title: Novel distance dependence of diffusion constants in hyaluronan aqueous solution resulting from its characteristic nano-microstructure.
abstract: Material transports in hyaluronan (HA) aqueous solution were investigated applying two different techniques, i.e., pulsed field gradient NMR (PFG-NMR) and photochemical quenching, to the measurement of diffusion constants to show a sharp contrast resulting from the difference of the spectroscopic observation time while the same probe molecules were commonly used in two experiments. The value from PFG-NMR reflects the relatively long transport along which the majority of the molecules are retarded by the mesh structure of HA solution. In such inhomogeneous fluids, the observable diffusion constant should generally depend on the observation time and, i.e., the averaged distance of diffusion. Quantitative discussion, which compares the obtained characteristic distance of diffusion with the pore size, clarifies the role of the nano-microstructure of HA solution forming small pores surrounded by the polymer chain networks.
authors.affiliation: RIKEN (The Institute of Physical and Chemical Research), Wako, Saitama 351-0198, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Masuda
authors.forename: K
authors.initials: K
authors.lastname: Ushida
authors.forename: H
authors.initials: H
authors.lastname: Koshino
authors.forename: K
authors.initials: K
authors.lastname: Yamashita
authors.forename: T
authors.initials: T
authors.lastname: Kluge
mesh_terms: D004058:Diffusion; D006820:Hyaluronic Acid / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D012996:Solutions; D014867:Water / Q000737:chemistry
chemical_list: D012996:Solutions; D014867:Water; D006820:Hyaluronic Acid