Photothermal Therapy Mediated By Gold Nanocage Composited With PDL1 And TGFβ Immotherapy For Improved Synergistic In Colorectal Cancer

Background:Colorectal cancer(CRC)is the second deadly cancer all over the world,and its prevalence increasing among people younger than 50 years.About half of CRC patients have distant metastases,especially liver and lung metastases,which are the main cause of death.In addition,CRC is a disease characterized by highly mutation and immune checkpoints have been activated,leading microsatellite instability and immunosuppressive tumor microenvironment.However,most patients with microsatellite instability in metastatic colorectal cancer cases do not benefit from using immune checkpoint inhibitor therapy alone.Photothermal therapy(PTT),which can generate abundant heat under light irradiation,is used to kill tumor cells.Nanomaterials are constructed as photothermal conversion agents for a wide range of biomedical applications,and show some advance in the treatment of various diseases.Nanomaterials can be designed to improving the targeting ability and on-demand treatment can be achieved by controlling external energy sources such as light.In order to achieve synergistic treatment.,PTT based on nanoparticles has been combined with other treatment modalities,including chemotherapy,radiotherapy(RT),photodynamic therapy(PDT),gene therapy,immunotherapy and chemodynamic therapy(CDT),especially in cancer treatment.Although photothermal therapy(PTT)assisted by nanoparticles have been considered as indispensable strategy in of biomedicine,it still has some urgent problems such as over heat poses damage to surrounding healthy tissues.Low-temperature PTT(also termed mild PPT)has shown its ability to overcome these problems in cancer treatment.HSP(Heat shock protein),especially the HSP90 and HSP70 families,enable cancer cells to survive in harsh environments.Down-regulation of HSP is considered an alternative strategy for cancer treatment.The structural dimensions of gold nanoparticles make them as idyllic photothermal transducers,easy to modification,low toxicity,high biocompatibility,and high surface-to-volume ratio all make them can be used to develop personalized medicine Nano therapeutics.The programmed cell death-1(PD1)and PD-ligand 1(PDL1)checkpoint plays a key role in tumor immune evasion.Therapeutic antibodies that block the PD1/PD L1 pathway can induce long-lasting and robust responses in various cancer patients,including CRC.Inhibitors targeting PD-1 or PDL1 improved the clinical outcome of CRC.Combining multiple inhibitors may produce a stronger and synergistic therapeutic response,thereby overcoming resistance.The immune homeostasis and tolerance induced by transforming growth factor(TGF)-β inhibits the expansion and function of a variety of immune cells.The co-administration of anti-PD-L1 antibodies and anti-TGFβ blocked TGFβ signaling pathway,promoted T cells infiltration in tumor,and led tumor regression.The combination can triggered an anti-tumor immune response.Blocking the increased immune infiltration by TGFβ can make cancer cells sensitive to PD1/PDL1 inhibitors,which is a promising treatment strategy for tumors with a TGFβ rich microenvironment.However,other treatment strategies should be inclusion for improve the immunotherapy outcome of the patient which limited by tumor heterogeneity and drug resistancePurpose:Herein,we designed and synthesized gold nanocages functionalized with primary macrophage membrane and surface anti-PDL1 antibody,and loaded with a TGFβinhibitor,galunisertib.And characterized their physicochemical properties and biological properties,using in vitro and in vivo experiments to test their treatment.The assembled nanoparticles-mediated low-temperature PTT,TGFβ inhibitor,and antiPDL1 combination proposed in this study provides fundamental and experimental basis for the new treatment strategy development for the colorectal cancer patients with metastatic.Method:(1)GNC-Gal@CMaP NPs were prepared,and we characterize their particle size,stability,morphology,biological function,drug loaded and release capacity,photothermal conversion capacity and photothermal stability.(2)Through in vitro experiments the cytotoxicity,targeting capability,specificity,ppt effect,molecular mechanisms underlying ppt effect and synergistic treatment effect were characterized by cell endocytosis,clone formation assay,western blot.(3)Sit up metastasis colorectal cancer mice model to tested therapeutic effect of GNC-Gal@CMaP NPs,text in vivo biocompatibility,targeting capability,immune activation by histological examination,immunofluorescence staining,flow cytometry.Result:(1)In this study,we prepared GNC-Gal@CMaP NPs.The GNC nanoparticle core loaded TGFβ inhibitor(galunisertib),with CM and PEG-aPDLl vesicles fused to the surface.The CM coating and galunisertib loading wasn’t affected photothermal conversion ability of GNC-Gal@CMaP.The drug release improved with the nearinfrared treated.These make GNC-Gal@CMaP NPs an excellent photothermal agent.(2)In vitro,GNC-Gal@CMaP NPs can targeting of cancer cells.Show less toxicity to normal cells.And the migration and proliferation of colorectal cancer cells all decreased by the synergistic effect of combined application of TGFβ inhibitor and anti-PDL1 and promoted cancer cell apoptosis.The TGFβ inhibitor can effectively down-regulate the expression of p-AKT,HSP70 and HSP90,realizing low-temperature photothermal therapy.(3)In vivo,GNC-Gal@CMaP NPs showed cancer cell-specific targeting ability and biological safety.GNC-Gal@CMaP NPs with NIR irradiation treatment led to highly suppression of primary tumor and eliminated the growth of untreated distant tumors.Immunotherapy effect have been enhanced by eliciting consistent abscopal effects.GNC-Gal@CMaP-mediated PTT bring T cell activation to improves the ICD efficacy by suppressing the TGFβ pathway responsible.Antigen-presenting cells activated stimulate effector T cell infiltration and expansion.Conclusion:In summary,GNC-Gal@CMaP targeting tumors specificity,anti-PDL1 antibody and galunisertib composited with gold nanocage-mediated PTT for improved synergistic effect and immunotherapy against CRC..This nanoplatform to improve the outcomes of CRC is promising for the extensive metastatic disease patients.