Figure 2.

Young and aged mBMMs were polarized to M0, M1, or M2 phenotypes, and challenged with titanium particles. The relative expression of pro-inflammatory cytokine TNF was analyzed (a) 6 h, (b) 12 h, and (c) 24 h after the initiation of particle stimulation. (d) TNF secretion was measured from the culture supernatants until 48 h by ELISA. * indicates statistical significance between similarly treated young and aged macrophages, whereas ‡ demonstrates significant effect of particle stimulation.