Surface-mediated delivery of DNA: Cationic polymers take charge

The last several years have seen a significant increase in the number of reports describing the use of cationic polymers to design new materials and nanoscale assemblies that promote the surface-mediated delivery of DNA to cells and tissues. In general, these approaches fall into one of two broad categories: (i) methods based upon the physical adsorption of pre-formed, colloidal aggregates of cationic polymer and DNA (polyplexes) to surfaces, and (ii) methods for the layer-by-layer adsorption of DNA and cationic polymers on surfaces to fabricate multilayered thin films that provide control over the release of DNA into solution or to cells. In this Opinion, we discuss several recent examples of each of these approaches and provide commentary on ways in which the physical and chemical behaviours of cationic polymers have played key roles and present future opportunities to develop new methods for localized and surface-mediated cell transfection in vitro and in vivo. (C) 2008 Elsevier Ltd. All rights reserved.