Nanoscale Cuprous Metal-organic Complex: Fabrication And Study On Reversal Of Tumor Multidrug Resistance

Multidrug resistance（MDR）which is often related to the overexpression of P-glycoprotein（P-gp）in drug-resistant cancer cells has been a major problem faced by current cancer chemotherapy.Reversing P-gp-related MDR by disrupting tumor redox homeostasis that regulates the expression of P-gp is a promising strategy.In this work,a hyaluronic acid（HA）modified nanoscale cuprous metal-organic complex（HA-CuTT）was developed to reverse P-gp-related MDR via two-way redox dyshomeostasis,which was achieved by both Cu⁺-catalyzed generation of·OH and disulfide bonds-mediated depletion of glutathione（GSH）.The main contents of the research are as follows:（1）Preparation and characterization of HA-CuTT@DOX:Firstly,a nanoscale cuprous metal-organic complex（CuTT）was fabricated via solvothermal in situ ligand synthesis,that is,solvothermal reaction between Cu²⁺and organic ligand 3-thiol-1,2,4-triazole（3-TT）to obtain Cu⁺ions and disulfide bonds to produce·OH and consume GSH.And then,we used electrostatic and coordination interactions between HA and CuTT to construct HA-CuTT nanoparticles with ability of targeting cancer cells.Finally,the chemotherapy drug doxorubicin（DOX）was loaded to obtain the final nanoparticle（HA-CuTT@DOX）,the loading capacity is 20.5%.We verified the successful construction of the nanoparticle with good particle size of about 200 nm,the solid quasi-spheroid morphology and good stability in medium,GSH response drug release ability,GSH consumption ability and·OH generation ability by SEM,TEM,DLS,UV-Vis,FTIR,XPS,drug release,GSH consumption,MB degradation,and ESR experiments,respectively.（2）Multidrug resistance reversal caused by HA-CuTT@DOX:Firstly,FCM analysis was performed to evaluate the cellular uptake and the targeting ability.The results showed that the nanoparticles can be effectively ingested by Hep G2 and Hep G2-ADR cells and have cancer cell targeting ability caused by HA.Then,intracellular·OH production and GSH consumption were verified by CLSM and intracellular GSH content detection kit,and the two-way redox dyshomeostasis was realized in Hep G2 and Hep G2-ADR cells.MTT experiments showed the excellent antitumor activity of the prepared nanoparticles,the IC50 of Hep G2 and Hep G2-ADR cells were 0.96 and 0.97μg/m L,respectively.Finally,we used CLSM,ELISA kit,mitochondrial damage evaluation,and ATP content detection kit to show that the nanoparticle can cause mitochondrial damage,reduce ATP level,and downregulate P-gp expression,thereby increasing intracellular drug accumulation,and ultimately reversing multidrug resistance.The results of animal model experiments showed that HA-CuTT@DOX can achieve effective inhibition（89.6%）of tumor growth in nude mice bearing Hep G2-ADR cells.This is the work to reverse P-gp-related MDR via two-way redox dyshomeostasis based on a HA modified nanoscale cuprous metal-organic complex,providing a new therapeutic paradigm for effective treatment of MDR-related cancer.