title: Reversible Modulation of DNA-Based Hydrogel Shapes by Internal Stress Interactions.
abstract: We present the assembly of asymmetric two-layer hybrid DNA-based hydrogels revealing stimuli-triggered reversibly modulated shape transitions. Asymmetric, linear hydrogels that include layer-selective switchable stimuli-responsive elements that control the hydrogel stiffness are designed. Trigger-induced stress in one of the layers results in the bending of the linear hybrid structure, thereby minimizing the elastic free energy of the systems. The removal of the stress by a counter-trigger restores the original linear bilayer hydrogel. The stiffness of the DNA hydrogel layers is controlled by thermal, pH (i-motif), K+ion/crown ether (G-quadruplexes), chemical (pH-doped polyaniline), or biocatalytic (glucose oxidase/urease) triggers. A theoretical model relating the experimental bending radius of curvatures of the hydrogels with the Young's moduli and geometrical parameters of the hydrogels is provided. Promising applications of shape-regulated stimuli-responsive asymmetric hydrogels include their use as valves, actuators, sensors, and drug delivery devices.
authors.affiliation: Institute of Chemistry and The Center for Nanoscience and Nanotechnology and ‡The Fritz Haber Research Center, The Hebrew University of Jerusalem , Jerusalem 91904, Israel.
authors.forename: Yuwei
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Institute of Chemistry and The Center for Nanoscience and Nanotechnology and ‡The Fritz Haber Research Center, The Hebrew University of Jerusalem , Jerusalem 91904, Israel.
authors.forename: Jason S
authors.initials: JS
authors.lastname: Kahn
authors.affiliation: Institute of Chemistry and The Center for Nanoscience and Nanotechnology and ‡The Fritz Haber Research Center, The Hebrew University of Jerusalem , Jerusalem 91904, Israel.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Guo
authors.affiliation: Institute of Chemistry and The Center for Nanoscience and Nanotechnology and ‡The Fritz Haber Research Center, The Hebrew University of Jerusalem , Jerusalem 91904, Israel.
authors.forename: Fujian
authors.initials: F
authors.lastname: Huang
authors.affiliation: Institute of Chemistry and The Center for Nanoscience and Nanotechnology and ‡The Fritz Haber Research Center, The Hebrew University of Jerusalem , Jerusalem 91904, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Fadeev
authors.affiliation: Institute of Chemistry and The Center for Nanoscience and Nanotechnology and ‡The Fritz Haber Research Center, The Hebrew University of Jerusalem , Jerusalem 91904, Israel.
authors.forename: Daniel
authors.initials: D
authors.lastname: Harries
authors.affiliation: Institute of Chemistry and The Center for Nanoscience and Nanotechnology and ‡The Fritz Haber Research Center, The Hebrew University of Jerusalem , Jerusalem 91904, Israel.
authors.forename: Itamar
authors.initials: I
authors.lastname: Willner
mesh_terms: D000814:Aniline Compounds / Q000737:chemistry; D043844:Crown Ethers / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D005949:Glucose Oxidase / Q000737:chemistry / Q000378:metabolism; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D011188:Potassium / Q000737:chemistry; D013314:Stress, Mechanical; D013816:Thermodynamics; D014510:Urease / Q000737:chemistry / Q000378:metabolism
chemical_list: D000814:Aniline Compounds; D043844:Crown Ethers; D020100:Hydrogels; C416807:polyaniline; D004247:DNA; D005949:Glucose Oxidase; D014510:Urease; D011188:Potassium