesis studies).

scholarly journals Docosahexaenoic fatty acid-containing phospholipids affect plasma membrane susceptibility to disruption by bacterial toxin-induced macroapertures

2020 ◽  
Author(s):  
Meng-Chen Tsai ◽  
Lucile Fleuriot ◽  
Sébastien Janel ◽  
David Gonzalez-Rodriguez ◽  
Camille Morel ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Large Scale ◽  
Umbilical Vein ◽  
Critical Role ◽  
Membrane Dynamics ◽  
Bacterial Toxin ◽  
Rhoa Gtpase ◽  
Docosahexaenoic Fatty Acid ◽  
Umbilical Vein Endothelial Cells ◽  
The Impact

AbstractMetabolic studies and animal knockout models point to the critical role of polyunsaturated docosahexaenoic acid (22:6, DHA)-containing phospholipids (PLs) in physiology. Here, we study the impact of DHA-PLs on the dynamics of transendothelial cell macroapertures (TEMs) tunnels triggered by the RhoA GTPase inhibitory exotoxin C3 from Clostridium botulinum. Through lipidomic analyses, we show that primary human umbilical vein endothelial cells (HUVECs) subjected to DHA-diet undergo a 6-fold DHA-PLs enrichment in plasma membrane at the expense of monounsaturated OA-PLs. In contrast, OA-diet had almost no effect on PLs composition. Consequently, DHA treatment increases the nucleation rate of TEMs by 2-fold that we ascribe to a reduction of cell thickness. We reveal that the global transcellular area of cells remains conserved through a reduction of the width and lifetime of TEMs. Altogether, we reveal a homeostasis between plasma membrane DHA-PLs content and large-scale membrane dynamics.

scholarly journals The Sun at the VLA's Metric and Decimetric Wavelengths

1990 ◽  
Vol 142 ◽  
pp. 523-524
Author(s):  
S. M. White ◽  
M. R. Kundu ◽  
N. Gopalswamy ◽  
E. J. Schmahl
Keyword(s):  
Large Scale ◽  
Dynamic Range ◽  
Active Regions ◽  
High Dynamic Range ◽  
The Sun ◽  
Large Array ◽  
Very Large Array ◽  
Preliminary Results ◽  
High Dynamic ◽  
Coronal Structures

During September 1988 (International Solar Month) we observed the Sun with the Very Large Array on 4 days in the period Sep. 11-17. The VLA was in its most compact configuration, which is ideal for studying large-scale coronal structures. Here we summarize some preliminary results of the observations at 0.333 and 1.5 GHz. Despite the presence of numerous active regions the Sun was actually very quiet, with no flares during our observing, and this allowed us to make high-dynamic-range maps.

High fidelity spectroscopic imaging at low radio frequencies to estimate plasma parameters of solar coronal mass ejections at higher coronal heights

2021 ◽  
Author(s):  
Devojyoti Kansabanik ◽  
Surajit Mondal ◽  
Divya Oberoi ◽  
Angelos Vourlidas
Keyword(s):  
Radio Emission ◽  
Coronal Mass Ejections ◽  
Large Scale ◽  
Dynamic Range ◽  
High Dynamic Range ◽  
Physical Parameters ◽  
Plasma Parameters ◽  
Radio Imaging ◽  
Gyrosynchrotron Emission ◽  
Murchison Widefield Array

<p>Coronal Mass Ejections (CMEs) are large-scale explosive eruptions of magnetised plasma from the Sun into the Heliosphere. Measuring the physical parameters of CMEs is crucial for understanding their physics and for assessing their geo-effectiveness. Radio observations offer the most direct means for estimating these plasma parameters when gyrosynchrotron (GS) emission is detected from the CME plasma. However, since the first detection by Bastian et al.2001, only a handful of studies have successfully detected GS emission from CME plasma. This is usually attributed to the challenges involved in obtaining the high dynamic range imaging required for observing this faint gyrosynchrotron emission in the vicinity of active solar emissions.</p><p>The newly developed imaging pipeline (Mondal et al., 2019) designed for the data from Murchison Widefield Array (MWA) marks a significant improvement in metrewave solar radio imaging. Our work suggests that we should now be able to routinely detect GS emission from CME plasma. We present an example where we have successfully detected radio emission from CME plasma and modelled it as GS emission, leading to reliable estimates of CME magnetic field as well as the distribution of energetic electrons (Mondal et al. 2020). In a different example we are able to detect the radio emission from the CME plasma out to as far as 8.3 solar radii. We find that the observed spectra are not always consistent with simple GS models. This highlights that more complicated physics might be at play and points to the need for building more detailed models for interpreting these emissions. We hope that with the availability of polarimetric imaging capability, which we are in the process of developing, this technique will provide a robust way to routinely measure CME magnetic fields along with its other physical parameters. We note that these are the weakest detections of GS emissions from CME plasma reported yet.</p>

