Polyvalent DNA-based bioorthogonal nano-agonist for robust chemo-immunotherapy

Chemo-immunotherapy, in which chemotherapeutic drugs activate immune system to suppress tumor growth and metastases, has great potential for clinical application. However, insufficient immunogenic cell death and serious side effects caused by tumor multidrug resistance and non-specific drug distribution, as well as inadequate and dysfunctional immune cells, greatly impair the effectiveness of chemo-immunotherapy. Herein, taking advantage of the functional diversity and structural programmability of nucleic acids, a DNA-based bioorthogonal nanoagonist is constructed to initiate and augment immune responses for robust chemo-immunotherapy. Benefiting from polyvalent targeting and template effects of DNA, the tailor-made nanoagonist shows prior bioorthogonal catalytic performance. Chemotherapeutic drug is bioorthogonally synthesized in situ under the catalysis of the nanoagonist, maximizing immunogenic cell death and minimizing systemic toxicity. The large amount of antigen and damage-associated molecular patterns released from dying tumor cells effectively initiates antitumor immunity. Meanwhile, the integration of high density of immunologic adjuvant can more effectively stimulate immune cells. The combination of bioorthogonal catalytic drug synthesis and immunostimulatory effect of DNA adjuvant not only destroys local primary tumors, but also eliminates distal metastasis. Moreover, the nanoagonist triggered the immune memory effect. The work extends the application of bioorthogonal chemistry to immunotherapy and provides a safe and powerful strategy for cancer chemo-immunotherapy.