Construct Anti-fouling Functional Surface On PVA Hydroqel By Graftinq Polymers With Photoinduced Electron Transfer-Reversible Addition Fragament Chain Transfer And Properties Research

Polyvinyl alcohol(PVA)hydrogel is a kind of biomaterials with excellent properties.However,it still has the biofouling problem after implanting.In this work,three kinds of functional surface including quaternary ammonium salt chitosan,zwitterionic and thermosensitive,were successfully constructed on PVA hydrogel by a novel,green and industrial method which named photoinduced electron transfer-reversible addition fragment chain transfer(PET-RAFT)polymerization.After grafting,the antifouling property of hydrogel was improved,the scope of application was expanded,and the risk of use was decreased.The main contents and conclusions are as follows:(1)Based on the research of Chen and Boyer,it can be inferred that the hydroxyl group of PVA hydrogel is bonding with the double bond of grafting monomer to form ether bond via PET-RAFT polymerization.The results of ATR-FTIR and XPS confirmed the result.The results of reactions factors showed that CPADB and photocatalyst with appropriate concentration could produce free radicals with stable concentration.Photocatalytic efficiency increased with the increase of light absorption intensity of photocatalyst.Further,the grafting rate of PVA hydrogel increased with the increase of monomer concentration.In absence of oxygen,the reaction efficiency was higher than in presence of oxygen.The reaction process was slow in initiate stage.After initiating it became faster,and finally became stable in the final stage.The temperature could greatly improve the grafting reaction efficiency.Moreover,PET-RAFT could carry out with a certain thickness of shield while using AlPc catalyst,but the reaction efficiency was low.(2)Glycidyl methacrylate(GMA)and 2-hydroxypropyl trimethylammonium chloride chitosan(HACC)were successfully grafted onto PVA hydrogel by two-steps methods of PET-RAFT polymerization and open-ring reaction.After grafting with GMA and HACC,the thermodynamic property and optical transmittance were decreased,and the hydrophilicity and mechanical properties were greatly improved.The cytotoxicity in vitro of PVA-g-pGMA and PVA-g-p(GMA-HACC)hydrogel were grade 0 and grade 1,respectively.Compared with PVA hydrogel,the antifouling properties of PVA-g-pGMA hydrogel became worse(protein adsorption increased about 50.78%and cell adhesion increased 23.08%-42.58%)due to the hydrophobic epoxy group of GMA.After grafting with HACC,the anti-fouling properties became better(anti-protein adsorption increased about 39.59%and anti-cell adhesion increased 44.50%-54.52%),due to the steric repulsion and surface hydration effect.(3)MEDSAH was successfully grafted onto PVA hydrogel surface by PET-RAFT polymerization in present oxygen.After grafting with MEDSAH,the thermodynamic and mechanical properties were decreased,the hydrophilicity was increased(water contact angle 14.6 °),and the optical transmittance was higher than 88.8%.The cytotoxicity in vitro of PVA-g-pMEDSAH hydrogel was grade 1.Base on the surface hydration effect and steric repulsion effect of pMEDSAH polymer brush,the anti-protein adsorption and anti-cell adhesion capacity of hydrogel were greatly improved by 59.53%and 71.82%-75.86%,respectively.(4)NIPAAm was successfully grafted onto PVA hydrogel surface by PET-RAFT polymerization with fluorescein in present oxygen.After grafting with NIPAAm,there was little effect on the thermodynamic and mechanical properties of PVA hydrogel.The hydrophilicity of hydrogel was increased with temperature sensitivity(water contact angle 4.3° at 25? and 37.4 °at 37?),and the optical transmittance was higher than 92.2%.The cytotoxicity in vitro of PVA-g-pNIPAAm hydrogel was grade 1,and its anti-protein adsorption capacity of hydrogel was increased with temperature sensitivity(56.09%at 25?,42.75%at 37?,).In addition,the anti-cell adhesion capacity of hydrogel was increased by 37.29%-46.65%.The mainly reasons for the improvement of anti-fouling capacity was the steric repulsion effect.(5)CBMA was successfully grafted onto PVA hydrogel surface by PET-RAFT polymerization with aluminum phthalocyanine chloride(AlPc)in present oxygen.After grafting with CBMA,the thermodynamic and mechanical properties of PVA hydrogel were decreased.The hydrophilicity of hydrogel was increased(water contact angle 16.8°),and the optical transmittance was influenced by residue of the AlPc catalyst.The cytotoxicity in vitro of PVA-g-pCBMA hydrogel was grade 1.Base on the surface hydration effect and steric repulsion effect of pCBMA polymer brush,the anti-protein adsorption and anti-cell adhesion properties were increased by 64.62%and 71.24%-77.70%,respectively.