A smart metal-polyphenol-DNAzyme nanoplatform for gene-chemodynamic synergistic tumor therapy

DNAzyme-based gene regulation shows great potential for the therapy of many cancers. However, ineffective delivery and insufficient cofactor supply pose challenges for potent gene therapy. In this study, we constructed a smart metal-polyphenol-DNAzyme nanoplatform (TA-Mn@Dz NPs) with intrinsic stability, effective delivery, and cofactor self-supply ability for gene-chemodynamic synergistic tumor therapy. Tannic acid, a plant-derived polyphenol, acts as an intermediate structural unit to mediate the assembly of Mn2+/DNAzyme and tumor acid environment-responsive nanocarriers. Intracellularly, the acidic environment triggers the decomposition of TA-Mn@Dz NPs to release DNAzyme and Mn2+. The Mn2+ ion not only boosts the catalytic cleavage of surviving mRNA for effective gene therapy but also activates chemodynamic therapy (CDT), generating highly toxic ·OH from endogenous H2O2. When tail intravenously injected into MCF-7 tumor-bearing mice, the TA-Mn@Dz NPs display desirable synergistic gene-chemodynamic antitumor effects, paving the way for developing DNAzyme-based multifunctional theranostic platforms for biomedical applications. STATEMENT OF SIGNIFICANCE: 1. A smart metal-polyphenol-DNAzyme nanoplatform was constructed for gene-chemodynamic synergistic tumor therapy. 2. Tannic acid act as intermediate structural units to mediate the assembly of Mn2+/DNAzyme and tumor acid environment-responsive nanocarriers. 3. The Mn2+-ion could not only boost the catalytic cleavage of surviving mRNA for effective gene therapy, but also catalyze endogenous H2O2 to form cytotoxic hydroxyl radicals for chemodynamic therapy. 4. Our work paves an extremely simple way to integrate gene therapy with CDT for the dual-catalytic tumor treatment.