Receptor-Mediated Entry of Pristine Octahedral DNA Nanocages in Mammalian Cells

Abstract

DNA offers excellent programming properties for the generation of nanometer-scaled polyhedral structures with a broad variety of potential applications. Translation to biomedical applications requires improving stability in biological fluids, efficient and selective cell binding, and/or internalization of the assembled DNA nanostructures. Here, we report an investigation on the selective mechanism of cellular uptake of pristine DNA nanocages in cells expressing the receptor "oxidized low-density lipoprotein receptor-1" (LOX-1), a scavenger receptor associated with cardiovascular diseases and, more recently, identified as a tumor marker. For this purpose a truncated octahedral DNA nanocage functionalized with a single biotin molecule, which allows DNA cage detection through the biotin-streptavidin assays, was constructed. The results indicate that DNA nanocages are stable in biological fluids, including human serum, and are selectively bound and very efficiently internalized in vesicles only in LOX-1-expressing cells. The amount of internalized cages is 30 times higher in LOX-1-expressing cells than in normal fibroblasts, indicating that the receptor-mediated uptake of pristine DNA nanocages can be pursued for a selective cellular internalization. These results open the route for a therapeutic use of pristine DNA cages targeting LOX-1-overexpressing tumor cells.

Progress toward Understanding the Interactions between DNA Nanostructures and the Cell

“…The authors showed that folate‐modified nanocages enter HeLa cells 40 times more than αFR‐negative A431 epidermal cancer cells, pointing to their specificity to αFR‐expressing cells after 24 h of incubation. In general, such specificity depends not only on the expression of αFR and but also on the expression of the receptor responsible for internalizing pristine nanocages, low‐density lipoprotein receptor (LOX‐1; see Section for the mechanistic details). Raniolo et al further compared the uptake of folate‐modified octahedral nanocages by HeLa cells, A431 cells, COS kidney fibroblasts, and COS cells that are engineered to overexpress LOX‐1 .…”

“…By performing molecular simulations, the authors showed that the TDNs approach the cell membrane with their corners to minimize electrostatic repulsion. In 2016, Vindigni et al studied the mechanism for the cellular uptake of DNA octahedral nano‐cages of ≈11 nm in diameter . The authors transfected COS fibroblasts with DNA plasmids that encode LOX‐1 for generating LOX‐1‐expressing COS cells.…”

“…ii) Densitometric analysis shows higher amounts of nanocages in LOX‐1 expressing COS cells than nontransfected COS cells at 4 and 37 °C, indicating selective uptake of nanocages by LOX‐1. Reproduced with permission . Copyright 2016, American Chemical Society.…”

“…In 2016, Vindigni et al assessed the route of trafficking for DNA octahedral nanocages inside COS fibroblasts . After 2 h of incubation, the authors performed immunofluorescence and detected minor accumulation of nanocages inside the lysosomes (with a Pearson coefficient of 0.37).…”

Self‐Assembly of Functional Discrete Three‐Dimensional Architectures in Water

“…Receptor-mediated uptake of ab iotin-functionalised octahedral DNAc age has also been reported by Desideri, Biocca and co-workers. [147] This octahedral construct is taken up preferentially by the oxidised low density lipoprotein receptor-1 (LOX-1) which is atumour and cardiovascular disease marker.…”