Molecular Imaging, Radiochemistry, and Environmental Pollutants

Abstract

The worldwide proliferation of persistent environmental pollutants is accelerating at an alarming rate. Not surprisingly, many of these pollutants pose a risk to human health. In this review, we examine recent literature in which molecular imaging and radiochemistry have been harnessed to study environmental pollutants. Specifically, these techniques offer unique ways to interrogate the pharmacokinetic profiles and bioaccumulation patterns of pollutants at environmentally relevant concentrations, thereby helping to determine their potential health risks.

Keywords: PET imaging; SPECT imaging; environmental pollutants; fluorescence imaging; molecular imaging.

FIGURE 1.

(A) Fluorescence microscopy images of different-sized polystyrene particles (25, 50, 250, and 700 nm) in zebrafish embryos (13). (B) Maximum-intensity-projection PET/CT images of mice at 6, 12, 24, and 48 h after administration of [⁸⁹Zr]Zr-desferrioxamine-polystyrene (20 nm; 1.85 MBq; 0.1 mg) via oral gavage (16). (C) Maximum-intensity-projection PET/CT images of mice at 1, 6, 12, 24, and 48 h after oral administration of [⁶⁴Cu]Cu-DOTA-polystyrene (200 nm; 4.81 MBq; 57.8 μg) (17). %ID = percent injected dose; hpf = hours postfertilization.

FIGURE 2.

(A and B) Representative PET images illustrating uptake of [¹⁸F]PFOA in mice at 2 time points after administration via tail vein injection (4.44 MBq) (A) and oral gavage (3.7 MBq) (B). b = bladder; f = fetus; h = heart; int = intestine; k = kidney; l = liver; p = placenta; s = stomach. (Reprinted with permission of (25).) (C) PET images of mice at 60 min after intravenous administration of 10 nm, 40 nm, 150 nm, or 10 μm of ¹³N-labeled Al₂O₃ nanoparticles (10–15 MBq, 5–8 mg). (Reprinted with permission of (27).) (D) SPECT/CT images of mice at 2, 24, 72, and 144 h after intravenous administration of ¹⁴¹Ce-labeled cerium oxide nanoparticles (6.7 MBq, 3.6 nmol). (Reprinted with permission of (29).)

FIGURE 3.

(A–C) Representative PET images of mice at 168 h after intratracheal administration (A), 24 h after oral administration (B), and 24 h after intravenous injection (C) of [⁸⁹Zr]Zr-desferrioxamine-pyr-diesel PM (1.85 MBq). Li = liver; Lu = lungs; Sp = spleen; St = stomach. (Reprinted with permission of (3).) (D–E) Whole-body SPECT/CT images of mice at 2, 18, and 48 h after intratracheal (D) and oral (E) administration of ¹²⁵I-labeled diesel exhaust particulates (3.7 MBq) (30).

FIGURE 4.

(A) Whole-body PET/CT images of mice at 1, 3.5, and 24 h after intravenous administration of 2.51–4.55 MBq (50 μg) of [⁶⁴Cu]Cu-GO-thin (left) or [⁶⁴Cu]Cu-GO-thick (right). (Reprinted with permission of (34).) (B) SPECT images of mice at 5, 20, 40, and 60 min after intratracheal administration of [¹²⁵I]I-nanoscale GO (1.85 MBq) (37). (C) Bioluminescence images of mice at 1, 3, and 7 d after intravenous administration of Hg²⁺ (0.02 μmol) and facilitated using intraperitoneally injected Hg²⁺-sensitive probe. (Reprinted with permission of (38).) %ID = percent injected dose.