Gillies R, Kollias N, Hasan T, Diddens H
Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Boston, USA.
J Photochem Photobiol B. 1996 Mar;33(1):87-90. doi: 10.1016/1011-1344(95)07222-5.
Benzoporphyrin derivative monoacid ring A (BPD-MA) is a second-generation photosensitizer for photodynamic therapy (PDT) that has shown good results in phase I clinical trials. Similar to other porphyrin derivatives, BPD-MA readily photobleaches during in-vivo PDT treatment. This study investigated the photodegradation of BPD-MA in fetal calf serum (FCS) solutions in vitro. Absorption and fluorescence spectra from dilute solutions of BPD-MA in 10% FCS were recorded before and immediately after irradiation with light at 694 nm. After irradiation, the appearance of a new fluorescence emission band at 650 nm and changes in the fluorescence excitation spectra indicate the formation of a photoproduct. Photoproduct formation was observed only when BPD-MA was bound to FCS and in oxygenated solutions. The spectroscopy of the photoproduct is consistent with the reaction of an oxygen species with the ring B vinyl group, forming a hydroxyaldehyde photoproduct. Monitoring the increase in photoproduct fluorescence during treatment may provide an in-vivo dosimeter to measure PDT efficacy.
苯并卟啉衍生物单酸环A（BPD-MA）是一种用于光动力疗法（PDT）的第二代光敏剂，已在I期临床试验中显示出良好效果。与其他卟啉衍生物类似，BPD-MA在体内PDT治疗过程中容易发生光漂白。本研究在体外研究了BPD-MA在胎牛血清（FCS）溶液中的光降解情况。在用694nm光照射之前和之后，立即记录了BPD-MA在10%FCS稀溶液中的吸收光谱和荧光光谱。照射后，650nm处出现新的荧光发射带以及荧光激发光谱的变化表明形成了一种光产物。仅当BPD-MA与FCS结合且在含氧溶液中时才观察到光产物的形成。光产物的光谱与氧物种与环B乙烯基的反应一致，形成了一种羟基醛光产物。在治疗过程中监测光产物荧光的增加可能会提供一种体内剂量计来测量PDT疗效。
