AuNP-Containing Hydrogels Based on Arabinogalactan and κ-Carrageenan with Antiradical Activity

The synthesis and the antiradical activity of composite hydrogels based on arabinogalactan-stabilized gold nanoparticles (AuNPs) and κ-carrageenan (κCG) were examined. It was found that the reducing and stabilizing properties of arabinogalactan (Ar-Gal) could be used to obtain hybrid composites. The AuNP content of the composites ranged from 0.3 to 7.8%, with an average particle size of 5.3-14.0 nm. The antiradical properties of these nanocomposites were demonstrated for the first time using the activated chemiluminescence method. The combination of the synthesized Ar-Gal-AuNPs composite and the natural gel-forming polysaccharide κCG at different ratios enabled a variety of composite hydrogels with different rheological and structural-mechanical properties to be produced. The effect of the Ar-Gal-AuNPs/κCG ratio and the presence of Ca²⁺ ions on the moisture-retaining ability, swelling properties and elastic modulus of the obtained hydrogels was investigated.