Advances in the Design of (Nano)Formulations for Delivery of Antisense Oligonucleotides and Small Interfering RNA: Focus on the Central Nervous System

RNA-based therapeutics have emerged as one of the most powerful therapeutic options used for the modulation of gene/protein expression and gene editing with the potential to treat neurodegenerative diseases. However, the delivery of nucleic acids to the central nervous system (CNS), in particular by the systemic route, remains a major hurdle. This review will focus on the strategies for systemic delivery of therapeutic nucleic acids designed to overcome these barriers. Pathways and mechanisms of transport across the blood-brain barrier which could be exploited for delivery are described, focusing in particular on smaller nucleic acids including antisense oligonucleotides (ASOs) and small interfering RNA (siRNA). Approaches used to enhance delivery including chemical modifications, nanocarrier systems, and target selection (cell-specific delivery) are critically analyzed. Learnings achieved from a comparison of the successes and failures reported for CNS delivery of ASOs versus siRNA will help identify opportunities for a wider range of nucleic acids and accelerate the clinical translation of these innovative therapies.

Automated summary

This review discusses the importance of RNA-based therapeutics in neurodegenerative diseases and strategies to overcome the challenges of delivering nucleic acids to the central nervous system. It analyzes the pathways and mechanisms of transport across the blood-brain barrier, as well as approaches like chemical modifications, nanocarrier systems, and target selection to enhance delivery. The comparison of success and failures in CNS delivery of ASOs versus siRNA will help accelerate the clinical translation of innovative therapies using a wider range of nucleic acids.