Study On Photodynamic/Photothermal Synergistic Effect And CT Imaging Based On Sulphur-containing Bismuth Compounds

Photodynamic therapy and photothermal therapy are the minimally invasive treatment with broad application prospects in the field of cancer therapy.They are powerful candidates for cancer clinical treatment methods in addition to traditional treatment methods.Both of them are based on the absorption of photon energy by photosensitizing drugs to induce cancer cell apoptosis for therapeutic purposes.Based on this,synergistic phototherapy systems based on two kinds of bismuth-related semiconductors were designed.A large number of bismuth-based semiconductors have been successfully used in photocatalysis before.Therefore,we choose these two compounds in this paper to transform the direction into sensitizer drugs for cancer treatment.The morphology,phase and chemical composition of the two semiconductor compounds were preliminarily studied,cell imaging in vivo experiments were performed and their biomedical properties were verified.The main research contents of this paper are as follows:BiAgOS-PEG nanoparticle for synergistic photo-triggered therapy and CT imaging was designed.Based on this,a single 808 nm near-infrared light-mediated therapeutic system was constructed.BiAgOS nanospheres were synthesized by hydrothermal method,in situ redox and ball milling successively.In order to improve their biocompatibility,the surface modification of polyethylene glycol was used to enhance the hydrophilicity of the samples.In general,BiAgOS-PEG has superior absorption and response in the visible to near-infrared region,and has admirable photodynamic effects and photothermal conversion efficiency under the excitation of 808 nm near-infrared laser.The results show that the material has good hydrophilicity and biocompatibility,and finally shows reliable anti-tumor properties in cell experiments and in vivo experiments.It is an ideal tumor diagnosis and treatment drug.A Bi2S3-GO complex with synergy photo-induced effect was prepared.Based on this composite,808 nm near-infrared light was established as a mediated in this therapy system.Bi2S3 nanoparticles were prepared by dropwise addition of a thioacetamide solution in an aqueous solution of bismuth nitrate,an ultrathin graphene oxide nanosheet was prepared by the Hummers method,and Bi2S3 was loaded onto the graphene oxide sheet.Subsequently,in the further study,the basic information of the phase,morphology and elemental composition of the complex were characterized.The photodynamic and photothermal properties were also tested by in vitro cell experiments to verify the further biomedical application.The results show that the Bi2S3-GO complex can generate a large amount of reactive oxygen speciesunder the excitation of 808 nm near-infrared laser,and also convert the light energy into heat to achieve high heat treatment of the tumor and finally kill the tumor cells.