结构DNA纳米技术应用新进展

DNA具有非凡的分子识别性能和显著的结构特征,这使得它在材料的纳米级调控方面具有独特的优越性,在许多领域也展现出广阔的应用前景。本文从模块化DNA自组装和DNA折纸术两个方面综述了近些年DNA纳米技术,包括近年来DNA纳米技术中比较新型的组装方法;并从DNA纳米结构作为模板定位纳米粒子和蛋白以及用于生物医药等方面介绍了DNA纳米技术的应用;同时,对DNA纳米技术发展及应用进行了展望。     

Benzene-1,3,5-tricarboxamide: a versatile ordering moiety for supramolecular chemistry

After their first synthesis in 1915 by Curtius, benzene-1,3,5-tricarboxamides (BTAs) have become increasingly important in a wide range of scientific disciplines. Their simple structure and wide accessibility in combination with a detailed understanding of their supramolecular self-assembly behaviour allow full utilization of this versatile, supramolecular building block in applications ranging from nanotechnology to polymer processing and biomedical applications. While the opportunities in the former cases are connected to the self-assembly of BTAs into one-dimensional, nanometer-sized rod like structures stabilised by threefold H-bonding, their multivalent nature drives applications in the biomedical field. This review summarises the different types of BTAs that appeared in the recent literature and the applications they have been evaluated in. Currently, the first commercial applications of BTAs are emerging. The adaptable nature of this multipurpose building block promises a bright future.     

Recent advances in short peptide self-assembly: from rational design to novel applications

Owing to their structural simplicity and robust self-assembled nanostructures, short peptides prove to be an ideal system to explore the physical processes of self-assembly, hydrogels, semi-flexible polymers, quenched disorder, and reptation. Rational design in peptide sequences facilitates cost-effective manufacturing, but the huge number of possible peptides has imposed obstacles for their characterization to establish functional connections to the primary, secondary, and tertiary structures. This review aims to cover recent advances in the self-assembly of designed short peptides, with a focus on physical driving forces, design rules, characterization methods, and exemplar applications. Super-resolution microscopy in combination with modern image analysis have been applied to quantify the structure and dynamics of peptide hydrogels, while small-angle neutron scattering and solid-state nuclear magnetic resonance continue to provide valuable information on structures over complementary length scales. Short peptides are attractive in biomedicine and nanotechnology, e.g., as antimicrobials, anticancer agents, vehicles for controlled drug release, peptide bioelectronics, and responsive cell culture materials.     

Supramolecular architectures generated by self-assembly of guanosine derivatives

Nature's use of a simple genetic code to enable life's complex functions is an inspiration for supramolecular chemistry. DNA nucleobases carry the key information utilizing a variety of cooperative and non-covalent interactions such as hydrophobic, van der Waals, pi-pi stacking, ion-dipole and hydrogen bonding. This tutorial review describes some recent advances in the form and function provided by self-assembly of guanine (G) based systems. We attempt to make connections between the structures of the assemblies and their properties. The review begins with a brief historical context of G self-assembly in water and then describes studies on lipophilic guanosine analogs in organic solvents. The article also focuses on examples of how G analogs have been used as building blocks for functional applications in supramolecular chemistry, material science and nanotechnology.     

DNA origami: a quantum leap for self-assembly of complex structures

The spatially controlled positioning of functional materials by self-assembly is one of the fundamental visions of nanotechnology. Major steps towards this goal have been achieved using DNA as a programmable building block. This tutorial review will focus on one of the most promising methods: DNA origami. The basic design principles, organization of a variety of functional materials and recent implementation of DNA robotics are discussed together with future challenges and opportunities.     

