An unforeseen feature of water as a biological fluid is demonstrated. Hyaluronan, a highly hydrated natural biopolymer, has an impact on the structure of water molecules in its extended hydration shells.

In this work, we explored the extended hydration shell structure of hyaluronan in aqueous solutions . Hyaluronan is a highly hydrated biopolymer found in the extracelular environment, such as synovial fluid between joints. Angle-resolved fs-ESHS measurements and nonlinear optical modeling show that hyaluronan behaves like a flexible chain surrounded by extended shells of orientationally correlated water. The spatial extent of the hydration shell is determined via temperature-dependent measurements and can reach up to 475 nm. (read more…)