scholarly journals Cell membrane deformation and bioeffects produced by tandem bubble-induced jetting flow

2015 ◽  
Vol 112 (51) ◽  
pp. E7039-E7047 ◽  
Author(s):  
Fang Yuan ◽  
Chen Yang ◽  
Pei Zhong
Keyword(s):  
Cell Membrane ◽  
Strain Rate ◽  
Cell Survival ◽  
Bubble Dynamics ◽  
Leading Edge ◽  
Experimental System ◽  
Maximum Diameter ◽  
Membrane Deformation ◽  
Membrane Poration ◽  
Area Strain

Cavitation with bubble–bubble interaction is a fundamental feature in therapeutic ultrasound. However, the causal relationships between bubble dynamics, associated flow motion, cell deformation, and resultant bioeffects are not well elucidated. Here, we report an experimental system for tandem bubble (TB; maximum diameter = 50 ± 2 μm) generation, jet formation, and subsequent interaction with single HeLa cells patterned on fibronectin-coated islands (32 × 32 μm) in a microfluidic chip. We have demonstrated that pinpoint membrane poration can be produced at the leading edge of the HeLa cell in standoff distance Sd ≤ 30 μm, driven by the transient shear stress associated with TB-induced jetting flow. The cell membrane deformation associated with a maximum strain rate on the order of 104 s−1 was heterogeneous. The maximum area strain (εA,M) decreased exponentially with Sd (also influenced by adhesion pattern), a feature that allows us to create distinctly different treatment outcome (i.e., necrosis, repairable poration, or nonporation) in individual cells. More importantly, our results suggest that membrane poration and cell survival are better correlated with area strain integral (∫​εA2dt) instead of εA,M, which is characteristic of the response of materials under high strain-rate loadings. For 50% cell survival the corresponding area strain integral was found to vary in the range of 56 ∼ 123 μs with εA,M in the range of 57 ∼ 87%. Finally, significant variations in individual cell’s response were observed at the same Sd, indicating the potential for using this method to probe mechanotransduction at the single cell level.

scholarly journals The transbilayer distribution of polyunsaturated phospholipids determines their facilitating effect on membrane deformation

Soft Matter ◽  
2020 ◽  
Vol 16 (7) ◽  
pp. 1722-1730 ◽  
Author(s):  
Marion L. Tiberti ◽  
Bruno Antonny ◽  
Romain Gautier
Keyword(s):  
Cell Membrane ◽  
Lipid Composition ◽  
Specific Protein ◽  
Membrane Deformation

In the cell, membrane deformation and fission (collectively referred to as ‘budding’) is driven by specific protein machineries but is also influenced by lipid composition.

Visualization of Cell Membrane Poration by Microbubble Oscillation

2015 ◽  
pp. 897-898
Author(s):  
S. Moosavi-Nejad ◽  
K. Tachibana ◽  
H. Akiyama ◽  
S. H. R. Hosseini
Keyword(s):  
Cell Membrane ◽  
Membrane Poration

Numerical and Experimental Investigation of Bubble Dynamics via Electrowetting-on-Dielectric (EWOD)

2016 ◽  
Author(s):  
Sheng Wang ◽  
Junxiang Shi ◽  
Hsiu-Hung Chen ◽  
Tiancheng Xu ◽  
Chung-Lung (C. L.) Chen
Keyword(s):  
Thin Film ◽  
Contact Angle ◽  
Bubble Dynamics ◽  
Bubble Diameter ◽  
Experimental System ◽  
Hydrophobic Surface ◽  
Numerical Results ◽  
The Body ◽  
Two Phase ◽  
Electrowetting On Dielectric

With the inspiration from electrowetting-controlled droplets, the potential advantages of electrowetting for bubble dynamics are investigated experimentally and numerically. In our experimental system, a 100 nanometer thin film gold metal was used as an electrode, and a 6.5 micrometer polydimethylsiloxane (PDMS) was spin-coated on the electrode acting both as an dielectric layer and hydrophobic surface. A two-phase model coupled with a electrostatics was used in our simulation work, where the body force due to the electric field acts as an external force. Our numerical results demonstrated that electrowetting can help the detachment of a small bubble by changing the apparent contact angle. Similar results were observed in our experiments that with electrowetting on dielectric, the contact angle of bubble on a hydrophobic surface will obviously decrease when a certain electrical field is applied either with a small size bubble (diameter around 1mm) or a relatively larger size bubble (diameter around 3 mm). When the applied voltage becomes high enough, both the experimental and numerical results demonstrate the characteristics of bubble detachment within a thin film liquid layer.