Stimuli-Responsive DNA Self-Assembly: From Principles to Applications

Stimuli-responsive DNA self-assembly shares the advantages of both designed stimuli-responsiveness and the molecular programmability of DNA structures, offering great opportunities for basic and applied research in dynamic DNA nanotechnology. In this minireview, we summarize the most recent progress in this rapidly developing field. The trigger mechanisms of the responsive DNA systems are first divided into six categories, which are then explained with illustrative examples following this classification. Subsequently, proof-of-concept applications in terms of biosensing, in vivo pH-mapping, drug delivery, and therapy are discussed. Finally, we provide some remarks on the challenges and opportunities of this highly promising research direction in DNA nanotechnology.     

由嵌段共聚物制备有形状的核壳结构聚合物纳米颗粒

嵌段共聚物可自发组装形成形貌丰富的纳米粒子和有序纳米结构的材料,为纳米材料和纳米技术领域提供了很重要的新材料和新手段.该领域的进一步发展提出了对嵌段共聚物的自组装体赋予功能性的要求,即需要通过可控聚合反应合成反应性嵌段共聚物,并且对其自组装的纳米粒子进行结构、形状及功能性的调控.本文针对以上研究目标,结合本课题组在该领...     

Liquid-crystal nanoscience: an emerging avenue of soft self-assembly

Liquid crystals are finding increasing applications in a wide variety of fields including liquid-crystal display technology, materials science, bioscience, etc., apart from acting as prototype self-organizable supramolecular soft materials and tunable solvents. Recently, keeping in pace with topical science, liquid crystals have entered into the fascinating domains of nanoscience and nanotechnology. This tutorial review describes the recent and significant developments in liquid-crystal nanoscience embracing contemporary nanomaterials such as nanoparticles, nanorods, nanotubes, nanoplatelets, etc. The dispersion of zero-, one- and two-dimensional nanomaterials in liquid crystals for the enhancement of properties, liquid-crystalline phase behavior of nanomaterials themselves, self-assembly and alignment of nanomaterials in liquid-crystalline media, and the synthesis of nanomaterials by using liquid crystals as 'templates' or 'precursors' have been highlighted and discussed. It is almost certain that the 'fourth state of matter' will play more prevalent roles in nanoscience and nanotechnology in the near future. Moreover, liquid-crystal nanoscience reflects itself as a beautiful demonstration of the contemporary theme "crossing the borders: science without boundaries".     

DNA constraints allow rational control of macromolecular conformation

We report that double-helical DNA constraints can be used to control the conformation of another molecule, RNA. When a covalently attached DNA constraint is structurally incompatible with the native Mg2+-dependent RNA conformation, RNA folding is disrupted, as revealed by nondenaturing gel electrophoresis and independently by chemical probing. Our approach is distinct from other efforts in DNA nanotechnology, which have prepared DNA objects by self-assembly, built static DNA lattices for assembly of other objects, and created nanomachines made solely of DNA. In contrast, our dynamic use of DNA to control the conformations of other macromolecules should have wide impact in nanotechnology applications ranging from materials science to biology.     

Recent advancements in DNA nanotechnology-enabled extracellular vesicles detection and diagnosis: A mini review

Extracellular vesicles (EVs) are cell-derived nanosized vesicles widely recognized for their critical roles in various pathophysiological processes. Molecular analysis of EVs is currently being considered an emerging tool for diseases diagnosis. However, the small size and heterogeneity of EVs has staggered the EVs research for diseases diagnosis. DNA nanotechnology enables self-assembly of versatile DNA nanostructures and has shown enormous potential in assisting EVs biosensing. In this review, we briefly introduce the recent advances in DNA nanotechnology approaches for EVs detection. The approaches were categorized based on the dimension of DNA nanostructures. We provide critical evaluation of these approaches, and summarize the pros and cons of specific methods. Further, we discuss the challenges and future perspectives in this field.     

