Functional DNA-Containing Nanomaterials: Cellular Applications in Biosensing, Imaging, and Targeted Therapy

Abstract

ConspectusDNA performs a vital function as a carrier of genetic code, but in the field of nanotechnology, DNA molecules can catalyze chemical reactions in the cell, that is, DNAzymes, or bind with target-specific ligands, that is, aptamers. These functional DNAs with different modifications have been developed for sensing, imaging, and therapeutic systems. Thus, functional DNAs hold great promise for future applications in nanotechnology and bioanalysis. However, these functional DNAs face challenges, especially in the field of biomedicine. For example, functional DNAs typically require the use of cationic transfection reagents to realize cellular uptake. Such reagents enter the cells, increasing the difficulty of performing bioassays in vivo and potentially damaging the cell’s nucleus. To address this obstacle, nanomaterials, such as metallic, carbon, silica, or magnetic materials, have been utilized as DNA carriers or assistants. In this Account, we describe selected examples of functional DNA-containing nanomaterials and their applications from our recent research and those of others. As models, we have chosen to highlight DNA/nanomaterial complexes consisting of gold nanoparticles, graphene oxides, and aptamer–micelles, and we illustrate the potential of such complexes in biosensing, imaging, and medical diagnostics.Under proper conditions, multiple ligand–receptor interactions, decreased steric hindrance, and increased surface roughness can be achieved from a high density of DNA that is bound to the surface of nanomaterials, resulting in a higher affinity for complementary DNA and other targets. In addition, this high density of DNA causes a high local salt concentration and negative charge density, which can prevent DNA degradation. For example, DNAzymes assembled on gold nanoparticles can effectively catalyze chemical reactions even in living cells. And it has been confirmed that DNA–nanomaterial complexes can enter cells more easily than free single-stranded DNA.Nanomaterials can be designed and synthesized in needed sizes and shapes, and they possess unique chemical and physical properties, which make them useful as DNA carriers or assistants, excellent signal reporters, transducers, and amplifiers. When nanomaterials are combined with functional DNAs to create novel assay platforms, highly sensitive biosensing and high-resolution imaging result. For example, gold nanoparticles and graphene oxides can quench fluorescence efficiently to achieve low background and effectively increase the signal-to-background ratio. Meanwhile, gold nanoparticles themselves can be colorimetric reporters because of their different optical absorptions between monodispersion and aggregation.DNA self-assembled nanomaterials contain several properties of both DNA and nanomaterials. Compared with DNA–nanomaterial complexes, DNA self-assembled nanomaterials more closely resemble living beings, and therefore they have lower cytotoxicity at high concentrations. Functional DNA self-assemblies also have high density of DNA for multiva...

Chemistry Can Make Strict and Fuzzy Controls for Bio-Systems: DNA Nanoarchitectonics and Cell-Macromolecular Nanoarchitectonics

“…However, both of these factors have been, at least partially, solved by attaching aptamers to nanomaterials such as gold particles and graphene oxide, or assembling many aptamer molecules to micelles. 337 In order to distinguish cell types still more precisely, a system to analyze multiple markers on the cells (rather than one marker on the cells) is attractive. 356 "Nano-Claw" involving multiple recognition site was prepared from DNA aptamers, and autonomous logic-based diagnosis was accomplished using multiple markers on the cancer cell surface.…”

Applications of gold nanoparticles in medicine and therapy

“…136 Biological imaging with simultaneous diagnosis and therapy will provide the multimodality needed for accurate targeted therapy. 137 AuNMs have been considered as one of the best contrast agents for disease diagnosis, and functionalization of AuNMs becomes essential for application of AuNMs in computed tomography (CT), X-ray and SERS imaging.…”

Luminescent gold nanoclusters as biocompatible probes for optical imaging and theranostics

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] Nevertheless, recent concerns about potential toxicity of, at least, some categories of nanomaterials, accelerated the research for highly biocompatible nanostructures. [14][15][16][17][18] According to recent literature, gold nanoclusters are good candidate to combine low toxicity [19,20] and interesting optical and electronic properties, [21] which make them useful in several fields as sensing, optoelectronic, energy storing and catalysis.…”