Delivery of RNAi Therapeutics to the Airways—From Bench to Bedside

Qiu, Yingshan; Lam, Jenny K. W.; Leung, Susan W. S.; Liang, Wanling

The viral vectors refer to the of use of viruses to deliver genetic materials to the cells. They are extremely efficient in transducing cells and providing either transient or long-term gene expression, depending on the type of viruses employed. Most of the in vivo studies used the adenoviruses, adeno-associated virus (AAV) and retroviruses to express the plasmid DNA encoding shRNA or miRNA to induce RNAi [68] . The most attractive property of viral vectors is that they have the ability to access the nucleus of the cells. Thus, they have high efficacy to express the RNA and subsequently regulate the gene expression [69] [70] [71] [72] . However, the clinical application of viral vectors is limited by the toxicity, insertional mutagenesis (associated with retroviruses) and immunogenicity (associated with adenoviruses) [63] . In addition, the smaller size of AVV limits the amount of therapeutic gene that can be inserted.