Study On Tumor Targeting Drug Delivery System Of TOS-DOX/TPGS Nanomicelle

Objective: To study the release effect and cytotoxicity of TOSDOX/TPGS nano-micelles in vitro,and pharmacodynamics in nude mice.To prolong the circulation time and reduce the toxicity of doxorubicin in the body.Methods: 1.Synthesis and characterization of TOS-DOX: Synthesis of D-alpha hydroxyphenol succinic acid(TOS)and DOX HCl,which were connected by the hydrazone bond.A comparative study was conducted on the synthesis of TOS-A-DOX with amide bonds.The structure of the compounds were characterized by 1H-NMR.2.Preparation and characterization of the TOS-DOX/TPGS: A thin film solvent evaporation method was used to prepare the TOS-A-DOX/TPGS and TOS-H-DOX/TPGS nano-micelles.The content of DOX was determined by ultraviolet spectrophotometer(UV),and the dosage and encapsulation rate were calculated.The particle size and Zeta potential of the TOS-A-DOX/TPGS and TOS-H-DOX/TPGS were determined with the particle size analyzer.In vitro release characteristics of TOS-ADOX/TPGS and TOS-H-DOX/TPGS were investigated by dynamic membrane dialysis.3.Studies on the cytotoxicity and uptake of TOS-DOX/TPGS: We investigated the effects of 24 h,48 h of TOS-A-DOX/TPGS and TOS-HDOX/TPGS on the growth of breast cancer cells MCF-7,gastric cancer cell MGC-803 and liver cancer cell SMMC-7721.The effects of TOS-ADOX/TPGS and TOS-H-DOX/TPGS on apoptosis of MCF-7 tumor cells were investigated.The concentration of Doxorubicin in MCF-7 tumor cells was determined by flow cytometry.Fluorescence microscopy were observed the uptake of Doxorubicin in the MCF-7 tumor cells.4.Pharmacodynamics study of TOS-DOX/TPGS in nude mice: The model of MCF-7 tumor nude mice was established.In this study,we conducted a study on the antitumor activity of the single-dose tail intravenous injection of TOS-A-DOX,TOS-H-DOX and DOX in nude mice,saline group for blank control.Then we observe the cell morphological changes of tumor and heart,liver,kidney and gastric tissue section.Results: 1.We successfully synthesized the two compounds TOS-HDOX and TOS-A-DOX.2.The TOS-H-DOX and TOS-A-DOX nano-micelles were successfully prepared by the film solvent evaporation method.The average particle size of the TOS-H-DOX nano-micelles was(98.06±3.25)nm,and Zeta potential was(1.315±0.34)m V.The average particle size of the TOS-A-DOX/TPGS nano-micelles was(102.45±2.81)nm,and Zeta potential was(1.623±0.25)m V.The encapsulation rate and drug loading rate of TOS-HDOX/TPGS were(93.54±2.49)% and(9.23±1.21)%,respectively.The encapsulation rate and drug loading rate of TOS-A-DOX/TPGS were(90.18±2.14)% and(8.83±0.19)% respectively.The release characteristics of the TOS-H-DOX/TPGS nano-micelles in vitro showed a special p H dependence.And the release of DOX was relatively complete at p H 5.0,but a little was released at p H 6.4~7.4.Doxorubicin was hardly released for TOS-A-DOX/TPGS nano-micelles at p H 5.0~7.4.3.In vitro cytotoxicity of TOS-H-DOX/TPGS nano-micelle were stronger than doxorubicin and TOS-A-DOX TPGS nano micelle in MCF-7,MGC-803,SMMC-7721 tumor cells.The cytotoxicity of doxorubicin and nano-micelles were both time-dependent.The early apoptosis rate in MCF-7 cell of DOX,TOS-H-DOX/TPGS and TOS-A-DOX/TPGS was 5.23%,11.7%,6.82% respectively.The ability to induce cell apoptosis of TOS-H-DOX was significantly better than that of free DOX and TOS-ADOX/TPGS.Flow cytometry results showed that the concentration of DOX to enter the nucleus increases over time.Doxorubicin entering the nucleus in MCF-7 tumor cells of TOS-H-DOX/TPGS nano-micelle was significantly more than the TOS-A-DOX/TPGS nano-micelle according to fluorescence microscopy results.4.The results of the pharmacodynamic study of MCF-7 tumor nude mice showed that the TOS-H-DOX/TPGS nano-micelle had the strongest antitumor activity,and its tumor inhibition rate was 68%.The weight change and histopathological section of the nude mice showed no obvious toxic side effects.Conclusion: This experiment has successfully prepared the TOS-HDOX/TPGS nano-micelle with small particle size and high encapsulation rate.The nano-micelle has good physical properties and slow release effect.It shows obvious effect in inhibiting tumor growth in vitro,and little side effects on the organization.It has a good application prospect as a novel anti-tumor drug targeting delivery system.