Crystalline Sodium Hyaluronate

Abstract

MOST hyaluronates in living tissues are in the form of protein complexes. Physical-chemical investigations on these complexes yield results which differ, depending on the source of the material and also on the extent to which the hyaluronic acid was purified of proteins¹. It appears necessary that, in addition to the descriptions of the divergences of these complexes, one should investigate the nature of the complexing itself. Two views are prevalent in this matter. Noguchi² advocates a pure electrostatic interaction between protein and polyuronide, and Partridge³ believes that the polyuronides have an orienting effect on proteins upon complexing. The last view presupposes certain stereospecific interactions besides electrostatic forces. Although hyaluronates are known to be birefringent and electron-microscopic investigations indicate a fibril structure⁴, X-ray diffraction studies have so far proved that hyaluronic acid films or fibres are of amorphous nature.