scholarly journals How Does a Cell Change Flow Direction Due to a Micro Groove?

2021 ◽  
Vol 19 (8) ◽  
pp. 164-181
Author(s):  
Shigehiro Hashimoto ◽  
Taketo Matsumoto ◽  
Shogo Uehara
Keyword(s):  
Flow Direction ◽  
Longitudinal Axis ◽  
Main Flow ◽  
Myoblast Cell Line ◽  
A Cell ◽  
Micro Flow ◽  
Main Flow Direction ◽  
Myoblast Cell ◽  
Mouse Myoblast

The change in direction of a cell flowing over an oblique micro groove has been analyzed in vitro. The micro flow-channel (0.05 mm height x 1 mm width x 25 mm length) with oblique micro grooves (4.5 μm depth) was manufactured on a polydimethylsiloxane (PDMS) disk by the micromachining technique. The angle between the main flow direction and the longitudinal axis of the groove is 45 degrees. The effect of variation of the groove width (0.03 mm, 0.04 mm, and 0.05 mm) was studied. Myoblasts (C2C12: mouse myoblast cell line) were used in the test. The main flow velocity (0.02 mm/s < vx < 0.23 mm/s) of the medium was controlled by the pressure difference between the inlet and the outlet. The shape of each flowing cell was tracked on a movie recorded by the camera attached to the eyepiece of the microscope. The experimental results show that the change of the direction of each cell by each groove depends on the shape of the cell, which depends on both the shape of the cell and the width of the groove.

Movement of Cell Flowing Over Oblique Micro Grooves in Flow Channel

2021 ◽  
Author(s):  
Shigehiro Hashimoto ◽  
Hiroki Yonezawa
Keyword(s):  
Flow Direction ◽  
Longitudinal Axis ◽  
Flow Channel ◽  
Main Flow ◽  
Flow Test ◽  
Micro Flow ◽  
Main Flow Direction ◽  
Mouse Myoblast ◽  
Made In

Abstract A micro flow-channel with bottom-microgrooves has been manufactured by photolithography technique for cell sorting. The movement of each cell passing over microgrooves has been analyzed in relation to cell deformation and alignment in vitro. The flow path (height 0.05 mm × width 1 mm × length 25 mm) between the two transparent PDMS disks has rectangular microgrooves (4.5 μm deep, 0.2 mm long) on the bottom. Variations are made in groove widths (0.03 mm, 0.04 mm, and 0.05 mm). The angle between the flow direction and the longitudinal axis of the groove is 45 degrees. Myoblasts (C2C12: mouse myoblast line) were used in the flow test. The main flow velocity of the medium (0.02 mm/s &lt; vx &lt; 0.23 mm/s) was controlled by the pressure difference between the inlet and the outlet. The shape of each flowing cell was tracked in a movie recorded by a camera attached to the eyepiece of the microscope. Experimental results show that the movement perpendicular to the main flow direction in the micro-groove can distinguish cells in relation to smaller deformations and larger alignment changes.

Oblique Micro Grooves on Bottom Wall of Flow Channel to Sort Cells

2020 ◽  
Author(s):  
Shigehiro Hashimoto
Keyword(s):  
Flow Direction ◽  
Longitudinal Axis ◽  
Flow Channel ◽  
Bottom Surface ◽  
Rectangular Shape ◽  
Myoblast Cell Line ◽  
Micro Flow ◽  
Myoblast Cell ◽  
Mouse Myoblast

Abstract The movement of a flowing cell near the oblique micro groove on the bottom surface in the micro flow channel has been measured to sort biological cells in vitro. The micro groove of the rectangular shape (4.5 μm depth, and 0.2 mm length) was fabricated on the polydimethylsiloxane (PDMS) disk by the photolithography technique. The angle between the flow direction and the longitudinal axis of the groove is 45 degree. Variation has been made on the width (0.03 mm &lt; w &lt; 0.05 mm) of the groove. A rectangular flow channel (0.05 mm height × 1 mm width × 25 mm length) has been constructed between two transparent PDMS disks. C2C12 (mouse myoblast cell line) was used in the test. A flow velocity (0.1 mm/s &lt; vx &lt; 2.4 mm/s) of the suspension of cells was controlled by the pressure difference between the inlet and the outlet. The shifted distance of each cell along the oblique groove depends on the diameter of the cell. The malnourished cell with the different density can be distinguished by the shifted distance according to the velocity of the cell.

