Macrophage clearance of Ag NW. Graph shows absolute numbers of macrophages (left), and silver-positive macrophages (right) in BALF on Days 1-21 post IT of S-Ag NWs (A-B), or L-Ag NWs (C-D). Results are from ANOVA considering dose, time, and particle length at p < 0.05. “d” indicates a significant difference from sham control group (in the same panel, sacrificed on the same day). “T” indicates a significant difference between animals (in the same panel, given the same treatment), but sacrificed on Day 1 versus Day 7.