Wang Lei, Gu Ying, Li Xiao-song, Liu Fan-guang, Yu Chang-qing
Department of Laser Medicine, Chinese PLA General Hospital, Beijing, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2007 Oct;27(10):2073-8.
The photobleaching and formation of photoproduct of hematoporphyrin monomethyl ether (HMME) was investigated in solution by fluorescence spectroscopy. Irradiation was performed by 532 nm double-frequency Nd : YAG laser at a fluence rate of 100 mW x cm(-2), meanwhile the collection of fluorescence spectra was implemented an by optical multi-channel analyzer (OMA). Utilizing the basis spectra constructed and least-square fitting, the intensity of HMME fluorescence (613 nm), photoproduct fluorescence (639 nm) and autofluorescence can be resolved respectively from the single measured spectrum. The correlation between fluorescence intensity and the concentration of HMME is consistent with linear function at concentrations not exceeding 10 microg x mL(-1). Monitoring the fluorescence spectroscopy during irradiation, three kinds of information were obtained, including photobleaching of HMME, formation and bleaching of photoproduct, as well as variation to fluorescence intensity due to the change of sample optical properties. Product generated by bleaching of photoproduct causes significant in sample optical properties. The implementation of fluorescence spectroscopy measurement and spectral analysis method presented here can be utilized effectively for both ex vivo investigation of photobleaching characteristics of photosensitizer and in vivo monitoring for dosimetry in photodynamic therapy.
采用荧光光谱法研究了血卟啉单甲醚（HMME）在溶液中的光漂白及光产物的形成。用532 nm倍频Nd:YAG激光以100 mW·cm⁻²的能量通量率进行辐照，同时用光学多通道分析仪（OMA）采集荧光光谱。利用构建的基线光谱和最小二乘法拟合，可从单次测量光谱中分别解析出HMME荧光（613 nm）、光产物荧光（639 nm）和自发荧光的强度。在浓度不超过10 μg·mL⁻¹时，荧光强度与HMME浓度之间的相关性符合线性函数。在辐照过程中监测荧光光谱，获得了三种信息，包括HMME的光漂白、光产物的形成与漂白以及由于样品光学性质变化导致的荧光强度变化。光产物漂白产生的产物会使样品光学性质发生显著变化。本文提出的荧光光谱测量和光谱分析方法可有效用于光敏剂光漂白特性的离体研究以及光动力治疗中剂量测定的体内监测。