The Anza array: A high-dynamic-range, broadband, digitally radiotelemetered seismic array

1984 ◽  
Vol 74 (4) ◽  
pp. 1469-1481
Author(s):  
Jon Berger ◽  
L. M. Baker ◽  
J. N. Brune ◽  
J. B. Fletcher ◽  
T. C. Hanks ◽  
...  
Keyword(s):  
Large Scale ◽  
Scaling Laws ◽  
Dynamic Range ◽  
Body Wave ◽  
Sampling Rate ◽  
Digital Transmission ◽  
High Dynamic Range ◽  
Seismic Array ◽  
High Rate ◽  
Small Aperture

Abstract A small aperture seismic array has been deployed along a 30-km stretch of the San Jacinto fault in the vicinity of the town of Anza, California. The array was installed to study specifically the scaling laws of body-wave spectra, the character of high-frequency ground motion, the physical interpretation of seismic stress drops, and the interaction of earthquakes. This region was chosen for these studies due to its high rate of seismic activity in the 2 ≦ M ≦ 4.5 range, the likelihood of a M > 6 event in the next decade, and the existence of the Southern California Batholith on either side of the fault, reducing problems associated with attenuation and large scale anisotropy. These studies employ an instrument package with a frequency response of 100 Hz, a dynamic range of 138 dB, a sampling rate of 250 times per second per component, and a 16-bit A/D converter. The array consists of 10 three-component stations, telemetered via digital VHF radio to a nearby mountain peak and thence via a microwave link to La Jolla, California. A minicomputer system monitors the array's performance, detects events, and records data upon demand. Initial results demonstrate the feasibility of digital transmission with an inherent increase in data quality over analog systems.

85-1: Visually Lossless Compression of High Dynamic Range Images: A Large-Scale Evaluation

2018 ◽  
Vol 49 (1) ◽  
pp. 1151-1154 ◽  
Author(s):  
Aishwarya Sudhama ◽  
Matthew D. Cutone ◽  
Yuqian Hou ◽  
James Goel ◽  
Dale Stolitzka ◽  
...  
Keyword(s):  
Large Scale ◽  
Dynamic Range ◽  
Lossless Compression ◽  
High Dynamic Range ◽  
Range Images ◽  
Scale Evaluation ◽  
High Dynamic

scholarly journals Patterning Biological Gels for 3D Cell Culture inside Microfluidic Devices by Local Surface Modification through Laminar Flow Patterning

Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1112
Author(s):  
Joshua Loessberg-Zahl ◽  
Jelle Beumer ◽  
Albert van den Berg ◽  
Jan Eijkel ◽  
Andries van der Meer
Keyword(s):  
Cell Culture ◽  
Laminar Flow ◽  
Cultured Cells ◽  
Umbilical Vein ◽  
Three Dimensional ◽  
Microfluidic Channel ◽  
Microfluidic Devices ◽  
Microfluidic Chips ◽  
Surface Patterns ◽  
Flow Velocities

Microfluidic devices are used extensively in the development of new in vitro cell culture models like organs-on-chips. A typical feature of such devices is the patterning of biological hydrogels to offer cultured cells and tissues a controlled three-dimensional microenvironment. A key challenge of hydrogel patterning is ensuring geometrical confinement of the gel, which is generally solved by inclusion of micropillars or phaseguides in the channels. Both of these methods often require costly cleanroom fabrication, which needs to be repeated even when only small changes need be made to the gel geometry, and inadvertently expose cultured cells to non-physiological and mechanically stiff structures. Here, we present a technique for facile patterning of hydrogel geometries in microfluidic chips, but without the need for any confining geometry built into the channel. Core to the technique is the use of laminar flow patterning to create a hydrophilic path through an otherwise hydrophobic microfluidic channel. When a liquid hydrogel is injected into the hydrophilic region, it is confined to this path by the surrounding hydrophobic regions. The various surface patterns that are enabled by laminar flow patterning can thereby be rendered into three-dimensional hydrogel structures. We demonstrate that the technique can be used in many different channel geometries while still giving the user control of key geometric parameters of the final hydrogel. Moreover, we show that human umbilical vein endothelial cells can be cultured for multiple days inside the devices with the patterned hydrogels and that they can be stimulated to migrate into the gel under the influence of trans-gel flows. Finally, we demonstrate that the patterned gels can withstand trans-gel flow velocities in excess of physiological interstitial flow velocities without rupturing or detaching. This novel hydrogel-patterning technique addresses fundamental challenges of existing methods for hydrogel patterning inside microfluidic chips, and can therefore be applied to improve design time and the physiological realism of microfluidic cell culture assays and organs-on-chips.

