Novel hyaluronic acid based supramolecular assemblies stabilized by multivalent specific interactions: Rheological behavior in aqueous solution

The behavior in aqueous medium of new hyaluronic acid (HA) based supramolecular assemblies was fully investigated by theological measurements. The physical networks Studied are stabilized by specific interactions between (i) monomeric ss-cyclodextrin (CD) and adamantane (AD) molecules or (ii) dimeric CD and AD molecules, each randomly grafted along the polysaccharide chain. The viscoelastic properties of the resulting "mono- and bi-sticker systems", in which inclusion complexes play the role of sticky point, were analyzed as a function of polymer concentration, temperature and addition of host competitive molecules. These networks were shown to exhibit a marked non-Maxwellian behavior. The mono- and bi-interchain complexes considerably slow down the global dynamic and are believed to involve unusual viscoelastic properties that clearly differ from those of alkylated HA-based systems. These rheological features could be explained by a special mechanism of association leading to the formation of networks constituted by double-chain strands connected by fourfold junction points.