Hu, Y., Ke, Y., & Willner, I. (2023). A pH‐Cascaded DNA Hydrogel Mediated by Reconfigurable A‐motif Duplex, i‐Motif Quadruplex, and T·A‐T Triplex Structures. Advanced Functional Materials, 33(45). Portico. https://doi.org/10.1002/adfm.202304966
Abstract:
AbstractGoverned by pH‐configurable A‐motif, i‐motif and T·A‐T triplex configurations, a cascaded DNA hydrogel subjecting to diverse pH values is presented. Under highly acidic conditions (pH 1.1), N1 protonation of adenine (pKa 3.5) in A‐strands generates AH+‐H+A units, resulting in a parallel A‐motif duplex crosslinked hydrogel. Under mild acid conditions (pH 5.2), the dissociation of A‐motif duplex into single A‐strands occurs due to the deprotonation of adenine, while N3 protonation of cytosine (pKa 6.5) in C‐strands creates hemi‐protonated C:C+ units, resulting in i‐motif bridged hydrogel. At neutral pH (pH 7.2), deprotonation of cytosine separates i‐motif crosslinkers. Simultaneously, the addition of auxiliary T‐strands results in the N3 protonation of thymine (pKa 10), generating T·A‐T triplex stabilized hydrogel. Under mildly alkaline conditions (pH 10.2), T·A‐T triplex separates into single T‐stands and A‐T duplex, resulting in the disassembly of DNA hydrogel. Therefore, a stepwise pH‐cascaded DNA hydrogel dictates the formation of structures following the pH steps 1.1 → 5.2 → 7.2 → 10.2 where pH‐triggered DNA secondary structures, including A‐motif, i‐motif and T·A‐T triplex, stabilize the hydrogel. The study advances DNA hydrogels from single pH‐responsiveness to multiple cascaded pH values, which opens up new possibilities for the development of smart hydrogels capable of adapting to various environmental conditions.
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Funding Info:
This research / project is supported by the A*STAR - Career Development Fund
Grant Reference no. : C210112014
This research / project is supported by the SERC Central Research Fund - UIBR
Grant Reference no. : KIMR220901aSERCRF
Description:
This is the peer reviewed version of the following article: Hu, Y., Ke, Y., & Willner, I. (2023). A pH‐Cascaded DNA Hydrogel Mediated by Reconfigurable A‐motif Duplex, i‐Motif Quadruplex, and T·A‐T Triplex Structures. Advanced Functional Materials, 33(45). Portico. https://doi.org/10.1002/adfm.202304966, which has been published in final form at doi.org/10.1002/adfm.202304966. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.