DNA-Driven Nanoparticle Assemblies for Biosensing and Bioimaging

DNA-Driven Dynamic Assembly/Disassembly of Inorganic Nanocrystals for Biomedical Imaging

DNA-mediated programming is emerging as an effective technology that enables controlled dynamic assembly/disassembly of inorganic nanocrystals (NC) with precise numbers and spatial locations for biomedical imaging applications. In this review, we will begin with a brief overview of the rules of NC dynamic assembly driven by DNA ligands, and the research progress on the relationship between NC assembly modes and their biomedical imaging performance. Then, we will give examples on how the driven program is designed by different interactions through the configuration switching of DNA-NC conjugates for biomedical applications. Finally, we will conclude with the current challenges and future perspectives of this emerging field. Hopefully, this review will deepen our knowledge on the DNA-guided precise assembly of NCs, which may further inspire the future development of smart chemical imaging devices and high-performance biomedical imaging probes.

Adsorption of BSA Protein in Aqueous Medium Using Vegetable Tannin Resin from Acacia mearnsii (Mimosa) and Modified Lignocellulosic Fibers from the Bark of Eucalyptus citriodora

Proteins are abundant biomolecules found in human cells, as well as pathogenic bacteria and viruses. Some of them become pollutants when released into water. Adsorption is an advantageous method for separating proteins in aqueous media since proteins are already immobilized on solid surfaces. Adsorbents with surfaces rich in tannins are efficient due to their affinity for strong interactions with the various amino acids that make up proteins. This work aimed to develop an adsorbent for protein adsorption in aqueous medium using lignocellulosic materials modified from eucalyptus bark and vegetable tannins. A more efficient resin was prepared containing 10% eucalyptus bark fibers and 90% tannin mimosa by condensation with formaldehyde, and it was characterized by UV-Vis, FTIR-ATR spectroscopy and determinations of degree of swelling, bulk and bulk density and specific mass. For UV-Vis spectroscopy the percentage of condensed and hydrolysable tannins in the extracts of fibers of the dry husks of Eucalyptus Citriodora was estimated and it was also determined your soluble solids. The study of bovine serum albumin (BSA) adsorption was carried out in batch with quantification by UV-Vis spectroscopy. The most efficient prepared resin obtained 71.6 ± 2.78% removal in a solution of 260 mg L-1 of BSA working in a better pH range of the aqueous solution of BSA in its isoelectric point, ~ 5, 32 ± 0.02, under these conditions, the synthesized resin can reach a maximum BSA adsorption capacity of ~ 26.7 ± 0.29 mg g-1 in 7 min. The new synthesized resin presents good prospects for adsorption of proteins or species that in their structure have higher percentages of amino functional groups or amino acids with aliphatic, acidic and/or basic hydrophilic characteristics.

Graphical Abstract

Hybridization-Driven Adsorption of Polyadenine DNA onto Gold Nanoparticles

The attachment of functional DNA to gold nanoparticles via polyadenine adsorption is a well-established technology. This approach was mainly viewed through the lens of changing the DNA charge in order to reduce the electrostatic barrier created by a similarly charged gold surface. However, altering the DNA charge results in the loss of its functionality. This work considers the adsorption process of polyadenines by force that artificially brings them closer to the surface. As a force source, we used the hybridization of a DNA strand carrying polyadenines with a complementary strand already attached to the surface. It was shown that the hybridization forces facilitated the adsorption of polyadenines. We believe that this approach is applicable in various areas where it is essential to preserve the functionality of DNA during conjugation with nanoparticles.

Special Issue: Ceramic and Metallic Biomaterials Nanoparticles for Applications in Medical Sciences

Nowadays, the development of new materials that can be used to treat, repair, diagnose, replace, or restore a function of the human body represents one of the key research topics for the worldwide scientists and medical industries [...]

