Field Of Structural DNA Nanotechnology Research Articles

An Improved Shape Annealing Algorithm for the Generation of Coated Deoxyribonucleic Acid Origami Nanostructures

Abstract In recent years, the field of structural DNA nanotechnology has advanced rapidly due to transformative design tools. Although these tools have been revolutionary, they still bear one overall limitation of requiring users to fully conceptualize their designs before designing. Recently, a simple computational casting technique was developed using generative optimization strategies to automate the DNA origami nanostructure design. This approach employs a shape annealing algorithm, which creates a formal language of honeycomb nanostructures with shape grammars and drives designs from the language toward a desired configuration using simulated annealing. This initial demonstration of the approach can generate novel scaffold routing schemes for creating solid or hollow structures constrained by the boundaries of polyhedral meshes. The results from the initial approach, particularly from the hollow structures, reveal a challenging design space. This simple technique generates novel scaffold routing schemes that do not replicate the overall polyhedral mesh shape and are limited in their ability to control scaffold path exploration in the design space. This paper demonstrates an approach for achieving different levels of consistent effective wall thicknesses and improving the quality of mesh coverage for hollow structures that can be tuned and optimized by introducing a more refined computational casting technique. We achieve these improvements through changes in the simulated annealing algorithm by adding a Hustin move set algorithm that dynamically adjusts the performance of the overall design and redefining how these hollow designs are articulated. This work illustrates how the technique can navigate a challenging design space to generate effective hollow designs.

Environmentally Controlled Oscillator with Triplex Guided Displacement of DNA Duplexes.

The use of DNA triplex association is advantageous for the reconfiguration of dynamic DNA nanostructures through pH alteration and can provide environmental control for both structural changes and molecular signaling. The combination of pH-induced triplex-forming oligonucleotide (TFOs) binding with toehold-mediated strand displacement has recently garnered significant attention in the field of structural DNA nanotechnology. While most previous studies use single-stranded DNA to displace or replace TFOs within the triplex, here we demonstrate that pH alteration allows a DNA duplex, with a toehold assistance, to displace TFOs from the components of another DNA duplex. We examined the dependence of this process on toehold length and show that the pH changes allow for cyclic oscillations between two molecular formations. We implemented the duplex/triplex design onto the surface of 2D DNA origami in the form outlining binary digits 0 or 1 and verified the oscillatory conformational changes between the two formations with atomic force microscopy.

Design Verification as Foundation for Advancing DNA Nanotechnology Applications.

Advances in the field of structural DNA nanotechnology have produced a growing number of nanostructures that are now being developed for diverse applications. Often, these nanostructures contain not only nucleic acids but also a myriad of other classes of molecules and materials such as proteins, lipids, sugars, and synthetic polymers. Increasing structural and compositional complexity promises new functional capabilities, but also demands new tools for design verification. Systematically verifying the design of DNA-scaffolded nanomaterials is necessary to identify and to refine their design rules, and to enable the field to progress toward "real world" applications. In this issue of ACS Nano, Bertosin et al. used single-particle cryo-electron microscopy to characterize the structure of multilayer DNA origamis following coating with oligolysine-based polymers, a class of material which has previously been shown to stabilize DNA nanostructures in physiological environments for use in biological applications. This Perspective summarizes their findings, discusses the broader challenges of verifying the design of DNA nanotechnologies incorporating complex materials, and highlights future directions for advancing their applications.

DNA Self-Assembly Mediated by Programmable Soft-Patchy Interactions.

Adding shape and interaction anisotropy to a colloidal particle offers exquisitely tunable routes to engineer a rich assortment of complex-architected structures. Inspired by the hierarchical self-assembly concept with block copolymers and DNA liquid crystals and exploiting the unique assembly properties of DNA, we report here the construction and self-assembly of DNA-based soft-patchy anisotropic particles with a high degree of modularity in the system's design. By programmable positioning of thermoresponsive polymeric patches on the backbone of a stiff DNA duplex with linear and star-shaped architecture, we reversibly drive the DNA from a disordered ensemble to a diverse array of long-range ordered multidimensional nanostructures with tunable lattice spacing, ranging from lamellar to bicontinuous double-gyroid and double-diamond cubic morphologies, through the alteration of temperature. Our results demonstrate that the proposed hierarchical self-assembly strategy can be applied to any kind of DNA nanoarchitecture, highlighting the design principles for integration of self-assembly concepts from the physics of liquid crystals, block copolymers, and patchy colloids into the continuously growing interdisciplinary research field of structural DNA nanotechnology.

MrDNA: a multi-resolution model for predicting the structure and dynamics of DNA systems.

