title: Dielectric aggregation kinetics of cells in a uniform AC electric field.
abstract: BACKGROUND
  Cell manipulation and separation technologies have potential biological and medical applications, including advanced clinical protocols such as tissue engineering.
  
  
  OBJECTIVE
  An aggregation model was developed for a human carcinoma (HeLa) cell suspension exposed to a uniform AC electric field, in order to explore the field-induced structure formation and kinetics of cell aggregates.
  
  
  METHODS
  The momentum equations of cells under the action of the dipole-dipole interaction were solved theoretically and the total time required to form linear string-like cluster was derived. The results were compared with those of a numerical simulation. Experiments using HeLa cells were also performed for comparison.
  
  
  RESULTS
  The total time required to form linear string-like clusters was derived from a simple theoretical model of the cell cluster kinetics. The growth rates of the average string length of cell aggregates showed good agreement with those of the numerical simulation. In the experiment, cells were found to form massive clusters on the bottom of a chamber. The results imply that the string-like cluster grows rapidly by longitudinal attraction when the electric field is first applied and that this process slows at later times and is replaced by lateral coagulation of short strings.
  
  
  CONCLUSIONS
  The findings presented here are expected to enable design of methods for the organization of three-dimensional (3D) cellular structures without the use of micro-fabricated substrates, such as 3D biopolymer scaffolds, to manipulate cells into spatial arrangement.
authors.affiliation: Department of Applied Physics, National Defense Academy, Kanagawa, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tada
authors.affiliation: Department of Applied Physics, National Defense Academy, Kanagawa, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Natsuya
authors.affiliation: Department of Applied Physics, National Defense Academy, Kanagawa, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Tsukamoto
mesh_terms: D004560:Electricity; D006367:HeLa Cells; D006801:Humans; D008954:Models, Biological; D023822:Tissue Engineering; D054457:Tissue Scaffolds
keywords: Dipole–dipole interaction; cell assembly analysis; cell cluster formation; power law scaling