Properties Of Hyaluronic Acid Cross-Linked By γ-Irradiation

Hyaluronic acid (HA) plays a prominent role in the medical service because of a unique water retention property, rheological property and biocompatibility. The clinical practice discovered that the natural HA has a poor stability in the organization and is degraded easily by the oxidant or the enzyme. The natural HA could not satisfy the viscoelasticity and the stability in certain occasions. For enhancing the viscoelasticity, lowering the water solubility and extending the degraded time, it is necessary that natural HA is crosslinked by restructure to obtain more crosslinked structure. GMA was first grafted onto HA to form GMAHA conjugates. After treating the solution of GMAHA derivatives by 60Co-y irradiation, cross-linked HA was prepared. Major achievements list as follows:1. The structer, dosage of GMA, and residue of TEA were characterized by FT-IR, water uptake capability, and viscosity of cross-linked HA. Results showed that the GMA protects HA's main functional group, HA derivatives have a high degree of crosslinking when GMA:HA=7:1. The residue of TEA is 1.352mg·L-1. This result is lower than Smg·L-1 remains in the national request. 2. HA gel could be defined as a strong hydrogel. When the HA's molecular weights was fixed, the water uptake capability of the HA gel decreased with the increase in the concentrarion of GMAHA and y-ray dosage with a certain range. Compare to natural HA, the antioxidant activities and the antienzymolysis activities raised considerably.3. The cross-linked HA's rheology, scavenging of DPPH were studied, too. The cross-linked HA still has the viscoelasticity. But the scavenging of DPPH was weaker than no-crosslinked HA.4. The weight of water absorbed by HA film was 10 times than themselves. Five days later, the HA film could retain 60% water. The HA film also have excellent potentials as carriers for the sustained release.