In vivo human breast cancer xenograft model in nude mice to observe the Survivin-siRNA biodistribution via fluorescence imaging. (A) Images taken at 1, 2, 4, and 8 h after injection of all formulations. (B) Fluorescent images obtained after dissection of the main organs from each formulation group. Figures in (A,B) are reprinted with open access permission from [64], copyright 2021 Shenyang Pharmaceutical University, published by Elsevier. (C) Biodistribution of Cu-labeled GO nanocarriers evaluated in ex vivo mice organs after 24 h of intravenous injection (NOTA: 2-S-(4-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid). Figures are reprinted with permission from [178], copyright 2016 Elsevier.