Hydration of polymeric components of cartilage--an infrared spectroscopic study on hyaluronic acid and chondroitin sulfate.
Hydrated polysaccharides are major constituents of cartilage and play an important role in its water-binding properties. Infrared (IR) spectroscopy and sorption isotherms have been used to investigate the hydration behavior of the glycosaminoglycans hyaluronic acid and chondroitin sulfate. IR-dichroism of the vibrational modes of the pyranose ring is found at relative humidities (RH) smaller than 84%. The IR-dichroism data for the vibrational modes of the pyranose ring have been analyzed with respect to the helical structure of these polysaccharides. The orientation vanishes at higher relative humidities (>84%), because a strong increase in the water uptake occurs in the observed sorption isotherms. Differences in the IR-absorbance of the O-H stretching mode of sorbed water between hyaluronic acid and chondroitin sulfate are shown to be caused by the additional hydration of the sulfate groups. The corresponding H-bonds are weaker than those of the hydration shell of the pyranose rings.
Servaty
R
R
Institute of Medical Physics and Biophysics, Medical Faculty, University of Leipzig, Liebigstr. 27, 04103, Leipzig, Germany.
Schiller
J
J
Binder
H
H
Arnold
K
K
D002356:Cartilage / Q000737:chemistry*; D002809:Chondroitin Sulfates / Q000737:chemistry; D006820:Hyaluronic Acid / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D013696:Temperature; D014867:Water / Q000378:metabolism*
D011108:Polymers; D011134:Polysaccharides; D014867:Water; D006820:Hyaluronic Acid; D002809:Chondroitin Sulfates