4﹒Preparation of Low Molecular Weight Hyaluronic Acid

Hyaluronic acid（HA）（together with its salts are called hyaluronan），a widely distribu ted glycosaminoglycan of high molecular weight and a structural component of extracellular and intercellular matrices。With enzymatic methods such as using hyaluronidase，chondroitinase，etc ﹒，or with chemical methods such as ascorbic acid treatment，hypochlorite treatment or hydrogen peroxide treat ment ．.