ABSTRACT
Delivery of informational molecules encompasses DNA and short-single strand oligonucleotides and to a smaller extent also RNA and ribozymes. In contrast to DNA therapeutics which turn genes on, some technologies can stop the expression of particular genes. Protein synthesis requires transcription from DNA into mRNA and its translation into a protein. Selective inhibition of transcription and translation can be achieved by binding of appropriate single-strand nucleotides to specific regions of the DNA or mRNA. The former seems to be advantageous because it represents the very first step in protein synthesis. In general, however, the chemical modifications of the backbone decrease affinity and specificity. While in some cases these molecules were shown to be toxic, the majority of studies show that toxic levels exceed therapeutic ones. Chemical modifications aimed at improved affinity and specificity have been performed also on the sugar group.
