The Preparation And Biological Effects Research Of Tungsten-based Semiconductor Heterojunction Nanomaterials

Semiconductor nanomaterials have been widely used in many fields due to their excellent properties.In recent years,with the development of nano-medicine,some functional inorganic semiconductor nanomaterials have been applied in the treatment of tumors.Radiotherapy(RT)has the function of local immune regulation,which can change the microenvironment of radiated tumors and even cause systemic immune response.However,high doses of radiotherapy alone often have many side effects and seldom induce systemic immune response.In this paper,we explore the related properties and mechanisms of tungsten-based nanomaterials and their applications in tumor therapy.Firstly,we report a radio/photodynamic/photothermal triple-combination cancer therapy mediated by WO2.9-WSe2-PEG heterojunction.On the one hand,the heterojunction contains high Z element,has strong X-ray attenuation ability,and can be used as a contrast agent for CT imaging;on the other hand,as a semiconductor material,it can realize photodynamic therapy based on electron-hole pair to generate reactive oxygen species.Meanwhile WO2.9-WSe2-PEG has strong near infrared absorption,good photothermal conversion efficiency can be used for photothermal therapy,and can be used as contrast agent for CT imaging.Secondly,we report a radiocatalytic platform using inorganic semiconductor nanoheterojunctions WO3@Ag2WO4@chitosan(WO3@Ag2WO4@CS)as radiation sensitizers to improve the radiotherapeutic effect of tumors by enhancing radiosensitization and reducing radioresistance.On one hand,WO3@Ag2WO4@CS with higher atomic number has better X-ray absorptivity and can deposit a large amount of radiation dose upon X-ray irradiation.In addition,due to the heterojunction structure,a large number of electron-hole pairs can be generated and separated under X-ray trigger.The WO3@Ag2WO4@CS nanoheterojunctions thus can effectively decompose the surrounding hydrogen peroxide/water into free radicals to kill cancer cells by electron-hole pairs.On the other hand,WO3@Ag2WO4@CS nanoheterojunctions also have the ability to consume intracellular GSH through redox reaction,leading to increased ROS level and reduced radioresistance.Our study provides a novel nanoradiosensitizer that can improve the radiotherapeutic efficacy by enhancing the radiation response and reducing radioresistance of tumor.