title: Characterization of cellular elastic modulus using structure based double layer model.
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.
authors.affiliation: Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea. kim6224k@kaist.ac.kr
authors.forename: Yeongjin
authors.initials: Y
authors.lastname: Kim
authors.forename: Mina
authors.initials: M
authors.lastname: Kim
authors.forename: Jennifer H
authors.initials: JH
authors.lastname: Shin
authors.forename: Jung
authors.initials: J
authors.lastname: Kim
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D003599:Cytoskeleton / Q000502:physiology; D055119:Elastic Modulus / Q000502:physiology*; D056945:Hep G2 Cells; D006801:Humans; D018625:Microscopy, Atomic Force / Q000379:methods; D018613:Microscopy, Confocal; D008954:Models, Biological; D013314:Stress, Mechanical