Effective Delivery Of Small Interfering RNA Research Articles

Non-Covalently Functionalized of Single-Walled Carbon Nanotubes by DSPE-PEG-PEI for SiRNA Delivery.

The expression of a gene can be specifically downregulated by small interfering RNA (SiRNA). Modified carbon nanotubes (CNT) can be used to protect SiRNA and facilitate its entry into cells. Regardless of that, simple and efficient functionalization of CNT is lacking. Effective SiRNA delivery can be carried out using non-covalently functionalized CNT, where non-covalent (versus covalent) functionalization is simpler and more expeditious. Non-covalently functionalized single walled carbon nanotubes (SWCNT) that include a lipopolymer are described here. Polyethylenimine (PEI) conjugated to 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (DSPE-PEG) was generated and the products used to disperse CNT to form DSPE-PEG-PEI/CNT (DGI/C), an agent capable of facilitating SiRNA delivery to cells in vitro and organs and cells in vivo.

Highly Efficient SiRNA Delivery Mediated by Cationic Helical Polypeptides and Polypeptide-Based Nanosystems.

RNA interference (RNAi) mediated by small interfering RNA (SiRNA) has recently emerged as a potent machinery in regulating gene expression at the post-translation step. Despite its efficiency and specificity, the biggest hurdle against its wide application is the safe and effective delivery of the SiRNA cargo into target cells. Here, we describe the highly effective SiRNA delivery mediated by the cationic helical polypeptides and polypeptide-based nanosystems both in vitro and in vivo via oral administration.

Effective small interfering RNA delivery in vitro via a new stearylated cationic peptide.

A crucial bottleneck in RNA interference-based gene therapy is the lack of safe and efficient delivery systems. Here, a novel small interfering RNA (siRNA) delivery peptide, STR-HK, was constructed by conjugating a stearyl end to the N-terminus of the peptide sequence HHHPKPKRKV, where PKPKRKV is an altered sequence of the nucleus localization signal (PKKKRKV) and contributes to the cytosol localization of STR-HK–siRNA complexes. Histidine is a linker and plays an important role in disrupting the endosomal membrane via the proton sponge effect. As expected, STR-HK formed complexes with siRNA with a particle size of 80–160 nm in diameter and efficiently delivered Cy3-labeled glyceraldehyde 3-phosphate dehydrogenase siRNA into PC-3 human prostate cancer cells. The transfection efficiency of STR-HK at molar ratio of 60/1 was comparable to that of Lipofectamine 2000, one of the most efficient commercially available transfection reagents. Furthermore, the STR-HK–siRNA complexes exhibited minimal cytotoxicity, which was significantly lower than that of Lipofectamine. Taken together, the strategy of conjugating the stearyl moiety with HHHPKPKRKV as a non-viral siRNA delivery system is advantageous.