Study On Co-delivery Of Multi-Drug By Folate Targeted Nanoparticles

Cancer,one of the major public health issues,affects human's life,which is treated by chemotherapy.However,chemotherapeutic agents still exsit many limitations in clincal such as poor targeting,low solubility,and side effects.In addition,cancer cells produce multi-drug resistance after long-term drug treatment,further reducing the clinical efficacy,which is also the most serious problem to slove.In some studies,it has been found that combining treatment of multiple chemotherapeutic drugs cloud greatly kill multi-drug resistant tumor cells by synergistic mechanisms of different drugs;nanosystems increase the solubility of drugs and reduce the toxicity of drugs;active targeting ligand significantly enhance the agents'targeting selectivity.According to these foundings,this research designed folate-targeted nanoparticles,loading doxorubicin(Dox)and curcumin(Cur),for multi-drug combination treatment of tumors.In details,Dox inhibits the replication and growth of cancer cells.Meanwhiles,Cur relieve the multidrug resistance of cancer cells.The nanoparticles are constructed by star-shaped polyester material(Tri-CL)which is widely used in antitumor studies due to high stability and high biocompatibility.As it reported,folate can bind folate receptors overexpressed on the surface of tumor cells,which was apalied as an active targeting ligan to further modify Tri-CL,enventaully synthesize star-shaped polymers(FA-Tri-CL).The specific experimental plans are as follows:(1)Synthesis of FA grafted star-shaped polymer(FA-Tri-CL):1,2,3-propyltricarboxylic acid and?-caprolactone(?-CL)were used to synthesize the star-shaped polymer by ring-opening polymerization.Then folic acid and Tri-CL are further joined to obtain a folic acid-targeted star polymer(FA-Tri-CL)by amidation reaction.FT-IR and ~1H-NMR were used to confirmed the structures of FA-Tri-CL.(2)Preparation of(Dox+Cur)-FA-NPs:Nanoparticles were prepared by solvent evaporation method.(1)Investigate the influence of the three factors such as drug concentration ratio,quality ratio of drugs and nanocarrier,volume ratio of oil phase and water phase on the characteristics of nanoparticles.The carrier material FA-Tri-CL and the drug were co-dissolved in acetone at a certain ratio as the oil phase,and 0.5%Poloxamer 188(P188)was dissolved in water as the aqueous phase.The best prescription obtained through the single factor inspection method is that both concentrations of Dox and Cur are 1.0 mg/m L,ratio of durg/material 1:12.5(w/w)and oil-water volume ratio 1:10.Under optimal prescription,the nanoparticle size of(Dox+Cur)-FA-NPs is 187.4?1.77 nm with 0.044?0.029(PDI)and-18.3?0.9 m V(Zata potential).The encapsulation rate of Dox and Cur is respectively 77.7?0.4%and 96.4?1.3%,the drug loading of Dox and Cur is respectively 15.0?0.6%and 19.9?1.1%.(2)The TEM showed that the(Dox+Cur)-FA-NPs are uniformly round,and their particle size were nearly 185 nm which is consistent with the Malvern particle size results.(3)XRD results showed that Dox and Cur are encapsulated in the core of nanoparticles,rather than on the surface of nanoparticles.(4)In vitro drug release experiments showed that(Dox+Cur)-FA-NPs have slow-release performance,and the release amount of Dox and Cur in p H=6.8 were more than in p H=7.4.(5)In vitro stability results showed that nanoparticles(Dox+Cur)-FA-NPs can be stored in aqueous solution for 15 days and in 10%FBS in DMEM for 48h.(3)The safety of nanoparticle and in vitro anti-tumor research:The MTT method was used to investigate the safety of nanoparticles.The results showed that blank nanoparticles(i.e Blank-NPs and Blank-FA-NPs)have good biosecurity for L929 cells;in vitro anti-tumor test showed that MCF-7/ADR cells have strong drug resistance,while can be relieved by the co-administration of Dox and Cur.Both(Dox+Cur)-FA-NPs and(Dox+Cur)-NPs increase the solubility of Dox and Cur,enhancing the anti-proliferative effect;flow cytometry experiments showed that MCF-7/ADR cells had an efflux mechanism to reduce the intracellular concentration of Dox,which can be sloved by the co-administration of Dox and Cur.In addition,(Dox+Cur)-NPs and(Dox+Cur)-FA-NPs can promote cell uptake efficiency,and the order of nanoparticles is as follows:(Dox+Cur)-FA-NPs>(Dox+Cur)-NPs>(Dox+Cur).(4)in vivo fluorescence distribution experiment:This experiment indicated that(Dox+Cur)-FA-NPs group have best tumor targeting among other groups,because which FA can actively binding folate receptors to improve the delivery efficiency of nanoparticles.(Dox+Cur)-FA-NPs also reduce the accumulation of drugs in the main organs such as the heart and liver,reduceing the damage to important organs.In conclusion,the(Dox+Cur)-FA nanosystem with stable storage was successfully prepared by simple preparation in this project,which increases the solubility of the drug.The combination of Dox and Cur in this system solves the multi-drug resistance of MCF-7/ADR cancer cells.It is worth noting that the grafting of folic acid increases the tumor targeted capability.