Preparation And Properties Of Self-Assembly Hydrogel Based On Cyclodextrin

Intelligent hydrogel has become one of the hot spots in the field of pharmacy and chemistry due to its unique stimulation-response mechanism and the diversity of reversible systems.Intelligent hydrogels based on natural polymer materials have good biocompatibility and bioavailability.In terms of drug transport,the hydrophilicity of cellulosic gels limits the transport of hydrophobic drugs,so ?-cyclodextrin(?-CD)with truncated hydrophobic cavities can be introduced.It is used to improve the solubility,stability,and bioavailability of hydrophobic drugs while overcoming the low solubility of?-CDs and the difficulty of drug release.For sewage treatment,cellulose and its derivatives have the advantages of wide source,low price,and good environmental friendliness.Combined with the P-CD cavity,the spontaneous binding of aromatic organic molecules such as phenol with a size of about 0.59 nm,this kind of hydrogel can be used to treat low concentration phenol wastewater.The existing intelligent hydrogels are often prepared with synthetic polymers or used toxic crosslinking agents,which affects their application.Using the principle of electrostatic self-assembly,this experiment makes cationic ?-CD and carboxymethyl cellulose(CMC)form a new pH sensitive hydrogel,and studies the effects of various assembly conditions on the ?-CD content in the gel and other hydrogel properties.It is used for controlling the release of hydrophobic drugs and the adsorption of phenol in wastewater.Firstly,cationic ?-CD was prepared by semi-dry method,and it was self-assembled with carboxymethyl cellulose in water to prepare hydrogel.The results show that the substitution degree of cationic P-CD increases gradually with the increase of the amount of cation etherizer.MTT experiment was used to verify its non-toxicity and good biocompatibility.Through FT-IR analysis,it is confirmed that the driving force of CMC/cationic P-CD hydrogel formation is electrostatic self-assembly.By TGA analysis,the thermal decomposition temperature of hydrogel was higher than that of CMC membrane,which indicated that its thermal stability was improved.The CMC/cationic?-CD hydrogel exhibits pH sensitivity,and the dissolution rate decreases with the increase of pH.The microscopic morphology is also significantly different under different pH.The change trend is consistent with the swelling behavior because the thickness of the crosslinking layer and the electrostatic repulsion between the CMC chains change,the gel dissolution rate begins to decrease with the increase of pH,and the gel structure becoming more dense with pH increasing.Under the condition that the assembly time is above 9min,the cationic ?-CD substitution degree is 0.41,and the mass fraction is 40%,the CD content in the assembly body is the highest,but the hydrogel strength increases with the increase in the substitution degree of the assembled cationic P-CD.Secondly,the load and slow release of CMC/cationic ?-CD hydrogel were studied.Using hydrophobic chloramphenicol as the model drug,the maximum drug load was 215.33 mg/g.The experimental results show that the amount of hydrogel loading is proportional to its P-CD content.In vitro simulated drug release experiments showed that CMC/cationic ?-CD hydrogel had a significant slow-release effect on chloramphenicol,and the drug release rate under neutral conditions was lower than that under acidic conditions.The kinetic data of the drug release process were fitted using the Korsmeyer-Peppas model,the Quasi-Fickian mechanism was met in the buffer of pH 4 and 6,and the Non-Fickian mechanism was met in the buffer of pH 7.Finally,the adsorption properties of hydrogel on phenol in wastewater were studied.The results showed that when the pH of the solution was 6,the adsorption time was more than 24 min,and the initial concentration was 70 mg/L,the adsorption of phenol by hydrogel was the highest,reaching 19.04 mg/g.The adsorption of phenol by hydrogel was in accordance with the standard.In the second-order kinetic model,the adsorption isotherm of hydrogel on phenol accords with the Freundlich model.