| ObjectiveWe synthesized multi-function polymeric micelles by using PEO-PCL,to establish a high efficient co-delivery system of docetaxel(DTX)and anti-uncleostemin siRNA(anti-NS siRNA).In conjunction with targeted groups,we study the effects of the co-delivery micelles on prostate cancer cells.Methods1.Synthesis and modification of polymers: With tBuCCL and Acetal-PEO(Mw=8655 g/mol)as the main reactive materials,PEO-PCL was synthesized as a main chain which had a hydrophilic head and hydrophobic tail.Spermine(SP)groups were modified into the polymer as a side chain to make the polymer electropositive in combination with siRNA.Different groups such as DCL peptide and TAT peptide were modified via divergent procedure.The chemical structure and molecular weight of the polymers were characterized by GPC,1H NMR,FT-IR.2.Establishment of the co-delivery micelles and research on its physicochemical property: We assembled a gene-drug co-delivery micelle by dialysis method using fully modified PEO-PCL,DTX and anti-NS siRNA.CMC was used to evaluate the empty micelle.Particle size and zeta potential were characterized by DLS.HPLC was used to measure the drug loading content and efficiency.The best formulation of micelle and siRNA was evaluated by using gel electrophoresis.3.Evaluation of effects of co-delivery micelles on castration resistant prostate cancer cells: MTT test was used to evaluate the cytotoxicity of the polymer and to evaluate the effect of different micelles on C4-2 and PC-3 cells.RT-qPCR and western blot were used to perform to analyze the expression level of NS mRNA and NS protein.ResultsThe structure of main chain and the modified polymers were confirmed by 1H NMR and FT-IR.And the molecular weight of PEO-PCL was overall 16359 g/mol.The CMC was testified to be 1.17 ?g/m L.Particle size of co-delivery micelles measured to be 152.8 nm,zeta potential of main chain and modified polymer was-12.8 mv and +15 mv,respectively.The N/P turned to be 25:1 when the co-delivery micelles was fully combined with siRNA by gel electrophoresis.The biggest drug loading content was 7.62% while its encapsulation efficiency was about 20.27%.The MTT test showed that the cell viability remained over 80% when the PEO-PCL polymer was over 256 ng/m L,and it could decrease to 20% when the DTX concentration in co-delivery micelles was 50 ?g/mL,which was significantly lower than the other micelles.RT-qPCR showed that the co-delivery micelles decreased the expression of NS gene in PCa cells,and western blot showed it also decreased the expression of NS protein in PCa cells.Compared to Lipofactmin 2000,the effect in C4-2 cells was better than PC-3 cells.Conclusion1.PEO-PCL polymers could self-assembly form micelle,it had good physical and chemical properties and good biocompatibility,which made it a potential carrier for the delivery of hydrophobic drugs.2.After conjunction with SP group,the micelle could effectively carry DTX and anti-NS siRNA to perform cytotoxicity.Meanwhile,it could decrease the expression of NS gene and NS protein,which had a synergistic effect and was better than DTX or gene drug alone.3.Through modified the DCL and TAT peptide on the hydrophilic end of polymeric micelles,it could effectively enhance the targeting towards castration resistant PCa C4-2 cells.4.Targeted co-delivery micelles could maximize the capacity to carry both chemotherapeutic drugs and gene drugs to inhibit the castration resistant prostate cancer cells,which makes it a potential application in CRPC treatment. |
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