Multisegmented one-dimensional nanorods prepared by hard-template synthetic methods

In the science and engineering communities, the nanoscience revolution is intensifying. As many types of nanomaterials are becoming more reliably synthesized, they are being used for novel applications in all branches of nanoscience and nanotechnology. Since it is sometimes desirable for single nanomaterials to perform multiple functions simultaneously, multicomponent nanomaterials, such as core-shell, alloyed, and striped nanoparticles, are being more extensively researched. Nanoscientists hope to design multicomponent nanostructures and exploit their inherent multiple functionalities for use in many novel applications. This review highlights recent advances in the synthesis of multisegmented one-dimensional nanorods and nanowires with metal, semiconductor, polymer, molecular, and even gapped components. It also discusses the applications of these multicomponent nanomaterials in magnetism, self-assembly, electronics, biology, catalysis, and optics. Particular emphasis is placed on the new materials and devices achievable using these multicomponent, rather than single-component, nanowire structures.     

反应性嵌段共聚物自组装制备无机纳米粒子研究进展

具有"核-壳"结构的嵌段共聚物胶束具有广泛的用途.本文介绍了反应性嵌段共聚物的自组装技术应用于制备具有独特的光、电、磁等以及催化特性的无机纳米粒子,特别是介绍了近年来在制备纳米贵金属粒子的研究进展.     

Noncovalent Helicene Structure between Nucleic Acids and Cyanuric Acid

Cyanuric acid (CA), a triazine heterocycle, is extensively utilized for noncovalent self-assembly. The association between poly(adenine) and CA into micron-length fibers was a remarkable observation made by Sleiman and co-workers, who proposed that adenine and CA adopt a hexameric rosette configuration in analogy with previously reported structures for CA assemblies. However, recent experimental observations from the Krishnamurthy group led to a reevaluation of the hexameric rosette model, wherein they have proposed a hydrogen-bonded helicene model as an alternative. Our molecular dynamics simulations show that the hexad model is indeed unlikely and that this novel noncovalent helicene geometry, where the adenine and CA bases form an extended helical hydrogen-bond network across the system, is a more probable structural motif. The existence of noncovalent helicene compounds may have wide-ranging applications in DNA nanotechnology and helicene chemistry.     

Pickering–Ramsden emulsions stabilized with chemically and morphologically anisotropic particles

Recent developments in nanotechnology have facilitated the use of surface-active colloidal particles with tailor-made anisotropic properties. These surface-active agents have introduced unprecedented emulsion systems that exhibit qualitatively different self-assembled/organized structures and material properties from those of emulsions with conventional surfactants or isotropic colloidal particles. The author highlights the recent experimental works that elucidate the fundamental roles of anisotropy in the self-assembly/organization in emulsions, while focusing predominantly on amphiphilicity and morphological anisotropy in a particle. The author also introduces recent works that harness these fundamental properties of anisotropy for realizing the characteristic emulsion state and its functionality, together with a work with large particles beyond colloidal scale.     

Constructing Large 2D Lattices Out of DNA-Tiles

The predictable nature of deoxyribonucleic acid (DNA) interactions enables assembly of DNA into almost any arbitrary shape with programmable features of nanometer precision. The recent progress of DNA nanotechnology has allowed production of an even wider gamut of possible shapes with high-yield and error-free assembly processes. Most of these structures are, however, limited in size to a nanometer scale. To overcome this limitation, a plethora of studies has been carried out to form larger structures using DNA assemblies as building blocks or tiles. Therefore, DNA tiles have become one of the most widely used building blocks for engineering large, intricate structures with nanometer precision. To create even larger assemblies with highly organized patterns, scientists have developed a variety of structural design principles and assembly methods. This review first summarizes currently available DNA tile toolboxes and the basic principles of lattice formation and hierarchical self-assembly using DNA tiles. Special emphasis is given to the forces involved in the assembly process in liquid-liquid and at solid-liquid interfaces, and how to master them to reach the optimum balance between the involved interactions for successful self-assembly. In addition, we focus on the recent approaches that have shown great potential for the controlled immobilization and positioning of DNA nanostructures on different surfaces. The ability to position DNA objects in a controllable manner on technologically relevant surfaces is one step forward towards the integration of DNA-based materials into nanoelectronic and sensor devices.     

