Agarose-silver particles films: Effect of calcium ascorbate in nanoparticles synthesis and film properties.

New nanoparticles containing biomaterials are emerging as versatile active platforms in a great number of applications, for example, as skin substitutes and therapeutic media. The present study describes the preparation of silver nanoparticles (AgNPs) embedded in agarose films and the impact of calcium ascorbate in the formation of ANPs as well as in the final properties of the films. Colloidal AgNPs were synthetized by two chemical reduction routes: (i) applying calcium ascorbate and NaBH and (ii) applying only NaBH. AgNPs synthetized using NaBH showed sizes ranging from 5 to 18 nm while AgNPs were calcium ascorbate was used showed micrometer from 164 to 955 nm size. Films were prepared in three formulations: agarose control film (A1); agarose + AgNPs without calcium ascorbate (A2) and agarose + AgNPs with calcium ascorbate (A3). The characterization of films by SEM and EDS showed agarose agglomerates in A2 and unreacted calcium ascorbate crystals on surface of A3. Thus, the presence of calcium ascorbate influenced the properties of A3 film. In addition, the antimicrobial analysis showed a silver particles release dependence on the film composition and only the A3 presented activity against Staphylococcus aureus. The results found in this study open an important way for development of new biomaterials, economically competitive, and with medical application.