Abstract
Nucleic acids hold promise as tools for engineering the immune system. However, for use in patients, their delivery must be improved to overcome challenges in specificity and intracellular delivery efficiency. Polymers, both natural and synthetic, are under investigation as nucleic acid delivery vehicles, and their chemical and physical properties are being engineered to enhance their efficacy. Through formulation with polymers, DNA, mRNA, siRNA, and other nucleic acids can serve as prophylactic or therapeutic vaccines by overexpressing or knocking down expression of genes that affect the immune response. Polymeric delivery is also useful for the transport of intrinsically immunostimulatory nucleic acids to specific compartments of cells. Recent innovative examples of polymer-based nucleic acid vaccines and immunomodulatory strategies will be discussed.