Dynamic DNA superstructures with emergent functions.

DNA nanotechnology enables the precise construction of intricate nanoscale structures. Over the past two decades, significant progress has been made in incorporating dynamic functionalities into these nanostructures. Concurrently, innovative strategies have emerged for their self-assembly and surface patterning into larger, more complex architectures.

Real-world experience of veno-arterial extracorporeal membrane oxygenation in severe aluminium phosphide poisoning.

Introduction: Mitochondrial toxicity caused by phosphine released from aluminium phosphide in the presence of moisture leads to haemodynamic collapse, and the mortality from aluminium phosphide ingestion is high. In anecdotal studies, veno-arterial extracorporeal membrane oxygenation appears to reduce mortality.

Methods: A retrospective, single-centre study was conducted of patients with aluminium phosphide poisoning managed between 2019 and 2023.

Economical and Versatile Subunit Design Principles for Self-Assembled DNA Origami Structures.

We describe a modular design approach for creating versatile DNA origami subunits that can target diverse self-assembled structures. The subunit consists of a constant "core module" with variable "bond modules" and "angle modules" added to its exterior, controlling interaction specificity, strength, and structural geometry. The design features flexible joints between subunits, implemented by using single-stranded angle modules, whose mechanical properties and possible conformations are characterized by cryogenic electron microscopy and coarse-grained molecular modeling.

Regulation of the ordinal DNA translocation cycle in bacteriophage Φ29 through trans-subunit interactions.

Certain viruses such as tailed bacteriophages and herpes simplex virus package double-stranded DNA into empty procapsids via powerful, ring-shaped molecular motors. High-resolution structures and force measurements on the DNA packaging motor of bacteriophage Φ29 revealed that its five ATPase subunits coordinate ATP hydrolysis with each other to maintain the proper cyclic sequence of DNA translocation steps about the ring. Here, we explore how the Φ29 motor regulates translocation by timing key events, namely ATP binding/hydrolysis and DNA gripping, through trans-subunit interactions.

Synthesis, Structural, and Morphological Studies of the Thermoelectric Semiconductor AgSb Cd Te.

The compound AgSbTe was synthesized by the high-temperature solid-state route using two methods: (i) continuous slow cooling and (ii) annealing at an intermediate temperature followed by quenching. Powder X-ray diffraction confirmed the principal phase with an () crystal structure. The slow-cooled samples showed the presence of AgTe impurities, while the annealed and quenched samples contained minor amounts of the secondary SbO phase.

Comparing the Amounts of External Root Resorption during Different Modalities of Orthodontics Treatment in Root Canal Treated Teeth Having Zirconia Crown and Contralateral Teeth with Vital Pulp.

Background: Different modalities of orthodontic treatment (OT) can have different amounts of external resorption of root (ERR) among root canal obturated teeth (ROT) having zirconia crowns and teeth with vital pulp (VPT).

Aim: This study was carried out to evaluate ERR in different modalities of OT in ROT having zirconia crowns and contralateral teeth with vital pulp.

Methods And Materials: 130 patients having ROT with zirconia crowns and contralateral teeth with vital pulp undergoing OT were included.

Impact of Grafting Density on the Assembly and Mechanical Properties of Self-Assembled Metal-Organic Framework Monolayers.

Polymer-grafted metal-organic frameworks (MOFs) can be used to form free-standing self-assembled MOF monolayers (SAMMs). Polymer chains can be introduced onto MOF surfaces through either the ligands or metal nodes using both grafting-to and grafting-from approaches. However, controlling the grafting density of polymer-grafted MOFs has not yet been achieved, because a means to control the density of grafting sites on the MOF surface has not been developed.

Piggybacking functionalized DNA nanostructures into live-cell nuclei.

DNA origami nanostructures (DOs) are promising tools for applications including drug delivery, biosensing, detecting biomolecules, and probing chromatin substructures. Targeting these nanodevices to mammalian cell nuclei could provide impactful approaches for probing, visualizing, and controlling biomolecular processes within live cells. We present an approach to deliver DOs into live-cell nuclei.

