Crosslinking Of Hyaluronic Acid By Irradiation

Hyaluronic Acid(HA)is a naturally derived,nonimmunogenic, nonadhesive glycosaminoglycan that plays a prominent role in various wound-healingprocesses,because its poor stability in the human body,it is necessary to modify the HA to get a higher molecular.Among the various way of improving the stability,crosslinking is a more easy way.High-energy radial is an effective way to form branches and crosslinkings. The free radicals appeared when the high-energy radial functioned on the polymer chain.The branches and crosslinking formed after the free radicals reacted to each other.It is a so effective way to get crosslinked structure that does not need any initiator or catalyzer.The high-energy radial applied to the modifying of HA will be a novelty way to get HA derivatives with high character of high purity,high crosslinkage and nontoxic.We focused on two most important aspect while experimentalizing:first we should change the structure of HA,then we must asure the salty of the product.We first tried Ultraviolet radiation,Microwave andγ-radial to find out which one is best.We choseγ-radial after compared with the other two,then we usedγ-radial to further study the crosslink of HA.It is necessary to add some cross-linking agent while doing the cross-linking because of the degradation theγ-radical did to HA.We chose Glycidyl Methacrylate(GM)to function as the cross-linking agent,not because it has double bounds,but also the good biocompatibility.We summarized that the molecular weight of HA,the concentration of GMHA and the dosage ofγ-radical were the most important factors that had obvious effect on the crosslinkage of HA.If control these factors properly,we can achieve the aim of preparing HA derivatives with controlled crosslinkage.At last,we prepared highly crosslinked HA liquid and study the rheology. We find that the rheology performance of the HA derivative we prepared has the accordance of the pseudoplastis fluid.Then we can summarize that this way of modifying can keep the rheology performanceof HA.