Size controllable DNA nanogels from the self-assembly of DNA nanostructures through multivalent host-guest interactions.

Nanogels made of biomolecules are one of the potential candidates as a nanocarrier for drug delivery applications. The unique structural characteristics and excellent biocompatibility of DNA suggest that DNA nanogels would be an ideal candidate. Herein, a general design strategy for the crafting of DNA nanogels with controllable size using the multivalent host-guest interaction between ß-CD functionalized branched DNA nanostructures as the host and a star-shaped adamantyl-terminated 8-arm poly(ethylene glycol) polymer as the guest is reported. Our results reveal that multivalent host-guest interactions are necessary for the nanogel formation. Nanogels exhibit excellent biocompatibility, good cell permeability and high drug encapsulation ability, which are promising features for their application as a drug carrier. The encapsulation of doxorubicin, an anticancer drug, inside the hydrophobic network of the nanogel and its delivery into cancer cells are also reported. We hope that the general design strategy demonstrated for the creation of DNA nanogels may encourage other researchers to use this approach for the design of DNA nanogels of other DNA nanostructures, and explore the potential of DNA nanogels in drug delivery applications.