Preparation And Preliminary Activity Study Of Juglone Nano Targeting Preparation

Juglone is a small naphthoquinone in Jugland mandshurica Maxim and Juglans regia L.Its pharmacological action is extensive,especially its anti-tumor effect.However,its chemical properties are unstable and easy to oxidize and decompose.Moreover,juglone has poor water solubility and stability,and its short half-life limits its direct use.Therefore,reasonable design of nano targeted drug delivery system combined with juglone can improve the bioavailability of juglone and maximize its pharmacological effect.Aiming at the above problems,the target drug delivery system was constructed.Folic acid was used to modify chitosan,then folic acid chitosan complex（FA-CS）was used as a stabilizer and coating agent to prepare folic acid chitosan selenium nanoparticles（FA-CS-Se NPs）.According to the study of the targeted drug delivery system,it was further combined with the anticancer drug juglone.Finally,the nano targeted preparation of juglone（folic acid chitosan nano selenium juglone）was constructed and studied.Firstly,folic acid chitosan was synthesized by acylation and purified by dialysis.Then response surface method was used to optimize the reaction conditions,and the optimal conditions for the synthesis of folate chitosan were selected.The reaction time was 23.97h,the reaction temperature was 49.96℃,the feed ratio of folic acid and chitosan was 1.5:1（w/w）.The average binding rate of folic acid and chitosan was 36.71%.Finally,folic acid chitosan was characterized by TLC and FTIR.The results showed that folic acid and chitosan were successfully combined.Secondly,nano selenium was prepared by reducing sodium selenite with ascorbic acid.By combining nano selenium with folic acid chitosan,a nano targeted drug delivery system was formed.Then,the particle size and distribution were measured by DLS.The average particle size of Se NPs was 202.8nm.The average particle sizes of CS senps and FA-CS-Se NPs are193.2nm and 105.5nm,respectively.It can be seen that the particle sizes of CS senps and FA-CS-Se NPs are smaller than that of Se NPs,which shows that chitosan has a better effect on the encapsulation of nano selenium,and the nano selenium without chitosan modification is more likely to aggregate,resulting in a faster increase of particle size.When zeta potential was measured by laser Doppler velocity,the absolute value of zeta potential of Se NPs was low,which indicated that it was unstable and easy to aggregate.Some studies have shown that when the zeta potential of nanoparticles is greater than 25m V,the nanosystem is relatively stable,and the zeta potential of CS-Se NPs and FA-CS-Se NPs is greater than 25m V,indicating that chitosan modified and wrapped nano selenium successfully improves the stability of the system.The morphology of FA-CS-Se NPs was observed by a transmission electron microscope（TEM）.FA-CS-Se NPs were monodisperse and spherical,and its surface was covered by a layer of even translucent membrane,which further proved that nano selenium was coated by folic acid chitosan.Besides,the diameter of folic acid chitosan selenium nanoparticles is about 100 nm under the electron microscope,which is the same as the average particle size determined in the earlier stage.Finally,folic acid chitosan nano selenium juglone liposome composite system was constructed and characterized,and preliminary activity studied.The response surface method was used to optimize the preparation process of walnut quinone liposomes.The optimal process was determined as follows:the ratio of lecithin to cholesterol was 6:1,the ratio of excipients to Walnut quinone was 28:1,and the optimal reaction time was 2 hours.The absorbance of the juglone liposome was measured by a UV spectrophotometer,and the final encapsulation rate was 80.05%.Dynamic laser scattering（DLS）was used to characterize the particle size and distribution,and the particle size and zeta potential were measured.A549 cells which did not express folate receptor on the cell surface and MCF-7 cells which overexpressed the folate receptor on the cell surface were selected to study the anticancer effect of the composite system.The MTT method was used to determine the IC₅₀of different concentrations of nano targeting preparation of juglone and juglone liposome for MCF-7 cells were3.975μg/m L and 4.833μg/m L,and the IC₅₀ for A549 cells were 4.646μg/m L and 5.038μg/m L,indicating that the nano targeting preparation of juglone is targeted to tumor cells with high expression of folic acid,so as to achieve the purpose of improving the tumor treatment effect.