scholarly journals Measurement of the Imaginary Part of the Clausius-Mossotti Factor of Particle/Cell via Dual Frequency Electrorotation

Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 329 ◽  
Author(s):  
Yung-Yi Lin ◽  
Ying-Jie Lo ◽  
U Lei
Keyword(s):  
Imaginary Part ◽  
Human Cancer ◽  
Three Dimensional ◽  
Optical Tweezer ◽  
Travelling Wave ◽  
Dual Frequency ◽  
Two Phase ◽  
Laser Tweezer ◽  
Human Cancer Cells ◽  
Phase Signal

A simple and inexpensive method using planar electrodes was proposed for the measurement of the imaginary part of the Clausius-Mossotti factor, K i , of particle/cell for electrorotation (ER) and travelling wave dielectrophoresis (twDEP). It is based on the balance between the dielectrophoretic and viscous torques on a particle undergoing ER subject to dual frequency operation in an ER chamber. A four-phase ac voltage signal with a given frequency is applied for generating ER for measurement, and another two-phase signal is applied at a selected frequency for generating a negative dielectrophoretic force for confining the particle motion, instead of using laser tweezer or three-dimensional electrodes in the literature. Both frequencies can be applied to the same electrodes in a four-electrode ER system and to alternative different electrodes in an eight-electrode ER system, and both systems are capable for providing accurate measurement. The measurements were validated by comparing with the theoretical result using sephadex particles in KCl solution, and with the existing experimental results for various human cancer cells in medium with conductivity from 0.01–1.2 S/m, using ER with optical tweezer and dual frequency twDEP. Contrast between the ER and the twDEP methods (the current two available methods) was discussed and commented. The present method could provide measurement for wider frequency range and more accurate result near K i = 0, in comparison with the results using the twDEP method. However, the twDEP method could perform much more rapid measurement. Detailed forces and torque were calculated inside the ER chamber for understanding the physics and assessing the characteristics of the dual frequency ER method. This study is of academic interest as the torque in ER and the force in twDEP can be calculated only when K i is known. It also finds biomedical applications as the K i -spectra can be served as physical phenotypes for different cells, and can be applied for deriving dielectric properties of cells.

A Modified Travelling Wave Dielectrophoretic Method for the Measurement of the Imaginary Part of the Clausius-Mossotti Factor Using Dual Frequency Operation

2014 ◽  
Vol 30 (6) ◽  
pp. 651-660 ◽  
Author(s):  
Y.-Y. Lin ◽  
U. Lei ◽  
Y.-J. Lo ◽  
M.-S. Wu ◽  
P.-C. Yang
Keyword(s):  
Imaginary Part ◽  
Human Cancer ◽  
Travelling Wave ◽  
Industrial Applications ◽  
Force Balance ◽  
Cell Manipulation ◽  
Single Frequency ◽  
Dual Frequency ◽  
Human Cancer Cells ◽  
Medium Conductivity

AbstractThe imaginary part of the Clausius-Mossotti factor, Ki, is crucial for quantitative particle/cell manipulation and characterization using travelling wave dielectrophoresis (twDEP) and electrorotation (ER). It can be measured rather easily using twDEP instead of using ER, as numerical calculation of the electric field and complicated devices are not needed for evaluating Ki using twDEP. However, the current single frequency twDEP method works only for particles/cells exhibiting negative dielectrophoresis (DEP), which is in general the case when cells are manipulated in physiological strength buffers with conductivity of order of 1S/m. In order to remove such a restriction, a modified twDEP method is proposed using dual frequency operation here capable of measuring the Ki spectra of particles/cells for the entire range of medium conductivity, irrespectively of whether the particles/cells exhibit positive or negative DEP. The success of the modified method relies on the adequate design of force balance between various forces in a designed micro channel, which was discussed in details. The method was validated, and demonstrated by measuring Ki spectra of three human cancer cells for medium conductivity from 0.01 ~ 1.2S/m. Both the method and the cell result find biomedical and other industrial applications.

scholarly journals Potential anticancer activity of curcumin analogs containing sulfone on human cancer cells

2016 ◽  
Vol 68 (1) ◽  
pp. 125-133 ◽  
Author(s):  
Qiuyan Zhang ◽  
Dongli Li ◽  
Yue Liu ◽  
Hui Wang ◽  
Changyuan Zhang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Human Cancer ◽  
Three Dimensional ◽  
In Vivo Studies ◽  
Anticancer Activities ◽  
Human Cancer Cells ◽  
Curcumin Analogs ◽  
Phosphorylated Akt ◽  
Transcription 3

Three curcumin analogs(S1-S3) containing sulfone were investigated for their effects on human prostate cancer PC-3, colon cancer HT-29, lung cancer H1299 and pancreatic cancer BxPC-3 cells. The three compounds were approximately 16-to 96-fold more active than curcumin in these cell lines as determined by the MTT assay. The effects of these compounds on cell growth were further studied in prostate cancer PC-3 cells in both two dimensional (2D) and three dimensional (3D) cultures. S1-S3strongly inhibited the growth and induced cell death in PC-3 cells, and the effects of these compounds were associated with suppression of nuclear factor kappa B (NF-?B) transcriptional activity. Moreover, treatment of PC-3 cells with all three compounds caused a decrease in the level of phosphorylated signal transducer and activator of transcription-3 (p-STAT3) (Tyr705),but not p-STAT3(Ser727). Only S1and S2decreased the presence of phosphorylated Akt (p-Akt) in PC-3 cells. These curcumin analogs warrant further in vivo studies for anticancer activities in suitable animal models.

