Tissue- and cell-specific targeting for the delivery of genetic information

Delivery of genetic information has been proposed to provide a plethora of novel therapeutic and prophylactic treatments. Although this field has made rather remarkable progress in the 50 years since the structure of DNA was initially reported,1 it is sobering to consider that gene therapy is far from a standard of medical practice.2 Ten years ago, experts in this field3 projected that gene therapy would become commonplace if three technical breakthroughs could be made: 1. Development of a gene transfer vector that could be taken off the shelf and used to target a desired tissue or cell type 2. Identification of methods to integrate delivered genetic material safely in a homologous recombinant fashion with the genetic target it is intended to replace or modulate 3. Introduction of genetic information where it would be responsive to appropriate physiological stimuli or signals Although progress has been made in all three of these areas, there are still more problems than solutions for each.