Capacitance-Based Real Time Monitoring of...
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Capacitance-Based Real Time Monitoring of Endocytosis Kyung-Hwa Yoo Dept. of Physics Yonsei University
Transcript of Capacitance-Based Real Time Monitoring of...
Capacitance-Based Real Time Monitoring of Endocytosis
Kyung-Hwa Yoo
Dept. of Physics
Yonsei University
Contents
1. Introduction- What is cell?- Capacitive cell sensors
2. Monitoring proliferation and cell death
3. Monitoring receptor-mediate endocytosis
4. Monitoring pinocytosis & phagocytosis
5. Summary
Introduction
What is cell?
structural and functional unit of all living organisms.
Image of HELA cell
Cell membraneCell membrane ( plasma membrane ): lipid by layer
a finite membrane potential due to different ionic concentrations between inside and outside of the cell
Capacitive Cell Sensors
The biological cells may be regarded as dielectric particles The capacitance depends on their morphology, number, etc.
Can we monitor cell activities in real time using the capacitance measurements ?
Sensor (I)
Fluidic channel
Silicon well
out
in
(c)
50nm100nm
Cell Death
Apoptosis
1 min 70min 90min
10μm
Trail apoptosis
170min 310min
TE2
0 200 400
0.85
0.90
0.95
1.00
C/C
o
Time(min)
50 ng/ml
100 ng/ml
150 ng/ml
cell-free medium
Ri Mi Lee, et al, Biosensors & Bioelectronics, 24, 2586 (2009)
Necrosis
0 200 400
0.80
0.85
0.90
0.95
1.00
C/C
o
Time(min)
200 mM
300 mM
500 mM
1 min 60min 200min
150 ng/ml ethanol necrosis
290mim 330min
TE2
Sensor (II)
0 10 20 30 40
1.2
1.5
1.8 NIH3T3
HeLa
TE2
G/G
o
Time(hr)
TRAIL
NIH3T3: mouse fibroblast cell line (noarmal cell)
HeLa: human cervical cancer cell line
TE2: human esophageal cancer cell line
50nm100nm
Endocytosis
Endocytosis
Receptor –mediated endocytosis
Replication-competent adenovirus
Hep1
Ri Mi Lee, et al, Biosensors & Bioelectronics, 25, 1325 (2010)
Replication-incompetent adenovirus
The capacitance peak is due to internalization of adenovirus
0 200 400
1.00
1.02
1.04
C
/C0
Time(min)
CAR Abs+Ad
Ad-E1/E3
The capacitance peak was ascribed to receptor-mediated endocytosis
Car fiber receptor
Blocked by Car-Abs
HEP1 cell
X
Replication-incompetent Ad tagged with GFP TIRF Image
Until 30 min. after 30 min.cell cell
adenovirus
TIRF: Total Internal Reflectance Fluorescence
Treated with CAR-specific Abs & replication-incompetent Ad tagged with GFP
TIRF Image
cell
X
X
Car-Abs
X
Receptor-mediated endocytosis of Antibody
Pinocytosis
internalization
Lysosomedisruption
PS particles(100 nm)
AUNPs(10 nm)
Observed by capacitance sensor
Pinocytosis
Pinocytosis
PS particles
cell
Phagocytosis
internalization
Phagosomedisruption
Observed by capacitance sensor
E-coli (1~2 μm)
Macrophage(RAW264.7)
Cell eating
Phagocytosis
RAW cells treated with live bacteria
RAW cells treated with dead bacteria
Phagocytosis:Confocal Images
21 min 22 min
23 min 24 min
Cell: GFP infection(green)
e. coli: mcherry(red)
Engulfing e.coli yellow
Array chip for high throughput screening
Computer
LCR meter
CO2 incubator (37oC, CO2: 5%)
co
scanner
connecting
Summary
• In the future, the capacitance sensor array will be a valuable
tool for high-throughput screening to identify antibodies or
ligands with high affinities to specific cell types.
• Three different kinds of endocytosis can be distinguishable
by capacitance sensor
Acknowledgements
Ri Mi Lee, Yoon Chung Park
( Department of Physics, Yonsei University)
Chae-Ok Yun, Pyung Hwan Kim, Joung-Woo Choi , Jun-Soo Shin
(College of Medicine, Yonsei University)
Donghyun Kim, Kyujung Kim
(School of Electrical and Electronic Engineering, Yonsei University)
