Effect of channel geometry on cell adhesion in microfluidic devices

Lab on a Chip ◽  
2009 ◽  
Vol 9 (5) ◽  
pp. 677-685 ◽  
Author(s):  
James V. Green ◽  
Tatiana Kniazeva ◽  
Mehdi Abedi ◽  
Darshan S. Sokhey ◽  
Mohammad E. Taslim ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Microfluidic Devices ◽  
Channel Geometry

Surface Engineering in Microfluidic Devices for the Isolation of Smooth Muscle Cells and Endothelial Cells

2007 ◽  
Vol 1004 ◽  
Author(s):  
Shashi Murthy ◽  
Brian Plouffe ◽  
Milica Radisic
Keyword(s):  
Tissue Engineering ◽  
Endothelial Cells ◽  
Shear Stress ◽  
Smooth Muscle ◽  
Cell Adhesion ◽  
Smooth Muscle Cells ◽  
Cell Sorting ◽  
Microfluidic Devices ◽  
Muscle Cells ◽  
Small Sample

AbstractMicrofluidic cell separation systems have emerged as attractive alternatives to traditional techniques in recent years. These systems offer the advantages of being able to handle small sample volumes and at the same time achieve highly selective separation. Conventional separation techniques, including both fluorescence-activated cell sorting (FACS) and magnetic-activated cell sorting (MACS), typically require a pre-processing incubation step to attach ligated tags (such as fluorescent dyes or magnetic beads) to cell surfaces prior to separation. These techniques are also constrained by infrastructure and high cost. Microfluidic devices with surface-immobilized adhesion molecules eliminate the need for pre-processing incubation and are a low cost alternative.We describe the selective adhesion of smooth muscle cells and endothelial cells in microfluidic devices coated with adhesion peptides. The device geometry is such that the shear stress varies linearly as a function of flow channel length, allowing simultaneous evaluation of the effects of surface chemistry and fluid shear on cell adhesion. The adhesion peptides, val-ala-pro-gly (VAPG) and arg-glu-asp-val (REDV), are known to bind selectively to smooth muscle cells and endothelial cells, respectively. These peptides were tethered to the device surface using silane chemistry and NHS-ester coupling. Cell adhesion was examined in a shear stress range of 1.3-4.0 dyn/cm2. Under these conditions, endothelial cells show significantly higher adhesion to REDV-coated devices compared to smooth muscle cells and fibroblasts. Correspondingly, smooth muscle cell adhesion in VAPG-coated devices is much greater than that of endothelial cells and fibroblasts. This selective binding behavior is also observed when mixed suspensions of the three cell types are flowed into both types of peptide-coated microfluidic devices. These results suggest that microfluidic devices coated with REDV and VAPG can be used as effective separation tools in various applications, such as tissue engineering. Specific examples of applications in cardiac and skin tissue engineering will be discussed.

Hydrodynamically-Confined Microflows for Cell Adhesion Strength Measurement

2010 ◽  
Author(s):  
Kevin V. Christ ◽  
Kevin T. Turner
Keyword(s):  
Cell Adhesion ◽  
Adhesion Strength ◽  
Cell Biology ◽  
Microfluidic Devices ◽  
Cell Behavior ◽  
Shear Stresses ◽  
Strength Measurement ◽  
Coated Surfaces ◽  
Biology Research ◽  
Standard Techniques

Cell adhesion plays a fundamental role in numerous physiological and pathological processes, and measurements of the adhesion strength are important in fields ranging from basic cell biology research to the development of implantable biomaterials. Our group and others have recently demonstrated that microfluidic devices offer advantages for characterizing the adhesion of cells to protein-coated surfaces [1,2]. Microfluidic devices offer many advantages over conventional assays, including the ability to apply high shear stresses in the laminar regime and the opportunity to directly observe cell behavior during testing. However, a key disadvantage is that such assays require cells to be cultured inside closed microchannels. Assays based on closed channels restrict the types of surfaces that can be examined and are not compatible with many standard techniques in cell biology research. Furthermore, while techniques for cell culture in microchannels have become common, maintaining the viability of certain types of cells in channels remains a challenge.

Well Plate—Coupled Microfluidic Devices Designed for Facile Image-Based Cell Adhesion and Transmigration Assays

2009 ◽  
Vol 15 (1) ◽  
pp. 102-106 ◽  
Author(s):  
Carolyn G. Conant ◽  
Michael A. Schwartz ◽  
Cristian Ionescu-Zanetti
Keyword(s):  
Cell Adhesion ◽  
Shear Flow ◽  
Cell Biology ◽  
Mononuclear Cells ◽  
Biological Significance ◽  
Microfluidic Devices ◽  
Response Curves ◽  
Single Experiment ◽  
Cell Monolayers ◽  
Biological Phenomena

