DNA-crosslinked acrylamide hydrogels: Fabrication and characterization of DNA/polymer hybrid hydrogel

Abstract

Polymer/DNA hybrid hydrogels represent a novel class of biomaterials that integrate the programmable nature of DNA with the mechanical strength of synthetic polymers. In this study, we present a simple and adaptable method to fabricate DNA-crosslinked polyacrylamide hydrogels using two 5′-acrydite-modified DNA strands and a partially complementary DNA crosslinker. The hydrogels were synthesized via radical-initiated polymerization using APS and TEMED, allowing the DNA strands to become covalently incorporated into the polymer network. Subsequent hybridization with the crosslinker strand formed a three-dimensional hydrogel structure. A systematic investigation of key parameters—such as DNA concentration, molar ratios, reaction temperature, and complementary sequence length—was conducted to optimize gel formation. The most rigid and stable hydrogel was achieved using 60 µM concentrations of each DNA strand in a 1:1:1 molar ratio. Gelation was optimal at lower temperatures, while higher temperatures resulted in losing hydrogen bonding and inhibited the formation of a stable gel network. Moreover, hydrogels fabricated using shorter complementary regions exhibited enhanced stability, likely due to a reduction in undesired intramolecular interactions. Morphological analysis confirmed the successful formation of a porous, interconnected structure. The developed DNA/polymer hybrid hydrogels exhibit promising properties for potential applications in bioengineering.