Kinetically Interlocking Multiple-Units Polymerization of DNA Double Crossover and Its Application in Hydrogel...

Area of Science:

• Supramolecular Chemistry
• DNA Nanotechnology
• Materials Science

Background:

• Developing stable supramolecular polymers with tunable properties remains a challenge.
• Kinetically interlocking multiple-units (KIMU) strategies offer a route to enhance polymer stability through cooperative noncovalent interactions.
• DNA nanotechnology provides a versatile platform for constructing complex molecular architectures.

Purpose of the Study:

• To design and characterize a novel kinetically interlocking multiple-units (KIMU) supramolecular polymerization system utilizing a DNA double crossover (DX) backbone.
• To investigate the stability and concentration dependence of the formed DNA supramolecular polymers.
• To construct a pH-responsive DNA supramolecular hydrogel by incorporating i-motif domains.

Main Methods:

• Design of DNA monomers featuring a double crossover (DX) backbone for rigidity and stability.
• Implementation of kinetically interlocking multiple-units (KIMU) interactions to stabilize supramolecular assembly.
• Incorporation of pH-responsive i-motif domains into DNA monomers for hydrogel formation.

Main Results:

• The DNA DX backbone imparts high molecular weight and stability to the supramolecular polymers.
• KIMU interactions ensure polymer formation is insensitive and stable even at ultralow monomer concentrations.
• The resulting DNA supramolecular hydrogel exhibits high mechanical strength and a low gelation concentration, responsive to pH changes.

Conclusions:

• The study successfully demonstrates a robust KIMU strategy for fabricating long, stable DNA supramolecular polymers by balancing reversibility and stability.
• The developed DNA polymers and hydrogels represent a significant advancement in smart materials.
• This work holds potential for applications in DNA nanostructures, DNA motors, and advanced DNA hydrogels.