Chemical Engineering, Arizona State University, 501 E. Tyler Mall, ECG 303, Tempe, AZ 85287-6106 85287, USA.
School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA.
J Mater Chem B. 2020 Jun 10;8(22):4930-4939. doi: 10.1039/d0tb00241k.
Radiation therapy is a common treatment modality employed in the treatment of cancer. High energy photons are the primary source of radiation but when administered, they leave an exit dose resulting in radiation damage to the adjacent healthy tissues. To overcome this, high energy electrons are employed in cases of skin cancer to minimize radiation induced toxicity. Despite these advances, measurement of delivered radiation remains a challenge due to limitations with existing dosimeters including labor intensive fabrication, complex read-out techniques and post-irradiation instability. To overcome these limitations, we have developed a novel colorimetric plasmonic gel nanocomposite for the detection of therapeutic levels of radiation delivered in electron beam therapy. The plasmonic nanocomposite consists of an agarose gel matrix encapsulating precursor gold ions, which are reduced to gold nanoparticles as a result of exposure to high energy electrons. The formation of gold nanoparticles renders a change in color to the agarose matrix, resulting in the formation of plasmonic gel nanocomposites. The intensity of the color formed exhibits a linear relation with the delivered electron dose, which can be quantified using absorbance spectroscopy. The plasmonic gel nanocomposites were able to detect doses employed in fractionated electron therapy, including in an anthropomorphic phantom used for planning radiation treatments in the clinic. Furthermore, the use of glutathione as a quenching agent facilitated qualitative and quantitative spatial mapping of the delivered dose. Our results indicate that the ease of fabrication, simplicity of detection and quantification using absorbance spectroscopy, determination of spatial dose profiles, and relatively low cost make the plasmonic gel nanocomposite technology attractive for detecting electron doses in the clinic.
放射疗法是治疗癌症的常用方法。高能光子是辐射的主要来源，但在给予时，它们会留下出口剂量，导致相邻健康组织的辐射损伤。为了克服这一点，在皮肤癌的情况下使用高能电子来最小化辐射诱导的毒性。尽管取得了这些进展，但由于现有剂量计的局限性，包括劳动密集型制造、复杂的读出技术和辐照后不稳定性，辐射的测量仍然是一个挑战。为了克服这些限制，我们开发了一种新型的比色等离子体凝胶纳米复合材料，用于检测电子束治疗中输送的治疗水平的辐射。等离子体纳米复合材料由琼脂糖凝胶基质组成，该基质包封前体金离子，这些金离子由于暴露于高能电子而被还原为金纳米粒子。金纳米粒子的形成使琼脂糖基质的颜色发生变化，从而形成等离子体凝胶纳米复合材料。形成的颜色的强度与输送的电子剂量呈线性关系，这可以通过吸收光谱进行定量。等离子体凝胶纳米复合材料能够检测分次电子治疗中使用的剂量，包括用于在临床中规划放射治疗的人体模型中的剂量。此外，使用谷胱甘肽作为猝灭剂有助于定性和定量空间映射输送剂量。我们的结果表明，制造的简便性、使用吸收光谱进行检测和定量的简单性、空间剂量分布的确定以及相对较低的成本使等离子体凝胶纳米复合材料技术在检测临床中的电子剂量方面具有吸引力。
