Chelator-free nanoprobes for nuclear molecular imaging.
(a) Biodistribution of Cit-CuS NPs (n = 5) and PEG-CuS NPs (n = 5) at 24 h after i.v. injection in tumor-bearing mice. (b) Micro-PET/CT images of tumor-bearing nude mice acquired at 1, 6, and 24 h after i.v. injection of PEG-[64Cu]CuS NPs. Yellow arrow = tumor; orange arrow = bladder, red arrow = standard. (c) Photographs of mice bearing subcutaneous U87 tumor before and at 24 h after NIR laser irradiation (upper panel). Representative microphotographs of tumors removed 24 h after NIR laser treatment (lower panel). Abbreviations: Cit-CuS NPs = citrate-coated CuS nanoparticles; PEG-CuS NPs = PEG-coated CuS nanoparticles; i.v. = intravenous; NIR = near-infrared. (d) Synthesis of cyclic RGD-PEGylated-AuNP probes labeled with radioactive iodine-125. (e) TEM images of cellular uptake after treated with 125I-cRP-AuNPs, U87MG cells (upper panel) and MCF-7 cells (lower panel). Arrows indicate cellular uptake of 125I-cRP-AuNPs in cells. (f) Small-animal SPECT/CT of 125I-cRP-AuNPs (upper panel), and cold-form-blocked 125I-cRP-AuNPs (lower panel) in nude mice bearing U87MG tumors xenografts after injection through tail vein. Yellow circles indicates tumor region (a-c adapted with permission from ref. 28. Copyright (2010) American Chemical Society & d-f adapted with permission from ref. 32. Copyright (2011) Wiley).