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Chemical and photochemical DNA “gears” reversibly control stiffness, shape-memory, self-healing and controlled release properties of polyacrylamide hydrogels
A new class of stimuli-responsive DNA-based polyacrylamide hydrogels is described. They consist of glucosamine–boronate ester-crosslinked polyacrylamide chains being cooperatively bridged by stimuli-responsive nucleic acids. The triggered closure and dissociation of the stimuli-responsive units lead...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Royal Society of Chemistry
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6346408/ https://www.ncbi.nlm.nih.gov/pubmed/30774895 http://dx.doi.org/10.1039/c8sc04292f |
Sumario: | A new class of stimuli-responsive DNA-based polyacrylamide hydrogels is described. They consist of glucosamine–boronate ester-crosslinked polyacrylamide chains being cooperatively bridged by stimuli-responsive nucleic acids. The triggered closure and dissociation of the stimuli-responsive units lead to switchable stiffness properties of the hydrogel. One hydrogel includes glucosamine–boronate esters and K(+)-ion-stabilized G-quadruplex units as cooperative crosslinkers. The hydrogel bridged by the two motifs reveals high stiffness, whereas the separation of the G-quadruplex bridges by 18-crown-6-ether yields a low stiffness hydrogel. By cyclic treatment of the hydrogel with K(+)-ions and 18-crown-6-ether, it is reversibly cycled between high and low stiffness states. The second system involves a photo-responsive hydrogel that reveals light-induced switchable stiffness functions. The polyacrylamide chains are cooperatively crosslinked by glucosamine–boronate esters and duplex nucleic acid bridges stabilized by trans-azobenzene intercalator units. The resulting hydrogel reveals high stiffness. Photoisomerization of the trans-azobenzene units to the cis-azobenzene states results in the separation of the duplex nucleic acid bridges and the formation of a low stiffness hydrogel. The control over the stiffness properties of the hydrogel matrices by means of K(+)-ions/crown ether or photoisomerizable trans-azobenzene/cis-azobenzene units is used to develop shape-memory, self-healing, and controlled drug-release hydrogel materials. |
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