Schneider Raphaël, Schmitt Frédéric, Frochot Céline, Fort Yves, Lourette Natacha, Guillemin François, Müller Jean-François, Barberi-Heyob Muriel
Synthèse Organométallique et Réactivité, UMR 7565 CNRS-UHP, Faculté des Sciences, BP 239, 54506 Vandoeuvre les Nancy, France.
Bioorg Med Chem. 2005 Apr 15;13(8):2799-808. doi: 10.1016/j.bmc.2005.02.025.
Photodynamic therapy (PDT) is a cancer treatment involving systemic administration of a tumor-localizing photosensitizer; this, when activated by the appropriate light wavelength, interacts with molecular oxygen to form a toxic, short-lived species known as singlet oxygen, which is thought to mediate cellular death. Targeted PDT offers the opportunity of enhancing photodynamic efficiency by directly targeting diseased cells and tissues. Two new conjugates of three components, folic acid/hexane-1,6-diamine/4-carboxyphenylporphyrine 1 and folic acid/2,2'-(ethylenedioxy)-bis-ethylamine/4-carboxyphenylporphyrine 2 were synthesized. The conjugates were characterized by 1H NMR, MALDI, UV-visible spectroscopy, and fluorescence quantum yield. The targeted delivery of these photoactive compounds to KB nasopharyngeal cell line, which is one of the numerous tumor cell types that overexpress folate receptors was studied. It was found that after 24 h incubation, conjugates 1 and 2 cellular uptake was on average 7-fold higher than tetraphenylporphyrin (TPP) used as reference and that 1 and 2 cellular uptake kinetics increased steadily over the 24 h period, suggesting an active transport via receptor-mediated endocytosis. In corresponding results, conjugates 1 and 2 accumulation displayed a reduction of 70% in the presence of a competitive concentration of folic acid. Survival measurements demonstrated that KB cells were significantly more sensitive to conjugated porphyrins-mediated PDT. Under the same experimental conditions and the same photosensitizer concentration, TPP displayed no photocytotoxicity while conjugates 1 and 2 showed photodynamic activity with light dose values yielding 50% growth inhibition of 22.6 and 6.7 J/cm2, respectively.
光动力疗法(PDT)是一种癌症治疗方法,涉及全身给予肿瘤定位光敏剂;当该光敏剂被适当的光波长激活时,它会与分子氧相互作用形成一种有毒的、寿命短暂的物质,即单线态氧,据认为单线态氧可介导细胞死亡。靶向光动力疗法提供了通过直接靶向病变细胞和组织来提高光动力效率的机会。合成了两种由三种成分组成的新型共轭物,即叶酸/己烷-1,6-二胺/4-羧基苯基卟啉1和叶酸/2,2'-(乙二氧基)-双乙胺/4-羧基苯基卟啉2。通过1H NMR、基质辅助激光解吸电离(MALDI)、紫外可见光谱和荧光量子产率对共轭物进行了表征。研究了这些光活性化合物向KB鼻咽癌细胞系的靶向递送,KB细胞系是众多过表达叶酸受体的肿瘤细胞类型之一。结果发现,孵育24小时后,共轭物1和2的细胞摄取量平均比用作对照的四苯基卟啉(TPP)高7倍,并且共轭物1和2的细胞摄取动力学在24小时内稳步增加,表明通过受体介导的内吞作用进行主动转运。相应地,在存在竞争浓度叶酸的情况下,共轭物1和2的积累减少了70%。存活测量表明,KB细胞对共轭卟啉介导的光动力疗法明显更敏感。在相同的实验条件和相同的光敏剂浓度下,TPP没有显示出光细胞毒性,而共轭物1和2表现出光动力活性,产生50%生长抑制的光剂量值分别为22.6和6.7 J/cm2。