Oligonucleotide therapeutics are nucleic acid polymers generally comprised of a few to several dozen bases (including modified bases) linked together. They are produced by chemical synthesis and act directly on organisms without being translated into proteins. Oligonucleotide therapeutics are characterized by the ability to target specific diseases. Another advantage is that it takes less time than conventional methods to find new therapeutic candidates because oligonucleotides are easy to design and synthesize.
However, it is a practical problem that oligonucleotide therapeutics are degraded and excreted rapidly after administration by exonucleases and endonucleases that are abundant in blood and cells. This problem is being addressed by the introduction of modified oligonucleotides to improve chemical stability in vivo and by the development of lesion-targeted DDS (drug delivery systems) technologies.