Diagnostic Radiology, Yale School of Medicine, New Haven, CT, 06511, USA,
Mol Imaging Biol. 2013 Oct;15(5):596-605. doi: 10.1007/s11307-013-0636-9.
Our goal was to use positron emission tomography (PET) to analyze the movement of radiolabeled agents in tissue to enable direct measurement of drug delivery to the brain.
Various (11)C- and (18) F-labeled compounds were delivered directly to an agarose phantom or rat striatum. Concentration profiles were extracted for analysis and fitted to diffusion models.
Diffusion coefficients ranged from 0.075 ± 0.0026 mm(2)/min ([(18) F]fluoride ion, 18 Da) to 0.0016 ± 0.0018 mm(2)/min ([(18) F]NPB4-avidin, 68 kDa) and matched well with predictions based on molecular weight (R (2) = 0.965). The tortuosity of the brain extracellular space was estimated to be 1.56, with the tissue clearance halftime of each tracer in the brain varying from 19 to 41 min.
PET is an effective modality to directly quantify the movement of locally delivered drugs or drug carriers. This continuous, noninvasive assessment of delivery will aid the design of better drug delivery methods.
我们的目标是使用正电子发射断层扫描（PET）分析放射性标记试剂在组织中的运动，以实现对药物向大脑输送的直接测量。
将各种（11）C-和（18）F-标记的化合物直接递送至琼脂糖模型或大鼠纹状体。提取浓度曲线进行分析，并拟合至扩散模型。
扩散系数范围从 0.075±0.0026mm(2)/min（[（18）F]氟离子，18Da）至 0.0016±0.0018mm(2)/min（[（18）F]NPB4-avidin，68kDa），与基于分子量的预测值吻合良好（R (2) = 0.965）。脑细胞外空间的曲折度估计为 1.56，每种示踪剂在脑中的清除半衰期从 19 分钟到 41 分钟不等。
PET 是直接定量局部递送的药物或药物载体运动的有效方式。这种连续、非侵入性的输送评估将有助于设计更好的药物输送方法。
