title: Sub-cellular force microscopy in single normal and cancer cells.
abstract: This work investigates the biomechanical properties of sub-cellular structures of breast cells using atomic force microscopy (AFM). The cells are modeled as a triple-layered structure where the Generalized Maxwell model is applied to experimental data from AFM stress-relaxation tests to extract the elastic modulus, the apparent viscosity, and the relaxation time of sub-cellular structures. The triple-layered modeling results allow for determination and comparison of the biomechanical properties of the three major sub-cellular structures between normal and cancerous cells: the up plasma membrane/actin cortex, the mid cytoplasm/nucleus, and the low nuclear/integrin sub-domains. The results reveal that the sub-domains become stiffer and significantly more viscous with depth, regardless of cell type. In addition, there is a decreasing trend in the average elastic modulus and apparent viscosity of the all corresponding sub-cellular structures from normal to cancerous cells, which becomes most remarkable in the deeper sub-domain. The presented modeling in this work constitutes a unique AFM-based experimental framework to study the biomechanics of sub-cellular structures.
authors.affiliation: VT MEMS Laboratory, The Bradley Department of Electrical and Computer Engineering, Blacksburg, VA 24061, USA.
authors.forename: H
authors.initials: H
authors.lastname: Babahosseini
authors.affiliation: Nonlinear Intelligent Structures Laboratory, Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487-0276, USA.
authors.forename: B
authors.initials: B
authors.lastname: Carmichael
authors.affiliation: VT MEMS Laboratory, The Bradley Department of Electrical and Computer Engineering, Blacksburg, VA 24061, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Strobl
authors.affiliation: Nonlinear Intelligent Structures Laboratory, Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487-0276, USA. Electronic address: nmahmoodi@eng.ua.edu.
authors.forename: S N
authors.initials: SN
authors.lastname: Mahmoodi
authors.affiliation: VT MEMS Laboratory, The Bradley Department of Electrical and Computer Engineering, Blacksburg, VA 24061, USA. Electronic address: agah@vt.edu.
authors.forename: M
authors.initials: M
authors.lastname: Agah
mesh_terms: D001940:Breast / Q000166:cytology* / Q000648:ultrastructure; D001943:Breast Neoplasms / Q000473:pathology* / Q000648:ultrastructure; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D018625:Microscopy, Atomic Force / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical
keywords: Atomic force microscope (AFM); Generalized Maxwell model; Human breast cells; Sub-cellular biomechanics