Silver Is Not Equal to Silver: Synthesis and Evaluation of Silver Nanoparticles with Low Biological Activity, and Their Incorporation into C12Alanine-Based Hydrogel

A new type of silver nanoparticles (AgNPs) was prepared and comprehensively studied. Scanning electron microscopy (SEM) and dynamic light scattering (DLS) analyses indicated that 24 nm AgNPs with narrow size distribution were obtained while Z-potential confirms their good stability. The composites of the obtained AgNPs with nontoxic-nature-inspired hydrogel were formed upon cooling of the aqueous solution AgNPs and C(12)Ala. The thermal gravimetric analysis (TGA) and the differential scanning calorimetry (DSC) do not show significant shifts in the characteristic temperature peaks for pure and silver-enriched gels, which indicates that AgNPs do not strongly interact with C(12)Ala fibers, which was also confirmed by SEM. Both AgNPs alone and in the assembly with the gelator C(12)Ala were almost biologically passive against bacteria, fungus, cancer, and nontumor human cells, as well as zebra-fish embryos. These studies proved that the new inactive AgNPs-doped hydrogels have potential for the application in therapy as drug delivery media.

Automated summary

A new type of silver nanoparticles (AgNPs) with good stability and narrow size distribution was prepared and studied. They were mixed with a non-toxic hydrogel, and no significant interaction between AgNPs and the hydrogel was observed. Furthermore, the AgNPs showed low biological activity against various cells and organisms, indicating their potential for drug delivery applications.