Switchable Bifunctional Stimuli‐Triggered Poly‐N‐Isopropylacrylamide/DNA Hydrogels1. Issue 38 (5th August 2014)

• Record Type: Journal Article
• Authors: Guo, Weiwei; Lu, Chun‐Hua; Qi, Xiu‐Juan; Orbach, Ron; Fadeev, Michael; Yang, Huang‐Hao; Willner, Itamar
• Is Part Of: Angewandte Chemie international edition. Volume 53:Issue 38(2014)
• Page Start: 10134
• Page End: 10138
• Publication Date: 2014-08-05
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201405692
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>DNA‐tethered poly‐<italic>N</italic>‐isopropylacrylamide copolymer chains, pNIPAM, that include nucleic acid tethers have been synthesized. They are capable of inducing pH‐stimulated crosslinking of the chains by i‐motif structures or to be bridged by Ag⁺ ions to form duplexes. The solutions of pNIPAM chains undergo crosslinking at pH 5.2 or in the presence of Ag⁺ ions to form hydrogels. The hydrogels reveal switchable hydrogel‐to‐solution transitions by the reversible crosslinking of the chains at pH 5.2 and the separation of the crosslinking units at pH 7.5, or by the Ag⁺ ion‐stimulated crosslinking of the chains and the reverse dissolution of the hydrogel by the cysteamine‐induced elimination of the Ag⁺ ions. The DNA‐crosslinked hydrogels are thermosensitive and undergo reversible temperature‐controlled hydrogel‐to‐solid transitions. The solid pNIPAM matrices are protected against the OH⁻ or cysteamine‐stimulated dissociation to the respective polymer solutions.</p> </abstract>