Truncated tetrahedral RNA nanostructures act as improved scaffolds for delivery of RNAi-based therapeutics

Authors

• P Zakrevsky
• WK Kasprzak
• WF Heinz
• N Dorjsuren
• EA Fields
• L Jaeger
• BA Shapiro

Abstract

Ribonucleic acid (RNA) has emerged as a preferred material for development of nano-scale constructs intended for biological application. Utilizing Watson-Crick base pairing and natural structural motifs, RNA nanoparticles (RNA NPs) can be constructed with exceptional control over their size, geometry and method of assembly. These RNA NPs can be used as a core scaffold to provide spatial and stoichiometric control of functional RNA moieties, such as siRNAs. Here we attempt to improve the RNAi potency of such systems by developing a scaffold with increased functional RNA capacity. Using our previously characterized hexameric RNA nanoring and additional structural motifs as modular building blocks, we have constructed a novel truncated-tetrahedron shaped RNA NP that is able to harbor twelve function moieties. Transfection experiments comparing the efficacy of Dicer substrate siRNA (DsiRNA) bearing tetrahedral NPs to other functionalized RNA NPs reveal tetrahedral NPs targeting the expression of eGFP induce greater silencing than other RNA NPs in cultured breast cancer cells expressing eGFP. This increase in silencing also translates into increased therapeutic efficacy, as transfection of tetrahedral NPs targeting polo like kinase 1 resulted in a greater reduction of cell viability than the use of other functionalized RNA scaffolds. Interestingly, the physical characteristics of the tetrahedral scaffold appear to play a significant role in its increased RNAi efficacy as fluorescently labeled tetrahedral NPs are more efficiently taken up by cells than other RNA NPs examined. Taken together with the tetrahedral scaffold’s increased functional capacity, our truncated tetrahedron NP exhibits great promise for therapeutic application.

Scientific Focus Area: Biomedical Engineering and Biophysics

This page was last updated on Friday, March 26, 2021