scholarly journals Microfluidics-Based Fabrication of Cell-Laden Hydrogel Microfibers for Potential Applications in Tissue Engineering

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1633 ◽  
Author(s):  
Gen Wang ◽  
Luanluan Jia ◽  
Fengxuan Han ◽  
Jiayuan Wang ◽  
Li Yu ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Endothelial Cells ◽  
Double Layer ◽  
Umbilical Vein ◽  
Single Layer ◽  
Microfluidic System ◽  
Hydrogel Scaffolds ◽  
Potential Applications ◽  
One Step ◽  
Umbilical Vein Endothelial Cells

Fibrous hydrogel scaffolds have recently attracted increasing attention for tissue engineering applications. While a number of approaches have been proposed for fabricating microfibers, it remains difficult for current methods to produce materials that meet the essential requirements of being simple, flexible and bio-friendly. It is especially challenging to prepare cell-laden microfibers which have different structures to meet the needs of various applications using a simple device. In this study, we developed a facile two-flow microfluidic system, through which cell-laden hydrogel microfibers with various structures could be easily prepared in one step. Aiming to meet different tissue engineering needs, several types of microfibers with different structures, including single-layer, double-layer and hollow microfibers, have been prepared using an alginate-methacrylated gelatin composite hydrogel by merely changing the inner and outer fluids. Cell-laden single-layer microfibers were obtained by subsequently seeding mouse embryonic osteoblast precursor cells (MC3T3-E1) cells on the surface of the as-prepared microfibers. Cell-laden double-layer and hollow microfibers were prepared by directly encapsulating MC3T3-E1 cells or human umbilical vein endothelial cells (HUVECs) in the cores of microfibers upon their fabrication. Prominent proliferation of cells happened in all cell-laden single-layer, double-layer and hollow microfibers, implying potential applications for them in tissue engineering.

scholarly journals DAYENU: a simple filter of smooth foregrounds for intensity mapping power spectra

2020 ◽  
Vol 500 (4) ◽  
pp. 5195-5213
Author(s):  
Aaron Ewall-Wice ◽  
Nicholas Kern ◽  
Joshua S Dillon ◽  
Adrian Liu ◽  
Aaron Parsons ◽  
...  
Keyword(s):  
Large Scale ◽  
Dynamic Range ◽  
Fourier Transforms ◽  
Power Spectra ◽  
High Dynamic Range ◽  
Spectrum Estimation ◽  
Sampled Data ◽  
Optimal Basis ◽  
Intensity Mapping ◽  
Band Limited

ABSTRACT We introduce DPSS Approximate lazY filtEriNg of foregroUnds (dayenu), a linear, spectral filter for H i intensity mapping that achieves the desirable foreground mitigation and error minimization properties of inverse co-variance weighting with minimal modelling of the underlying data. Beyond 21-cm power-spectrum estimation, our filter is suitable for any analysis where high dynamic-range removal of spectrally smooth foregrounds in irregularly (or regularly) sampled data is required, something required by many other intensity mapping techniques. Our filtering matrix is diagonalized by Discrete Prolate Spheroidal Sequences which are an optimal basis to model band-limited foregrounds in 21-cm intensity mapping experiments in the sense that they maximally concentrate power within a finite region of Fourier space. We show that dayenu enables the access of large-scale line-of-sight modes that are inaccessible to tapered discrete Fourier transform estimators. Since these modes have the largest SNRs,dayenu significantly increases the sensitivity of 21-cm analyses over tapered Fourier transforms. Slight modifications allow us to use dayenu as a linear replacement for iterative delay clean ing (dayenurest). We refer readers to the Code section at the end of this paper for links to examples and code.

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