TY - JOUR

T1 - Towards in vivo applications of111 Ag perturbed angular correlation of γ-rays (PAC) spectroscopy

AU - Tosato, Marianna

AU - Asti, Mattia

AU - Di Marco, Valerio

AU - Jensen, Marianne L.

AU - Schell, Juliana

AU - Dang, Thien Thanh

AU - Koster, Ulli

AU - Jensen, Mikael

AU - Hemmingsen, Lars

PY - 2022

Y1 - 2022

N2 - 111Ag-perturbed angular correlation of gamma-rays (PAC) spectroscopy provides information on the nuclear quadrupole interactions, and thereby on the local structure and dynamics of the silver ion binding site. Brownian rotational motion, i.e. rotational diffusion, of 111Ag-labeled molecules will significantly affect the PAC spectra. Here we illustrate this effect, by simulating 111Ag PAC spectra for 111Ag-labeled molecules with molecular masses spanning from 102 to 106 g/mol, reflecting a span from fast (small molecules) to slow (large molecules) rotational diffusion on the PAC time scale. The simulated spectra are compared to 111Ag-PAC data obtained from a pilot study involving 111Ag(I) bound to a designed chelator exhibiting fast reorientation in solution, as well as to 111Ag-labeled species formed by 111Ag(I) in human serum, exhibiting slow (or no) reorientation on the PAC time scale. The simulated and experimental data illustrate typical PAC signals that are likely to be observed in vivo, when following the fate of 111Ag-labeled compounds. Potential in vivo applications are stability studies of 111Ag-radiopharmaceuticals, dissociation studies of 111Ag from the labeled molecule followed by binding to another (bio)molecule, or binding of 111Ag-labeled probes to larger carriers such as proteins.

AB - 111Ag-perturbed angular correlation of gamma-rays (PAC) spectroscopy provides information on the nuclear quadrupole interactions, and thereby on the local structure and dynamics of the silver ion binding site. Brownian rotational motion, i.e. rotational diffusion, of 111Ag-labeled molecules will significantly affect the PAC spectra. Here we illustrate this effect, by simulating 111Ag PAC spectra for 111Ag-labeled molecules with molecular masses spanning from 102 to 106 g/mol, reflecting a span from fast (small molecules) to slow (large molecules) rotational diffusion on the PAC time scale. The simulated spectra are compared to 111Ag-PAC data obtained from a pilot study involving 111Ag(I) bound to a designed chelator exhibiting fast reorientation in solution, as well as to 111Ag-labeled species formed by 111Ag(I) in human serum, exhibiting slow (or no) reorientation on the PAC time scale. The simulated and experimental data illustrate typical PAC signals that are likely to be observed in vivo, when following the fate of 111Ag-labeled compounds. Potential in vivo applications are stability studies of 111Ag-radiopharmaceuticals, dissociation studies of 111Ag from the labeled molecule followed by binding to another (bio)molecule, or binding of 111Ag-labeled probes to larger carriers such as proteins.

KW - COORDINATION GEOMETRY

KW - LIPID VESICLES

KW - METAL-IONS

KW - STABILITY

KW - STATE

KW - RADIOMETALS

KW - LIPOSOMES

KW - SILVER(I)

KW - COMPLEX

KW - BINDING

U2 - 10.1016/j.apradiso.2022.110508

DO - 10.1016/j.apradiso.2022.110508

M3 - Journal article

C2 - 36283328

VL - 190

JO - Applied Radiation and Isotopes

JF - Applied Radiation and Isotopes

SN - 0969-8043

M1 - 110508

ER -