Movement of Myoblast Flowing Through Electric Field Perpendicular to Flow Channel

2021 ◽  
Author(s):  
Shigehiro Hashimoto ◽  
Kiyoshi Yoshinaka
Keyword(s):  
Electric Field ◽  
Flow Direction ◽  
Reference Electrode ◽  
Major Axis ◽  
Surface Electrodes ◽  
Myoblast Cell Line ◽  
Main Flow Direction ◽  
Flat Edge ◽  
Myoblast Cell ◽  
Mouse Myoblast

Abstract The sorting technology with little invasion to cells would be applied to regenerative medicine and diagnosis. In this study, dielectrophoresis is focused on. The dielectrophoretic effect on the flowing myoblasts was maximized by adjusting several parameters: the shape of the electrodes, the amplitude and frequency of the alternating current. The suspension of C2C12 (mouse myoblast cell line) was injected into the channel, and the movement of each flowing cell was analyzed at the microscopic movie image. A pair of titanium-coated (200 nm thick) asymmetric surface electrodes (a triangular electrode with a tip angle of 0.35 rad and a rectangular reference electrode with a flat edge) was manufactured by photolithography technique. With the alternating square cyclic wave at the frequency of 3 MHz and the amplitude of current of ± 7.5 mA, 70 μm movement along the electric field (perpendicular to the main flow direction) of the cell was obtained. The movement along the electric field is governed by several parameters of the cell: the diameter, the deformation ratio, and the direction of the major axis. The method can be applied to cell sorting.

Behavior of Myoblast Under Shear Stress in Couette Type of Flow

2020 ◽  
Author(s):  
Shigehiro Hashimoto
Keyword(s):  
Shear Stress ◽  
Shear Flow ◽  
Flow Direction ◽  
Experimental System ◽  
Longitudinal Axis ◽  
Time Lapse ◽  
Rotating Speed ◽  
Culture Plate ◽  
Myoblast Cell

Abstract Behavior of myoblast has been investigated under the uniform shear flow in vitro. The culture medium was sandwiched with the constant gap between the lower stationary culture plate and the upper rotating parallel plate to make a Couette type of the shear flow. By the rotating speed of the upper disk, the wall shear stress (τ) on the lower culture plate was controlled. C2C12 (mouse myoblast cell) was used in the test. After cultivation without flow for 24 hours for adhesion of cells on the lower plate, τ &lt; 2 Pa was continuously applied on cells for 7 days in the incubator. Behavior of each cell was traced at the time lapse images observed by an inverted phase contrast microscope placed in an incubator. Experimental results show that cells differentiate to myotubes under τ &lt; 2 Pa. Both the cell cycle and the cell length tend to scatter in the wider range, and the longitudinal axis of each cell tends to align to the flow direction by the shear stress of 1 Pa. The experimental system is useful to study quantitative relationships between the shear stress and the cell behavior: deformation, orientation, and differentiation.

Behavior of Cell Passing Through Micro Slit Between Micro Machined Plates

2021 ◽  
Author(s):  
Shigehiro Hashimoto ◽  
Kiyoshi Yoshinaka ◽  
Hiroki Yonezawa
Keyword(s):  
Phase Contrast ◽  
Rectangular Cross Section ◽  
Pressure Head ◽  
Degree Of Deformation ◽  
Contrast Microscope ◽  
Myoblast Cell Line ◽  
Myoblast Cell ◽  
Mouse Myoblast ◽  
Made In

Abstract Deformation of each cell, as it passes through the micro-slit in the flow channel, has been investigated in vitro. A slit with a rectangular cross section (height 10 μm, width 0.4 mm, length 0.1 mm) was made in the center of the flow path by photolithography technique. Myoblasts (C2C12: mouse myoblast cell line) were used for the test. The flow rate of the medium, in which the cells were suspended, was controlled by a pressure head between the inlet and the outlet. Deformation of each cell passing through the micro-slit was observed with an inverted phase contrast microscope. Using the contour of the image of each cell passing through the slit intermittently, several parameters were analyzed: the two-dimensional projected area, the degree of deformation by ellipse approximation, and the deformation direction. The experimental results show that elongation of the cell in the slit tends to decrease the area of the cell.

scholarly journals Geigerin-induced cytotoxicity in a murine myoblast cell line (C2C12)

2017 ◽  
Vol 84 (1) ◽  
Author(s):  
Christo J. Botha ◽  
Sarah J. Clift ◽  
Gezina C.H. Ferreira ◽  
Mxolisi G. Masango
Keyword(s):  
Flow Cytometry ◽  
Cell Line ◽  
Ethical Issues ◽  
Sesquiterpene Lactones ◽  
Annexin V ◽  
Metabolic Activation ◽  
Suitable Model ◽  
Myoblast Cell Line ◽  
Myoblast Cell