Metal–DNA Coordination-Driven Self-Assembly: A Conceptual Methodology to Expand the Repertoire of DNA Nanobiotechnology

The past several decades have witnessed a rapid revolution of DNA nanotechnology. DNA nanostructures are mainly synthesized with two approaches, by assembly of purely DNA-based nanostructures through complementary base pairing or grafting DNA onto nanoparticles (NPs). Despite the progress made, developing simple and universal methods for the synthesis of DNA nanoarchitectures with specific morphologies and functionalities is still a challenge. This article introduces the reader to a new biomimetic methodology that leads to the controlled synthesis of DNA nanoarchitectures based on metal–DNA coordination chemistry and, furthermore, demonstrates the broad biomedical applications of these functional materials. In particular, we highlight the coordination-driven 1) surface-functionalization of NPs with DNA molecules and 2) direct self-assembly of metal–DNA nanostructures. Finally, challenges and opportunities of this approach to develop nanobiotechnology are provided.     

Precise and Controllable Assembly of Block Copolymers†

With the development of nanotechnology, the precise synthesis of nanoparticles with nicely-defined dimensions and structures has been well-developed, and the functionalization and subsequent applications of the resultant nanostructures are becoming increasingly important. Comparing to inorganic nanoparticles, the nanostructures based on soft matters, especially block copolymer assemblies, are much lower in cost, easier to fabricate and richer in morphology. However, the dimensional control over the block copolymer assemblies is not as easy. Only in recent decade, with the discovery of living Crystallization-Driven Self-Assembly (CDSA) by Manners and Winnik, researchers become able to precisely tune the sizes of block copolymer assemblies in a relatively wide range. This discovery has inspired tremendous research effort in the self-assembly field, and considerable progress has been made recently. This review summarizes the main progress in the precise and controllable self-assembly field in the past five years, and is mostly focused on four aspects, including in-depth understanding of the assembly methods, extension of this method to two-dimensional nanostructures, utilization of this method to fabricate hierarchical structures, and the potential applications of these well-defined nanostructures. We hope not only to make a periodic systematic summary of previous studies, but also to provide some useful thinking for the future development of this field.     

Characterization of 3D DNA Assemblies Using Cryogenic Electron Microscopy

DNA nanotechnology utilizes DNA double strands as building units for self-assembly of DNA nanostructures.The specific base-pairing interaction between DNA molecules is the basis of these assemblies.After decades of development,this technology has been able to construct complex and programmable structures.With the increase in delicate nature and complexity of the synthesized nanostructures,a characterization technology that can observe these structures in three dimensions has become necessary,and developing such a technology is considerably challenging.DNA assemblies have been studied using different characterization methods including atomic force microscopy(AFM),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).However,the three-dimensional(3D)DNA assemblies always collapse locally due to the dehydration during the drying process.Cryogenic electron microscopy(cryo-EM)can overcome the challenge by maintaining three-dimensional morphologies of the cryogenic samples and reconstruct the 3D models from cryogenic samples accordingly by collecting thousands of two-dimensional(2D)projection images,which can restore their original morphologies in solution.Here,we have reviewed several typical cases of 3D DNA-assemblies and highlighted the applications of cryo-EM in characterization of these assemblies.By comparing with some other characterization methods,we have shown how cryo-EM promoted the development of structural characterization in the field of DNA nanotechnology.     

Exploring the self-assembly of glycopeptides using a diphenylalanine scaffold

Diphenylalanine, a key building block for organic nanotechnology, forms discrete, rigid and hollow nanotubes that are assembled spontaneously upon their dilution from organic phase into aqueous solution. Here we report the efficient preparation of several S-linked glycosylated diphenylalanine analogues bearing different monosaccharide, di-saccharide and sialic acid residues. The self-assembly studies revealed that these glycopeptides adopted various structures and glycosylation could be a tool to manipulate the self-assembly process. Moreover, the solubility of these analogues was found to be much greater than diphenylalanine, which could open new applications based on these nanostructures.