Construction Of Pt/SiNWs Nanoheterojunction And The Study Of Hydrogen Thermal Therapy To Eliminate Oxidative Stress

Among current cancer treatment strategies,both traditional and emerging tumor treatment strategies play an important role in the treatment of tumors.However,in the process of treatment,the surplus reactive oxygen molecules produced by the stimulation of tumor cells cause DNA damage,aggravate tumor cell oxidative stress and cause genome instability,which makes tumor cells dedifferentiate and evolve into stem cell-like tumors cell.Stem cell-like tumor cells are ordinary tumor cells with stem properties.They have strong tolerance and are not easy to be destroyed.They will continue to produce new tumor cells.They are one of the fundamental reasons for tumor recurrence and metastasis.Therefore,exploring a therapeutic strategy that effectively eliminates tumors while preventing the conversion of tumor cells to stem cell-like tumor cells has become an urgent problem to be solved.Hydrogen is an endogenous signal molecule with biological safety.It can be used as a reducing homeostasis regulator to eliminate oxidative stress by neutralizing the most toxic hydroxyl free radicals in reactive oxygen species.Hydrogen has shown a certain effect on inflammation and oxidation-related diseases.Based on this,this project designed a photocatalytic nanoheterojunction based on silicon nanowires(SiNWs).The nanoheterojunction interacts with the surface-modified hyaluronic acid(HA)and the CD44 receptor on the surface of cancer cells to target tumor cells.Then under the irradiation of 808 nm laser,the electrons on the surface of silicon nanowires undergo interband transition and transfer to the surface of platinum nanoparticles.In the micro-acid environment of the tumor,the electrons on the surface of the platinum nanoparticles combine with hydrogen ions to generate hydrogen gas.Initially,hydrogen reduces the level of intracellular reactive oxygen species,but due to the strong oxidative stress ability of tumors and the nanoheterojunction converts light energy into heat energy under the action of 808 nm,which leads to a rapid rebound of intracellular reactive oxygen molecules and promotes cell apoptosis.At the same time,the continuous hydrogen produced by the nano heterojunction will reduce the large amount of reactive oxygen molecus in the cell,eliminate the oxidative stress of the cell and prevent it from evolving into stem cell-like tumor cells.Various experiments such as cytotoxicity in vitro and tumor suppression in vivo have proved that the nanoheterojunction targeting cancer cells effectively inhibits the growth of cancer cells without obvious side effects.The hydrogen heat synergistic treatment group eliminates the oxidative stress of tumor cells.Compared with the normal photothermal treatment group,there was no tumor recurrence after the drug was stopped.At the same time,various stemness-related experiments in vivo and in vitro have proved that the hydrogen heat synergistic treatment effectively prevents the dedifferentiation behavior of ordinary tumor cells.The nanomaterials designed in this subject are expected to provide ideas for preventing tumor recurrence and metastasis.