Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, North 14, West 9, Kita-ku, Sapporo, 060-0814, Japan.
Analyst. 2020 May 7;145(9):3236-3244. doi: 10.1039/d0an00168f. Epub 2020 Mar 5.
The partial pressure of oxygen (pO) and the extracellular pH in the tumour microenvironment are essential parameters for understanding the physiological state of a solid tumour. Also, phosphate-containing metabolites are involved in energy metabolism, and interstitial inorganic phosphate (Pi) is an informative marker for tumour growth. This article describes the simultaneous mapping of pO, pH and Pi using 750 MHz continuous-wave (CW) electron paramagnetic resonance (EPR) and a multifunctional probe, monophosphonated trityl radical pTAM-D. The concept was demonstrated by acquiring three-dimensional (3D) maps of pO, pH and Pi for multiple solution samples. This was made possible by combining a multifunctional radical probe, fast CW-EPR spectral acquisition, four-dimensional (4D) spectral-spatial image reconstruction, and spectral fitting. The experimental results of mapping pO, pH and Pi suggest that the concept of simultaneous mapping using EPR is potentially applicable for the multifunctional measurements of a mouse tumour model.
氧分压 (pO) 和肿瘤微环境中的细胞外 pH 值是理解实体瘤生理状态的重要参数。此外，含磷代谢物参与能量代谢，间质无机磷 (Pi) 是肿瘤生长的信息标志物。本文描述了使用 750 MHz 连续波 (CW) 电子顺磁共振 (EPR) 和多功能探头单膦化三苯甲基自由基 pTAM-D 同时绘制 pO、pH 和 Pi 的方法。通过对多个溶液样本进行三维 (3D) pO、pH 和 Pi 图谱的采集，证明了这一概念的可行性。这是通过结合多功能自由基探针、快速 CW-EPR 光谱采集、四维 (4D) 光谱-空间图像重建和光谱拟合来实现的。pO、pH 和 Pi 图谱绘制的实验结果表明，EPR 同时绘制的概念可能适用于小鼠肿瘤模型的多功能测量。
