Hyaluronic Acid

Rheological BehaviorThe dynamic viscosity of native HAdepends on the shear rate as for non-Newtonian liquids, showing decreaseof dynamic viscosity with an increaseof the shear rate. This reflects adisruption of the hydrogen-bondedsystem.Alkyl-modified HA has a typicalNewtonian liquid viscosity behaviour.The observed decrease in zero shearviscosity and the appearance of theviscosity independence on the appliedshear rate can be attributed to theformation of intra-molecularhydrophobic associates, resulting inthe collapse of the macromolecularcoils.Dynamic Viscosity (Pa.s)1010.10.01Non-Newtonian behaviorNewtonian behavior0.0011 10 100Shear Rate (1/s)Dynamic viscosity dependencies on the appliedshear rate of the native HA (c=6.8 mg/mL) (emptytriangle); 100 mol.% - modified hexyloxy-HA atconcentrations of 6.1 mg/mL (full circle), 7.4mg/mL (empty circle) and 5.0 mg/mL (full triangle).35