Evaluation of Commercial Latex as a Positive Control for In Vitro Testing of Bioceramics

2014 ◽  
Vol 631 ◽  
pp. 357-362 ◽  
Author(s):  
Emanuelle Stellet Lourenço ◽  
Juliana Côrtes ◽  
Joyce Costa ◽  
Adriana Linhares ◽  
Gutemberg Alves
Keyword(s):  
Cell Viability ◽  
Cell Survival ◽  
Low Cost ◽  
Control Cell ◽  
Experimental System ◽  
Biological Evaluation ◽  
Negative Control ◽  
International Standards ◽  
Positive Controls

Several tests for the biological evaluation of bioceramic materials and medical devices are provided in specific international standards, where in vitro tests have a major role. Tests involving exposure of cells in culture require the use of validated positive controls, which, in the same preparation and treatment conditions, present a substantial and well-known cytotoxicity. The present work aimed to test and validate 3 different sources of low cost, commercially available latex, as positive controls in cytotoxicity tests for bioceramic materials performed by indirect exposure. The tested origins for latex samples were: surgical gloves without powder, 100% pure amber latex hospital-grade tourniquets and 60 % latex White tubing. MC3T3-E1 murine pre-osteoblasts in culture were exposed to conditioned media (extracts) of each material tested, along with sintered stoichiometric hydroxyapatite bioceramics, and polystyrene beads as negative control. Cell viability was determined by XTT and Crystal Violet Exclusion tests. Concentration curves of the extracts were performed to obtain the DC50. Only the 100% pure amber latex tubing was proven to be cytotoxic, with cell survival less than 5%. This material did not affected neighboring groups at the same experimental system. Moreover, latex samples showed great repeatability in different tests against latex and biomaterials, with consistent toxicity under 20% cell survival as shown in 3 different cell viability parameters. We conclude that fragments of latex ambar tubing are suited as effective positive controls in tests of medical bioceramic materials.

scholarly journals Influence of the Balance Hole Circumferential Position on the Cavitation Performance of the Semiopen Impeller Centrifugal Pump

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xiaorui Cheng ◽  
Jiaheng Luo ◽  
Bo Xiong ◽  
Yimeng Jiang
Keyword(s):  
Centrifugal Pump ◽  
Axial Force ◽  
Cavitation Bubble ◽  
Bubble Dynamics ◽  
Leading Edge ◽  
The Other ◽  
Cavitation Performance ◽  
Working Surface ◽  
Low Specific Speed ◽  
Specific Speed

In order to study the influence of the circumferential position of the balance hole on the cavitation performance of the semiopen impeller centrifugal pump, a low specific speed semiopen impeller centrifugal pump is taken as the object, and 4 kinds of circumferential positions of balance holes are designed. The SST k-ω turbulence model and the Rayleigh–Plesset cavitation bubble dynamics equation are used to calculate the full flow field of the centrifugal pump. Research shows that, under cavitation conditions, as the circumferential position of the balance hole is farther away from the blade working surface, the cavitation performance of the pump is reduced, and the larger θ (the angle of the balance hole and the leading edge of the blade in the direction of rotation) is, the easier the jet cavitation occurs near the balance hole. On the other hand, with the development of cavitation, the axial force of the impeller has also changed greatly. In contrast, the farther the balance hole is arranged in the circumferential direction (i.e., the greater θ), the more limited is the ability of the balance hole to balance the axial force.

scholarly journals Advanced nanostructures for cell membrane poration

2019 ◽  
Vol 30 (26) ◽  
pp. 264002 ◽  
Author(s):  
Apresio K Fajrial ◽  
Xiaoyun Ding
Keyword(s):  
Cell Membrane ◽  
Membrane Poration
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