Reshaped Local and Systemic Immune Responses Triggered by a Biomimetic Multifunctional Nanoplatform Coordinating Multi-Pathways for Cancer Therapy.

Immunotherapy has fundamentally transformed the clinical cancer treatment landscape; however, achieving intricate and multifaceted modulation of the immune systems remains challenging. Here, a multipathway coordination of immunogenic cell death (ICD), autophagy, and indoleamine 2,3-dioxygenase-1 (IDO1) was achieved by a biomimetic nano-immunomodulator assembled from a chemotherapeutic agent (doxorubicin, DOX), small interfering RNA (siRNA) molecules targeting IDO1 (siIDO1), and the zeolitic imidazolate framework-8 (ZIF-8). After being camouflaged with a macrophage membrane, the biomimetic nanosystem, named mRDZ, enriched in tumors, which allowed synergistic actions of its components within tumor cells. The chemotherapeutic intervention led to a compensatory upregulation in the expression of IDO1, consequently exerting an inhibitory effect on the reactive oxygen species (ROS) and autophagic responses triggered by DOX and ZIF-8. Precise gene silencing of IDO1 by siIDO1 alleviated its suppressive influence, thereby facilitating increased ROS production and improved autophagy, ultimately bolstering tumor immunogenicity. mRDZ exhibited strong capability to boost potent local and systemic antitumor immune responses with a feature of memory, which led to the effective suppression of the growth, lung metastasis, and recurrence of the tumor. Serving as an exemplary model for the straightforward and potent reshaping of the immune system against tumors, mRDZ offers valuable insights into the development of immunomodulatory nanomaterials for cancer therapy.