Abstract
Recently there has been a surge in interest involving the application of oligonucleotides, including small interfering RNA (siRNA) and antisense oligonucleotides (ASOs), for the treatment of chronic diseases that have few available therapeutic options. This emerging class of drugs primarily operates by selectively suppressing target genes through antisense and/or RNA interference mechanisms. While various commercial medications exist for delivering oligonucleotides to the hepatic tissue, achieving effective delivery to extra hepatic tissues remains a formidable challenge. Here, we review recent advances in oligonucleotide technologies, including nanoparticle delivery, local administration, and 2'-O-hexadecyl (C16)-conjugation that work to extend the applicability of siRNAs and ASOs to nerve tissues. We discuss critical factors pivotal for the successful clinical translations of these modified or engineered oligonucleotides in the context of treating neurodegenerative diseases such as Alzheimer's disease and amyotrophic lateral sclerosis.