| Malignant tumor is a serious disease that endangers human life and health.Chemotherapy is still one of the main methods of tumor treatment.However,traditional chemotherapeutics have some problems,such as poor water solubility,lack of targeting and fluorescence indication.With the progress of chemotherapy,the DNA damage repair mechanism which is constantly activated within tumor cells will also cause drug resistance to DNA damage agents.The(poly(ADP-ribose)polymerase,PARP)inhibitor 4-amino-1,8-naphthalimide(ANI)has the strong inhibition of DNA damage repair,and combined with DNA damage agents can effectively overcome tumor drug resistance.ANI is also a fluorescent molecule that can be converted to aggregation-induced emisssion(AIE)molecules through chemical modification.In addition,glycosylated pillar[n]arenes can interact with guest molecules to construct supramolecular nano-delivery systems in the form of nanovesicles and micelles,which can not only achieve tumor targeting,but also give full use to the advantages of good biocompatibility and simple synthesis of glycosylated pillar[n]arenes.Based on this,PARP inhibitor prodrug(Pro-ANI)with AIE effect was synthesized,and combined with the drug delivery advantages of glycosylated pillar[5]arenes(GP5),a supramolecular nano-delivery system GP5?Pro-ANI was constructed for anti-tumor resistance and drug uptake visualization in tumor cells.The main contents and results are as follows:(1)Preparation and characterization of the nano-delivery system GP5?Pro-ANI:Firstly,by amidation reaction,the PARP inhibitor 4-amino-1,8-naphthalimide(ANI)was grafted onto a hydrophilic chain with quaternary ammonium terminal to obtain the guest prodrug Pro-ANI with AIE effect;Galactose was modified on pillar[5]arenes by clicking reaction to get the host molecule GP5.Supramolecular nano-delivery system GP5?Pro-ANI was obtained by electrostatic interaction between GP5 and Pro-ANI.The results showed that the system can perform host and guest assembly in a ratio of 1:1.It was observed by SEM/TEM that GP5?Pro-ANI was spherical nanovesicles with a particle size of 268 nm(PDI 0.464),which could be used to load chemotherapy drugs DOX(encapsulation rate 30%).The results of in vitro simulated release experiments showed that GP5?Pro-ANI was responsive to esterase stimulation in the tumor microenvironment and had good release performance,with the release rates of DOX and ANI being 90%and 80%,respectively,within 3 h.In addition,the AIE effect of Pro-ANI was characterized by cyan fluorescence excited at 350 nm in the aggregated state of solid and in water.The structure of supramolecular vesicles formed by Pro-ANI and GP5 further enhanced the AIE emission of Pro-ANI,which was characterized by the redshift of emission wavelength and the increased fluorescence intensity.The AIE effect can be used for subsequent cell drug uptake visualization.(2)Antitumor effect study in vitro of the nano-delivery system GP5?Pro-ANI:The paper mainly studied the cell uptake,tumor targeting,biocompatibility and anti-tumor effect of drugs,as well as the mechanism of inducing tumor cell death.Specific uptake of GP5?Pro-ANI by tumor cells was observed by laser confocal microscopy,and cyan fluorescence was observed in cytoplasm and nucleus.Cytotoxicity tests showed that GP5?Pro-ANI did not affect the viability of normal cells,DOX@GP5?Pro-ANI had better lethal effect on hepatocellular carcinoma cells(HepG2)and drug-resistant strain(HepG2-ADR)than DOX.Western Blot results showed that the expression level of DNA repair protein PARP was down-regulated,the expression of autophagy key protein was inhibited,and the level of apoptosis protein was increased in DOX@GP5?Pro-ANI treated cells.In addition,cell colony formation and cell scratching experiments showed that DOX@GP5?Pro-ANI has the ability of anti-tumor cell proliferation and anti-tumor cell migration.In conclusion,a supramolecular nanodelivery system based on pillar[n]arenes and PARP inhibitors was constructed,which has tumor targeting,esterase responsive release function and AIE effect.By inhibiting tumor cell DNA damage repair,combining DNA damage reagents to attack tumor DNA,autophagic inhibition,up-regulation of apoptosis,and chemotherapy sensization were achieved.This system provides a new strategy for drug uptake visualization and drug resistance therapy. |
PDF Full Text Request