Cell Deformability & Cell Adhesion
Series of microphotographs showing the micropipette experiment setup. Featured on the cover of Cellular and Molecular Bioengineering (2010) A. Initial setup. The left pipette is holding an ICAM-1 coated bead (4.5µm in diameter) and the right pipette is holding a human neutrophil. B-E. Time course of the engulfment of the IL-8 bead (2.8 µm in diameter). Snapshots are taken at the initial contact time (B), and subsequent times after contact: C. 20 seconds, D. 70 seconds, E. 320 seconds.
Most of our work centers on the deformability of blood cells and how blood cell deformability plays a role in health and disease. We interested in what kinds of things can affect the deformability of cells and how changes in deformability affect the flow of blood and delivery of oxygen to living tissues. We use very small glass pipettes and glass fibers to apply measured forces to the surfaces of individual cells and we observe the deformation using a microscope with an attached television camera.
There are three main classes of blood cells:
- red blood cells
- white blood cells
Red blood cells carry oxygen and carbon dioxide to and from the tissues. They are the most numerous (and most easy to deform) of the cells and make up approximately 40-45% of the blood volume. Most of the rest of the blood volume is plasma, and white cells and platelets generally make up less than 1% of the volume.
Platelets are smaller than red cells and are involved in clotting. White blood cells come in a variety of types, and are important in fighting disease. The two most common white cells are neutrophils and lymphocytes. These are larger than red blood cells and deform more slowly than red blood cells.
- Dynamics of adhesion molecule domains on neutrophil membranes: surfing the dynamic cell topography. Eur Biophys J. 42, 851-5. (2013 Dec 01).
- Development of membrane mechanical function during terminal stages of primitive erythropoiesis in mice. Exp Hematol. 41, 398-408.e2. (2013 Apr 01).
- Quantifying the mechanical properties of the endothelial glycocalyx with atomic force microscopy. J Vis Exp. In press. (2013 Jan 01).