Although the field of structural DNA nanotechnology has been advancing with an astonishing pace, de novo design of complex 3D nanostructures and functional devices remains a laborious and time-consuming process. One reason for that is the need for multiple cycles of experimental characterization to elucidate the effect of design choices on the actual shape and function of the self-assembled objects. Here, we demonstrate a multi-resolution simulation framework, mrdna, that, in 30 min or less, can produce an atomistic-resolution structure of a self-assembled DNA nanosystem. We demonstrate fidelity of our mrdna framework through direct comparison of the simulation results with the results of cryo-electron microscopy (cryo-EM) reconstruction of multiple 3D DNA origami objects. Furthermore, we show that our approach can characterize an ensemble of conformations adopted by dynamic DNA nanostructures, the equilibrium structure and dynamics of DNA objects constructed using off-lattice self-assembly principles, i.e. wireframe DNA objects, and to study the properties of DNA objects under a variety of environmental conditions, such as applied electric field. Implemented as an open source Python package, our framework can be extended by the community and integrated with DNA design and molecular graphics tools.

Triangulated Wireframe Structures Assembled Using Single-Stranded DNA Tiles.

The field of structural DNA nanotechnology offers a wide range of design strategies with which to build structures with a desired aspect ratio, size, and shape. Compared with traditional close-packed DNA structures, triangulated wireframe structures require less material per surface or volume unit and improve the stability in biologically relevant conditions due to the reduced electrostatic repulsion. Herein, we expand the design space of the DNA single-stranded tile method to cover a range of anisotropic, finite, triangulated wireframe structures as well as a number of one-dimensional crystalline assemblies. These structures are composed of six-arm junctions with a single double helix as connecting edges that assemble in physiologically relevant salinities. For a reliable folding of the structures, single-stranded spacers 2-4 nucleotides long have to be introduced in the junction connecting neighboring arms. Coarse-grained molecular dynamics simulations using the oxDNA model suggests that the spacers prevent the stacking of DNA helices, thereby facilitating the assembly of planar geometries.

Concept and Development of Framework Nucleic Acids.

The blooming field of structural DNA nanotechnology harnessing the material properties of nucleic acids has attracted widespread interest. The exploitation of the precise and programmable Watson-Crick base pairing of DNA or RNA has led to the development of exquisite nucleic acid nanostructures from one to three dimensions. The advances of computer-aided tools facilitate automated design of DNA nanostructures with various sizes and shapes. Especially, the construction of shell or skeleton DNA frameworks, or more recently dubbed "framework nucleic acids" (FNAs) provides a means to organize molecules or nanoparticles with nanometer precision. The intrinsic biological properties and tailorable functionalities of FNAs hold great promise for physical, chemical, and biological applications. This Perspective highlights state-of-the-art design and construction, of precisely assembled FNAs, and outlines the challenges and opportunities for exploiting the structural potential of FNAs for translational applications.

Design methods for 3D wireframe DNA nanostructures

The field of structural DNA nanotechnology aims at the systematic development of self-assembling nanostructures using DNA as the construction material. Research in this area is progressing rapidly, and the controlled, computer-aided design of increasingly complex structures is becoming feasible. One thread of this endeavour is the design and characterisation of self-assembling 3D nanostructures based on wireframe polyhedral models. This article aims to illustrate some of the key developments in this direction, in sufficient detail so that the reader can achieve a general understanding of the main concepts and approaches. The emphasis is on the design principles rather than experimental methodology, and the role of computer science and computational tools is set forth.

Intrinsic Dynamics Analysis of a DNA Octahedron by Elastic Network Model

DNA is a fundamental component of living systems where it plays a crucial role at both functional and structural level. The programmable properties of DNA make it an interesting building block for the construction of nanostructures. However, molecular mechanisms for the arrangement of these well-defined DNA assemblies are not fully understood. In this paper, the intrinsic dynamics of a DNA octahedron has been investigated by using two types of Elastic Network Models (ENMs). The application of ENMs to DNA nanocages include the analysis of the intrinsic flexibilities of DNA double-helices and hinge sites through the calculation of the square fluctuations, as well as the intrinsic collective dynamics in terms of cross-collective map calculation coupled with global motions analysis. The dynamics profiles derived from ENMs have then been evaluated and compared with previous classical molecular dynamics simulation trajectories. The results presented here revealed that ENMs can provide useful insights into the intrinsic dynamics of large DNA nanocages and represent a useful tool in the field of structural DNA nanotechnology.

Structural DNA nanotechnology: state of the art and future perspective.

Over the past three decades DNA has emerged as an exceptional molecular building block for nanoconstruction due to its predictable conformation and programmable intra- and intermolecular Watson–Crick base-pairing interactions. A variety of convenient design rules and reliable assembly methods have been developed to engineer DNA nanostructures of increasing complexity. The ability to create designer DNA architectures with accurate spatial control has allowed researchers to explore novel applications in many directions, such as directed material assembly, structural biology, biocatalysis, DNA computing, nanorobotics, disease diagnosis, and drug delivery. This Perspective discusses the state of the art in the field of structural DNA nanotechnology and presents some of the challenges and opportunities that exist in DNA-based molecular design and programming.

