RAP-peptide functionalized biomimetic nanoformulation with pathological ROS/pH-responsive drug release for target immunotherapy in glioma.

Glioblastoma (GBM) is one of the most aggressive malignancies of the central nervous system. Gemcitabine (GEM), a pyrimidine analogue with broad-spectrum anticancer activity, can activate the cGAS-STING pathway and alleviate the immunosuppressive microenvironment of GBM. However, its clinical application is hampered by the formidable challenge of crossing the blood-brain barrier (BBB) and accumulating at the tumor lesion. Herein, a dual-responsive biomimetic nanoprodrug (RMM@GEM NPs) was exploited to enhance the efficient BBB penetration and target cargo delivery by functionalization of glioblastoma cell membranes (MM) camouflaging and further targeting peptide RAP modification. After its selective accumulation at glioma lesion, RMM@GEM NPs accelerates GEM release under the tumor pathological stimuli of reactive oxygen species (ROS) and acidic microenvironment to robustly activate the STING signaling cascades (increased p-STING, p-TBK1, p-IRF3, and p-NF-κB). Simultaneously, cyclodextrin-mediated cholesterol depletion further suppresses PD-L1 expression and alleviates T-cell exhaustion. These findings highlight RMM@GEM NPs as a promising strategy to enhance immune responses in "cold" tumor, providing a potential candidate for efficient and safe immunotherapy in GBM.