Core-Shell Dendriplexes with Sterically Induced Stoichiometry for Gene Delivery

The development of dendriplexes as nanoarchitectures with sterically induced stoichiometry for gene delivery applications is described. The ability of four generations of amino-functionalized gallic acid-triethylene glycol (GATG) dendrons and PEG-dendritic block copolymers to efficiently condense pDNA was evaluated. A characteristic nitrogen to phosphate ratio (N/P) for complete pDNA condensation was revealed for each dendrimer. Larger N/P ratios had little effect on the size and xi potential of the dendriplexes. Dendriplexes are envisioned as core-shell nanostructures, where the relative size between the condensed pDNA at the core and the shell dendrimers limits the core-shell stoichiometry by steric reasons. By application of the Mansfield-Tomalia-Rakesh equation, a 3-fold reduction in the number of shell dendrimers has been estimated on increasing the dendrimer generation one unit. Overall, the dendritic architecture (generation and PEGylation) determines the properties of the dendriplexes, offering a great opportunity for fine-tuning the requirements for specific gene therapy applications.