Construction of three-dimensional DNA hydrogels from linear building blocks

Area of Science:

• Materials Science
• Biotechnology
• Nanotechnology

Background:

• DNA self-assembly offers a versatile platform for creating novel materials.
• Controlling the architecture and properties of DNA-based nanostructures is crucial for advanced applications.

Purpose of the Study:

• To synthesize and characterize a three-dimensional DNA hydrogel using double-stranded DNA (dsDNA) building blocks.
• To investigate the thermoresponsive behavior and rheological properties of the DNA hydrogel.

Main Methods:

• Utilized self-assembly of sticky-ended dsDNA to form a 3D hydrogel.
• Employed diffusion-ordered NMR spectroscopy (DOSY NMR) to determine diffusion coefficients at elevated temperatures.
• Conducted temperature-dependent and frequency-dependent rheological measurements.
• Analyzed hydrogel structure using Atomic Force Microscopy (AFM).

Main Results:

• The DNA hydrogel exhibits thermoresponsive behavior, with supramolecular dsDNA structure length varying with temperature.
• A gel point was identified at 42±1°C, below which the material acts as a high-viscosity gel (G' >> G'').
• Rheological measurements at 20°C indicated a mesh size (ξ) of 15 nm.
• AFM revealed densely packed, entangled DNA chains, potentially including interlocked rings and catenanes.

Conclusions:

• The self-assembled DNA hydrogel is a promising thermoresponsive material with tunable properties.
• The study provides insights into the structural organization and mechanical characteristics of DNA hydrogels.
• This work contributes to the development of DNA-based materials for various scientific and technological applications.