Kostenich G, Orenstein A, Roitman L, Malik Z, Ehrenberg B
Plastic Surgery Department, Sheba Medical Center, Tel Hashomer, Israel.
J Photochem Photobiol B. 1997 May;39(1):36-42. doi: 10.1016/s1011-1344(96)00005-x.
An in vivo fluorescence monitoring and photodynamic therapy (PDT) study was performed using the new photosensitizer lutetium texaphyrin (Lu-Tex). This photosensitizer is water soluble and has the additional advantage of strong absorption near 730 nm. C26 colon carcinoma was transplanted in the foot of BALB/c mice. In vivo fluorescence spectroscopy was applied to study Lu-Tex tissue distribution kinetics. For this purpose, fluorescence intensity both in the foot with the tumor and in the normal foot was measured in vivo by the laser-induced fluorescence (LIF) system. For PDT, both feet of the mice were irradiated simultaneously with the use of a new high intensity pulsed light delivery system, the Photodyne. The results of the LIF measurements showed that the maximal fluorescence intensity ratio between the normal and tumor bearing foot (FIR) was observed 24-48 h after the agent injection. Photoirradiation with doses from 90 to 240 J cm-2 (0.6 J cm-2 per 2 ms pulse, 1 Hz) 24 h after injection of Lu-Tex at a dose of 10 mg kg-1 caused significant tumor necrosis and delay in the tumor growth rate. The antitumor effect was enhanced with increasing light doses. Normal tissue response to PDT with Lu-Tex was determined as the damage index of the normal foot, which was irradiated simultaneously with the tumor bearing foot. The normal tissue response after PDT with Lu-Tex was compared with 5-aminolevulinic acid (ALA) induced protoporphyrin IX (PP), chlorin e6 (Chl) and Photofrin (PII) at the same values of antitumor effect. The results showed that at 50, 80 and 100% inhibition of tumor growth the orders of the values of normal foot damage indexes were as follows: ALA > Lu-Tex > or = PII > Chl, PII > ALA > Lu-Tex > Chl and PII > Lu-Tex > ALA > Chl respectively.
使用新型光敏剂钬特辛（Lu-Tex）进行了一项体内荧光监测和光动力疗法（PDT）研究。这种光敏剂可溶于水，并且在730nm附近具有强吸收的额外优势。将C26结肠癌移植到BALB/c小鼠的足部。应用体内荧光光谱法研究Lu-Tex的组织分布动力学。为此，通过激光诱导荧光（LIF）系统在体内测量肿瘤所在足部和正常足部的荧光强度。对于光动力疗法，使用新型高强度脉冲光输送系统Photodyne同时照射小鼠的两只脚。LIF测量结果表明，在注射药物后24 - 48小时观察到正常足部与荷瘤足部之间的最大荧光强度比（FIR）。在以10mg/kg的剂量注射Lu-Tex后24小时，用90至240J/cm²（每2ms脉冲0.6J/cm²，1Hz）的剂量进行光照射，导致显著的肿瘤坏死并延缓肿瘤生长速度。随着光剂量增加，抗肿瘤效果增强。将Lu-Tex光动力疗法对正常组织的反应确定为与荷瘤足部同时照射的正常足部的损伤指数。将Lu-Tex光动力疗法后的正常组织反应与在相同抗肿瘤效果值下的5-氨基乙酰丙酸（ALA）诱导的原卟啉IX（PP）、二氢卟吩e6（Chl）和血卟啉衍生物（PII）进行比较。结果表明，在肿瘤生长抑制率为50%、80%和100%时，正常足部损伤指数值的顺序分别为：ALA > Lu-Tex > 或 = PII > Chl，PII > ALA > Lu-Tex > Chl以及PII > Lu-Tex > ALA > Chl。
