Study On Supramolecular Hydrogels As Carriers For Sustained Insulin Release

The supramolecular inclusion of α-cyclodextrin (a-CD) and PEG contained block copolymer Pluronic F127or Jeffamine ED-2003was used to build a supramolecular hydrogel system. Meanwhile, block copolymer Pluronic F127may also build a hydrogel system. We will determine whether they are carriers for insulin. The result shows that the supramolecular hydrogel system which Pluronic F127and a-CD form may realize the sustained release of insulin.The supramolecular inclusion of a-cyclodextrin (a-CD) and PEG contained block copolymer Pluronic F127was used to build a supramolecular hydrogel system. The composition and gelation behavior of the system were evaluated. There were two kinds of crosslinks in the hydrogels. One was the microcrystalline of packed PEG/a-CD inclusion complexes, and the other was the aggregated hydrophobic blocks of Pluronic F127. The compositions of a gel system loaded insulin have been optimized. The results are as follows:Pluronic F127=4wt%, a-CD=9.7wt%, insulin=4wt%. Because of excellent property of the above optimized gel, it may serve as a carrier of insulin.The structure of the gel is characterized by XRD and SEM. The XRD analytic result of the gel system occurs the microcrystalline of packed PEG/a-CD inclusion complexes. Meanwhile, the XRD analytic results of them show porous structure. The reason for this is caused by high water content of the gel.In terms of the in vitro insulin release, the brust release of the optimized gel becomes lower than others. Meanwhile, the release period of the gel shows greater than that of the gel of PEG/a-CD. This may be because there are two crosslinks and more stable structure.The cytotoxicity text may study the biocompatibility of the compositions of gel. What are cell survival rates when the compositions of gel are cultured with cells at a different time. The result shows the cell survival rates reach all>80%at a different time when the concentration of the gel is lower than109mg/L. So the test suggests the compositions of gel have not an inhibitory effect for cell and own the biocompatibility.The in vivo insulin release test may study the pharmacokinetic properties of the gel. The result shows the plasma concentration of the in vivo insulin of the gel is1fig/L at8h point and the peak of it is46|ig/L while the plasma concentration of the original insulin is lower than1μg/L at2h point. So the result suggests the gel has extended the action of the insulin.