von der Osten-Sacken Carolin, Staufer Theresa, Rothkamm Kai, Kuhrwahl Robert, Grüner Florian
University Medical Center Hamburg-Eppendorf, Department of Radiation Oncology, Medical Faculty, University of Hamburg, Martinistraße 52, 20246 Hamburg, Germany.
Institute for Experimental Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
Biomedicines. 2024 Jul 5;12(7):1500. doi: 10.3390/biomedicines12071500.
There is a rising awareness of the toxicity of micro- and nanoplastics (MNPs); however, fundamental precise information on MNP-biodistribution in organisms is currently not available. X-ray fluorescence imaging (XFI) is introduced as a promising imaging modality to elucidate the effective MNP bioavailability and is expected to enable exact measurements on the uptake over the physical barriers of the organism and bioaccumulation in different organs. This is possible because of the ability of XFI to perform quantitative studies with a high spatial resolution and the possibility to conduct longitudinal studies. The focus of this work is a numerical study on the detection limits for a selected XFI-marker, here, palladium, to facilitate the design of future preclinical in vivo studies. Based on Monte Carlo simulations using a 3D voxel mouse model, the palladium detection thresholds in different organs under in vivo conditions in a mouse are estimated. The minimal Pd-mass in the scanning position at a reasonable significance level is determined to be <20 ng/mm for abdominal organs and <16 μg/mm for the brain. MNPs labelled with Pd and homogeneously distributed in the organ would be detectable down to a concentration of <1 μg/mL to <2.5 mg/mL in vivo. Long-term studies with a chronic MNP exposure in low concentrations are therefore possible such that XFI measurements could, in the future, contribute to MNP health risk assessment in small animals and humans.
人们对微塑料和纳米塑料（MNPs）的毒性认识日益提高；然而，目前尚无关于MNPs在生物体中生物分布的基本精确信息。X射线荧光成像（XFI）作为一种有前景的成像方式被引入，以阐明MNPs的有效生物利用度，并有望对其跨越生物体物理屏障的摄取以及在不同器官中的生物蓄积进行精确测量。这是可行的，因为XFI能够进行高空间分辨率的定量研究，并且有可能开展纵向研究。这项工作的重点是对选定的XFI标记物（此处为钯）的检测限进行数值研究，以促进未来临床前体内研究的设计。基于使用三维体素小鼠模型的蒙特卡罗模拟，估计了小鼠体内不同器官在体内条件下的钯检测阈值。在合理的显著性水平下，扫描位置处腹部器官的最小钯质量被确定为<20 ng/mm，脑部为<16 μg/mm。在体内，均匀分布在器官中的钯标记MNPs在浓度低至<1 μg/mL至<2.5 mg/mL时将可被检测到。因此，进行低浓度MNPs长期慢性暴露的研究是可能的，这样未来XFI测量可能有助于评估小动物和人类中MNPs的健康风险。
