Copper Sulfide Nanoparticle-based Localized Drug Delivery System As An Effective Cancer Synergistic Treatment And Theranostic Platform

We developed a new theranostic nanoplatform based on hollow mesoporous copper sulfide nanoparticles(HMCuS NPs).Firstly,HMCuS NPs with hollow mesoporous structure,strong near-infrared(NIR)absorption and photothermal conversion efficiency could serve as not only a drug carrier but also a powerful contrast agent for photoacoustic imaging(PAT)to guide diagnosis,photothermal therapy(PTT)and photodynamic therapy(PDT).Secondly,iron transported by Tf could make the endoperoxide bridge cleavage of AS to produce reactive oxygen species(ROS)to kill tumor cells,while the high level of TfR on the surface of tumor cells make Tf possess tumor targeting,which have attracted increasing attention of scientists from all over the world.Last but not the least,peritumoral(PT)injection could create diffusion molecular retention(DMR)tumor targeting effect,which could improve curative effect as well as reduce the toxicity of normal organs and tissues after slow vascular uptake and extensive diffuse through the interstitium and tumor retention.These special characters produce massive advantages for cancer treatment.Therefore,this project combines above benefits to make a mutifunctional system with tumor targeting,PTT,PDT,PAT,chemotherapy and DMR effect.In this study,we made AS/Tf-HMCuS NPs by introducing HMCuS NPs as the drug carrier,loading AS after physical mixing,and then employing Tf modified on HMCuS NPs through physical absorption.After investigation of preparation techniques,we screened out the best preparation method of mixing time 24 h in room temperature,weight ratio of 1:5,drug loading 28.2%,the most optimal mass ratio of HMCuS NPs to Tf was 2:1.The particle size of AS/Tf-HMCuS NPs was 205±5.4 nm and zeta potential was-25.5±3.6 mV.The cellular uptake behavior,cytotoxicity in vitro and intracellular ROS detection with or without irradiation of AS/Tf-HMCuS NPs were tested with MCF-7.We labeled HMCuS NPs and Tf-HMCuS NPs with FITC to evaluate the internalization.The result indicated that HMCuS NPs could bring AS into cells effectively,which could be enhanced by Tf so that the internalization amount of Tf-HMCuS NPs at 2 h reached up to about 99.9%.The cell inhibition of AS/Tf-HMCuS NPs was better than AS significantly,with only 7.4% of cell viability with irradiation at 72 h,while the viability of MCF-7 cells treated with HMCuS NPs still exceeded 90%(without laser irradiation).Therefore,HMCuS NPs was a relatively safe nanocarrier.In addition,AS/Tf-HMCuS NPs produced the strongest fluorescence because of the synergistic effect caused by AS and Tf,which was enhanced by irradiation.That proves the considerable photodynamic effect of AS/Tf-HMCuS NPs.In addition,the result of the optical imaging test showed that the fluorescent dye carried by Tf-HMCuS could stay up to 96 h in tumor site after PT injection.Besides,the result of photoacoustic tomography test illustrated the opportunity to be a kind of photoacoustic tomography contrast.In vivo antitumor efficacy studies showed that tumor-bearing mice treated with AS/Tf-HMCuS NPs through PT injection under NIR laser irradiation displayed the strongest inhibition rate of about 74.8%,even with the halved frequency of administration.Furthermore,we used immunofluorescence to track the distriputing process of drug in tumor and thus proved the mechanism of DMR.In biodistribution study,the tumor targeting efficiency of AS/Tf-HMCuS NPs after intravenous injection was only 22.01%,while that reached to 78.63% after PT injection.Therefore,the approach of localized delivery through DMR combined with multi-mechanism therapy may be a promising method for cancer treatment.