Preparation And Properities Of Hydroxyethyl Chitosan Modified By PEGylated Rosin Derivatives

Chitosan hydrogel is a kind of substance with three-dimensional networks,which is formed by crosslinking of the water-soluble chitosan or its derivatives.It has various properties such as high water absorption-retention ability,biological activity and biodegradability.It is widely used in pharmaceutical production,food processing and other fields.In this paper,amphiphilic compounds were prepared by using rosin derivatives and chitosan as the raw materials,which mainly involved dehydroabietyl glycidyl ether modified hydroxyethyl chitosan(DAGE-g-HECTS),dehydroabietyl polyethylene glycol glycidyl ether modified hydroxyethyl chitosan(DA(EO)mGE-g-HECTS),and dehydroabietyl polyethylene glycol aldehyde modified hydroxyethyl chitosan(DA(EO)5CHO-g-HECTS).Hydroxyethyl chitosan and amphiphilic compounds were crosskinked with the glycerophosphate(GP)or genipin(GE).The gelation property,drug loading and drug release properties of the hydrogels were studied.The main research contents included the preparation and properties of HECTS,DAGE-g-HECTS,DA(EO)mGE-g-HECTS and DA(EO)5CHO-g-HECTS.1.The preparation and properties of HECTSHydroxyethyl chitosan(HCECTS)was prepared by two methods.The structure of the product was assessed with FT-IR and 1H NMR,and the substitution degree of the product was determined by using elemental analysis.Based on the substitution degree of the product,the conditions for the preparation of HECTS were optimized by orthogonal experiments.The GP and GE were used as crosslinking agents to realize the gelation of HECTS,and the gelation process of the hydrogels was studied.While the HECTS hydrogels were used as carriers and chloramphenicol was used as analogue drug,the drug release property of the hydrogels was preliminarily studied.The results showed that when the n(Bromoethanol):n(CTS unit)=5:1,n(NaOH):n(CTS unit)=10:1,reaction temperature was 50? and reaction time was 36 h,the substitution degree of product was 112.39%.The HECTS/GP hydrogel was temperature sensitive,but the HECTS/GE hydrogel had no temperature response.In vitro release experiments indicated that the cumulative release of drug-loaded hydrogels in artificial gastric juice(pH=1.2)was significantly higher than that in artificial intestinal juice(pH=7.4).The release behaviors of the hydrogels in vitro were best explained by first-order kinetic model.2.The preparation and properties of DAGE-g-HECTSDAGE-g-HECTS was prepared by using DAGE and HECTS as the raw materials.The composition of the product was characterized by FT-IR spectroscopy,1H NMR spectroscopy and elemental analysis.The surface activity and emulsifying property of the product were also studied.The results showed that the DG of DAGE-g-HECTS increased from 17.78%to 44.31%,the corresponding critical micelle concentration in aqueous solution decreased from 1.0806 g/L to 0.2472 g/L,but the minimum surface tension was about 36 mN/m.With the increase of the grafting degree,the stability time of benzene-water emulsion formed with DAGE-g-HECTS as emulsifier was extended from 291 s to 881 s.3.The preparation and properties of DA(EO)mGE-g-HECTSDA(EO)mGE-g-HECTS was prepared by using DA(EO)mGE and HECTS as the raw materials.Characterization of the product was performed using FT-IR,UV and 1H NMR.The grafting degree of the product was determined by elemental analysis.The emulsifying property and surface activity of DA(EO)mGE-g-HECTS aqueous solution were studied respectively.The DA(EO)mGE-g-HECTS hydrogels could form by using the GE as crosslinking agent.Chloramphenicol was use as a drug model to study the drug release performance of the hydrogels.The results showed that DA(EO)mGE-g-HECTS had better surface activity,foam performance and emulsification property.The DG of the DA(EO)10GE-g-HECTS and the amount ratio of the crosslinking agent affected the drug release rate.First-order kinetic model could fit the release of chloramphenicol better.4.The preparation and properties of DA(EO)5CHO-g-HECTSDA(EO)5CHO-g-HECTS was prepared by using DA(EO)5CHO and HECTS as the raw materials.The structure of the product was evaluated using FT-IR,UV and 1H NMR.The grafting degree of the product was determined by elemental analysis.The emulsifying property and surface activity of DA(EO)5CHO-g-HECTS aqueous solution were studied.The DA(EO)5CHO-g-HECTS hydrogels could form by using the GE as crosslinking agent.And with chloramphenicol as mimic drug,the drug release performance of the hydrogels was studied.The results showed that DA(EO)5CHO-g-HECTS had better surface activity,foam performance and emulsification property.The DG of DA(EO)5CHO-g-HECTS affected the drug release rate,and their behavior conformed to the first-order kinetic model.