Engineering Inorganic Materials with DNA Nanostructures

Nucleic acid nanotechnology lays a foundation for the user-friendly design and synthesis of DNA frameworks of any desirable shape with extreme accuracy and addressability. Undoubtedly, such features make these structures ideal modules for positioning and organizing molecules and molecular components into complex assemblies. One of the emerging concepts in the field is to create inorganic and hybrid materials through programmable DNA templates. Here, we discuss the challenges and perspectives of such DNA nanostructure-driven materials science engineering and provide insights into the subject by introducing various DNA-based fabrication techniques including metallization, mineralization, lithography, casting, and hierarchical self-assembly of metal nanoparticles.

Chemically modified nucleic acids and DNA intercalators as tools for nanoparticle assembly

The self-assembly of inorganic nanoparticles to larger structures is of great research interest as it allows the fabrication of novel materials with collective properties correlated to the nanoparticles' individual characteristics. Recently developed methods for controlling nanoparticle organisation have enabled the fabrication of a range of new materials. Amongst these, the assembly of nanoparticles using DNA has attracted significant attention due to the highly selective recognition between complementary DNA strands, DNA nanostructure versatility, and ease of DNA chemical modification. In this review we discuss the application of various chemical DNA modifications and molecular intercalators as tools for the manipulation of DNA-nanoparticle structures. In detail, we discuss how DNA modifications and small molecule intercalators have been employed in the chemical and photochemical DNA ligation in nanostructures; DNA rotaxanes and catenanes associated with reconfigurable nanoparticle assemblies; and DNA backbone modifications including locked nucleic acids, peptide nucleic acids and borane nucleic acids, which affect the stability of nanostructures in complex environments. We conclude by highlighting the importance of maximising the synergy between the communities of DNA chemistry and nanoparticle self-assembly with the aim to enrich the library of tools available for the manipulation of nanostructures.

Rolling Circle Amplification as an Efficient Analytical Tool for Rapid Detection of Contaminants in Aqueous Environments

Environmental contaminants are a global concern, and an effective strategy for remediation is to develop a rapid, on-site, and affordable monitoring method. However, this remains challenging, especially with regard to the detection of various contaminants in complex water environments. The application of molecular methods has recently attracted increasing attention; for example, rolling circle amplification (RCA) is an isothermal enzymatic process in which a short nucleic acid primer is amplified to form a long single-stranded nucleic acid using a circular template and special nucleic acid polymerases. Furthermore, this approach can be further engineered into a device for point-of-need monitoring of environmental pollutants. In this paper, we describe the fundamental principles of RCA and the advantages and disadvantages of RCA assays. Then, we discuss the recently developed RCA-based tools for environmental analysis to determine various targets, including heavy metals, organic small molecules, nucleic acids, peptides, proteins, and even microorganisms in aqueous environments. Finally, we summarize the challenges and outline strategies for the advancement of this technique for application in contaminant monitoring.

Toehold-Mediated Selective Assembly of Compact Discrete DNA Nanostructures

Production of small discrete DNA nanostructures containing covalent junctions requires reliable methods for the synthesis and assembly of branched oligodeoxynucleotide (ODN) conjugates. This study reports an approach for self-assembly of hard-to-obtain primitive discrete DNA nanostructures-"nanoethylenes", dimers formed by double-stranded oligonucleotides using V-shaped furcate blocks. We scaled up the synthesis of V-shaped oligonucleotide conjugates using pentaerythritol-based diazide and alkyne-modified oligonucleotides using copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) and optimized the conditions for "nanoethylene" formation. Next, we designed nanoethylene-based "nanomonomers" containing pendant adapters. They demonstrated smooth and high-yield spontaneous conversion into the smallest cyclic product, DNA tetragon aka "nano-methylcyclobutane". Formation of DNA nanostructures was confirmed using native polyacrylamide gel electrophoresis (PAGE) and atomic force microscopy (AFM) and additionally studied by molecular modeling. The proposed facile approach to discrete DNA nanostructures using precise adapter-directed association expands the toolkit for the realm of DNA origami.