在 3D 聚合物凝胶剂量计中用 Pluronic F-127 基质替代明胶可以改善磁共振、热和光学性能。

Substituting gelatine with Pluronic F-127 matrix in 3D polymer gel dosimeters can improve nuclear magnetic resonance, thermal and optical properties.

机构信息

Institute of Materials Science and Engineering, Lodz University of Technology, Lodz, Poland.

出版信息

Phys Med Biol. 2018 Sep 6;63(17):175010. doi: 10.1088/1361-6560/aad9d5.

Abstract

This work discusses the substitution of a gelatine physical gel matrix with a matrix made of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (Pluronic F-127) in five 3D radiotherapy polymer gel dosimeters: MAGAT, PAGAT, NIPAM, VIPAR (VIP) and VIPAR (VIC). The current research outcomes showed that not each polymer gel dosimeter could be manufactured with Pluronic F-127. Two of the polymer gel dosimeters (PAGAT and VIP) containing the Pluronic F-127 matrix allowed for some proper dose response for radiotherapy dosimetry (a response to a dose range of e.g. 0‒50 Gy). The new best performing Pluronic-based polymer gel dosimeters were characterised by improved nuclear magnetic resonance properties, when being compared to gels with gelatine matrix at the same monomer content. These are: (i) a ~33% higher dose sensitivity; (ii) a comparable or slightly higher linear and dynamic dose range and (iii) a lower (new VIP composition, VIP3) or equivocal (new PAGAT composition, PAGAT2-Pluronic) dose threshold. However, there might be optimised gelatine based polymer dosimeters demonstrating even better sensitivity. UV-vis spectrophotometry measurements revealed that Pluronic matrices ensure six-times lower (VIP3-Pluronic) and eight-times lower (PAGAT2-Pluronic) absorbance (at 400 nm) of non-irradiated gels compared to gelatine matrices, which makes the new polymer gel dosimeters optically improved in comparison to their corresponding gelatine-based compositions. The differences in absorption reduce for higher wavelengths. Differential scanning calorimetry measurements revealed the following temperature stability ranges for the gels: (i) VIP with gelatine matrix: 0 °C‒26 °C, (ii) VIP3 with Pluronic matrix: 13.8 °C-55.2 °C, (iii) PAGAT2 with gelatine matrix: 0 °C-80 °C and (iv) PAGAT2 with Pluronic matrix: 21.4 °C-55.2 °C. In conclusion, Pluronic F-127 is an attractive co-polymer to serve as a substitute for the gelatine matrix in some 3D polymer gel dosimeters.

摘要

这项工作讨论了在五种 3D 放射治疗聚合物凝胶剂量计中，用聚（环氧乙烷）-嵌段-聚（丙二醇）-嵌段-聚（环氧乙烷）（Pluronic F-127）基质替代明胶物理凝胶基质：MAGAT、PAGAT、NIPAM、VIPAR（VIP）和 VIPAR（VIC）。目前的研究结果表明，并非每种聚合物凝胶剂量计都可以用 Pluronic F-127 制造。两种含有 Pluronic F-127 基质的聚合物凝胶剂量计（PAGAT 和 VIP）允许对放射治疗剂量进行一些适当的剂量响应（例如，对 0-50 Gy 的剂量范围的响应）。与具有明胶基质的凝胶相比，新的表现最佳的基于 Pluronic 的聚合物凝胶剂量计具有改进的磁共振性能，具有相同的单体含量。这些是：（i）剂量灵敏度提高约 33%；（ii）线性和动态剂量范围相当或略有提高；（iii）剂量阈值降低（新 VIP 组成，VIP3）或不确定（新 PAGAT 组成，PAGAT2-Pluronic）。然而，可能有优化的基于明胶的聚合物剂量计表现出更好的灵敏度。紫外可见分光光度法测量表明，与明胶基质相比，Pluronic 基质使未辐照凝胶的吸光度降低六倍（VIP3-Pluronic）和八倍（PAGAT2-Pluronic）（在 400nm 处），这使得新的聚合物凝胶剂量计在光学上优于其相应的基于明胶的组合物。吸收的差异在较高波长下减小。差示扫描量热法测量显示了凝胶的以下温度稳定范围：（i）明胶基质的 VIP：0°C-26°C，（ii）Pluronic 基质的 VIP3：13.8°C-55.2°C，（iii）明胶基质的 PAGAT2：0°C-80°C，（iv）Pluronic 基质的 PAGAT2：21.4°C-55.2°C。总之，Pluronic F-127 是一种有吸引力的共聚体，可以替代某些 3D 聚合物凝胶剂量计中的明胶基质。