Study On Preparation Of Copper Nanoparticles With Tumor Microenvironment Response For Anti-breast Cancer Effect

Cancer is a serious threat to human health around the world.Nanotechnology based on the tumor microenvironment(TME)offers a class of novel,highly effective and more specific oncology therapeutic opportunities.Among them,chemodynamic therapy(CDT)takes advantage of the redox reactivity in TME without external energy activation,which can reduce the adverse effects on healthy organs to a certain extent.In this paper,we propose a strategy for chemodynamic therapy using polyethylene glycol block copolymer as a carrier and delivering Cu²⁺to tumor cells.In the first part,polyethylene glycol derivatives were successfully synthesized using anionic polymerization and click reactions,and copper nanoparticles were formed by electrostatic adsorption with Cu⁺.It is proved the successful synthesis of polyethylene glycol derivatives through detection methods such as hydrogen nuclear magnetic resonance spectroscopy and infrared spectroscopy.The copper nanoparticles prepared from the polymer have a particle size of about 100 nm,a potential of-10±1m V,and are in a highly dispersed state.The XPS test verified that the polymer was successfully loaded with Cu²⁺,and EDS showed that each element was uniformly distributed on the nanoparticles.According to the 7-day stability test,it can be seen that the particle size,potential,and PDI of copper nanoparticles have no obvious changes within 7 days,and they have a high degree of stability.In the second part,the in vitro performance experiment simulates the redox reaction of copper nanoparticles in the tumor microenvironment.DTNB detects the consumption of GSH by copper nanoparticles at different concentrations,and also shows that copper nanoparticles can consume GSH.At the same time,the valence state of copper after the reaction with GSH can be detected by XPS,and it can be seen that Cu²⁺in the copper nanoparticles is converted to Cu⁺.Methylene blue and p-benzoic acid are used as indicators to detect the generation of hydroxyl radicals,indicating that under the catalysis of Cu⁺,H₂O₂ can indeed generate hydroxyl radicals.The final result shows that under the conditions of simulating the tumor microenvironment,Cu²⁺can indeed react with GSH to produce Cu⁺,and then Cu⁺catalyzes H₂O₂ to produce hydroxyl radicals,and there is a cascade reaction,which provides a theoretical basis for the following cell experiments.In the third part,through cell experiments,we explored the toxicity of copper nanoparticles to cells and triggering redox reactions in tumor cells.The MTT experiment of normal cells shows that the toxicity of copper nanoparticles is relatively small.For tumor cells,copper nanoparticles have great lethality on MCF-7 tumor cells.We have verified that copper nanoparticles can consume GSH to induce H₂O₂production·OH.The reducing glutathione kit can detect that copper nanoparticles can consume GSH,and the DCFH-DA probe can detect that copper nanoparticles can induce Tumor cells produce·OH.This redox reaction is attributable to the conversion of Cu²⁺and Cu⁺due to the effects of GSH and H₂O₂ in the microenvironment of tumor cells,resulting in a cascade reaction in tumor cells.The research in this paper provides a precedent for the polymer carrier as the transport of copper ions,and provides a new idea for future research on the transport of metal ions to achieve different anti-tumor functions.