Mice were injected with 0.5 mg/kg of ICG MPs via (A) intranasal, (B) intravenous, and (C) intraperitoneal administration routes. At set time points, accumulation was measured in the liver, spleen, kidney, heart, lungs, superficial cervical lymph nodes (SCLN), and inguinal lymph nodes (ILN) using IVIS. Values are reported as mean total flux [p/s] ± SEM (n=4).