Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant, 3, 21100 Varese, Italy.
J Photochem Photobiol B. 2013 Oct 5;127:123-32. doi: 10.1016/j.jphotobiol.2013.08.011. Epub 2013 Aug 28.
Antimicrobial photodynamic treatment combines the use of photosensitizers (PSs) and visible light to kill bacterial cells. Cationic porphyrins are PSs largely used against bacteria and, among them, those featuring one positive charge on each of the 5,10,15,20-tetraaryl substituent (tetracationic) are the most used. The aim of this study was to synthesize two dicationic 5,15-di(N-alkyl-4-pyridyl)porphyrins, bearing methyl (PS 3) and benzyl (PS 4) N-alkylating groups, and to compare the efficiency in antibacterial photodynamic treatment, upon irradiation with a halogen-tungsten white lamp. The killing efficiency of the PS 4 was constantly found higher than that of the PS 3 against both pure and mixed cultures of laboratory model microorganisms as well as against wild wastewater microflora. The two PSs are comparable as regards singlet oxygen generation, but show a different repartition coefficient; the more lipophilic benzylated PS 4 shows a better interaction with the bacterial cells than the methylated one (PS 3). The data support the hypothesis that an efficient PS-cell binding is required to obtain significant effects. A correlation among cell binding, photoinactivation and PS lipophilicity is suggested.
抗菌光动力疗法结合了光敏剂（PS）和可见光的使用来杀死细菌细胞。阳离子卟啉是一种主要用于对抗细菌的 PS，其中每个 5、10、15、20-四芳基取代基上带有一个正电荷的那些（四阳离子）是最常用的。本研究旨在合成两种二阳离子 5、15-二（N-烷基-4-吡啶基）卟啉，带有甲基（PS 3）和苄基（PS 4）N-烷基化基团，并比较在卤素-钨白灯照射下进行抗菌光动力治疗的效率。发现 PS 4 的杀菌效率始终高于 PS 3，无论是针对实验室模型微生物的纯培养物还是混合培养物，还是针对野生废水微生物区系。这两种 PS 在单线态氧生成方面相当，但分配系数不同；疏水性更强的苄基化 PS 4 与细菌细胞的相互作用优于甲基化 PS 3（PS 3）。这些数据支持了这样一种假设，即需要有效的 PS-细胞结合才能获得显著效果。建议将细胞结合、光灭活和 PS 疏水性之间的相关性。
