<i>In Situ</i> Growth of Silver Nanoparticles into Reducing-End Carbohydrate-Based Supramolecular Hydrogels for Antimicrobial Applications

Hydrogels with antibacterial activities have the potential for many biomedical applications, such as wound healing, because of their capacity to maintain a moist environment and prevent infections. In this work, an ultrasound-induced supramolecular hydrogel consisting of easily accessible reducing-end-free glucosaminylbarbiturate-based hydrogelators that serve the <i>in situ</i> fabrication of silver nanoparticles (AgNPs), excluding the addition of any external reducing or stabilizing agents, has been developed. The innovative synthetic approach relied on the use of <i>N,N'</i>-disubstituted barbituric acid derivatives as a versatile chemical platform that site-selectively reacted with the amino function of glucosamine. A series of glucosaminylbarbiturate were synthesized, and we identified one carbohydrate-based hydrogelator that produced a thixotropic supramolecular hydrogel after ultrasound-mediated breaking of an intralocked hydrogen bond. AgNPs@hydrogels were prepared through <i>in situ</i> reduction of silver ions mediated by the reducing properties of carbohydrates. The AgNPs@hydrogel composite revealed good antimicrobial properties toward both Gram-positive and Gram-negative bacteria. These findings contribute to the development of carbohydrate-based supramolecular hydrogels and make them promising efficient and safe soft materials for antimicrobial therapy.