Self-assembly of nanocrystal checkerboard patterns via non-specific interactions.

Checkerboard lattices-where the resulting structure is open, porous, and highly symmetric-are difficult to create by self-assembly. Synthetic systems that adopt such structures typically rely on shape complementarity and site-specific chemical interactions that are only available to biomolecular systems (e.g.

Mechanism of DNA origami folding elucidated by mesoscopic simulations.

Many experimental and computational efforts have sought to understand DNA origami folding, but the time and length scales of this process pose significant challenges. Here, we present a mesoscopic model that uses a switchable force field to capture the behavior of single- and double-stranded DNA motifs and transitions between them, allowing us to simulate the folding of DNA origami up to several kilobases in size. Brownian dynamics simulations of small structures reveal a hierarchical folding process involving zipping into a partially folded precursor followed by crystallization into the final structure.

A Programmable DNAzyme for the Sensitive Detection of Nucleic Acids.

Nucleic acids in biofluids are emerging biomarkers for the molecular diagnostics of diseases, but their clinical use has been hindered by the lack of sensitive detection assays. Herein, we report the development of a sensitive nucleic acid detection assay named SPOT (sensitive loop-initiated DNAzyme biosensor for nucleic acid detection) by rationally designing a catalytic DNAzyme of endonuclease capability into a unified one-stranded allosteric biosensor. SPOT is activated once a nucleic acid target of a specific sequence binds to its allosteric module to enable continuous cleavage of molecular reporters.

Piggybacking functionalized DNA nanostructures into live cell nuclei.

DNA origami (DO) are promising tools for or applications including drug delivery; biosensing, detecting biomolecules; and probing chromatin sub-structures. Targeting these nanodevices to mammalian cell nuclei could provide impactful approaches for probing visualizing and controlling important biological processes in live cells. Here we present an approach to deliver DO strucures into live cell nuclei.

Controlling Silicification on DNA Origami with Polynucleotide Brushes.

DNA origami has been used as biotemplates for growing a range of inorganic materials to create novel organic-inorganic hybrid nanomaterials. Recently, the solution-based silicification of DNA has been used to grow thin silica shells on DNA origami. However, the silicification reaction is sensitive to the reaction conditions and often results in uncontrolled DNA origami aggregation, especially when growth of thicker silica layers is desired.

Interplay between stochastic enzyme activity and microtubule stability drives detyrosination enrichment on microtubule subsets.

Microtubules in cells consist of functionally diverse subpopulations carrying distinct post-translational modifications (PTMs). Akin to the histone code, the tubulin code regulates a myriad of microtubule functions, ranging from intracellular transport to chromosome segregation. However, how individual PTMs only occur on subsets of microtubules to contribute to microtubule specialization is not well understood.

Spatiotemporal Control over Polynucleotide Brush Growth on DNA Origami Nanostructures.

DNA nanotechnology provides an approach to create precise, tunable, and biocompatible nanostructures for biomedical applications. However, the stability of these structures is severely compromised in biological milieu due to their fast degradation by nucleases. Recently, we showed how enzymatic polymerization could be harnessed to grow polynucleotide brushes of tunable length and location on the surface of DNA origami nanostructures, which greatly enhances their nuclease stability.

Versatile computer-aided design of free-form DNA nanostructures and assemblies.

Recent advances in structural DNA nanotechnology have been facilitated by design tools that continue to push the limits of structural complexity while simplifying an often-tedious design process. We recently introduced the software MagicDNA, which enables design of complex 3D DNA assemblies with many components; however, the design of structures with free-form features like vertices or curvature still required iterative design guided by simulation feedback and user intuition. Here, we present an updated design tool, MagicDNA 2.

Transcending shift-invariance in the paraxial regime via end-to-end inverse design of freeform nanophotonics.

