Effect of concentration and molecular weight on the rheology of hyaluronic acid/bovine calf serum solutions.

Rheological measurements were conducted on hyaluronic acid (HA)/bovine calf serum (BCS) solutions that can be used as analogues of synovial or periprosthetic fluid. The presence of HA affected profoundly the rheological properties of the solutions, with increased concentrations and higher molecular weight of HA leading to higher viscosities as well as more pronounced shear thinning in steady-shear flow. In dynamic oscillatory flow, the elastic character of the solutions became more pronounced and the cross-over frequency decreased upon increasing concentration and molecular weight of HA. The relevance of these results in the context of appropriate selection of a lubricating environment that mimics physiological conditions is discussed.