A polymer nanogel-based therapeutic nanovaccine for prophylaxis and direct treatment of tumors via a full-cycle immunomodulation

Construction of a cancer nanovaccine that can simultaneously activate immune cells and exert efficient tumor treatment still remains a challenge. Herein, we showcase a proof-of-concept demonstration of an advanced therapeutic nanovaccine formulation based on poly(<i>N</i>-vinylcaprolactam) nanogels (NGs) which were loaded with manganese dioxide (MnO₂), the sonosensitizer chlorin e6 (Ce6), and the immune adjuvant cyclic GMP-AMP (cGAMP). The gels were furthermore coated with apoptotic cancer cell membranes (AM). On the one hand, the AM promoted the recognition of NGs by antigen presenting cells (APCs) in lymph nodes due to their enhanced immunogenicity, then the loaded Mn and cGAMP could mature APCs <i>via</i> stimulator of interferon genes (STING) activation for triggering immunity to prevent tumor growth. On the other hand, the NGs could selectively release Mn²⁺ for hydroxyl radical production and Ce6 to generate single oxygen under ultrasound irradiation of tumors, respectively, thereby exerting local chemodynamic/sonodynamic therapy to induce immunogenic cell death (ICD). Moreover, the Mn²⁺ could also activate STING in tumors to synergize with ICD for potentiated immune responses. Overall, the biomimetic NG-based therapeutic nanovaccine could directly evoke immune system, and also conduct local tumor treatment to further activate ICD, thus realizing a full-cycle immunomodulation (tumor killing for ICD/antigen production, and tumor cells/APCs immune activation) to tackle bilateral tumor growth.