Development Of Energy-conversion Materials Based On Oxygen Family Elements For Tumor Theranostics Research

In recent years,with the high incidence of cancer and people's higher pursuit of health,how to achieve accurate diagnosis and efficient treatment of cancer has become a major problem in the medical field.With the rapid development of nanotechnology,more and more functional nanomaterials have been used in the diagnosis and treatment of major diseases,and also opened up a new field of nano-theranostic medicine.Among them,there is a class of highly applicable energy-conversion nanomaterials that have attracted widespread attention,which can convert different forms of energy into each other.Like plant photosynthesis,which converts solar energy into chemical energy,this kind of nanomaterials can realize the conversion between light energy,the conversion of light energy and chemical energy,the conversion of light energy and electric energy,the conversion of light energy and thermal energy,the conversion of magnetic energy and electric energy,and the thermal energy,the conversion of thermal energy and electrical energy,the conversion between thermal energy and chemical energy,and the conversion of chemical energy.It overcomes the barrier between energy and provides unlimited possibilities for the application of nanomaterials.At the same time,the oxygen family element nanomaterials have been widely utilized in the field of biomedicine due to its good biosafety and excellent physical and chemical properties.Therefore,the development of a new generation of energy conversion oxygen family nanomaterials and the corresponding applications to the biomedical field have important academic significance and clinical potential,and also provides inspirations for the further development of nanomaterials.Based on the application requirements of nanomedicine,this thesis studies the preparation of energy conversion oxygen family nanomaterials and the applications in biomedicine field through nano-synthesis technology and controllable functional design.It mainly includes the following aspects:1.Disulfide-polyethylene glycol nanomaterials for tumor microenvironment-responsive self-enhanced magnetic resonance?MR?imaging and photothermal therapy?PTT?/chemodynamic therapy?CDT?:This chapter includes the design of iron disulfide-polyethylene glycol?FeS₂-PEG?nanomaterials with good photothermal conversion properties.The FeS₂-PEG nanomaterial plays three functions:1)converting light energy into thermal energy under near-infrared 808 nm laser irradiation to achieve PTT of breast tumor;2)responding to the mild acidity and overproduced hydrogen peroxide in specific tumor microenvironment and then initiating the conversion between chemical energy to produce highly oxidizing hydroxyl radicals to achieve the CDT of breast tumors;3)the changes of surface iron valence and magnetic properties of FeS₂ after reaction with tumor microenvironment would activated MR imaging signals to realized self-enhanced MR imaging.Finally,the heat generated by the photothermal conversion can promote the production of hydroxyl radicals to guarantee synergistic therapy.Moreover,the experiments in vitro and in vivo show that the nanomaterials have good MR imaging effect and energy conversion ability to achieve the tumor treatment,which provides inspirations for the further development of iron-based energy conversion materials and solid foundation for the diagnosis and efficient treatment of breast tumors.2.Polyvinylpyrrolidone modified-stannous selenide nanomaterials for photoacoustic imaging-guided photothermal/pyroelectric dynamics synergistic therapies:This chapter further describes the Polyvinylpyrrolidone modified-stannous selenide nanomaterials?SnSe-PVP?with photothermal conversion and pyroelectric conversion properties,which are utilized for the diagnosis and treatment of tumor.Irradiation of the SnSe-PVP nanomaterials with NIR-II 1064 nm light generated enough heat to both diagnose a tumor with photoacoustic imaging and kill its cancerous cells.Moreover,the temperature difference generated during the photothermal and cooling process induced a potential difference on the surfaces of the SnSe-PVP nanorods and generated electrons to react with water,which produced ROS to attack the cancer cells,realizing a synergetic therapy.All the results provided a promising and meaningful exploration for future clinical translation,involving irradiation of the pyroelectric nanomaterials with a relatively low intensity of NIR-II light for several cycles to generate high levels of heat to kill cancer cells,and in this way reducing the damage to normal tissues.3.Biodegradable transferrin loaded magnesium peroxide nanomaterials?TMNSs?for breast tumor-specific molecular dynamics treatment:This chapter describes the synthesis of biodegradable transferrin loaded magnesium peroxide nanomaterials and the corresponding application of acting as nanoprodrugs for tumor therapy.In response to the acidic and low catalase activity of tumor microenvironment,the TMNSs will produce enough H₂O₂ rapidly.The product of H₂O₂ damages the structure of transferrin on the surface of TMNSs.The transferrin releases the trapped Fe³⁺,followed by the Fenton reaction to kill cancer cells,in addition to the well-known high concentration lethality of H₂O₂.This therapy uses the conversion between chemical energy shows selectivity to tumors.Exctingly,all the ultimate products(Mg²⁺,H₂O,O₂)are nontoxic,surmounting the concerns about potential side effects of current nanoagents and commercial drugs in vivo.This new type of biodegradable nanomaterials has unparalleled clinical application potential and is expected to provide a reference for further nanoprodrugs cultivation.