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In DNA nanotechnology, DNA molecules are designed, engineered, and assembled into arbitrary-shaped architectures with predesigned functions. Static DNA assemblies often have delicate designs with structural rigidity to overcome thermal fluctuations. Dynamic structures reconfigure in response to external cues, which have been explored to create functional nanodevices for environmental sensing and other applications. However, the precise control of reconfiguration dynamics has been a challenge due partly to flexible single-stranded DNA connections between moving parts. Deformable structures are special dynamic constructs with deformation on double-stranded parts and single-stranded hinges during transformation. These structures often have better control in programmed deformation. However, related deformability and mechanics including transformation mechanisms are not well understood or documented. In this review, we summarize the development of dynamic and deformable DNA nanostructures from a mechanical perspective. We present deformation mechanisms such as single-stranded DNA hinges with lock-and-release pairs, jack edges, helicity modulation, and external loading. Theoretical and computational models are discussed for understanding their associated deformations and mechanics. We elucidate the pros and cons of each model and recommend design processes based on the models. The design guidelines should be useful for those who have limited knowledge in mechanics as well as expert DNA designers.
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Statistical mechanics of a double-stranded rod model for DNA melting and elasticity
The double-helical topology of DNA molecules observed at room temperature in the absence of any external loads can be disrupted by increasing the bath temperature or by applying tensile forces, leading to spontaneous strand separation known as DNA melting. Here, continuum mechanics of a 2D birod is combined with statistical mechanics to formulate a unified framework for studying both thermal melting and tensile force induced melting of double-stranded molecules: it predicts the variation of melting temperature with tensile load, provides a mechanics-based understanding of the cooperativity observed in melting transitions, and reveals an interplay between solution electrostatics and micromechanical deformations of DNA which manifests itself as an increase in the melting temperature with increasing ion concentration. This novel predictive framework sheds light on the micromechanical aspects of DNA melting and predicts trends that were observed experimentally or extracted phenomenologically using the Clayperon equation.
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- Award ID(s):
- 1662101
- PAR ID:
- 10223162
- Date Published:
- Journal Name:
- Soft Matter
- Volume:
- 16
- Issue:
- 33
- ISSN:
- 1744-683X
- Page Range / eLocation ID:
- 7715 to 7726
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d0sm00521e