Geigeria poisoning in sheep, locally known as ‘vermeersiekte’, is an economically important plant poisoning in southern Africa. The toxic principles contained by the toxic plants are believed to be several sesquiterpene lactones, such as geigerin, vermeeric acid and vermeerin, which cause striated muscle lesions in small stock. Because of ethical issues surrounding the use of live animals in toxicity studies, there is currently a dire need to establish an in vitro model that can be used to replace traditional animal experimentation. The objective of this study was to determine the cytotoxicity of geigerin in a murine myoblast cell line (C2C12) using methyl-thiazol-tetrazolium (MTT) and lactate dehydrogenase (LDH) assays, annexin V and propidium iodide (PI) flow cytometry and transmission electron microscopy (TEM). Mouse myoblasts were exposed to 2.0 mM, 2.5 mM and 5.0 mM geigerin for 24, 48 and 72 h. A concentration-dependent cytotoxic response was observed. Apoptosis was detected by means of annexin V flow cytometry during the first 24 h and apoptotic bodies were also visible on TEM. According to the LDH and PI flow cytometry results, myoblast cell membranes were not injured. We concluded that the murine myoblast cell line (C2C12) is a suitable model for future studies planned to evaluate the cytotoxicity of other and combinations of sesquiterpene lactones, with and without metabolic activation, implicated in ‘vermeersiekte’ and to elucidate the subcellular effects of these myotoxins on cultured myoblasts.

Large Eddy Simulation of the 7-7-7 Shaped Film Cooling Hole at Axial and Compound Angle Orientations

2020 ◽  
Author(s):  
Kevin Tracy ◽  
Stephen P. Lynch
Keyword(s):  
Large Eddy Simulation ◽  
Film Cooling ◽  
Flow Direction ◽  
Main Flow ◽  
Blowing Ratio ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Cooling Hole ◽  
Main Flow Direction ◽  
Compound Angle

Abstract Shaped film cooling holes are used extensively for film cooling in gas turbines due to their superior performance in keeping coolant attached to the surface, relative to cylindrical holes. However, fewer studies have examined the impact of the orientation of the shaped hole axis relative to the main flow direction, known as a compound angle. A compound angle can occur intentionally due to manufacturing, or unintentionally due to changes in the main flow direction at off-design conditions. In either case, the compound angle causes the film cooling jet to roll up into a strong streamwise vortex that changes the lateral distribution of coolant, relative to the pair of vortices that develop from an axially oriented film cooling hole. In this study, Large Eddy Simulation (LES) using the Wall-Adapting Local Eddy Viscosity (WALE) model was performed on the publicly available 7-7-7 shaped film cooling hole, at two orientations (0°, 30°) and two blowing ratios (M = 1, 3). Laterally-averaged film effectiveness was largely unchanged by a compound angle at a blowing ratio of 1, but improved at a blowing ratio of 3. For both blowing ratios, the lateral distribution of film was more uniform with the addition of a 30° compound angle. Both wall normal and lateral turbulent convective heat transfer was increased by the addition of a compound angle at both blowing ratios.

scholarly journals A Theacrine-Based Supplement Increases Cellular NAD+ Levels and Affects Biomarkers Related to Sirtuin Activity in C2C12 Muscle Cells In Vitro

Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3727
Author(s):  
Petey W. Mumford ◽  
Shelby C. Osburn ◽  
Carlton D. Fox ◽  
Joshua S. Godwin ◽  
Michael D. Roberts
Keyword(s):  
Cell Line ◽  
Mitochondrial Biogenesis ◽  
C2c12 Myoblast ◽  
Mrna Levels ◽  
Nicotinamide Phosphoribosyltransferase ◽  
Protein Levels ◽  
Myoblast Cell Line ◽  
Rodent Cell ◽  
Myoblast Cell