scholarly journals Nanophotonics enhanced coverslip for phase imaging in biology

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Lukas Wesemann ◽  
Jon Rickett ◽  
Jingchao Song ◽  
Jieqiong Lou ◽  
Elizabeth Hinde ◽  
...  
Keyword(s):  
Human Cancer ◽  
Three Dimensional ◽  
Live Cells ◽  
Phase Imaging ◽  
Human Cancer Cells ◽  
Nanophotonic Devices ◽  
Optical Generation ◽  
Transparent Objects ◽  
Medical Diagnostic ◽  
Intensity Images

AbstractThe ability to visualise transparent objects such as live cells is central to understanding biological processes. Here we experimentally demonstrate a novel nanostructured coverslip that converts phase information to high-contrast intensity images. This compact device enables real-time, all-optical generation of pseudo three-dimensional images of phase objects on transmission. We show that by placing unstained human cancer cells on the device, the internal structure within the cells can be clearly seen. Our research demonstrates the significant potential of nanophotonic devices for integration into compact imaging and medical diagnostic devices.

scholarly journals Two-dimensional and three-dimensional cell culture models in vitro: pros and cons

2018 ◽  
Vol 17 (3) ◽  
pp. 188-196
Author(s):  
E. S. Galimova ◽  
M. М. Galagudza
Keyword(s):  
Cell Culture ◽  
Human Cancer ◽  
Three Dimensional ◽  
3D Cell Culture ◽  
Two Dimensional ◽  
Human Cancer Cells ◽  
Culture Models ◽  
Pros And Cons ◽  
Molecular Aspects

Discovery and development of new chemical compounds with putative anti-cancer properties requires reliable predictive preclinical models for in vitro screening of efficacy. Such models mainly include cultures of human cancer cells: two-dimensional (2D) and three-dimensional (3D) cell culture systems. In this review, we discuss the molecular aspects of cells cultured in 2D and 3D, and their relevance to cancer study, focusing on key examples from the recent literature. Advantages, disadvantages and perspectives of described models are also analyzed.

scholarly journals Perfused Three-dimensional Organotypic Culture of Human Cancer Cells for Therapeutic Evaluation

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Xiao Wan ◽  
Steven Ball ◽  
Frances Willenbrock ◽  
Shaoyang Yeh ◽  
Nikola Vlahov ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Organotypic Culture ◽  
Human Cancer ◽  
Three Dimensional ◽  
Human Cancer Cells ◽  
Therapeutic Evaluation

A new method for the three-dimensional in vitro growth of human cancer cells

1983 ◽  
Vol 147 (2) ◽  
pp. 454-460 ◽  
Author(s):  
H KUPCHIK ◽  
R LANGER ◽  
C HABERERN ◽  
S ELDERINY ◽  
M OBRIEN
Keyword(s):  
Cancer Cells ◽  
Human Cancer ◽  
Three Dimensional ◽  
New Method ◽  
In Vitro Growth ◽  
Human Cancer Cells

Indirubin derivatives inhibit SFKs/Stat signaling associated with apoptosis in human cancer cells

Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
S Nam ◽  
R Buettner ◽  
X Liu ◽  
J Turkson ◽  
D Kim ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Human Cancer ◽  
Human Cancer Cells ◽  
Stat Signaling

Structure-Reactivity Relationships on Substrates and Inhibitors of the Lysine Deacylase Sirtuin 2 from Schistosoma Mansoni (SmSirt2)

2019 ◽  
Author(s):  
Daria Monaldi ◽  
Dante Rotili ◽  
Julien Lancelot ◽  
Martin Marek ◽  
Nathalie Wössner ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Human Cancer ◽  
Egg Laying ◽  
Human Cancer Cells ◽  
Parasite Survival ◽  
Survival And Reproduction ◽  
Emergence Of Resistance ◽  
First Time ◽  
Parasitic Life Cycle

The only drug for treatment of Schistosomiasis is Praziquantel, and the possible emergence of resistance makes research on novel therapeutic agents necessary. Targeting of Schistosoma mansoni epigenetic enzymes, which regulate the parasitic life cycle, emerged as promising approach. Due to the strong effects of human Sirtuin inhibitors on parasite survival and reproduction, Schistosoma sirtuins were postulated as therapeutic targets. In vitro testing of synthetic substrates of S. mansoni Sirtuin 2 (SmSirt2) and kinetic experiments on a myristoylated peptide demonstrated lysine long chain deacylation as an intrinsic SmSirt2 activity for the first time. Focused in vitro screening of the GSK Kinetobox library and structure-activity relationships (SAR) of identified hits, led to the first SmSirt2 inhibitors with activity in the low micromolar range. Several SmSirt2 inhibitors showed potency against both larval schistosomes (viability) and adult worms (pairing, egg laying) in culture without general toxicity to human cancer cells.<br>

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