Table 1.

Properties of therapeutic nucleic acids.

Cargo	Properties	Target Site	Function and Mechanism
pDNA	Circular, large (5–15 kbp) double-stranded DNA	Nucleus	Encodes a cDNA expression cassette under the control of a strong promoter/enhancer unit
siRNA	Short noncoding double-stranded RNA with 21–25 bp sequence	Cytosol	RNAi; unwound into single-strand bound in RISC that recognizes the complementary mRNA sequence, resulting in mRNA cleavage.
miRNA	MicroRNA, short noncoding endogenous double-stranded RNA	Cytosol	Regulate gene expression post-transcriptionally by binding of mRNA and thus preventing translation of mRNA into protein
mRNA	Single stranded sequence transcribed from DNA	Cytosol	Translated into proteins in the cytoplasm
sgRNA	Noncoding short RNA sequence binding Cas9 protein	Nucleus	sgRNA guides the nuclease Cas9 to a selective target DNA sequence via complementary binding to make a DSB
ASO	Chemically stabilized short single-stranded antisense oligonucleotide	Cytosol/Nucleus	Bind to mRNA and prevent translation, or to induce exon skipping
PMO	Synthetic uncharged ASO, in which the ribosyl rings and phospodiesters in the backbone are replaced with methylenemorpholine rings and a phosphorodiamidate backbone, respectively.	Nucleus	Bind to pre-mRNA in the nucleus and alter gene splicing, resulting in the exclusion or inclusion of particular genetic fragments in the mature mRNA

pDNA: plasmid DNA; siRNA: small interfering RNA; miRNA: mRNA: messenger RNA; RISC: RNA-induced silencing complexes; sgRNA: single guide RNA; ASOs: antisense oligonucleotides; PMOs: phosphorodiamidate morpholino oligomers; DSB: double-strand break.