光热治疗辅助的上转换光动力治疗纳米材料

Upconversion Photodynamic Therapy Nanomaterials Assisted by Photothermal Therapy

光动力治疗(PDT)是利用光敏剂(PS)在适当光源激发下,与氧气等分子发生反应,生成具有细胞毒性的活性氧物质(ROS),进而杀死肿瘤细胞。与传统治疗方法相比,光动力治疗具有副作用小、精准治疗、毒性低、美容效果好等众多优点,是近年来备受关注的癌症治疗方法。然而光动力治疗具有严重的氧依赖性质,会导致组织中的氧气浓度迅速下降,而肿瘤部位本身因无限增殖而处于乏氧状态,这会严重影响光动力治疗效果。另外,肿瘤部位的内源还原性物质会升高,进而灭活PDT所产生的活性氧物质,导致疗效降低。因此,单一的光动力治疗效果并不理想。为了解决该问题,将光敏剂Ce6通过介孔二氧化硅共水解的方式装载到上转换纳米颗粒表面,在808 nm光照射下实现PDT。随后包裹聚多巴胺,在增加生物相容性的同时,还能利用其自身的光热性质,进行光热治疗。最终通过光热治疗的辅助成功提高了上转换光动力治疗的治疗效果。

Photodynamic therapy(PDT)is the use of photosensitizers to react with molecules such as oxygen under appropriate light sources,generating cytotoxic reactive oxygen species and killing tumor cells.Compared with traditional treatment methods,photodynamic therapy has many advantages such as small side effects,precise treatment,low toxicity,and good cosmetic effects,making it a highly regarded cancer treatment method in recent years.However,photodynamic therapy has a serious oxygen dependent nature,which can lead to a rapid decrease in oxygen concentration in the tissue,while the tumor site itself is in a state of hypoxia due to infinite proliferation,which seriously affects the effectiveness of photodynamic therapy.In addition,the endogenous reducing substances at the tumor site will increase,thereby inactivating the reactive oxygen species produced by PDT,leading to a decrease in therapeutic efficacy.Therefore,the effectiveness of a single photodynamic therapy is not ideal.To solve this problem,the photosensitizer was coated and loaded onto the surface of upconversion nanoparticles through mesoporous silica,and PDT was achieved under 808 nm light irradiation.Subsequently,polydopamine is encapsulated to prevent drug leakage while also utilizing its own photothermal properties for photothermal therapy.Finally,the therapeutic effect of upconversion photodynamic therapy was successfully improved through the assistance of photothermal therapy.