Gsponer Natalia S, Spesia Mariana B, Durantini Edgardo N
Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, X5804BYA Río Cuarto, Córdoba, Argentina.
Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, X5804BYA Río Cuarto, Córdoba, Argentina.
Photodiagnosis Photodyn Ther. 2015 Mar;12(1):67-75. doi: 10.1016/j.pdpdt.2014.12.004. Epub 2015 Jan 2.
The effect of divalent cations, EDTA and chitosan (CS) on the uptake and photoinactivation of Escherichia coli produced by 5,10,15,20-tetrakis(4-N,N,N-trimethylammoniumphenyl)porphyrin (TMAP(4+)), 5,10-di(4-methylphenyl)-15,20-di(4-N,N,N-trimethylammoniumphenyl)porphyrin (MPAP(2+)) and 5,10,15,20-tetra(4-sulphonatophenyl)porphyrin (TPPS(4-)) were examined under different conditions. These porphyrins were rapidly bound to E. coli cells (<2.5min) and the uptake of photosensitizers was not dependent on incubation temperature, reaching values of 0.61, 0.18 and 0.08nmol/10(8) cells for TMAP(4+), MPAP(2+) and TPPS(4-), respectively. The addition of Ca(2+) or Mg(2+) to the cultures enhanced the uptake of MPAP(2+) and TPPS(4-) by cells. In contrast, the amount of TMAP(4+) bound to cells was decreased. The presence of EDTA produced an increase in the uptake of porphyrins by cells, while CS mainly enhanced the amount of TPPS(4-) bound to E. coli. The photoinactivation of E. coli cells mediated by TMAP(4+) was highly effective even at low concentration (1μM) and short irradiation period (5min). However, a reduction in the phototoxicity was found for TMAP(4+) in presence of Ca(2+) and Mg(2+). In contrast, the phototoxic activity mediated by MPAP(2+) and TPPS(4-) was increased. Addition of EDTA did not show effect on the photoinactivation induced by cationic porphyrins, while a small enhance was found for TPPS(4-). Moreover, inactivation of E. coli cells was achieved in the presence CS. This cationic polymer was antimicrobial by itself in the dark. Using a slightly toxic CS concentration, the phototoxic activity induced by TMAP(4+) was diminished. This effect was mainly observed at lower concentration of TMAP(4+) (0.5-1μM). In contrast, an increase in E. coli photoinactivation was obtained for MPAP(2+) and TPPS(4-) in presence of CS. Thus, this natural polymeric destabilizer agent mainly benefited the photoinactivation mediated by TPPS(4-).
研究了二价阳离子、乙二胺四乙酸（EDTA）和壳聚糖（CS）对由5,10,15,20-四（4-N,N,N-三甲基铵苯基）卟啉（TMAP(4+)）、5,10-二（4-甲基苯基）-15,20-二（4-N,N,N-三甲基铵苯基）卟啉（MPAP(2+)）和5,10,15,20-四（4-磺酸钠苯基）卟啉（TPPS(4-)）产生的大肠杆菌摄取和光灭活的影响，实验在不同条件下进行。这些卟啉能迅速与大肠杆菌细胞结合（<2.5分钟），且光敏剂的摄取不依赖于孵育温度，TMAP(4+)、MPAP(2+)和TPPS(4-)分别达到0.61、0.18和0.08nmol/10(8)个细胞的值。向培养物中添加Ca(2+)或Mg(2+)可增强细胞对MPAP(2+)和TPPS(4-)的摄取。相反，与细胞结合的TMAP(4+)量减少。EDTA的存在使细胞对卟啉的摄取增加，而CS主要增加了与大肠杆菌结合的TPPS(4-)量。由TMAP(4+)介导的大肠杆菌细胞光灭活即使在低浓度（1μM）和短照射时间（5分钟）下也非常有效。然而，在Ca(2+)和Mg(2+)存在下，发现TMAP(4+)的光毒性降低。相反，由MPAP(2+)和TPPS(4-)介导的光毒性活性增加。添加EDTA对阳离子卟啉诱导的光灭活没有影响，而对TPPS(4-)有轻微增强作用。此外，在CS存在下实现了大肠杆菌细胞的灭活。这种阳离子聚合物本身在黑暗中具有抗菌作用。使用毒性稍低的CS浓度，TMAP(4+)诱导的光毒性活性降低。这种效应主要在较低浓度的TMAP(4+)（0.5 - 1μM）下观察到。相反，在CS存在下，MPAP(2+)和TPPS(4-)对大肠杆菌的光灭活增加。因此，这种天然聚合物去稳定剂主要有利于由TPPS(4-)介导的光灭活。
