Nanocomposite DNA hydrogels with temperature sensitivity

Ahmet T. Uzumcu, Orhan Guney, Oguz Okay*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Citations (Scopus)

Abstract

DNA hydrogels are promising soft materials because of the distinctive properties of DNA such as biocompatibility, coil-globule transition, molecular recognition, and selective binding. However, such hydrogels synthesized so far suffer from poor mechanical properties and low dimensional stability, which limit their stress-bearing technological applications. Here, we introduce a novel concept for the preparation of high-strength double-stranded (ds) DNA hydrogels with temperature sensitivity. The hydrogels were synthesized by free-radical polymerization of N-isopropylacrylamide in aqueous Laponite dispersions containing ds-DNA in a highly entangled state. The nanoparticles of synthetic Laponite clay act as a dynamic cross-linker to form a three-dimensional physical network due to strong clay-polymer interactions. We observed that ds-DNA maintains its native structure and function during the formation of nanocomposite hydrogels. Cyclic heating/cooling experiments conducted between below and above the melting temperature of ds-DNA reveal a drastic increase in the elastic modulus of nanocomposite hydrogels due to the thermally induced denaturation and renaturation of DNA within the physical network. The hydrogels prepared at various Laponite contents display the characteristics of both poly(N-isopropylacrylamide) and ds-DNA e.g., temperature sensitivity, denaturation and renaturation of DNA strands, and they exhibit a high tensile fracture stress (up to 53 kPa) and elongation to break (up to 544%).

Original languageEnglish
Pages (from-to)169-178
Number of pages10
JournalPolymer
Volume100
DOIs
Publication statusPublished - 25 Sept 2016

Bibliographical note

Publisher Copyright:
© 2016 Elsevier Ltd

Funding

This work was supported by the Scientific and Technical Research Council of Turkey (TUBITAK), KBAG 114Z312 , and by Istanbul Technical University Scientific Research Project (ITU-BAP). Project No: 39773. OO thanks the Turkish Academy of Sciences (TUBA) for the partial support.

FundersFunder number
ITU-BAP39773
TUBITAKKBAG 114Z312
Türkiye Bilimsel ve Teknolojik Araştirma Kurumu
Istanbul Teknik Üniversitesi

    Keywords

    • Denaturation
    • DNA
    • Mechanical properties
    • Nanocomposite hydrogels
    • Swelling

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