Advances in targeted gene delivery

Gene therapy has the potential to treat both acquired and inherited genetic diseases. Generally, two types of gene delivery vectors are used - viral vectors and non-viral vectors. Non-viral gene delivery systems have attracted significant interest due to their lower toxicity, lack of immunogenicity and ease of production compared to viral vectors. To achieve the goal of maximal therapeutic efficacy with minimal adverse effects, the cell-specific targeting of non-viral gene delivery systems has attracted research interest. Targeting through cell surface receptors; the enhanced permeability and retention effect, or pH differences are potential means to target genes to specific organs, tissues, or cells. As targeting moieties, receptor specific ligand peptides, antibodies, aptamers and affibodies have been incorporated into synthetic non-viral gene delivery vectors to fulfil the requirement of active targeting. This review provides an overview of different potential targets and targeting moieties for target specific gene delivery systems