High Aspect\nRatio Polymer Nanocarriers for Gene Delivery\nand Expression in Plants

Plant genetic engineering\nmethods are critical for food\nsecurity\nand biofuel production and to enable molecular farming. Here, we elucidated\nhow polymeric high aspect ratio nanocarriers can enable DNA delivery\nto <i>Nicotiana benthamiana</i> plants and transient expression.\nWe demonstrated that a nanocarrier with 20 nm width, 80 nm length,\nand a polymer-to-DNA ratio of N/P = 3.0 afforded the most efficient\nDNA delivery and expression among the parameter space investigated.\nAdditionally, we showed that polymer–DNA complexes with a moderate\npositive charge of ∼14 mV favored penetration through the cell\nwall and membranes with the assistance of cell wall degrading enzymes.\nTogether, these results establish a narrow window of aspect ratios\nand charges of the nanocarrier–DNA complex that enables DNA\ndelivery to plants using polymeric nanocarriers. This fundamental\nnanocarrier structure–function relationship informs the design\nof soft-material nanocarriers for nucleic acid delivery in plant cells\nto facilitate a wide range of plant biotechnology applications.