Biocompatibility and inflammatory response of silver tungstate, silver molybdate, and silver vanadate microcrystals.

Silver tungstate (α-AgWO), silver molybdate (β-AgMoO), and silver vanadate (α-AgVO) microcrystals have shown interesting antimicrobial properties. However, their biocompatibility is not yet fully understood. Cytotoxicity and the inflammatory response of silver-containing microcrystals were analyzed in THP-1 and THP-1 differentiated as macrophage-like cells, with the alamarBlue™ assay, flow cytometry, confocal microscopy, and ELISA. The present investigation also evaluated redox signaling and the production of cytokines (TNFα, IL-1β, IL-6, and IL-8) and matrix metalloproteinases (MMP-8 and -9). The results showed that α-AgVO (3.9 μg/mL) did not affect cell viability ( > 0.05). α-AgWO (7.81 μg/mL), β-AgMoO (15.62 μg/mL), and α-AgVO (15.62 μg/mL) slightly decreased cell viability ( ≤ 0.003). All silver-containing microcrystals induced the production of O and this effect was mitigated by Reactive Oxygen Species (ROS) scavenger and N-acetylcysteine (NAC). TNFα, IL-6 and IL-1β were not detected in THP-1 cells, while their production was either lower ( ≤ 0.0321) or similar to the control group ( ≥ 0.1048) for macrophage-like cells. The production of IL-8 by both cellular phenotypes was similar to the control group ( ≥ 0.3570). The release of MMP-8 was not detected in any condition in THP-1 cells. Although MMP-9 was released by THP-1 cells exposed to α-AgVO (3.9 μg/mL), no significant difference was found with control ( = 0.7). Regarding macrophage-like cells, the release of MMP-8 and -9 decreased in the presence of all microcrystals ( ≤ 0.010). Overall, the present work shows a promising biocompatibility profile of, α-AgWO, β-AgMoO, and α-AgVO microcrystals.