Wrocław University of Science and Technology, Division of Medicinal Chemistry and Microbiology, Faculty of Chemistry, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
Wrocław University of Science and Technology, Division of Medicinal Chemistry and Microbiology, Faculty of Chemistry, Wybrzeże Wyspiańskiego 27, 50-370, Wrocław, Poland.
Photodiagnosis Photodyn Ther. 2019 Sep;27:218-226. doi: 10.1016/j.pdpdt.2019.05.042. Epub 2019 Jun 1.
This study reports successful photodynamic inactivation of planktonic and biofilm cells of Enterococcus faecalis using Methylene Blue (MB) in combination with gold nanoparticles synthesized using the cell-free filtrate obtained from 3-day biomass of Trichoderma asperellum strain. Monodispersed colloidal gold nanoparticles were characterized by UV-vis absorption, TEM and DLS to be 13 ± 3 nm spheres. Diode lasers with the peak-power wavelength ʎ = 660 nm (output power of 21, 41 and 68 mW; power density of 55, 108 and 179 mW∙cm, respectively, were used as a light source to study the effects of MB alone, the gold nanoparticles alone (AuNPs) and the MB + AuNPs mixture on the viability of E. faecalis cells. The lethal effect of planktonic cells was achieved for MB after 30 min of laser irradiation with energy fluence of 322 J∙cm. When MB + AuNPs mixture was used as photosensitizer, the lethal effect was achieved with energy fluence of 292 J∙cm. The biofilm culture was more resistant to photo-inactivation and the best bactericidal effect of MB as photosensitizer was found after light dose of 483 J∙cm. The bacterial cell viability was reduced by 99.92%. It was proved that MB + AuNPs mixture synergistically enhances the kill of the studied microorganism as the same light dose resulted in 99.991% kill.
本研究报告了使用亚甲基蓝（MB）与从 Aspergillus tricuspidatum 菌株 3 天生物量获得的无细胞滤液合成的金纳米粒子结合，成功光动力灭活粪肠球菌浮游细胞和生物膜细胞。单分散胶体金纳米粒子通过紫外可见吸收、TEM 和 DLS 进行表征，为 13±3nm 的球体。峰值功率波长为 λ=660nm 的二极管激光器（输出功率分别为 21、41 和 68mW；功率密度分别为 55、108 和 179mW·cm-2）用作光源，研究了 MB 单独、金纳米粒子单独（AuNPs）和 MB+AuNPs 混合物对粪肠球菌细胞活力的影响。在激光辐照 30 分钟后，MB 的浮游细胞致死效应达到 322J·cm-2 的能量通量。当 MB+AuNPs 混合物用作光敏剂时，在 292J·cm-2 的能量通量下达到致死效应。生物膜培养物对光灭活更具抗性，当使用 MB 作为光敏剂时，最佳杀菌效果出现在光剂量为 483J·cm-2 时。细菌细胞活力降低了 99.92%。证明 MB+AuNPs 混合物协同增强了对研究微生物的杀伤作用，因为相同的光剂量导致 99.991%的杀伤。
