Bacteriophage-Mimetic DNA Origami Needle for Targeted Membrane Penetration and Cytosolic Cargo Delivery

Inspired by the natural ability of bacteriophages to deliver genetic material directly into host cells, we employed a bottom-up approach to construct a multifunctional synthetic DNA origami needle-like structure. This origami is functionalized with trastuzumab antibodies, cholesterol, protective polymers, and two dyes, which together enable selective targeting and insertion into SKBR3 cancer cells. A disulfide-linked dye payload was attached to the apex of the needle, allowing controlled release in the cytoplasm triggered by the high intracellular glutathione concentration. Real-time tracking of the payload confirmed both successful targeting of the origami structure and subsequent direct cytosolic delivery. By mimicking fundamental mechanisms of bacteriophages, we propose that this artificial needle structure can serve as a prototypical device for the targeted delivery of small-molecule drugs directly into the cytosol.