Research On The Construction Of Hydroxyethyl Cellulose-based Self-assembled Functional Hydrogel System

In recent years,biomass based material such as cellulose has draw great attention for its abundant sources,excellent biodegradability and biocompatibility,and the cellulose derivatives have been applied to all aspects of production and living.Among its applications,more and more research groups have focused on the cellulose-based hydrogels,such hydrogels can be given the advantages of natural products and the value of cellulose is improved as well.Hydroxyethyl cellulose-based hydrogel was prepared by the method of self-assembly in this study,and functional guest molecules were introduced in the hydrogel to investigate its applications.Hydrophobic modified hydroxyethyl cellulose(HEC-C12)and water soluble?-cyclodextrin polymers were synthesized by Williamson etherification method and crosslinking method,respectively.The preparation of HEC-C12 was optimized by considering its dynamic viscosity and swelling ratio,and that of ?-CDP took water solubility into consideration to optimize synthesizing conditions.Then the structrues and the surface morphologies of the macromolecules were characterized.Finally,the grafting amount of C12 onto HEC was determined as 4%,the molecular weight and the water solubility of ?-CDP were1731.1 kDa and 0.45 g mL-1,respectively.The drug-loaded hydroxyethyl cellulose-based hydrogel can be synthesized by loading drug molecules after the formation of the hydrogel.C12 side chains on HEC as guest molecules can be encapsulated into the cavities of ?-CDP for the self-assembly of gel-(?)CDP-HEC,and the critical concentrations of HEC-C12 and ?-CDP were determined by the results of dynamic viscosity,swelling ratio and rheological property.The surface morphology of gel-(?)CDP-HEC was observed by SEM.The amounts of residual cavities of ?-CDP in gel-(?)CDP-HEC were detected by phenolphthalein probe method,and the hydrophobic EG molecules can be loaded into gel-(?)CDP-HEC.The loading amounts of EG were determined by UV-vis,the bacteriostasis characteristics against Escherichia coli GIM 1.173 have been proved by agar cup-plate diffusion method.The results demonstrated that gel-(?)CDP-HEC had a potential bacteriostasis effect.Drug molecules can be loaded onto the the self-assembled hydroxyethyl cellulose-based hydrogel in another way,for example,ibuprofen molecules were encapsulated and solubilized by ?-CDP to form ?-CDP/IBU.The content of active residual cavities of ?-CDP with inclusion ability in ?-CDP/IBU was determined by phenolphthalein probe method,then the residual cavities were used to form self-assembled hydrogel(gel-(?)CDP-HEC/IBU)in water spontaneously with hydrophobic C12 side chains on HEC-C12.The critical concentrations ofHEC-C12 and ?-CDP/IBU in the self-assembled hydrogel were determined as the dynamic viscosity results shown.Gel-(?)CDP-HEC/IBU was characterized by SEM and PXRD,IBU loading amounts were determined by UV-vis,and the in vitro IBU release characteristics of gel-(?)CDP-HEC/IBU was investigated by dialysis bag diffusion technique.In addition,the Korsmeyer-Peppas kinetic model gave a better correlation for the release of IBU.