The Potosensitive Modification Study Of Amino Polysaccharide

Hyaluronic acid (HA) is a kind of amino polysaccharide. Because of its excellent biocompatibility and biodegradable, it can be used widely for biological and medical materials. But it need crosslinking to improve its application performance due to its strong hydrophilic. The studies about hyaluronic acid crosslinking modification were mainly used chemical crosslinking methods, photo crosslinking modification were rarely seen. UV photo crosslinking modification is a kind of high efficient and environmental friendly and green method. The photosensitive macromolecular named polyvinylacohol (PVA) bearing styrylpyridinium group (PVA-SbQ) was introduced into HA system and can be cross-linked under UV radiation to form network, which can improve the performance of HA and spread the applied scope of HA. In this paper, the photosensitive modification and application of HA were mainly studied. We focused on the research of the photo-cross-linked PVA-SbQ/Hyaluronic acid hydrogel and photo-cross-linked HA-ADH/PVA-SbQ porous membrane. The application of the photo-cross-linked composite in drug release and protein adsorption was also explored. The major work was consisted of the following two parts.In part 1, photo-cross-linked PVA-SbQ/Hyaluronic acid hydrogel with different irradiation time and quality proportion were made by mixing the solutions of PVA-SbQ and HA followed by photo-cross-linked. The structure of the hydrogel was analyzesed and the viscosity and swelling ratio of the HA/ PVA-SbQ hydrogel on different irradiation time were discussed. The equilibrium swelling ratio under different pH, temperature and salt concentration were systematically researched. The swelling dynamics of the hydrogel with different quality proportion was studied. Based on the above, the drug release performance of the hydrogel was studied. The results showed that the PVA-SbQ/hyaluronic acid solution (m(HA: m(PVA-SbQ)=1:3) began to conversion from dilute gel state to solid gel state at the irradiation time of 450 s and the hydrogel had multiple sensitivity(pH, temperature and salt concentration). The swelling dynamics experiments showed that the dominate process was water diffusion into polymer network. The drug release performance study showed that hydrogel could load more drugs with the content of PVA-SbQ increasing and the new pattern can delayed the drug release speed.In part 2, firstly the adipic acid dihydrazide was introduced into HA. Then it was joined together with PVA-SbQ and PEG (pore forming agent). Third, after the UV light, PEG was removed from the membrane; the HA-ADH/PVA-SbQ porous membrane was prepared. Its structure was examined by means of SEM and FTIR. The properties of the HA-ADH/PVA-SbQ porous membrane had been studied. The results show that a level ofμm pore in surface morphology of the porous membrane was formed. After light cross-linking, the network structure of porous membrane has been formed. The hydrophobicity and moisture absorption of porous membrane were improved effectively. The porous membrane which the quality content of HA-ADH is 33% has the largest bovine serum protein adsorption capacity.