Delivery Systems for RNA Interference Therapy: Current Technologies and Limitations

In recent years, RNA interference technology has been extensively studied for its therapeutic potential against a wide variety of diseases. It aims to silence the expression of undesired genes associated with the target disease by the administration of RNA interference agents. However, these agents (nucleic acids) are unstable in the circulatory system and lack target specificity. Drug delivery systems are, therefore, crucial for the successful practice of the technique. A wide array of delivery systems has been developed to conquer these challenges, such as viral vectors, inorganic drug carriers, polymeric carriers and lipid-based carriers, with, however, significant limitations. In addition to the existing technologies, novel, innovative drug delivery systems, such as the configurable xenobot, are emerging at a rapid pace and have the potential to take the realm of biomedicine to the next level. This review summarizes technical difficulties in the development of drug delivery systems and current technologies developed for delivering RNAi agents with a discussion on their limitations.