D-a-tocopherol Succinate-based Salinomycin Prodrug Nanocarriers With Paclitaxel Loaded For Targeted And Combined Cancer Treatment

The metastasis and recurrence of breast cancer is one of the current problems of the tumor treatment.Most studies have shown that the traditional clinical treatment just kill most differentiated tumor cells,which reduces tumor volume for some time or even disappear.But it is hard to kill a small number of dormant tumor cells with stem cell properties(cancer stem cells,CSCs).Enriched CSC has strong tumori-genicity,which can increase the proliferation and differentiates into new tumor tissue.Therefore,the combine chemotherapy of tumor stem cells and common tumor cells may cure cancer completely.This research uses the specific inhibitor of CSCs salinomycin(SAL)and chemotherapy drugs(PTX)as model drugs,and designs the combined antineoplastic nanoparticle delivery systems.The research includes four parts.The first step,the cystamine as a linkers connect TOS and SAL to form a prodrug(TOS-ss-SAL).The second step is to use good bio-compatibility polymer hyaluronic acid(HA)as skeleton materials,which can design amphiphilic graft copolymer(HA-TOS,HT)with CD44 targeting and amphiphilic graft copolymer(Bio-HA-TOS,BHT)that owning the CD44 targeting and Biotin receptor.The BHT can apply for the surface modification of salinomycin prodrug self-assembled nanoparticles NPs(TS).We can appraise the successful synthesis of the HT,BHT and TS prodrug by the result of NMR and FTIR.The second part is about the formation and the pyhsic-chemical properties’ s investigation of the prodrug nanoparticles(TS NPs,HTS NPs and BHTS NPs)and the reducibility sensitivity is confirmed by the fracture of the prodrug nanoparticles in the10 m M DTT.The stability of the nanoparticles is verified by the experiments of the serum of the prodrug nanoparticles and incubation,which can meet the demend intravenously.With the experiments of the inhibition rate of stem cell form mammospheres and CSCs cycle,the cytobiology confirms that its carrier can be effectively used to kill cancer stem and hinder its cycle.And also,it confirms that prodrug nanoparticles play a part in killing the cancer stem cells whose hydrophobic core can be used as a carrier entrapment traditional chemotherapy drugs.We can use the Coubased TS NPs to make fluorescent markers.The flow cytometry experiment comfirms nanoparticles targeting is able to increase cellular uptake,which shows that the HTS NPs and BHTS NPs cells intake level is significantly higher than the undecorated TS NPs.And the receptor saturation experiment verifies the CD44 and Biotin receptor mediated mechanism of cellular uptake and the result of the fluorescent inverted microscope imaging observation is consistent with flow cytometry.In the third part,PTX-TS NPs,PTX-HTS NPs,PTX-BHTS NPs are made by emulsion solvent evaporation.The X-ray diffraction experiment confirms PTX and TS that disperse better in nanoparticles with the amorphous state;The encapsulation rate of PTX of three nanoparticles is determined by membrane filtration method-high performance liquid chromatography(HPLC)about 87.24%-92.61%.The particle size of nanoparticles is from 190.7 nm to 280.2 nm.The zeta potential is around-6 mv to-29 mv.And PDI is 0.16-0.27.The uniform circular nanoparticles are observed by TEM.With the vitro release experiments,we verify that the nanoparticles accelerated the release of PTX under the action of the reduced glutathione(GSH),indicating that the nanoparticles have the sensitive characteristics which can release drug in tumor microenvironment.The fourth part mainly tells that PTX-based TS NPs cytotoxic experiment shows that TS NPs can effectively inhibit tumor cell proliferation by itself and prodrug nanoparticles and PTX have synergistic antitumor effect.Compared to TS NPs and free PTX,PTX-TS NPs obviously increase the proliferation inhibition,among which PTXBHTS NPs with dual targeted modification shows the most significant proliferation inhibition effect;The inhibition of 3D tumor sphere growth experiment is consistent with the results of cytotoxic experiment.Compared with the free PTX and blank-TS,PTX-TS NPs has obvious tumor sphere growth inhibition effect and PTX-BHTS NPs shows the significant inhibit the growth of the tumor sphere and destroy the tumor ball structure.To sum up,thanks to the prodrug nanoparticles with dual-modified have the potential to deliver drugs efficiently and accurately to breast cancer cells and stem cells,thereby it can achieve a better anti-tumor effect.