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Abstract Combining surface‐initiated, TdT (terminal deoxynucleotidyl transferase) catalyzed enzymatic polymerization (SI‐TcEP) with precisely engineered DNA origami nanostructures (DONs) presents an innovative pathway for the generation of stable, polynucleotide brush‐functionalized DNA nanostructures. We demonstrate that SI‐TcEP can site‐specifically pattern DONs with brushes containing both natural and non‐natural nucleotides. The brush functionalization can be precisely controlled in terms of the location of initiation sites on the origami core and the brush height and composition. Coarse‐grained simulations predict the conformation of the brush‐functionalized DONs that agree well with the experimentally observed morphologies. We find that polynucleotide brush‐functionalization increases the nuclease resistance of DONs significantly, and that this stability can be spatially programmed through the site‐specific growth of polynucleotide brushes. The ability to site‐specifically decorate DONs with brushes of natural and non‐natural nucleotides provides access to a large range of functionalized DON architectures that would allow for further supramolecular assembly, and for potential applications in smart nanoscale delivery systems. 

Abstract Recently, the DNA brick strategy has provided a highly modular and scalable approach for the construction of complex structures, which can be used as nanoscale pegboards for the precise organization of molecules and nanoparticles for many applications. Despite the dramatic increase of structural complexity provided by the DNA brick method, the assembly pathways are still poorly understood. Herein, we introduce a “seed” strand to control the crucial nucleation and assembly pathway in DNA brick assembly. Through experimental studies and computer simulations, we successfully demonstrate that the regulation of the assembly pathways through seeded growth can accelerate the assembly kinetics and increase the optimal temperature by circa 4–7 °C for isothermal assembly. By improving our understanding of the assembly pathways, we provide new guidelines for the design of programmable pathways to improve the self‐assembly of DNA nanostructures. 

Abstract Inspired by biological motor proteins, that efficiently convert chemical fuel to unidirectional motion, there has been considerable interest in developing synthetic analogues. Among the synthetic motors created thus far, DNA motors that undertake discrete steps on RNA tracks have shown the greatest promise. Nonetheless, DNA nanomotors lack intrinsic directionality, are low speed and take a limited number of steps prior to stalling or dissociation. Herein, we report the first example of a highly tunable DNA origami motor that moves linearly over micron distances at an average speed of 40 nm/min. Importantly, nanomotors move unidirectionally without intervention through an external force field or a patterned track. Because DNA origami enables precise testing of nanoscale structure‐function relationships, we were able to experimentally study the role of motor shape, chassis flexibility, leg distribution, and total number of legs in tuning performance. An anisotropic rigid chassis coupled with a high density of legs maximizes nanomotor speed and endurance. 

Abstract Dynamic DNA structures, a type of DNA construct built using programmable DNA self‐assembly, have the capability to reconfigure their conformations in response to environmental stimulation. A general strategy to design dynamic DNA structures is to integrate reconfigurable elements into conventional static DNA structures that may be assembled from a variety of methods including DNA origami and DNA tiles. Commonly used reconfigurable elements range from strand displacement reactions, special structural motifs, target‐binding DNA aptamers, and base stacking components, to DNA conformational change domains, etc. Morphological changes of dynamic DNA structures may be visualized by imaging techniques or may be translated to other detectable readout signals (e.g., fluorescence). Owing to their programmable capability of recognizing environmental cues with high specificity, dynamic DNA structures embody the epitome of robust and versatile systems that hold great promise in sensing and imaging biological analytes, in delivering molecular cargos, and in building programmable systems that are able to conduct sophisticated tasks. 

Deterministic assembly of metallic nanoparticles ( e.g. gold nanoparticles) into prescribed configurations has promising applications in many fields such as biosensing and drug delivery. DNA-directed bottom-up assembly has demonstrated unparalleled capability to precisely organize metallic nanoparticles into assemblies of designer configurations. However, the fabrication of assemblies comprising delicate nanoparticle arrangements, especially across large dimensions ( e.g. micron size), has remained challenging. In this report, we have designed DNA origami hexagon tiles that are capable of assembling into higher-order networks of honeycomb arrays or tubes with dimensions up to several microns. The versatile addressability of the unit tile enables precise and periodic positioning of nanoparticles onto these higher-order DNA origami frame structures. Overall, we have constructed a series of 9 gold nanoparticle architectures with programmable configurations ranging from nanometer-sized clusters to micrometer-sized lattices. We believe these architectures shall hold great application potential in numerous biomedical fields.