| Aug 18, 2022 |
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(Nanowerk News) The design of macroscopic material with desired chemical, physical, and mechanical properties from the molecular level up is an ongoing challenge for self-assembly and nanotechnology.
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Due to its unparalleled programmability and biocompatibility, structural DNA nanotechnology has proved to be a potent approach to such designs, where the self-assembled nanostructures are responsive via a variety of mechanisms including DNA strand displacement, conformation change of specific motifs, targeting with DNA aptamers (see for instance: “Cancer-fighting nanorobots programmed to seek and destroy tumors“), and DNAzyme domains.
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Whereas these approaches promise great potential for sensitive biosensing, controllable drug delivery, medical diagnosis, and disease treatment, most reconfigurations of the self-assembled nanostructures are limited to the scale of nanometers.
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Now, in new work reported in Advanced Materials (“Powering ≈50 µm Motion by a Molecular Event in DNA Crystals”), researchers demonstrate an engineered DNA crystal actuator system that can reversibly expand and contract over 50 µm in response to multiple external stimuli.
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During this expansion/contraction process, the porosity (thus the permeability) of the crystal greatly changes, which provides a mechanism to reversibly encapsulate/release nanoparticles or proteins.
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| Schematic design of stimuli-responsive DNA crystals. a) The DNA tensegrity triangle motif. b) The self-assembled crystal of DNA triangles. The solid pink circles labeled with P represent 5′-phosphates. c) 2D ligated DNA crystals. Note that DNA frameworks are held along horizontal direction by sticky-end cohesion (red). d) DNA crystal expansion responds to external stimuli. e) An overall view of the expansion/contraction of DNA crystals. (Reprinted with permission by Wiley-VCH Verlag)
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The authors of the study envision that their work will lead to several exciting possibilities as smart materials, including: 1) the easily observable size change of DNA crystals could be exploited as a report for chemical detection; and 2) the system can serve as a sponge to store and release nanometer-sized particles and to delivery macromolecular drugs (e.g., small nucleic acids and proteins).
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