Alginate-based composite sponge containing silver nanoparticles synthesized in situ

Silver-based biomaterials have been developed in a variety of bactericidal applications, especially for wound dressings. In this study, silver nanoparticles (AgNPs) were synthesized in a sodium alginate solution and then the composite sponge containing AgNPs was prepared from the nanocolloid solution. The alginate-stabilized AgNPs had the mean negative zeta potential of −52.5 mV, suggesting that the surface charge prevents the nanoparticles from aggregating through electrostatic repulsion. The alginate–AgNPs composite sponge had a highly enhanced antimicrobial activity compared to the alginate sponge. In spite of excellent cytocompatibility of the alginate sponge, the viability of the cell treated with the alginate–AgNPs composite sponge extract decreased to 86% of the control. The amount of proinflammatory cytokines released from macrophages treated with the alginate–AgNPs composite sponge was reduced. For the preparation of AgNPs-embedded composites, alginate can be a potential candidate stabilizing AgNPs and providing synergistic antimicrobial and antiinflammatory activities with AgNPs.