CCL2 and infection: The presence of 33 nm AgNPs at infection led to significantly up-regulated TNF-α, IL-10, CCL2 and down-regulated IL-6 production (p≤0.05) (Fig. 7A, C, D, E), while 46 nm AgNPs significantly down-regulated TNF-α and IL-6 (p≤0.05) (Fig. 7A, C).