Polydopamine/Melanin-Based Nano-Probes For Tumor Theranostic

Polydopamine and melanin are widely used biopolymer materials with strong ultraviolet light absorption,which have wide-band absorption in the range of ultraviolet light to near-infrared light,and have high photothermal conversion efficiency.Therefore,polydopamine and melanin not only show a certain photoprotective effect,but also have the potential of photothermal therapy.Polydopamine and melanin can modify the surface of various materials due to their rich functional groups,and effectively improve the adhesion and biocompatibility of other materials to biological cells.Based on these properties,the appropriate design and application of polydopamine and melanin will help to establish a platform for the integration of cancer diagnosis and treatment,which means,to integrate the diagnosis and treatment of cancer into the same nanocarrier,and at the same time realize the visualization treatment of cancer.Based on polydopamine,this dissertation has constructed two nanomaterials with integrated diagnostic and therapeutic functions for imaging guided tumor therapy.The main research contents are as following:1.A one-step reaction method was used to synthesize a nano-composite(black phosphorus@polydopamine)with a uniform size and good dispersion.At the same time,the prepared nanotheranostics has the following advantages: stronger absorption and higher photothermal conversion efficiency and improved stability Black phosphorus@polydopamine can achieve enrichment at the tumor site through the tumor enhanced permeability and retention effect,thereby achieving tumor photothermal therapy under the guidance of multimodal imaging.2.Glucose oxidase loaded and melanin-coated manganese dioxide nanocomposites for the combination of photothermal and starvation therapy under the guidance of multimodal imaging by synthesis of ultrathin manganese dioxide nanosheets in aqueous phase using natural biomolecule melanin as a template.The redox reaction between manganese dioxide and hydrogen peroxide in the hypoxic tumor area increases the oxygen content of the tumor tissue and releases manganese ions for nuclear magnetic imaging.Owning to the high photothermal conversion performance of melanin in the near-infrared region,the photothermal treatment of the tumor is achieved under a near-infrared light irradiation.The glucose oxidase can catalyze the production of hydrogen peroxide by glucose,reduce the blood glucose concentration at the tumor site,which could achieve a hunger-like treatments.In summary,in this dissertation,two kinds of polydopamine-based composite nanotheranostics were designed for tumor therapy under the guidance of multimodal imaging.The results of this research provide new ideas and directions for the application of polydopamine in biomedical field.