ABSTRACT
Rapid progress in functional genomics analysis, biotechnology, and bio-organic chemistry in recent years has led to potential new drug classes. They include peptides, monoclonal antibodies (or antibody fragments), antisense oligonucleotides, ribozymes, catalytic DNA fragments, decoy DNA, interfering double-stranded RNA (RNAi), aptamers, and, of course, recombinant proteins and plasmid DNA (Lebleu
and references therein). Delivering these relatively large molecular weight and usually hydrophilic “informational” molecules at their most appropriate site, e.g., in the right intracellular compartment of the targeted tissue, is a formidable challenge that is still far from being met satisfactorily. Expression from recombinant viral vectors has been developed for the
in situ
production of recombinant proteins, ribozymes, or antisense RNAs. This strategy cannot be easily applied to all cases mentioned previously and has its own limitations in terms of efficiency, safety, or tissue targeting. Numerous nonviral delivery vectors have been engineered in order to bypass biological barriers; most of them are still at an early stage of development and generally suffer from poor efficiency compared to viral vectors.
