Chemo-immunotherapy by dual-enzyme responsive peptide self-assembling abolish melanoma

Herein, we designed Comp. 1 to simultaneously respond to two enzymes: alkaline phosphatase and matrix metalloproteinase 2, which is commonly found in highly malignant cancer cell lines containing B16-F10 murine melanoma cells and CT26 murine colon carcinoma cells. We used the regional differences in the expression levels of dual-markers to accurately release immune molecule IND into tumor microenvironment for the activation of anti-tumor related immune effects, while in-situ self-assembly occurs. The dual-enzyme response process can further regulate the peptide precursors' self-assembly in the form of short rod-shaped nanofibers, enabling the delivery of the loaded chemotherapeutic drug HCPT into the cancer cells and further allowing the peptide as-semblies to escape from lysosomes and return to cytoplasm in the form of tiny nanoparticles to induce apoptosis of cancer cells. This process does not occur in the single-positive breast cancer cell line MCF-7 or the normal hepatocytes cell line LO2, indicating the selectivity of the cancer cells exhibited using our strategy. In vivo studies revealed that Comp. 1 can effectively cooperate with chemotherapy to enhance the immunotherapy effect and induce immune responses associated with elevated pro-inflammatory cytokines in vivo to inhibit malignant tu-mors growth. Our dual-enzyme responsive chemo-immunotherapy strategy feasible in anti-tumor treatment, provides a new avenue for regulating peptide self-assembly to adapt to diverse tumor properties and may eventually be used for the development of novel multifunctional anti-tumor nanomedicines.