Functional DNA Nanostructures for Theranostic Applications

Abstract

There has been tremendous interest in constructing nanostructures by exploiting the unparalleled ability of DNA molecules in self-assembly. We have seen the appearance of many fantastic, "art-like" DNA nanostructures in one, two, or three dimensions during the last two decades. More recently, much attention has been directed to the use of these elegant nanoobjects for applications in a wide range of areas. Among them, diagnosis and therapy (i.e., theranostics) are of particular interest given the biological nature of DNA. One of the major barricades for the biosensor design lies in the restricted target accessibility at the solid-water interface. DNA nanotechnology provides a convenient approach to well control the biomolecule-confined surface to increase the ability of molecular recognition at the biosensing interface. For example, tetrahedral DNA nanostructures with thiol modifications can be self-assembled at the gold surface with high reproducibility. Since DNA tetrahedra are highly rigid and well-defined structures with atomic precision and versatile functionality, they provide scaffolds for anchoring of a variety of biomolecular probes (DNA, aptamers, peptides, and proteins) for biosensing. Significantly, this DNA nanostructure-based biosensing platform greatly increases target accessibility and improves the sensitivity for various types of molecular targets (DNA, RNA, proteins, and small molecules) by several orders of magnitude. In an alternative approach, DNA nanostructures provide a framework for the development of dynamic nanosensors that can function inside the cell. DNA tetrahedra are found to be facilely cell permeable and can sense and image specific molecules in cells. More importantly, these DNA nanostructures can be efficient drug delivery nanocarriers. Since they are DNA molecules by themselves, they have shown excellent cellular biocompatibility with minimal cytotoxicity. As an example, DNA tetrahedra tailored with CpG oligonucleotide drugs have shown greatly improved immunostimulatory effects that makes them a highly promising nanomedicine. By taking them together, we believe these functionalized DNA nanostructures can be a type of intelligent theranostic nanodevice for simultaneous sensing, diagnosis, and therapy inside the cell.

Fluorescent nanoprobes for sensing and imaging of metal ions: Recent advances and future perspectives

“…GO is an extraordinary optical sensing material that can serve either as an energy acceptor or as an energy donor for a fluorophore. Functional DNAs [272-275], such as aptamers [276], have been used as metal-ion specific receptors for sensitive and selective metal ion detection [277,278]. For instance, the Ye group [279] has developed a ssDNA–GO architecture probe for multiplex detection of sequence-specific DNA, thrombin, Ag + , Hg 2+ and cysteine, with a LOD of 1 nM, 5 nM, 20 nM, 5.7 nM and 60 nM, respectively (Figure 18C).…”

Design and Fabrication of Plasmonic Nanostructures with DNA for Surface‐Enhanced Raman Spectroscopy Applications

“…Recently, DNA has emerged as a powerful nanoscale building block for the construction of complex and hierarchical plasmonic nanostructures in a highly controllable and programmable manner, [23][24][25] owing to the high specificity of Watson-Crick base-pairing. DNA is comprised of four bases with A-T and G-C pairings, hence providing a precise means of programing DNA hybridization processes via a rational design of the sequence.…”

Bio-surface engineering with DNA scaffolds for theranostic applications

“…Given the biological nature of DNA nanostructures, they have shown good cellular biocompatibility with minimal cytotoxicity. Therefore, DNA nanostructures have attracted much interest in theranostic applications [21]. In this review, we summarize recent progress in the development of DNA nanostructures in one, two and three dimensions, with a highlight on their biological applications, particularly diagnostics and therapeutics.…”