Catalytic deoxyribozyme has great potential for gene regulation, but the poor efficiency of the cleavage of mRNA and the lack of versatile DNAzyme vehicles remain big challenges for potent gene therapy. By the rational designing of a diverse vehicle of polydopamine-Mn2+ nanoparticles (MnPDA), we demonstrate that MnPDA has integrated functions as an effective DNAzyme delivery vector, a self-generation source of DNAzyme cofactor for catalytic mRNA cleavage, and an inherent therapeutic photothermal agent as well as contrast agent for photoacoustic and magnetic resonance imaging. Specifically, the DNAzyme-MnPDA nanosystem protects catalytic deoxyribozyme from degradation and enhances cellular uptake efficiency. In the presence of intracellular glutathione, the nanoparticles are able to in situ generate free Mn2+ as a cofactor of DNAzyme to effectively trigger the catalytic cleavage of mRNA for gene silencing. In addition, the nanosystem shows high photothermal conversion efficiency and excellent stability against photothermal processing and degradation in complex environments. Unlike previous DNAzyme delivery vehicles, this vehicle exhibits diverse functionalities for potent gene regulation, allowing multimodal imaging-guided synergetic gene regulation and photothermal therapy both in vitro and in vivo.
Keywords: DNAzyme; deoxyribozyme; gene therapy; multimodal imaging; photothermal therapy.