Pegylated Reduced-graphene Oxide Hybridized With Fe₃O₄ Nanoparticles For Cancer Photothermal-Immunotherapy

Malignant tumors are one of the main killers threatening human health,and their metastasis and recurrence are the main causes of death.In recent years,immunotherapy,a method of killing tumor cells by activating the body's immune system,has attracted widespread attention as an emerging treatment for cancer treatment.Compared with traditional cancer treatment methods,this method can effectively inhibit the metastasis and recurrence of cancer,and achieve ideal results in cancer treatment such as myeloma,renal cancer,non-small cell lung cancer and malignant melanoma.However,immunotherapy still has disadvantages such as high cost,poor universality,and limited efficacy of solid tumors with large load.With the development of nanotechnology,the use of nano-functional materials to combine traditional cancer treatments with immunotherapy to achieve multi-modal treatment of cancer has attracted widespread attention.Among them,the use of nanomaterials to achieve photothermia treatment combined with immunotherapy has made great progress in cancer treatment.Photothermal therapy can not only effectively kill large-loaded solid tumors,but also can cause the immune response of the body by producing tumor-associated inflammatory proteins,and then combine with immunotherapy to achieve synergistic killing of tumors.In summary,this thesis uses a framework of Fe₃O₄ nanoparticle?FNPs?to construct a magnetic resonance imaging mediated photoimmunotherapy material for FNPs composite reduced graphene oxide?rGO?and its application in the treatment of malignant breast cancer.Using the magnetic properties of FNPs to achieve magnetic resonance imaging in mice,further combined with the photothermal effect of rGO to achieve photothermal treatment of mouse tumors;and using the immunostimulatory properties of rGO and FNPs alter the characteristics of the tumor microenvironment to achieve immunotherapy of mouse breast cancer.The specific content of this paper is as follows:Firstly,FNPs/rGO-PEG functional nano-drugs with excellent performance were prepared by electrostatic interaction of FNPs with rGO and modification of PEG-NH₂ on FNPs/rGO surface.UV-visible absorption spectroscopy?UV-Vis?,transmission electron microscopy?TEM?and other instruments were used to study the morphology,structure and photothermal conversion efficiency of the drug.Secondly,the photothermal killing effect and tumor of the nano-functional drug were studied by in vitro cell model.Evaluation of cell antigen activity studies,as well as activation of immune cells in vitro and inhibition of tumor-associated macrophages,and uptake and presentation of tumor antigens;further,magnetic resonance imaging using Fe magnetics,while FNPs/rGO-PEG can Effectively change the tumor microenvironment and inhibit the production of M2 Macrophages,which is widely used in immunotherapy applications.Finally,from the animal model,the photoimmunotherapy effect and the MRI ability of this drug are evaluated and optimized to achieve FNPs/rGO-PEG.Therapeutic treatment of nanofunctional drugs in mouse breast cancer tumors.In summary,FNPs and rGO are synthesized by electrostatic interaction and surface modified by PEG-NH₂.FNPs/rGO-PEG nanocomposites are photothermal therapy?PTT?under 805nm laser irradiation.Excellent reagent for PTT.At the same time,the magnetic effect of FNPs is used to realize MRI,thereby achieving integration of tumor diagnosis and treatment.The immunostimulatory properties of rGO and FNPs induce the systemic anti-tumor immune effect of the body at the same time of treatment;finally,the synergistic treatment of photothermal therapy and immunotherapy can effectively inhibit the formation and growth of metastatic tumors while achieving orthotopic tumor therapy,and thus may have potential application value in anti-tumor immunotherapy based on dendritic cells.