title: Continuous depth-sensing nano-mechanical characterization of living, fixed and dehydrated cells attached on a glass substrate.
abstract: Continuous depth-sensing nano-indentation on living, fixed and dehydrated fibroblast cells was performed using a dynamic contact module and vertically measured from a pre-contact state to the glass substrate. The nano-indentation tip-on-cell approaches took advantage of finding a contact surface, followed by obtaining a continuous nano-mechanical profile along the nano-indentation depths. In the experiment, serial indentations from the leading edge, i.e., the lamellipodium to nucleus regions of living, fixed and dehydrated fibroblast cells were examined. Nano-indentations on a living cell anchored upon glass substrate were competent in finding the tip-on-cell contact surfaces and cell heights. For the result on the fixed and the dehydrated cells, cellular nano-mechanical properties were clearly characterized by continuous harmonic contact stiffness (HCS) measurements. The relations of HCS versus measured displacement, varied from the initial tip-on-cell contact to the glass substrate, were presumably divided into three stages, respectively induced by cellular intrinsic behavior, the substrate-dominant property, and the substrate property. This manifestation is beneficial to elucidate how the underlying substrate influences the interpretation of the nano-mechanical property of thin soft matter on a hard substrate. These findings, based upon continuous depth-sensing nano-indentations, are presumably valuable as a reference to related work, e.g., accomplished by atomic force microscopy.
authors.affiliation: Department of Materials Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Yun-Ta
authors.initials: YT
authors.lastname: Yang
authors.forename: Chou-Ching K
authors.initials: CC
authors.lastname: Lin
authors.forename: Jiunn-Der
authors.initials: JD
authors.lastname: Liao
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Chang
authors.forename: Ming-Shaung
authors.initials: MS
authors.lastname: Ju
mesh_terms: D016475:3T3 Cells; D000362:Agar / Q000494:pharmacology; D000818:Animals; D001696:Biomechanical Phenomena / Q000187:drug effects; D002448:Cell Adhesion / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D003890:Desiccation; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects; D005898:Glass / Q000737:chemistry*; D051379:Mice; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000379:methods*; D016707:Tissue Fixation / Q000379:methods*
chemical_list: D000362:Agar