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As the prominent feature of the development and progression of head and neck squamous cell carcinoma (HNSCC) is immunosuppression, therapeutic strategies to restore antitumor immunity have shown promising prospects. The efficacy of chemotherapy, a mainstay in HNSCC treatment, is exemplified by cytotoxic effects as well as immunostimulation, whereas compensatory activation of prosurvival signals in tumor tissues may compromise its efficacy. Aberrant activation of Src is present in many human malignancies including HNSCC, and is implicated in chemotherapy resistance. In this regard, tumor-microenvironment-responsive prodrug nanomicelles (PDO NPs) are rationally designed to combine chemotherapy (oxaliplatin, OXA) and Src inhibitors (dasatinib, DAS) for HNSCC therapy. PDO NPs are constructed by chemically modifying small-molecule prodrugs (DAS-OXA) loaded in block copolymer iPDPA with pH-triggered transforming capability. PDO NPs can controllably release drugs in response to tumor acidity, thus increasing tumor accumulation and therapeutic efficacy. Moreover, PDO NPs can elicit pyroptosis of tumor cells and induce T-cell-mediated antitumor immunity in murine HNSCC models. In summary, nanoprodrugs integrating Src inhibitors enhance the immunological effects of chemotherapy and provide insight into promising approaches for augmenting immunochemotherapy for HNSCC. STATEMENT OF SIGNIFICANCE: In this study, pH-responsive nanomicelles (PDO NPs) were constructed by loading a small molecular prodrug synthesized by the Src inhibitor dasatinib and the chemotherapy drug oxaliplatin into the amphiphilic block copolymer iPDPA to improve the immunological effects of chemotherapy for HNSCC. These nanomicelles can efficiently accumulate in tumor cells and achieve pH-responsive drug release. The PDO NPs can induce pyroptosis of tumor cells and potentiate antitumor immunity in subcutaneous and syngenetic orthotopic HNSCC mouse models, which may present a promising strategy to enhance immunochemotherapy for HNSCC.

The absence of tumor antigens leads to a low response rate, which represents a major challenge in immune checkpoint blockade (ICB) therapy. Pyroptosis, which releases tumor antigens and damage‐associated molecular patterns (DAMPs) that induce antitumor immunity and boost ICB efficiency, potentially leads to injury when occurring in normal tissues. Therefore, a strategy and highly efficient agent to induce tumor‐specific pyroptosis but reduce pyroptosis in normal tissues is urgently required. Here, a smart tumor microenvironmental reactive oxygen species (ROS)/glutathione (GSH) dual‐responsive nano‐prodrug (denoted as MCPP) with high paclitaxel (PTX) and photosensitizer purpurin 18 (P18) loading is rationally designed. The ROS/GSH dual‐responsive system facilitates the nano‐prodrug response to high ROS/GSH in the tumor microenvironment and achieves optimal drug release in tumors. ROS generated by P18 after laser irradiation achieves controlled release and induces tumor cell pyroptosis with PTX by chemo‐photodynamic therapy. Pyroptotic tumor cells release DAMPs, thus initiating adaptive immunity, boosting ICB efficiency, achieving tumor regression, generating immunological memory, and preventing tumor recurrence. Mechanistically, chemo‐photodynamic therapy and control‐release PTX synergistically induce gasdermin E (GSDME)‐related pyroptosis. It is speculated that inspired chemo‐photodynamic therapy using the presented nano‐prodrug strategy can be a smart strategy to trigger pyroptosis and augment ICB efficiency., A smart tumor microenvironmental reactive oxygen species/glutathione dual‐responsive nano‐prodrug (denoted as MCPP) with high paclitaxel and photosensitizer purpurin 18 loading is designed. Chemo‐photodynamic therapy using the presented nano‐prodrug strategy can be a smart strategy to trigger pyroptosis and augment the efficiency of immune checkpoint blockade therapy.

The combination of chemotherapy and immunotherapy motivates a potent immune system by triggering immunogenic cell death (ICD), showing great potential in inhibiting tumor growth and improving the immunosuppressive tumor microenvironment (ITM). However, the therapeutic effectiveness has been restricted by inferior drug bioavailability. Herein, we reported a universal bioresponsive doxorubicin (DOX)-based nanogel to achieve tumor-specific co-delivery of drugs. DOX-based mannose nanogels (DM NGs) was designed and choosed as an example to elucidate the mechanism of combined chemo-immunotherapy. As expected, the DM NGs exhibited prominent micellar stability, selective drug release and prolonged survival time, benefited from the enhanced tumor permeability and prolonged blood circulation. We discovered that the DOX delivered by DM NGs could induce powerful anti-tumor immune response facilitated by promoting ICD. Meanwhile, the released mannose from DM NGs was proved as a powerful and synergetic treatment for breast cancer in vitro and in vivo, via damaging the glucose metabolism in glycolysis and the tricarboxylic acid cycle. Overall, the regulation of tumor microenvironment with DOX-based nanogel is expected to be an effectual candidate strategy to overcome the current limitations of ICD-based immunotherapy, offering a paradigm for the exploitation of immunomodulatory nanomedicines., Graphical abstract Engineering DOX-based mannose nanogel via GSH-sensitive –SS– bond crosslinker was reported, which not only destroyed the glycolysis process of tumor cells, but also induced robust immunogenic cell death against tumors.Image 1