A DNAzyme-Based Nanohybrid for Ultrasound and Enzyme Dual-Controlled mRNA Regulation and Combined Tumor Treatment.

Despite the significant potential of RNA-cleaving DNAzymes for gene regulation, their application is limited by low therapeutic efficacy and lack of cell-specific control. Here, a DNAzyme-based nanohybrid designed for ultrasound (US)-controlled, enzyme-activatable mRNA regulation is presented, enabling tumor cell-selective combination therapy. The nanohybrid is constructed by coordination-directed self-assembly of an enzymatically-triggerable therapeutic DNAzyme (En-Dz) and natural sonosensitizer hemoglobin (Hb). Controlled US exposure induces reactive oxygen species generation from Hb units, which not only facilitates efficient endosomal escape of En-Dz, but also promotes the translocation of specific enzyme from the nucleus to the cytoplasm, thereby enhancing gene regulation efficacy. Notably, the enzyme-triggered, spatiotemporally-controlled activation of En-Dz's catalytic activity results in enhanced cancer-cell selectivity in the therapeutic treatment. Furthermore, the combination of enzyme-activated mRNA regulation and sonodynamic therapy significantly enhances anti-tumor efficacy both in vitro and in vivo. This work highlights the potential of integrating a sonodynamic strategy to overcome the current limitations of DNAzyme-based gene regulators, providing a spatiotemporally-controlled approach for precise tumor treatment.