Rheological properties of aqueous solutions of biopolymeric hyaluronan

Aqueous solutions of hyaluronic acid (hyaluronan, HA) were studied. The HA compound is a natural polysaccharide, biopolymer. It plays an Important role In numerous biological processes as a component of the extracellular matrix, connective tissues and, especially, human and animal synovial joints. Natural and artificial solutions of the HA have demonstrated the viscoelastic nature (1,2). These properties are shown to be related to the microstructure parameters (bulk concentration, molecular weight) and external parameters (temperature, stress, shear rate) (3,4). We emphasise the role of the flow properties of polymeric systems. It is found a liquid crystalline "order" can be "induced" during the material flow (3,5). The dynamic properties, such as the elastic shear modulus and viscous shear modulus, are given. These results are discussed in relation to the postulated function of hyaluronic acid in synovial joint and with respect to possibilities o their application in medicine and pharmacology.