The Study On 5-Fu Imprinted Hydrogel As Controlled Release Drug Carrier

Hydrogel is generally used as drug carriers due to its wide resources and biocompatibility in the field of drug delivery. Meanwhile, molecular imprinting, as a increasingly developing technology, has large potential use in life sciences. Especially used in the drug delivery arena , their specific recognition sites are considered to enhance the amount of drug carried by the matrices as well as to sustain the pace of the drug release from the imprinted polymers.In this text, 5-fluorouracil was used as the template to synthesize imprinted hydrogels in aqueous and organic system respectively. In the aqueous solution, 2-hydroxyethylmetacrylate was used as the main component, methacrylic acid as the functional monomer, ethyleneglycol dimethacrylate as the crosslinker and ammonium persulfate as the initiator. However, in organic phase, 2-hydroxyethylmetacrylate was used as the backbone monomer, methacrylic acid as the functional monomer, ethyleneglycol dimethacrylate as the crosslinker and 2,2'-azoisobutyronitrile as the initiator.Tests of drug loading capacity showed that the hydrogels synthesized in aqueous solution were unable to load drug, while those synthesized in organic phase were capable to.bind. Experiments of different functional monomer- template molar ratio of 16:1,8:1,4:1 and non-imprinted hydrogel to load 5-fluorouracil showed that when the functional monomer- template molar ratio was 8:1, imprinted hydrogel loaded more drug than the others did, which amounted to 0.0914mg/g.Meanwhile the amount of 5-fluorouracil loaded on the hydrogel increased with its increasing concentration in the surrounding environment, while the difference between imprinting and non-imprinted hydrogels, loading amount decreased. Tests on the drug release behavior of the hydrogels in stimulated biological fluids indicated that all the imprinted hydrogels controlled the drug release better than the non-imprinting ones, and hydrogels whose functional monomer-template molar ratio was 8:1 exhibited the best to control the 5-fluorouracil release process.The hydrogels showed a larger degree of swelling when the proportion of 5-fluorouracil previously in the hydrogels increased. The same type of hydrogel showed a larger equilibrium water content in environment whose pH=9.18 than that of pH=6.86. Hydrogels were characterized with SEM, FT-IR, and DSC, that revealed that the hydrogel surface was poreless and smooth, in which the template drug of 5-fluorouracil had interacted with monomers into solid solutions through hydrogen bonds and unreacted monomers did no longer exist.The mechanism of the release process from dry hydrogels containing the template drug has been explained, for which a mathematical model was established. A experiment has been performed to test the mathematical model, whose outcomes were consistent with the conclusions drown from the model.