NIR Ⅱ Mediated Mild Hyperthermia Enhances The Icd Effect Of Oxaliplatin Into Optimization Research Of Chemotherapy And Immunotherapy

【Objective】To identify the research and mechanism exploration of the anti-tumor effect of nanomicelles P16@Pt(IV)-C16@IR1061(NP3).【Methods】1.Through MTT experiment and immunofluorescence staining to verify the mild hyperthermia(43℃)to enhance the sensitivity of 4T1breast cancer cells to anticancer drugs and the immunogenic cell death(ICD)effect.2.Synthesis of oxidation-sensitive amphiphilic polymer P1,C16-OXAPt(IV)-Suc,Pt(IV)-C16 through polymerization.P1 wraps Pt(IV)-C16 and Near-Infrared II(NIR II)dye IR1061 to form nanomicelles P1@Pt(IV)-C16@IR1061(NP3),transmission electron microscope(TEM),Malvern Zetasizer Nano ZS90 laser particle size analyzer,ultraviolet absorption spectroscopy and inductively coupled plasma mass spectrometry,etc.The micelles are identified and quantified.The FOTRIC225s thermal imaging camera records the photothermal properties of nanomicelles.3.Flow cytometry,Pt endocytosis and 2D and 3D fiuorescence confocal endocytosis were performed to observe the enrichment of nanomicelles in 4T1 cell.The MTT experiment,3D cell sphere activity and toxicity experiment and flow cytometry experiments were used to verify the killing effect of nanomicelle NP3 under mild hyperthermia on tumor cells.4.To verify the distribution of nanomicelles in vivo and the enrichment of tumor sites through animal live imaging and important animal organs and tissues,FOTRIC 225s infrared thermal imaging camera records the heating effect of nanomicelles on tumor sites.Observe the anti-tumor effect of nanomicelles under the mild hyperthermia by recording the tumor volume,body weight and survival period of mice.Finally,flow cytometry,serum cytokine detection and tissue immunofluorescence were used to analyze the effect of nanomicelles on the enhancement of tumor immune response under mild hyperthermia.【Results】1.Compared with 37℃,anti-cancer drugs can effectively reduce cell viability at 43℃,induce cells to express more CRT and HMGB1,and produce a stronger ICD effect.2.We have successfully synthesized polymers P1 and Pt(IV)-C16through the identification of hydrogen NMR spectroscopy.After a series of characterizations,we successfully constructed the nanosystem P1@Pt(IV)-C16@IR1061(NP3),which has good photothermal performance,stability,and conversion efficiency.3.Nanomicelle NP3 can be endocytosed and taken up by tumor cells.The killing effect of NP3 on tumor cells is obviously stronger than that of small molecules oxaliplatin and NP3 under the effect of warming.It can also promote the increase of Pt-DNA crosslinks and DNA damage.The ICD effect is significantly enhanced.4.In animal experiments,we verified that nanomicelles can continuously target the tumor and have a good heating effect at the tumor.Nanomicelles have the best tumor suppressing effect under the mild hyperthermia,and they also have a stronger ICD effect on the tumor site.And the effect of CD4~+/CD8~+T cell infiltration.【Conclusions】1.It is confirmed that the warm effect(43℃)can effectively improve the sensitivity of 4T1 cells to oxaliplatin,increase the cross-linking of oxaliplatin and DNA,and promote the ICD effect.2.The warming effect induced by NIR II light can form more Pt-DNA cross-linking compounds,leading to more serious DNA damage and enhanced anti-tumor activity,resulting in a stronger ICD effect.3.Nanoparticle NP3 has the strongest tumor suppressive effect under mild hyperthermia,and the induced ICD effect is enhanced.By stimulating the maturation of DC cells,it can improve and lasting immune response in vivo to achieve the best anti-tumor effect.