Design Of Disulfiram/Cu Delivery Systems Forcombinational Cancer Therapy

Disulfiram(DSF),an alchonism drug,has been recently identified as an anticancer agent for various cancers.The anticancer mechanism studies reveal that DSF shows a copper-potentiated anticancer activity owing to the generation of copper(II)diethyldithiocarbamate(Cu(DTC)2),which has much higher cytotoxicity than DSF.Despite lots of exploriations and encouraging results in lots of in vitro studies and clinical trials,many issues(for example,the poor bioavailability,rapid clearance in body,lack of selective tumor inhibition,and exogeneous copper supplement)are still needed to be addressed.Therefore,in this dissertation,we developed a small molecular prodrug and nanoparticulate drug delivery systems with the aim of optimizing the delivery strategies of DSF/Cu2+ and improving the antitumor efficacy and selectivity.These systems integrated tumor microenvironment-responsive drug release/activation and multimodal combinational cancer therapy,which is based on the DSF/Cu2+-induced chemotherapy and other treatment models such as oxidative stress amplification therapy,chemodynamic therpay,and photothermal therapy.In detail,this dissertation included four parts:1.A small molecular prodrug DQ with tumor reactive oxygen species(ROS)-activating release of DTC was designed.It showed enhanced stability in blood and H2O2-responsive prodrug activation.Fluorescence competition study demonstrated that Cu(DTC)2 can be generated by DQ in the presence of H2O2 and Cu2+.In the in vitro studies,DQ showed much better cytocompatibility to normal cells(NIH 3T3)than DSF.However,in the presence of H2O2,DQ and DSF exhibited comparable anticancer activity in 4T1 cancer cells.Furtheremore,DQ can upregulate the intracellular ROS level and consume antioxidant substances like glutathione(GSH),leading to oxidative stress amplification and cell apoptosis.The in vivo antitumor study suggested that DQ could efficiently inhibit the growth of 4T1 tumors,showing superior antitumor effect to DSF and excellent biocompatibility.2.A DQ and Cu2+ co-delivery nanosystem(MPDG)based on nanoscale copper(II)metal-organic framework(MOF)was designed for catalytic self-supplying H2O2 and subsequent cascade reaction for enhanced chemodynamic-chemotherapeutic combination therapy.Glucose oxidase(GOD)was covalently conjugated to nano MOF for catalyzing high concentration of glucose in cancer cells to generate H2O2,which could activate prodrug DQ to release DTC that binds with Cu2+ in MOF to generate cancericidal Cu(DTC)2 in situ.Furtheremore,H2O2 can react with Cu2+ to obtain highly cytotoxic ·OH for chemodynamic therapy.In vitro anticancer study revealed that significantly enhanced anticancer activity of MPDG was fulfilled in the presence of high concentration of glucose,where intracellular ROS level was remarkably upregulated and the GSH content declined.In vivo antitumor study manifested that MPDG could effectively inhibit tumor growth,showing better anticancer efficacy than MPD and MPG groups,which were the prodrug-and GOD-loaded alone groups,respectively.3.Nanomedicines loading Cu(DTC)2 alone and co-loading Cu(DTC)2 and Cu S were developed by biominerlization-mimicking method using bovine serum albumin(BSA)as a nanocarrier.This method is straightforward,time-saving,organic solvent-free,and esay to control the loading ratios of Cu(DTC)2 and Cu S.Cu(DTC)2-loaded nanoparticles had a high loading content in the range of 21%-24%.The loading contents and compositions of Cu(DTC)2 and Cu S in co-loaded nanoparticles can be facilely tuned by varying the feeding molar ratios of S2-/DTC.The obtained BSD NPs showed enhanced absorption of near infrared light,with better photothermal effect than the Cu S or Cu(DTC)2-loaded nanoparticles.The photothermal mechanisms of BSD NPs with different S2-/DTC feeding ratios were proposed.The optimal BSD-1:1 showed excellent phtotothermal conversion efficiency,photostability,and photoacoustic imaging capacitiy.In vitro study manifested that enhanced cellular uptake of BSD-1:1 and chemo-photothermal combinational therapy of B16 melanoma cells were realized after 808 nm laser irradiation.The in vivo photoacoustic imaging-guided therapy further revealed that BSD-1:1 could efficiently accumulate at tumor tissues at 8 h post injection,ablating tumor tissues by a chemo-photothermal combination therapy.We believe that this “in situ drug generation and controllable loading” strategy could be easily expaned to construction of various metal-based nanotheranostics with the merits of excellent reproducibility and scalable synthesis,holding a great potential in applications and clinical translation.