Gold Nanostar With Dual Nanozymes Activities For Cascade Catalytic-photothermal Synergistic Therapy

Gold nanoparticles as photothermal agents for photothermal therapy have attracted widespread attention.However,the limited tissue penetration ability of light seriously hinders its practical application,so the gold nanoparticles need to be combined with other therapeutic agents to improve the therapeutic effect,resulting in the complex structure and cumbersome synthesis process of most gold nanoplatforms.Therefore,it is necessary to construct gold nanoparticles with single structure and diverse functions.In this paper,a novel multifunctional gold nanostar(GNS)was constructed by a simple one-step synthesis method,which could combine the photothermal property and the double nanozymes activities into a single gold nano-system,and could be used for efficient tumor cascade catalytic-photothermal synergistic therapy.The concrete study contents and conclusions were shown below:1.This research prepared multifunctional GNS taking biodegradable poly(γ-glutamic acid)as the medium by simple and green one-step synthesis method.Adjusting the concentration of each reactant to optimize its size and shape for the best photothermal property and enzyme-like activity,and then selecting the GNS prepared under the optimal reaction conditions for subsequent in vitro characterization and in vivo research.The prepared GNS had a uniform star shape and good stability with a hydration particle size of191 nm.2.GNS possessed excellent photothermal conversion property,glucose oxidase-and peroxidase-like activities.It converted glucose in situ into hydrogen peroxide in the tumor microenvironment and then catalyzed hydrogen peroxide highly expressed and in situ generated in the tumor to a large number of hydroxyl radicals,which could cause severe oxidative damage to the cancer cells for effective cascade amplification catalytic therapy.When irradiated by 808 nm laser,GNS not only performed efficient photothermal therapy,but also enhanced the cascade catalytic activity 1.4times by utilizing its own photothermal effect.In addition,the photothermal conversion efficiency of GNS was up to 35.7%.3.GNS showed excellent synergistic cascade catalytic-photothermal therapeutic effect in vitro and in vivo experiments,which could effectively inhibit tumor growth.Its cell killing rate reached 85.4%,and the in vivo anti-tumor rate was as high as 97.0%.The ability of GNS with photoacoustic and infrared thermal imaging in vivo could guide efficient tumor therapy and realize the integration of tumor diagnosis and treatment.In addition,in vitro and in vivo experiments showed that GNS had high biosafety.In summary,this research constructed GNS materials with precisely controllable morphology and size and high biocompatibility.In vitro and in vivo experiments have proved that GNS can achieve efficient tumor cascade catalytic-photothermal synergistic therapy.Therefore,the multifunctional GNS would provide a new approach for cascade catalytic and photothermal synergistic cancer therapy by single gold nanoparticle systems.