Fig. 6

Distribution and accumulation of PS nanoparticles in the spleen. Spectral images of mouse spleen sections after a single intravenous injection of carboxylated (a, b) or PEGylated (c, d) polystyrene nanoparticles, 5 min (a, c) and 4 days (b, d) after exposure. Red arrows indicate translocated particles to the white pulp during the 4-day after exposure period. a′–d′: spectrum profiles of ROIs in the corresponding images. The spectrum of each ROI is marked with the same color as it is delineated in the microscopic image. Green curves represent particle fluorescence (positive controls); red curves represent tissue autofluorescence (negative controls). Scale bars 100 µm