DNA‐templated lithography and nanofabrication for the fabrication of nanoscale electronic circuitry

The field of structural DNA nanotechnology has undergone significant expansion in recent years as exciting new techniques and understanding have been developed, allowing for the design and assembly of complex and intricate two‐ and three‐dimensional nanostructures. Many of these designed DNA motifs have found use in precise positioning of nanomaterials and thereby can aid in studies, reactions, and assembly of other nanostructures. This review discusses the history and progression of DNA‐based nanofabrication with an emphasis on the use of DNA nanostructures for electronics applications.

DNA-nanoparticle assemblies go organic: Macroscopic polymeric materials with nanosized features

BackgroundOne of the goals in the field of structural DNA nanotechnology is the use of DNA to build up 2- and 3-D nanostructures. The research in this field is motivated by the remarkable structural features of DNA as well as by its unique and reversible recognition properties. Nucleic acids can be used alone as the skeleton of a broad range of periodic nanopatterns and nanoobjects and in addition, DNA can serve as a linker or template to form DNA-hybrid structures with other materials. This approach can be used for the development of new detection strategies as well as nanoelectronic structures and devices.MethodHere we present a new method for the generation of unprecedented all-organic conjugated-polymer nanoparticle networks guided by DNA, based on a hierarchical self-assembly process. First, microphase separation of amphiphilic block copolymers induced the formation of spherical nanoobjects. As a second ordering concept, DNA base pairing has been employed for the controlled spatial definition of the conjugated-polymer particles within the bulk material. These networks offer the flexibility and the diversity of soft polymeric materials. Thus, simple chemical methodologies could be applied in order to tune the network's electrical, optical and mechanical properties.Results and conclusionsOne- two- and three-dimensional networks have been successfully formed. Common to all morphologies is the integrity of the micelles consisting of DNA block copolymer (DBC), which creates an all-organic engineered network.

Challenges and opportunities for structural DNA nanotechnology.

DNA molecules have been used to build a variety of nanoscale structures and devices over the past 30 years, and potential applications have begun to emerge. But the development of more advanced structures and applications will require a number of issues to be addressed, the most significant of which are the high cost of DNA and the high error rate of self-assembly. Here we examine the technical challenges in the field of structural DNA nanotechnology and outline some of the promising applications that could be developed if these hurdles can be overcome. In particular, we highlight the potential use of DNA nanostructures in molecular and cellular biophysics, as biomimetic systems, in energy transfer and photonics, and in diagnostics and therapeutics for human health.

Beyond biology

As biology demonstrates, evolutionary algorithms are an extraordinarily powerful way to design complex nanoscale systems. While we can harness the biological apparatus for replicating and selecting DNA sequences to evolve enzymes and to some extent, organisms, we would like to build replication machinery that would allow us to evolve designs for a much wider variety of materials and systems. Here we describe work that uses techniques from the new field of structural DNA nanotechnology to modularly design nanoscale components that together can be assembled into a system for self-replicating a new form of chemical information or genome, and thus for evolving a new type of chemical sequence.

Structural DNA Nanotechnology: From Bases to Bricks, From Structure to Function

The two fields of structural DNA nanotechnology and functional nucleic acids have been independently coevolving, with the former seeking to arrange and bring about movement of nucleic acid modules precisely and with control in space and the latter producing modules with incredible diversity in effective recognition and function. Here, we track the key developments in structural DNA nanotechnology that reveal a current trend that is seeing the integration of functional nucleic acid modules into their architectures to access a range of new functions. This contribution will seek to provide a perspective for the field of structural DNA nanotechnology where the integration of such functional modules on precisely controlled architectures can uncover phenomena of interest to physical chemists.

Structural DNA nanotechnology: growing along with Nano Letters.

During the past decade, the field of structural DNA nanotechnology has grown enormously, not only in the number of its participants but also qualitatively in its capabilities. A number of goals evident in 2001 have been achieved: These include the extension of self-assembled crystalline systems from 2D to 3D and the achievement of 2D algorithmic assembly. A variety of nanoscale walking devices have been developed. A key unanticipated development was the advent of DNA origami, which has vastly expanded the scale of addressable DNA structures. Nanomechanical devices have been incorporated into 2D arrays, and into 2D origami structures, as well, leading to capture systems and to a nanomechanical assembly line. DNA has been used to scaffold non-DNA species, so that one of its key goals has been achieved. Biological replication of DNA nanostructures with simple topologies has also been accomplished. The increase in the number of participants in the enterprise holds great promise for the coming decade.

ARTIFICIALLY DESIGNED DNA NANOSTRUCTURES

In the field of structural DNA nanotechnology, researchers create artificial DNA sequences to self-assemble into target molecular superstructures and nanostructures. The well-understood Watson–Crick base-pairing rules are used to encode assembly instructions directly into the DNA molecules. A wide variety of complex nanostructures has been created using this method. DNA directed self-assembly is now being adapted for use in the nanofabrication of functional structures for use in electronics, photonics, and medical applications.