Microfluidic devices have become invaluable tools in recent years to model biological phenomena. Here, the authors present a well plate microfluidic (WPM) device for conducting cell biology assays under shear flow. Physiological shear flow conditions of cell-cell and cell-ligand adhesion within this device produce results with higher biological significance than conventional well plates. The WPM format also produced significant work flow advantages such as faster liquid handling compared to static well plate assays. The authors used the VLA-4—VCAM-1 cell adhesion model as the basis for a rapid, higher throughput adhesion inhibition screen of monoclonal antibodies against VLA-4. Using the WPM device, they generated IC50 dose-response curves 96 times faster than conventional flow cells. The WPM device was also used to study transmigration of mononuclear cells through endothelial cell monolayers. Twenty-four channels of transmigration data were generated in a single experiment.

scholarly journals Surface modification of PDMS-based microfluidic devices with collagen using polydopamine as a spacer to enhance primary human bronchial epithelial cell adhesion

2020 ◽  
Author(s):  
Mohammadhossein Dabaghi ◽  
Shadi Shahriari ◽  
Neda Saraei ◽  
Kevin Da ◽  
Abiram Chandiramohan ◽  
...  
Keyword(s):  
Cell Culture ◽  
Surface Modification ◽  
Cell Adhesion ◽  
Microfluidic Devices ◽  
Extracellular Matrix Protein ◽  
Shear Stresses ◽  
Bronchial Epithelial ◽  
Ecm Proteins ◽  
Coating Methods ◽  
Organ On A Chip

AbstractPolydimethylsiloxane (PDMS) is a silicone-based synthetic material that is used in various biomedical applications due to its properties, including transparency, flexibility, permeability to gases, and ease of use. Though PDMS facilitates and realizes the fabrication of complicated geometries at the micro and nano scales, it does not optimally interact with cells for adherence and proliferation. Different strategies have been proposed to render PDMS to enhance cell attachment. The majority of these surface modification techniques have been offered for a static cell culture system. However, dynamic cell culture systems such as organ-on-a-chip devices are demanding platforms that recapitulate the complexity of a living tissue microenvironment. For organ-on-a-chip platforms, PDMS surfaces are usually coated by ECM proteins, which occur as a result of physical, weak bonding between PDMS and ECM proteins, and this binding can be degraded when it is exposed to shear stresses. This work reports static and dynamic coating methods to covalently bind collagen within a PDMS-based microfluidic device using polydopamine (PDA). These coating methods were evaluated using water contact angle measurement and atomic force microscopy (AFM) to find the optimum coating conditions. The biocompatibility of collagen-coated PDMS devices was assessed by culturing primary human bronchial epithelial cells (HBECs) in microfluidic devices. It was shown that both PDA coating methods could be used to bind collagen, thereby improving cell adhesion (around three times higher) without showing any discernible difference. These results suggested that such a surface modification can be used to coat an extracellular matrix protein onto PDMS-based microfluidic devices.

In situ bio-functionalization and cell adhesion in microfluidic devices

2005 ◽  
Vol 78-79 ◽  
pp. 556-562 ◽  
Author(s):  
Z.L. Zhang ◽  
C. Crozatier ◽  
M. Le Berre ◽  
Y. Chen
Keyword(s):  
Cell Adhesion ◽  
Microfluidic Devices

Rapid Prototyping of PDMS Devices With Applications to Protein Crystallization

2007 ◽  
Author(s):  
Walter Gonzalez-Domenzain ◽  
Ashwin A. Seshia
Keyword(s):  
Rapid Prototyping ◽  
Protein Crystallization ◽  
Three Dimensional ◽  
Vertical Channel ◽  
Microfluidic Devices ◽  
Sample Processing ◽  
Channel Geometry ◽  
Parallel Sample ◽  
Ink Jet ◽  
Reaction Volumes

This paper describes a microfabrication process for constructing three-dimensional microfluidic structures in polydimethylsiloxane (PDMS). Rapid prototyping of microfluidic devices is possible starting from ink-jet printed masks and by utilising replica molding to create fluidic structures in PDMS from SU-8 and SPR-220 masters pre-patterned on a silicon or glass substrate. Multi-layer bonded and stacked alignment of up to 13 different functional polymer microfluidic layers with through-layer fluidic interconnects has been demonstrated. Pneumatically actuated valves have also been demonstrated for the regulation of sub-10 nL of fluid volumes. The geometric design of the valves is described with experimental verification conducted on rounded and vertical channel profiles to examine the effects of channel geometry on valve leak rates. The PDMS-based technology allows for the fabrication of devices with extremely small reaction volumes and parallel sample processing, making these devices ideally suited to applications which require high throughput processing and the ability to conduct parallel assays with very limited volumes of reagent and sample. We describe the applications of this technology to protein crystallization in particular.

scholarly journals Surface Modification of PDMS-Based Microfluidic Devices with Collagen Using Polydopamine as a Spacer to Enhance Primary Human Bronchial Epithelial Cell Adhesion

