Brain-targeted antigen-generating nanoparticles improve glioblastoma prognosis

The exploration of multifunctional nanomedicine has prompted interest in improving glioblastoma (GBM) prognosis. In this study, we constructed tumor microenvironment (TME)-responsive magnetic therapeutic nanoparticles (BK@MTNPs) as a multifunctional drug delivery platform. It contains the following components. [Des-arg(Sheets et al., 2020) bradykinin (BK), which contributes to the transient opening of the blood-brain barrier (BBB) and targeting of GBM cells; nanoparticles (NPs) encapsulated in MTNPs, which act as an in vivo magnetic resonance (MR) imaging agent; crizotinib, which is an inhibitor of protein kinase c-Met; and the immune drug anti-PDL1 antibody. These components were loaded into BK@MTNPs for complete tumoricidal effects. Abundant glutathione in the TME can promote BK@MTNP degradation by interrupting the disulfide bonds between cysteine residues. Such BK@MTNPs support a synergistic tumoricidal effect by inducing DNA damage, activating the transcription of the tumor suppressor gene PTEN, inhibiting glioblastoma stem cell function, activating cytotoxic T lymphocytes, and reprogramming tumor-associated macrophages. BK@MTNPs showed a significant increase in antitumor activity compared with free drugs in vitro. Furthermore, in mice bearing orthotopic GBM, treatment with BK@MTNPs resulted in marked tumor inhibition and greatly extended survival time with minimal side effects. This study demonstrates the advantages of chemo-immunotherapeutic NPs accumulated in the GBM area and their effective inhibition of GBM growth, thus establishing a delivery platform to promote antitumor immunity against GBM.