Multifunctional Cationic Lipid-Based Nanoparticles Facilitate Endosomal Escape and Reduction-Triggered Cytosolic siRNA Release

Abstract

Small interfering RNA (siRNA) has garnered much attention in recent years as a promising avenue for cancer gene therapy due to its ability to silence disease-related genes. Effective gene silencing is contingent upon the delivery of siRNA into the cytosol of target cells and requires the implementation of delivery systems possessing multiple functionalities to overcome delivery barriers. The present work explores the multifunctional properties and biological activity of a recently developed cationic lipid carrier, (1-aminoethyl)iminobis[N-(oleicylcysteinyl-1-amino-ethyl)propionamide]) (ECO). The physicochemical properties and biological activity of ECO/siRNA nanoparticles were assessed over a range of N/P ratios to optimize the formulation. Potent and sustained luciferase silencing in a U87 glioblastoma cell line was observed, even in the presence of serum proteins. ECO/siRNA nanoparticles exhibited pH-dependent membrane disruption at pH levels corresponding to various stages of the intracellular trafficking pathway. It was found that disulfide linkages created during nanoparticle formation enhanced the protection of siRNA from degradation and facilitated site-specific siRNA release in the cytosol by glutathione-mediated reduction. Confocal microscopy confirmed that ECO/siRNA nanoparticles readily escaped from late endosomes prior to cytosolic release of the siRNA cargo. These results demonstrate that the rationally designed multifunctionality of ECO/siRNA nanoparticles is critical for intracellular siRNA delivery and the continuing development of safe and effective delivery systems.

Self-assembled triangular DNA nanoparticles are an efficient system for gene delivery

“…Therefore, the following important improvement for this nano-platform is to allow the endosomes to open and release more its cargo into cytoplasm. Previous studies have revealed that modified lipid polymers could enhance the osmolysis of endosomes, such as polyxylitol-based gene carrier XGC [52], distearoyl phosphoethanolamine-polycarboxybetaine (DSPE-PCB) [53], and cationic lipid carrier ECO [54]. To further improve the siRNA delivery capability with this design requirement taken into consideration, we could develop a composite nanocarrier through modified lipid polymers based on our ssRNA-TNP nanosystem.…”

Enhanced antitumor efficacies of multifunctional nanocomplexes through knocking down the barriers for siRNA delivery

“…In recent years, several novel systems have been designed to conquer multiple barriers for siRNA delivery [22,23]. In spite of the notable improvement attained, none of them fully covered the essential benefits required in extracellular, cellular, and intracellular delivery, which largely limits the clinical application.…”

“…In spite of the notable improvement attained, none of them fully covered the essential benefits required in extracellular, cellular, and intracellular delivery, which largely limits the clinical application. Cationic lipid-based nanoparticles prepared by Gujrati et al [22] have demonstrated desired endosomal escape and reductiontriggered release, but their lack of tumor-targeting capability has limited the in vivo application. The dynamic polyconjugates developed by Rozema et al [23] have successfully combined the functions of passive targeting, active targeting, endosomal escape, and glutathione-sensitive release.…”

Multiplexed Nanomedicine for Brain Tumors: Nanosized Hercules to Tame Our Lernaean Hydra inside?

“…The formulation of nano vehicles for RNAi is critical for the clinical success. Early efforts focused on dendrimer inspired nano constructs and solid nanoparticles (NPs), followed by the biomimetic development of tumor derived exosome-based experimental therapeutics for brain delivery [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. The engineering potential of cell type selectivity for these vehicles is limited.…”

“…Multi-targeting capacity is vital for nanoRNAi formulations against patient specific GBM The evolution of nano carriers for siRNAs started with single core solid nano constructs based on classic materials such as gold [24], iron oxide, chitosan [5,17], porous silica [8], sugar [15], solid lipids [3,4,6,9] and an array of dendrimer inspired NPs [12]. Some of these applications showed early promise in effective RNAi of key GBM growth-promoting genes: Jensen et al demonstrated that gold NP mediated siRNA knockdown of the oncoprotein Bcl2Like12 (Bcl2L12) reduced tumor growth [24]; Costa et al demonstrated effective GBM inhibition using anti-miR-21 oligonucleotides, a different approach for tumor promoting miR-21 silencing [4];…”