Design And Preparation Of Nanocomposites For Tumor Synerc Istic Therapy

In recent years,with the development of nanotechnology,nanomaterials have been widely used in biomedical fields,such as drug delivery,disease diagnosis and therapy.Compared with the disadvantages of high cost and large side effects of traditional treatment methods,nanomaterials can be enriched in the tumor area through the EPR effect,which facilitated tumor cells to be treated in situ in the tumor area and reduce the adverse reactions to normal cells.Therefore,it is of great significance to develop nanocomposites for tumor treatment.In this thesis,we designed and prepared a series of nanocomposites to study their own physicochemcial properties,biocompatibility,and tumor-killing performance.The main research is as follows:(1)We prepared polydopamine and ammonium bicarbonate coated,doxorubinin loaded hollow cerium oxide nanocomposites,and studied their photothermal properties,drug release profiles,and hydroxyl radical generation ability.When the nanoparticles enter the tumor cells,it is first irradiated with near-infrared light.Polydopamine absorbs near-infrared light and converts it into heat.It can be used for photothermal treatment,and it can decompose ammonium bicarbonate to generate gas,breaking the polydopamine shell to release the drug and exposing cerium dioxide surface to convert hydrogen peroxide into hydroxyl radicals at acidic conditions.Through photothermal and hydroxyl radical generation tests as well as a series of in vitro and in vivo biological assessments,it shows that the prepared nanomaterials have good biocompatibility and can effectively inhibit tumor growth in mice.(2)We designed a tandem nanocatalyst that encapsulates glucose oxidase on the surface of nitrogen-doped carbon nanospheres.When nanocomposites enter tumor cells,glucose oxidase first consumes glucose to produce gluconic acid and hydrogen peroxide.Nitrogen-doped carbon nanospheres have the ability to mimic peroxidase,which can convert hydrogen peroxide into high toxic hydroxyl radicals.A series of physicochemical and biological assessments prove that nanocomposites can reduce the ATP and heat shock protein content in cells,which enhances the efficiency of photothermal therapy.