Immunity/metabolism dual-regulation via an acidity-triggered bioorthogonal assembly nanoplatform enhances glioblastoma immunotherapy by targeting CXCL12/CXCR4 and adenosine-A2AR pathways.

Blocking the C-X-C motif chemokine ligand-12/C-X-C motif chemokine receptor-4 (CXCL12/CXCR4) signal offers the potential to induce immunogenic cell death (ICD) and enhance immunotherapy of glioblastoma (GBM). However, traditional intracellular targeted delivery strategies and adenosine-mediated tumor immunosuppression limit its therapeutic efficacy. Herein, we present an acidity-triggered self-assembly nanoplatform based on bioorthogonal reaction to potentiate GBM immunotherapy through dual regulation of metabolism and immune pathways. AMD3100 (CXCR4 antagonist) and CPI-444 (adenosine 2A receptor inhibitor) were formulated into micelles, denoted as AMD@iNPDBCO and CPI@iNPN3, respectively. Upon administration, the pH-sensitive poly(2-azepane ethyl methacrylate) group of AMD@iNPDBCO responds to the acidic tumor microenvironment, exposing the DBCO moiety, resulting in highly efficient bioorthogonal reaction with azide group on CPI@iNPN3 to form large-sized aggregates, ensuring extracellular drug release. The combination of AMD3100 and CPI-444 contributes to ICD induction, dendritic cell maturation, and immunosuppressive milieu alleviation by reducing tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells, leading to a robust antitumor response, thereby significantly prolonging survival in orthotopic GBM-bearing mice. Furthermore, the nanoplatform remarkably amplifies immuno-radiotherapy by potently evoking cytotoxic CD8+ T cell priming, and synergized with immune checkpoint blockade by delaying CD8+ T cell exhaustion. Our work highlights the potential of the in situ assembly nanoplatform tailored for delivery of extracellular-targeted therapeutic agents for boosting GBM immunotherapy.