Research On The Construction Of Folate-conjugated Polymer Complex Micelles As Combined Drug Delivery System

Objective:To synthesize folate-polyethyleneglycol-phosphatidyl ethanolamine(FA-PEG-PE)，and prepare the kind of complex micelles were synthesized through thefolate-polyethyleneglycol-phosphatidyl ethanolamine (FA-PEG-PE) and5-fluorouracil(5-FU)of chemically bonded in polyethyleneglycol-phosphatidyl (PEG-PE), And thedoxorubicin (DOX)of physical parcel in the hydrophobic nuclear of Polymer ComplexMicelles as combined drug delivery system, to evaluate the pharmacodynamics andcytotoxicity activity in vitro of the Polymer Complex Micelles respectively.Methods:FA-PEG-PE was synthesized via acylation reactivity at room temperature andidentified by infrared and differential thermal analysis. To select5-FU and DOX combineddrug as model, Preparating Folate-conjugated Polymer Complex Micelles as combineddrug delivery system. The doxorubicin loaded folate-polyethyleneglycol-phosphatidylethanolamine (FA-PEG-PE) and5-fluorouracil-polyethyleneglycol-phosphatidyl(5-FU-PEG-PE) were prepared by dialysis and were characterized by drug loading content,morphology and particle size, and their in vitro drug release rates were measured, livercancer (H22) of solid tumor animal model for tumors in mice,The tumor inhibition growthof FA-PEG-PE+5-FU-PEG-PE/DOX,5-FU-PEG-PE/DOX and5-FU-PEG-PE wereevaluated by intravenous injection, to calculate the inhibition of tumor growth rate andthymus index, spleen index,and observe the pathological section and each organ toxicity byoptical microscope.To Input raw data in the computer,and analyzed by One-way ANOVA ofSPSS16.0for Windows statistical software. To select folate receptor-positive HeLa cell asmodel cell and carried out MTT experiment to investigate the cytotoxicity of the freeFolate-conjugated Polymer Complex Micelles as combined drug delivery system 5-FU-PEG-PE/DOX and free5-FU、 DOX were used as control preparations when theFolate-conjugated Polymer Complex Micelles as combined drug delivery system werestudied in vitro. According to the free folate has competitive inhibition for folate receptor,the Folate-conjugated Polymer Complex Micelles as combined drug delivery system hasthe targeting ability to HeLa cell via folate receptor-mediated.Results: The results of infrared and differential thermal analysis result showed thatFA-PEG-PE was synthesized successfully. The carrier material of FA-PEG-PE CMC,FA-PEG-PE:5-FU-PEG-PE（1:1） and FA-PEG-PE:5-FU-PEG-PE（2:1）Were show to beas low as1.5×10-5mol/L,1.52×10-5mol/L,1.61×10-5mol/L,respeetively. Doxorubicinloaded folate-polyethyleneglycol-phosphatidyl ethanolamine (FA-PEG-PE) and5-fluorouracil-polyethyleneglycol-phosphatidyl (5-FU-PEG-PE) were prepared withloading content of1.08%, Average particle size of162.5nm, her size was uniform, theshape was integrated,and slow release in vitro. The animal level of pharmacodynamicexperiments showed that high doses of the highest inhibition rate reached about80%byintravenous injection of FA-PEG-PE+5-FU-PEG-PE/of DOX and5-FU-PEG-PE/DOXhigh-dose group, significantly higher than six times doses of5-FU-PEG-PE group。Itshowed that5-FU and DOX small doses combined of folic acid targeted complex polymermicelles Inhibiting tumor activity stronger than six times doses of polymer micelle5-FU-PEG-PE. The inhibition rate5-FU positive control group was higher than complexpolymer micelles as combined drug delivery system。MTT experiment showed that theinhibition ability of Folate-conjugated polymer complex micelles（FA-PEG-PE+5-FU-PEG-PE/DOX） show significantly stronger inhibiting ratescompared with other control groups, which could be inhibited by excess free folate，couldbe effectively targeted to HeLa cells，Conclusion: It is obvious effect of5-fluorouracil and doxorubicin small doses ofcombination, using two drugs to the tumor characteristics of the different segments of thecell division cycle, which can effectively inhibit and kill residual cancer cells.FA-PEG-PE+5-FU-PEG-PE/DOX could be targeted into positive tumor cells with folatereceptors via folate receptor mediated endocytosis specifically, and facilitate the delivery of the encapsulated anti-tumor drugs into tumor cells and tumor vasculature endothelial cellstransmission.