Degradation of high-molecular-weight hyaluronan:: a rotational viscometry study

The flow behavior of four hyaluronan (HA) samples was studied along with the influence of the material of the viscometer on the flow parameters investigated. The changes in viscosity were measured by a rotational Viscometer equipped with metal or Teflon cups and coaxial cylindrical spindles. Within 5 hours of the experiment, a moderate increase of viscosity was observed in all samples. The shear flow measurements of HA samples indicated a non-Newtonian behavior. In another set of experiments, kinetics of HA degradation after addition of H2O2 was compared using both types of cups and spindles. The course of viscosity decrease due to oxidative degradation was observed to differ substantially for the two types of the material, from which the viscometer cups and spindles were built.