Abstract
Platelets, essential for hemostasis, are easily activated via biochemical and mechanical stimuli. Cell stiffness is a vital parameter modulating the mechano-transduction of exogenous mechanical stimuli. While methods exist to measure cell stiffness, no ready method exists for measuring platelet stiffness that is both minimally-contacting, imparting minimal exogenous force and non-activating. We developed a minimal-contact methodology capable of trapping and measuring the stiffness of individual platelets utilizing dielectrophoresis (DEP)-mediated electrodeformation. Parametric studies demonstrate a non-uniform electric field in the MHz frequency range (0.2–20 MHz) is required for generating effective DEP forces on platelets, suspended in isotonic buffer with conductivity ~100–200 μS/cm. A nano-Newton DEP force (0.125–4.5 nN) was demonstrated to be essential for platelet electrodeformation, which could be generated with an electric field with strength of 1.5–9 V/μm. Young’s moduli of platelets were calculated using a Maxwell stress tensor model and stress-deformation relationship. Platelet stiffness was determined to be in the range of 3.5 ± 1.4 and 8.5 ± 1.5 kPa for resting and 0.4% paraformaldehyde-treated cells, respectively. The developed methodology fills a gap in approaches of measuring individual platelet stiffness, free of inadvertent platelet activation, which will facilitate further studies of mechanisms involved in mechanically-mediated platelet activation.
Original language | English (US) |
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Pages (from-to) | 903-913 |
Number of pages | 11 |
Journal | Annals of Biomedical Engineering |
Volume | 44 |
Issue number | 4 |
DOIs | |
State | Published - Apr 1 2016 |
Keywords
- Cell stiffness
- Dielectrophoresis
- Electrodeformation
- Electrodeformation
- Mechanotransduction
- Platelets
- Young’s modulus
ASJC Scopus subject areas
- Biomedical Engineering