Department of Biomedical Engineering, Faculty of Electrical and Computer Engineering, Tarbiat Modares University, Tehran, Iran.
Appl Spectrosc. 2010 Dec;64(12):1350-4. doi: 10.1366/000370210793561682.
Photodynamic therapy (PDT) is an effective treatment method for various types of invasive tumors. The efficiency of PDT treatment depends, to a great extent, on optimal dosimetry of light, the photosensitizer used, and on tissue oxygenation. Fluorescence spectroscopy can be employed for measurement of drug concentration in target tissue and can provide a basis for in vivo evaluation of treatment efficiency. We have developed an integrated system that can be used to determine photosensitizer concentration in vivo based on fluorescence measurements. In our study, we performed fluorescence measurements on colon tumors of Balb/c mice in which CT26 cells were injected subcutaneously in the right flank. 5-Aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) was used as the photosensitizer. ALA was administered intraperitoneally at a dose of 200 mg/kg and PpIX fluorescence profiles were followed up to 34 h after ALA administration. Maximum fluorescence intensity was found 8 h after ALA administration. Also, we determined the relationship between PpIX concentration in colon tumor tissue of Balb/c mice and its fluorescence intensity at the peak of the spectrum (635 nm). This was used to determine the PpIX content in the target tissue as a function of time after ALA administration.
光动力疗法（PDT）是一种治疗各种侵袭性肿瘤的有效方法。PDT 治疗的效率在很大程度上取决于光的最佳剂量、使用的光敏剂以及组织的氧合作用。荧光光谱法可用于测量靶组织中的药物浓度，并为体内治疗效率评估提供依据。我们已经开发出一种集成系统，可基于荧光测量来确定体内光敏剂浓度。在我们的研究中，我们对皮下注射 CT26 细胞于右侧肋腹的 Balb/c 小鼠的结肠肿瘤进行了荧光测量。使用 5-氨基酮戊酸（ALA）诱导的原卟啉 IX（PpIX）作为光敏剂。以 200mg/kg 的剂量腹腔内给予 ALA，并在 ALA 给药后 34 小时内跟踪 PpIX 荧光曲线。在 ALA 给药 8 小时后发现最大荧光强度。此外，我们还确定了 Balb/c 小鼠结肠肿瘤组织中 PpIX 浓度与其光谱峰值处的荧光强度（635nm）之间的关系。这用于确定 ALA 给药后 PpIX 在靶组织中的含量随时间的变化。
