Study On Photodynamic Therapy Of Tumor And Detection Of Circulating Tumor Cells Based On Au/SiNWs Nano-platform

Photodynamic therapy?PDT?is a therapeutic method to achieve the therapeutic effect by irradiating photosensitizer?PS?,at a specific wavelength to produce cytotoxic reactive oxygen species?ROS?.Compared with traditional treatments such as surgical resection,radiotherapy and chemotherapy,PDT has the advantages of low toxicity,low invasion and minimally invasive,and has been widely used in the treatment of various cancers.However,the photosensitizers currently used in clinic have some problems,such as hypoxia inhibition,poor penetration of excited light tissue and so on,so it is difficult to be used in the treatment of deep tumors.Therefore,it is urgent to develop a photodynamic material to overcome the inhibition of hypoxia and stimulate the penetration of light tissue to improve the therapeutic effect of PDT.Based on this,Schottky Au/SiNWs deposited by MnO₂?Au/SiNWs-MnO₂?were designed for photodynamic therapy of tumors.After Au/SiNWs-MnO₂ enters tumor cells,the surface MnO₂ nanoparticles react with glutathione?GSH?overexpressed in tumor cells,and the resulting Mn²⁺reacts with H₂O₂ to produce·OH and O₂.After MnO₂ reaction on the surface of Au/SiNWs-MnO₂,Au/SiNWs was exposed.Under 808 nm laser irradiation,Au/SiNWs can catalyze the reaction of H₂O₂,O₂ and H₂O to form·OH and·O₂^-.In the study of anti-tumor activity in vitro and in vivo,Au/SiNWs-MnO₂ showed high cytotoxicity and excellent anti-tumor ability.Therefore,Au/SiNWs can be used as an inorganic photosensitizer excited by near-infrared light,which solves the problems of hypoxia inhibition of photosensitizer and poor penetration of excited light tissue.The Au/SiNWs-MnO₂ designed in this paper explores the idea for the development of inorganic photosensitizer excited by near-infrared light.Photodynamic therapy of cancer has been used in clinic,but the recurrence and metastasis of tumor is still the key to the difficult cure of cancer.Circulating tumor cells?CTCs?are tumor cells that fall off from the tumor site and enter into human peripheral blood.Their exfoliation continues the whole stage of tumor development and can provide direct and accurate tumor information.Therefore,the detection of residual tumor cells and CTCs,after photodynamic therapy is of great significance in predicting tumor recurrence and metastasis.Based on this,based on the modification of Au/SiNWs platform,the surface-enhanced Raman spectroscopy?SERS?substrate material?Au/SiNWs-CD133?was designed for the detection of CTCs.Au/SiNWs-CD133 surface-modified specific antibody?Anti-CD133?can capture MCF-7 cells,and its unique one-dimensional structure and Au NPs can enhance Raman signals.Au/SiNWs-CD133 shows excellent Raman signal enhancement ability and solves the problem of slow detection speed of CTCs.The Au/SiNWs-CD133 designed in this paper provides an idea for capturing and quickly detecting CTCs.