Kinetically Interlocking Multiple‐Units Polymerization of DNA Double Crossover and Its Application in Hydrogel Formation

Abstract

A novel kinetically interlocking multiple-units (KIMU) supramolecular polymerization system with DNA double crossover backbone is designed. The rigidity of DX endows the polymer with high molecular weight and stability. The observed concentration of the formed polymers is insensitive and stable under ultralow monomer concentration owing to the KIMU interactions, in which multiple noncovalent interactions are connected by the phosphodiester bonds. Furthermore, a pH-responsive DNA supramolecular hydrogel is constructed by introducing a half i-motif domain into the DNA monomer. The rigidity of DNA polymer endows the hydrogel with high mechanical strength and low gelation concentration. This study enriches the KIMU strategy and offers a simple but effective way to fabricate long and stable supramolecular polymers by balancing the reversibility and stability. It also shows great potentials to construct next generation of smart materials, such as DNA nanostructures, DNA motors, and DNA hydrogels.

Small Molecule‐Templated DNA Hydrogel with Record Stiffness Integrates and Releases DNA Nanostructures and Gene Silencing Nucleic Acids

“…At 4 wt% (CA included), G ’ of these dA 30 ‐dsDNA 20 hydrogels reaches 3×10 4 Pa, values well outside those reported for previous unmodified DNA hydrogels. [ 9,10 ] The modulus are now more similar to conventional polymer hydrogels, with our 1.4 w% hydrogel being equivalent to an 8% poly(acrylamide) gel with 1.8% N , N ’‐methylenebis(acrylamide) crosslinker synthesized at 20 °C. [ 16 ] Due to the predictability of DNA self‐assembly from its sequence, it was possible to design the crosslinks with different motifs, such as the regular double‐stranded helix (dsDNA 13 , dsDNA 20 ), the i‐motif (C 4 , C 8 ) or the G‐quadruplex (G 4 , G 8 ) (Figure 2c), the formation of which is supported by circular dichroism spectroscopy (CD) (Figure S2, Supporting Information).…”

“…To our knowledge, this is the highest storage modulus of any hydrogel made from unmodified DNA. [ 2 , 7 , 10 , 19 ] It even surpasses many hydrogels incorporating modified DNA, double‐networks or other alterations to make the materials stronger. [ 20 ] It also possesses a high thermal stability, the 1.7 wt% gel keeping its moduli virtually unchanged at 37 ˚C (Figure S9 , Supporting Information) and the 4.7 wt% gel retaining a storage modulus above 10 4 Pa even at 85 °C (Figure S10 , Supporting Information), and has qualitatively been observed staying a gel at 100 °C.…”

Self‐sieving DNA over superhydrophobic surfaces: A Raman spectroscopy study

“…Four physiologically compatible buffers with different characteristics (see Section 5) were used in this work to suspend and dehydrate the droplet. The solutions containing mono or divalent cations are commonly used in cell and molecular biology experiments to provide physiological‐compatible environment (buffers 1–3; see Section 5) or to facilitate nucleic acids adsorption in imaging procedures [ 23 ] (buffers 3 and 4; see Section 5). Depositing a droplet containing nucleic acids over a SHS, we obtained oriented DNA bundles in all the cases.…”

Design and application of stimuli-responsive DNA hydrogels: A review

“…In addition, we noticed that Liu's research group combined DNA Nanomotor [ 54 ], Kinetically interlocking multiple-units [ 55 ] and I-motif into DNA hydrogels, which greatly improved the mechanical strength and pH response efficiency of hydrogels. Further, by using branched DNA and a programmable link [ 56 ], Liu's group built a DNA hydrogel for different responses, whose mechanical properties could be adjusted by three orders of magnitude, and branched out to achieve a good response to K + by introducing G-four-strand sequences.…”