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 132
Author(s):  
Mohammadhossein Dabaghi ◽  
Shadi Shahriari ◽  
Neda Saraei ◽  
Kevin Da ◽  
Abiram Chandiramohan ◽  
...  
Keyword(s):  
Cell Culture ◽  
Extracellular Matrix ◽  
Surface Modification ◽  
Cell Adhesion ◽  
Cell Attachment ◽  
Microfluidic Devices ◽  
Bronchial Epithelial ◽  
Ecm Proteins ◽  
Coating Methods ◽  
Organ On A Chip

Polydimethylsiloxane (PDMS) is a silicone-based synthetic material used in various biomedical applications due to its properties, including transparency, flexibility, permeability to gases, and ease of use. Though PDMS facilitates and assists the fabrication of complicated geometries at micro- and nano-scales, it does not optimally interact with cells for adherence and proliferation. Various strategies have been proposed to render PDMS to enhance cell attachment. The majority of these surface modification techniques have been offered for a static cell culture system. However, dynamic cell culture systems such as organ-on-a-chip devices are demanding platforms that recapitulate a living tissue microenvironment’s complexity. In organ-on-a-chip platforms, PDMS surfaces are usually coated by extracellular matrix (ECM) proteins, which occur as a result of a physical and weak bonding between PDMS and ECM proteins, and this binding can be degraded when it is exposed to shear stresses. This work reports static and dynamic coating methods to covalently bind collagen within a PDMS-based microfluidic device using polydopamine (PDA). These coating methods were evaluated using water contact angle measurement and atomic force microscopy (AFM) to optimize coating conditions. The biocompatibility of collagen-coated PDMS devices was assessed by culturing primary human bronchial epithelial cells (HBECs) in microfluidic devices. It was shown that both PDA coating methods could be used to bind collagen, thereby improving cell adhesion (approximately three times higher) without showing any discernible difference in cell attachment between these two methods. These results suggested that such a surface modification can help coat extracellular matrix protein onto PDMS-based microfluidic devices.

Supported Bilayer Membranes for Reducing Cell Adhesion in Microfluidic Devices

2021 ◽  
Author(s):  
Julia R Clapis ◽  
Mengqi Jonathan Fan ◽  
Michelle L Kovarik
Keyword(s):  
Cell Adhesion ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Microfluidic Devices ◽  
Microfluidic Channels ◽  
Bilayer Membranes ◽  
Supported Bilayer

The high surface area-to-volume ratio of microfluidic channels makes them susceptible to fouling and clogging when used for biological analyses,including cell-based assays. We evaluated the role of electrostatic and van...

scholarly journals Cell adhesion and proliferation on common 3D printing materials used in stereolithography of microfluidic devices

Lab on a Chip ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 2372-2382 ◽  
Author(s):  
Kati Piironen ◽  
Markus Haapala ◽  
Virpi Talman ◽  
Päivi Järvinen ◽  
Tiina Sikanen
Keyword(s):  
Cell Adhesion ◽  
3D Printing ◽  
Cell Survival ◽  
Microfluidic Devices ◽  
3D Printed ◽  
Materials Used ◽  
Cell Adhesion And Proliferation

This work reveals the material impacts on long-term cell survival and adhesion on 3D printed surfaces manufactured by stereolithography.

scholarly journals Modifying Wicking Speeds in Paper-Based Microfluidic Devices by Laser-Etching

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 773
Author(s):  
Brent Kalish ◽  
Mick Kyle Tan ◽  
Hideaki Tsutsui
Keyword(s):  
Flow Control ◽  
Point Of Care ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Diagnostic Tools ◽  
Laser Etching ◽  
Simple Process ◽  
Channel Geometry ◽  
Fluid Delivery ◽  
Reaction Zones

Paper-based microfluidic devices are an attractive platform for developing low-cost, point-of-care diagnostic tools. As paper-based devices’ detection chemistries become more complex, more complicated devices are required, often entailing the sequential delivery of different liquids or reagents to reaction zones. Most research into flow control has been focused on introducing delays. However, delaying the flow can be problematic due to increased evaporation leading to sample loss. We report the use of a CO2 laser to uniformly etch the surface of the paper to modify wicking speeds in paper-based microfluidic devices. This technique can produce both wicking speed increases of up to 1.1× faster and decreases of up to 0.9× slower. Wicking speeds can be further enhanced by etching both sides of the paper, resulting in wicking 1.3× faster than unetched channels. Channels with lengthwise laser-etched grooves were also compared to uniformly etched channels, with the most heavily grooved channels wicking 1.9× faster than the fastest double-sided etched channels. Furthermore, sealing both sides of the channel in packing tape results in the most heavily etched channels, single-sided, double-sided, and grooved, wicking over 13× faster than unetched channels. By selectively etching individual channels, different combinations of sequential fluid delivery can be obtained without altering any channel geometry. Laser etching is a simple process that can be integrated into the patterning of the device and requires no additional materials or chemicals, enabling greater flow control for paper-based microfluidic devices.

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