| Natural polysaccharide cellulose polymer hydrogel materials have shown wide potential applications in the biomaterial field,such as drug delivery,because of their safety,biocompatibility,biodegradability and environmental sensitivity,especially pH sensitivity of cellulose-based hydrogel carrier make them can be used for the preparation of oral controlled drug delivery systems.However,there are also some defects limits their application on account of complex preparation process,overlong preparation time and high preparation cost,even more important is the residual chemical cross-linkers,organic solvents,and photoinitiators that may cause cytotoxicity.Two solutions based on cellulose hydrogel be designed to solve these problems.1.The construction of cellulose/cyclodextrin(CD)hydrogel drug delivery.To overcome these,a one-pot reaction was adopted,and a concept of a β-CD hydrogel cage was proposed.Hydroxyethyl cellulose(HEC)was used as the raw material with the adjustment of the stoichiometric relationship among the cross-linking agent of epichlorohydrin,alkali environment,and β-CD amount,and an elastic β-CD hydrogel cage system was established.After the β-CD was caged,the contents of active β-CD in hydrogel products be measured by weight measurement and photometric titration,respectively.The 70% loading amount of CD is far beyond the experiment result by chemical grafting.Furthermore,compared to the pure HEC hydrogel,the hydrogel mechanical strength improved obviously after the β-CD was caged,and we obtained a faster water swelling rate at the same time.Finally,a hydrophobic molecule of phenolphthalein(PP)was used to evaluated the activity of caged β-CD in the hydrogel.In addition,the absorption and release of PP by an elastic β-CD hydrogel cage at certain time intervals were also studied.The results demonstrate that the β-CD hydrogel cage was used as a functional molecule carrier to quickly absorb and sustain the release of PP.2.The construction of core-shell structure cellulose hydrogel drug delivery system.Herein,we synthesized a drug delivery system that based on β-CD and cellulose to achieve drug-control release by two steps strategies.First,we synthesis a water-soluble β-CD polymer by the reaction of β-CD with EPI in certain amount of alkaline.Then the prepared β-CDP was dissolved in aqueous solution to solubilizing hydrophobic drugs by host-guest interaction between drug molecule and β-CD and forms a homogeneous drug/β-CDP solution.The second step is adding cellulose to the drug/β-CDP solution and making the mixture into hydrogel capsule directly instead of separate drug/β-CDP inclusion compound from solution.The design of hydrogel capsule shell is based on the polycomplexation between SA and Ca+2,in the condition of simulated gastric juice and simulated intestinal fluid,the Ion-exchange interactionand hydrogen-bond interaction make hydrogel capsule shell can achieve controllable break in different pH.The design of hydrogel capsule core is based on the control release capability of CMC and HEC.In different cellulose mix ratio,the capsules core can achieve control release for IBU.In addition,the GPC,SEM and FTIR also be used for the characterization of preparation hydrogel capsules. |
