Abstract
The mechanical characterization of cells is important for understanding cellular behavior and physiological functions. We used atomic force microscopy (AFM) to obtain a force–displacement curve and estimate the elastic modulus of hepatocellular carcinoma cells (HEP-G2) utilizing both linear Hertz–Sneddon (HS) and non-linear elastic models. In order to overcome the limitations of HS model, which assumes a linear homogeneous cell body, a cell is modeled as a double-layered body with an outer cytoplasmic layer made mostly of interconnected fibers of cytoskeleton proteins and a nucleus. By disrupting all cytoskeletal protein networks, we estimate the elastic modulus of the core nucleus using FEM for a single ellipsoid. Based on the nucleic modulus and cellular dimensions found by 3D confocal imaging, we develop a novel double-layered cellular (DLC) finite element model. The DLC model provides a more reliable estimate of the elastic modulus of the cell than conventionally used HS model and correlates closely with experimental results.




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Abbreviations
- DLC:
-
Double-layered cell
- SLC:
-
Single-layered cell
- HS:
-
Hertz–Sneddon
- VBL:
-
Vinblastine
- CD:
-
Cytochalasin D
- OA:
-
Okadaic acid
- VOC:
-
Vinblastine/okadaic acid/cytochalasin D
- CK18:
-
Cytokeratin 18
- MT:
-
Microtubule
- IF:
-
Intermediate filament
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Acknowledgments
This research was supported by grants from the Fundamental Research Project that were distributed by the Korean Institute of Machinery and Materials and Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (2010-0022871). The authors are grateful to Jungwoo Hong, Bummo Ahn, and Jinsung Hong from the Soft Biomechanics and Biomaterials Laboratory and Biorobotics Laboratory of KAIST for cell preparation and for their enthusiastic discussion and help. In addition, we thank Dr. Junhee Lee, Dr. Shin Huh, and Dr. Wandu Kim from the Nanotechnology Research Team of KIMM for their technical assistance with AFM.
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Kim, Y., Kim, M., Shin, J.H. et al. Characterization of cellular elastic modulus using structure based double layer model. Med Biol Eng Comput 49, 453–462 (2011). https://doi.org/10.1007/s11517-010-0730-y
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DOI: https://doi.org/10.1007/s11517-010-0730-y