Self-assembling complexes for in vivo gene delivery.

Non-viral DNA-containing particles represent a potentially attractive alternative to viruses for in vivo gene therapy applications. However, the inability to form small particles that remain stable and non-aggregating in vivo has limited their usefulness to date. The relatively simple self-assembling complexes that function so efficiently for in vitro gene delivery fail to provide similar gene delivery capabilities in vivo. Now for the first time, significant advances are being made into defining many of the in vivo barriers preventing stable particle formation. This improved understanding has been manifested into a rational design approach to DNA particle formation. This review highlights many of the recent studies in which rational design was employed in an effort to form polymer/DNA particles (polyplexes) that resist in vivo aggregation and inactivation.