Berlin 2008 – scientific programme
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BP: Fachverband Biologische Physik
BP 13: Biopolymers
BP 13.3: Talk
Tuesday, February 26, 2008, 17:45–18:00, PC 203
Microrheology of hyaluronan solutions: implications for the endothelial glycocalyx — •Nadja Nijenhuis1, Daisuke Mizuno2, Christoph F. Schmidt3, Hans Vink1, and Jos A.E. Spaan1 — 1University of Amsterdam, Amsterdam, The Netherlands — 2Kyushu University, Fukuoka, Japan — 3Georg-August-Universität, Göttingen, Germany
The endothelial glycocalyx (EG) forms an anti-adhesive surface at the luminal side of a blood vessel, acting both as a molecular sieve and as a mechanotransducer of fluid shear stress to the underlying endothelial cell layer. One of the components involved in these processes is the highly hydrated glycosaminoglycan (GAG) hyaluronan (HA). HA is the largest of the GAGs present in the EG. We used an optical tweezers setup and laser interferometry to measure the high band-width storage (G') and loss (G") modulus of HA solutions. The HA networks, consisting of approximately physiological molecular weight chains and concentrations had a frequency regime up to about 1000 Hz in which the mechanical response was more elastic than viscous. The addition of hyaluronidase to the entangled HA solution rapidly changed its rheological behavior: G' decreased, the entangled network character disappeared, and viscosity became dominant over elasticity.