Near-Infrared-Enpowered Nanomotor-Mediated Targeted Chemotherapy and Mitochondrial Phototherapy to Boost Systematic Anti-Tumor Immunity.

Phototherapy is an important strategy to inhibit tumor growth and activate anti-tumor immunity. However, the effect of photothermal/photodynamic therapy (PTT/PDT) is restricted by limited tumor penetration depth and unsatisfactory potentiation of anti-tumor immunity. Here, we constructed a near-infrared (NIR)-driven nanomotor with a mesoporous silicon nanoparticle (MSN) as the core, end-capped with Antheraea pernyi silk fibroin (ApSF) comprising arginine-glycine-aspartate (RGD) tripeptides. Upon NIR irradiation, the resulting ApSF-coated MSNs (DIMs) loading with photosensitizers (ICG derivatives, IDs) and chemotherapeutic drugs (doxorubicin, Dox) could efficiently penetrate into the internal tumor tissues and achieve effective phototherapy. Combined with chemotherapy, a triple-modal treatment (PTT, PDT, and chemotherapy) approach was enabled to cause the immunogenic cell death of tumor cells and to accelerate the release of damage-associated molecular patterns. In vivo results suggested that DIMs could promote the maturation of dendritic cells and surge the number of infiltrated immune cells. Meanwhile, DIMs could polarize macrophages from M2 to M1 phenotypes and reduce the percentages of immunosuppressive Tregs, which reverse the immunosuppressive tumor microenvironment and activate systemic anti-tumor immunity. By achieving synergistic effects on the tumor inhibition and the anti-tumor immunity activation, DIMs show great promise as new nanoplatforms to treat metastatic breast cancer. This article is protected by copyright. All rights reserved.