Traditional optical elements and conventional metasurfaces obey shift-invariance in the paraxial regime. For imaging systems obeying paraxial shift-invariance, a small shift in input angle causes a corresponding shift in the sensor image. Shift-invariance has deep implications for the design and functionality of optical devices, such as the necessity of free space between components (as in compound objectives made of several curved surfaces).

Thermally reversible pattern formation in arrays of molecular rotors.

Control over the mesoscale to microscale patterning of materials is of great interest to the soft matter community. Inspired by DNA origami rotors, we introduce a 2D nearest-neighbor lattice of spinning rotors that exhibit discrete orientational states and interactions with their neighbors. Monte Carlo simulations of rotor lattices reveal that they exhibit a variety of interesting ordering behaviors and morphologies that can be modulated through rotor design parameters.

Steric Communication between Dynamic Components on DNA Nanodevices.

Biomolecular nanotechnology has helped emulate basic robotic capabilities such as defined motion, sensing, and actuation in synthetic nanoscale systems. DNA origami is an attractive approach for nanorobotics, as it enables creation of devices with complex geometry, programmed motion, rapid actuation, force application, and various kinds of sensing modalities. Advanced robotic functions like feedback control, autonomy, or programmed routines also require the ability to transmit signals among subcomponents.

Prediction and Control in DNA Nanotechnology.

DNA nanotechnology is a rapidly developing field that uses DNA as a building material for nanoscale structures. Key to the field's development has been the ability to accurately describe the behavior of DNA nanostructures using simulations and other modeling techniques. In this Review, we present various aspects of prediction and control in DNA nanotechnology, including the various scales of molecular simulation, statistical mechanics, kinetic modeling, continuum mechanics, and other prediction methods.

Discovery of two-dimensional binary nanoparticle superlattices using global Monte Carlo optimization.

Binary nanoparticle (NP) superlattices exhibit distinct collective plasmonic, magnetic, optical, and electronic properties. Here, we computationally demonstrate how fluid-fluid interfaces could be used to self-assemble binary systems of NPs into 2D superlattices when the NP species exhibit different miscibility with the fluids forming the interface. We develop a basin-hopping Monte Carlo (BHMC) algorithm tailored for interface-trapped structures to rapidly determine the ground-state configuration of NPs, allowing us to explore the repertoire of binary NP architectures formed at the interface.

A bistable and reconfigurable molecular system with encodable bonds.

Molecular systems with ability to controllably transform between different conformations play pivotal roles in regulating biochemical functions. Here, we report the design of a bistable DNA origami four-way junction (DOJ) molecular system that adopts two distinct stable conformations with controllable reconfigurability by using conformation-controlled base stacking. Exquisite control over DOJ's conformation and transformation is realized by programming the stacking bonds (quasi-blunt-ends) within the junction to induce prescribed coaxial stacking of neighboring junction arms.

Influence of Polymer Characteristics on the Self-Assembly of Polymer-Grafted Metal-Organic Framework Particles.

Polymer-grafted metal-organic frameworks (MOFs) can combine the properties of MOFs and polymers into a single, matrix-free composite material. Herein, we examine polymer-grafted MOF particles (using UiO-66 as a model system) to examine how the molecular weight, grafting density, and chemical functionality of the polymer graft affects the preparation of free-standing self-assembled MOF monolayers (SAMMs). The physical properties of the monolayers are influenced by the choice of polymer, and robust, flexible monolayers were achieved more readily with poly(methyl acrylate) when compared to poly(methyl methacrylate) or poly(benzyl methacrylate).

Molecular dynamics of DNA translocation by FtsK.

The bacterial FtsK motor harvests energy from ATP to translocate double-stranded DNA during cell division. Here, we probe the molecular mechanisms underlying coordinated DNA translocation in FtsK by performing long timescale simulations of its hexameric assembly and individual subunits. From these simulations we predict signaling pathways that connect the ATPase active site to DNA-gripping residues, which allows the motor to coordinate its translocation activity with its ATPase activity.