Chemical determination of singlet oxygen from photosensitizers illuminated with LED: New calculation methodology considering the influence of photobleaching
Chemical determination of singlet oxygen from photosensitizers illuminated with LED: New calculation methodology considering the influence of photobleaching
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DOI：
10.1016/j.jphotochem.2012.01.018
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发表时间：
2012-03-15
影响因子：
4.3
通讯作者：
Caetano, Wilker
中科院分区：
文献类型：
--
作者：
Gerola, Adriana Passarella;Semensato, Juliana;Caetano, Wilker
单线态氧（O-1（2））是光动力学疗法（PDT）中负责破坏靶细胞的活性物质之一。然而，O-1（2）产率（phi（Delta））的量化涉及使用非常昂贵的设备的寿命测量。另一种方法是使用化学捕集器，在本例中为尿酸（UA），其迅速与O-1（2）反应，提供phi（Delta）的评估。另一方面，在这类实验中，在采用LED作为照射源的PS吸收的光子的量化中，重要的是评估PS光谱中光源的重叠。此外，虽然一些PS是光稳定的，但其他PS可能会经历光漂白，导致吸收的光子量因PS降解而随照射时间而变化。拟议的方法纠正了这一问题。建议的剂量测定方法，采用VA和吸收光子的计算，考虑到叶绿素和氧杂蒽染料的光漂白导致的phi（德尔塔）值，同意与文献。(C)2012 Elsevier B. V.保留所有权利。
The singlet oxygen (O-1(2)) is one of the reactive species responsible for the destruction of target cells in Photodynamic Therapy (PDT). However, the quantification of O-1(2) yields (phi(Delta)) involves lifetime measurements with very expensive equipment. An alternative methodology is the use of a chemical trap, in the present case uric acid (UA), which promptly reacts with O-1(2) providing the evaluation of phi(Delta). On the other hand, in the quantification of the photons absorbed by the PS employing LED as irradiation sources in this kind of experiments, it is important to evaluate the overlap of the light source in the PS spectrum. Additionally, while some PS are photostable, others may undergo photobleaching leading the amount of absorbed photons to vary with the illumination time due to PS degradation. The proposed methodology corrects this problem. The proposed dosimetry method employing VA and the absorbed photon calculations taking into account chlorophyll and xanthene dyes photobleaching resulted in phi(Delta) values that agree with the literature. (C) 2012 Elsevier B.V. All rights reserved.