Preparation Of Gold Nanocages/Photosensitizer Composite Nano-agents For PDT/PTT Combination Therapy Of Tumor

Malignant tumours have become one of the most serious diseases that threaten human health and cause death.Compared to traditional tumour therapy,optical therapy has attracted a great deal of attention due to its characteristics of non-trauma,non-invasive and convenient operation,local selectivity,low drug resistance and few side effects.The main components of this therapy are photothermal therapy（PTT）and photodynamic therapy（PDT）,the witch’s working principle is to stimulate photosensitizers with appropriate wavelengths of light.Local high temperature or reactive oxygen species are produced to induce apoptosis and/or death of tumor cells.It is not difficult to see from the working principle that PDT is obviously dependent on oxygen molecules,while oxygen deficiency is a significant feature of solid tumors.Compared with PDT,PTT is not dependent on oxygen molecules.However,PTT requires a higher intensity of light source,and tumor cells will produce heat shock protein for self-protection during treatment,which leads to low treatment efficiency of PTT and easy recurrence.Therefore,the single optical treatment mode still has some limitations and can not achieve the ideal therapeutic effect.This paper focuses on improving the efficiency of optical therapy for tumor,and designs and prepares Au nanocages（ANC）based nanopreparations for PDT/PTT combined therapy for tumor.Specific work is as follows:1.With ANC as core and photothermal preparation,Pheophorbide A（Pheo）as photosensitizer,modified load via Au-S bond,Nano-preparations（ANC@FEA/Pheo）were prepared by modifying polyethylene glycol/polyaspartic acid（FA-PEG-PAsp）water-soluble polymers with active targeting ligand folic acid for PTT/PDT combination therapy of tumors.The results show that ANC@FEA/Pheo is a hollow cubic cage with a diameter of 135.3 nm and exhibits excellent photodynamic and photothermal activity after laser irradiation at 650 nm and 808 nm.In vitro cell experiments showed that ANC@FEA/Pheo had good biocompatibility and showed obvious phototoxicity to He La cells after 650 nm and 808 nm laser irradiation.2.Aiming at the problem of oxygen deficiency in tumor environment,the treatment procedure was simplified.In this paper,the oxygen-carrying anthracene peroxycompound was used as the ¹O₂ release source,ANC was used as photothermal preparation,and the load was modified by Au-S bond.A single near-infrared photoactivated nanopreparation（ANC@FEA/EPO）was prepared by modifying polyethylene glycol/polyaspartic acid（FA-PEG-PAsp）water-soluble polymer with active targeting ligand folic acid for PTT/PDT combination therapy in tumors.The results show that ANC@FEA/EPO is a hollow cubic cage with a diameter of about150.6 nm.After being irradiated by a laser at 808 nm,it exhibits excellent photothermal and non-oxygen molecule concentration-dependent photodynamic activity.In vitro cell experiments showed that ANC@FEA/EPO had good biocompatibility and showed obvious phototoxicity to He La cells after 808 nm laser irradiation.