Real-time, label-free monitoring of cell viability based on cell adhesion measurements with an atomic force microscope.
BACKGROUND
The adhesion of cells to an oscillating cantilever sensitively influences the oscillation amplitude at a given frequency. Even early stages of cytotoxicity cause a change in the viscosity of the cell membrane and morphology, both affecting their adhesion to the cantilever. We present a generally applicable method for real-time, label free monitoring and fast-screening technique to assess early stages of cytotoxicity recorded in terms of loss of cell adhesion.


RESULTS
We present data taken from gold nanoparticles of different sizes and surface coatings as well as some reference substances like ethanol, cadmium chloride, and staurosporine. Measurements were recorded with two different cell lines, HeLa and MCF7 cells. The results obtained from gold nanoparticles confirm earlier findings and attest the easiness and effectiveness of the method.


CONCLUSIONS
The reported method allows to easily adapt virtually every AFM to screen and assess toxicity of compounds in terms of cell adhesion with little modifications as long as a flow cell is available. The sensitivity of the method is good enough indicating that even single cell analysis seems possible.
Department of Chemistry, University of Marburg, Marburg, Germany.
Fang
F
Yang
Department of Chemistry, University of Marburg, Marburg, Germany.
René
R
Riedel
Department of Physics, University of Marburg, Marburg, Germany.
Pablo
P
Del Pino
Department of Physics, University of Marburg, Marburg, Germany.
Beatriz
B
Pelaz
Department of Physics, University of Marburg, Marburg, Germany.
Alaa Hassan
AH
Said
Department of Physics, University of Marburg, Marburg, Germany.
Mahmoud
M
Soliman
Department of Pharmacy, University of Marburg, Marburg, Germany.
Shashank R
SR
Pinnapireddy
Department of Physics, University of Marburg, Marburg, Germany.
Neus
N
Feliu
Department of Physics, University of Marburg, Marburg, Germany.|CIC biomaGUNE, San Sebastián, Spain.
Wolfgang J
WJ
Parak
Department of Pharmacy, University of Marburg, Marburg, Germany.
Udo
U
Bakowsky
Department of Chemistry, University of Marburg, Marburg, Germany. hampp@uni-marburg.de.|Material Science Center, University of Marburg, Marburg, Germany. hampp@uni-marburg.de.
Norbert
N
Hampp
D002448:Cell Adhesion; D002470:Cell Survival; D006046:Gold / Q000737:chemistry; D006367:HeLa Cells; D006801:Humans; D061986:MCF-7 Cells; D053768:Metal Nanoparticles / Q000737:chemistry*; D018625:Microscopy, Atomic Force / Q000379:methods*
D006046:Gold
AFM; Cell adhesion; Cell viability; Cytotoxicity; Fast-screening measurement; Gold nanoparticles