An injectable signal-amplifying device elicits a specific immune response against malignant glioblastoma

Despite exciting achievements with some malignancies,immunotherapy for hypoimmunogenic cancers,especially glioblastoma(GBM),remains a formidable clinical challenge.Poor immunogenicity and deficient immune infiltrates are two major limitations to an effective cancer-specific immune response.Herein,we propose that an injectable signal-amplifying nanocomposite/hydrogel system consisting of granulocyte-macrophage colony-stimulating factor and imiquimod-loaded antigen-capturing nanoparticles can simultaneously amplify the chemotactic signal of antigen-presenting cells and the"danger"signal of GBM.We demonstrated the feasibility of this strategy in two scenarios of GBM.In the first scenario,we showed that this simultaneous amplification system,in conjunction with local chemotherapy,enhanced both the immunogenicity and immune infiltrates in a recurrent GBM model;thus,ultimately making a cold GBM hot and suppressing postoperative relapse.Encouraged by excellent efficacy,we further exploited this signal-amplifying system to improve the efficiency of vaccine lysate in the treatment of refractory multiple GBM,a disease with limited clinical treatment options.In general,this biomaterial-based immune signal amplification system represents a unique approach to restore GBM-specific immunity and may provide a beneficial preliminary treatment for other clinically refractorymalignancies.

Synergistic enhancement of immunological responses triggered by hyperthermia sensitive Pt NPs via NIR laser to inhibit cancer relapse and metastasis

The combination of tumor ablation and immunotherapy is a promising strategy against tumor relapse and metastasis.Photothermal therapy(PTT)triggers the release of tumor-specific antigens and damage associated molecular patterns(DAMPs)in-situ.However,the immunosuppressive tumor microenvironment restrains the activity of the effector immune cells.Therefore,systematic immunomodulation is critical to stimulate the tumor microenvironment and augment the anti-tumor therapeutic effect.To this end,polyethylene glycol(PEG)-stabilized platinum(Pt)nanoparticles(Pt NPs)conjugated with a PD-L1 inhibitor(BMS-1)through a thermo-sensitive linkage were constructed.Upon near-infrared(NIR)exposure,BMS-1 was released and maleimide(Mal)was exposed on the surface of Pt NPs,which captured the antigens released from the ablated tumor cells,resulting in the enhanced antigen internalization and presentation.In addition,the Pt NPs acted as immune adjuvants by stimulating dendritic cells(DCs)maturation.Furthermore,BMS-1 relieved T cell exhaustion and induced the infiltration of effector T cells into the tumor tissues.Thus,Pt NPs can ablate tumors through PTT,and augment the anti-tumor immune response through enhanced antigen presentation and T cells infiltration,thereby preventing tumor relapse and metastasis.