There is evidence in rodents to suggest that theacrine-based supplements modulate tissue sirtuin activity as well as other biological processes associated with aging. Herein, we examined if a theacrine-based supplement (termed NAD3) altered sirtuin activity in vitro while also affecting markers of mitochondrial biogenesis. The murine C2C12 myoblast cell line was used for experimentation. Following 7 days of differentiation, myotubes were treated with 0.45 mg/mL of NAD3 (containing ~2 mM theacrine) for 3 and 24 h (n = 6 treatment wells per time point). Relative to control (CTL)-treated cells, NAD3 treatments increased (p < 0.05) Sirt1 mRNA levels at 3 h, as well as global sirtuin activity at 3 and 24 h. Follow-up experiments comparing 24 h NAD3 or CTL treatments indicated that NAD3 increased nicotinamide phosphoribosyltransferase (NAMPT) and SIRT1 protein levels (p < 0.05). Cellular nicotinamide adenine dinucleotide (NAD+) levels were also elevated nearly two-fold after 24 h of NAD3 versus CTL treatments (p < 0.001). Markers of mitochondrial biogenesis were minimally affected. Although these data are limited to select biomarkers in vitro, these preliminary findings suggest that a theacrine-based supplement can modulate select biomarkers related to NAD+ biogenesis and sirtuin activity. However, these changes did not drive increases in mitochondrial biogenesis. While promising, these data are limited to a rodent cell line and human muscle biopsy studies are needed to validate and elucidate the significance of these findings.

scholarly journals Cytoprotective potential of anti-ischemic drugs against chemotherapy-induced cardiotoxicity in H9c2 myoblast cell line

2013 ◽  
Vol 63 (4) ◽  
pp. 493-503 ◽  
Author(s):  
Tiam Feridooni ◽  
Chris Mac Donald ◽  
Di Shao ◽  
Pollen Yeung ◽  
Remigius U. Agu
Keyword(s):  
Cell Death ◽  
Cell Line ◽  
Cancer Drug ◽  
H9c2 Cell ◽  
Drug Induced ◽  
Cardiac Model ◽  
Myoblast Cell Line ◽  
Myoblast Cell ◽  
H9c2 Cell Line

Abstract To investigate potential prevention or attenuation of anti- cancer drug induced cardiotoxicity using anti-ischemic drugs, a rat myoblast (H9c2) cell line was used as our in vitro cardiac model. Irinotecan and doxorubicin were found to be cytotoxic for the H9c2 cell line with IC50 of 30.69 ± 6.20 and 20.94 ± 6.05 mmol L-1, respectively. 5-Flurouracil and cladribine were not cytotoxic and thus IC50 could not be calculated. When 100 mmol L-1 doxorubicin was incubated for 72 hours with 50 mmol L-1 diltiazem, 100 mmol L-1 dexrazoxane and 100 mmol L-1 losartan, respectively, there was a 58.7 ± 10.2, 52.2 ± 11.7 and 44.7 ± 5.4 % reduction in cell death. When 200 mmol L-1 irinotecan was incubated for 72 hours with 100 mmol L-1 dexrazoxane, losartan and diltiazem, respectively, a 27.7 ± 6.9, 25.6 ± 5.1, and 19.1 ± 2.3 % reduction in cell death was observed. Our data suggests that losartan and diltiazem were as effective as dexrazoxane in protecting the cells against irinotecan- and doxorubicin-induced cell toxicity. These findings offer potential uses of anti- -ischemic drugs for ablation of cytotoxicity in response to mitochondrial injury, thereby improving patient outcomes and reducing health-care costs.

Influence of Chord Length and Inlet Boundary Layer on the Secondary Losses of Turbine Blades

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Helmut Sauer ◽  
Robin Schmidt ◽  
Konrad Vogeler
Keyword(s):  
Boundary Layer ◽  
Layer Thickness ◽  
Boundary Layer Thickness ◽  
Flow Direction ◽  
Velocity Ratio ◽  
Main Flow ◽  
Chord Length ◽  
Displacement Thickness ◽  
Wide Range ◽  
Main Flow Direction

In this paper, results concerning the influence of chord length and inlet boundary layer thickness on the endwall loss of a linear turbine cascade are discussed. The investigations were performed in a low speed cascade tunnel using the turbine profile T40. The turning of 90 deg and 70 deg, the velocity ratio in the cascade from 1.0 to 3.5 as well as the chord length of 100 mm, 200 mm, and 300 mm were specified. In a measurement distance of one chord behind the cascade in main flow direction, an approximate proportionality of endwall loss and chord was observed in a wide range of velocity ratios. At small measurement distances (e.g., s2/l=0.4), this proportionality does not exist. If a part of the flow path within the cascade is approximately incorporated, a proportionality to the chord at small measurement distances can be obtained, too. Then, the magnitude of the endwall loss mainly depends on the distance in main flow direction. At velocity ratios near 1.0, the influence of the chord decreases rapidly, while at a velocity ratio of 1.0, the endwall loss is independent of the chord. By varying the inlet boundary layer thickness, no correlation of displacement thickness and endwall loss was achieved. A calculation method according to the modified integral equation by van Driest delivers the wall shear stress. Its influence on the endwall loss was analyzed.

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