Chien Hsiung-Fei, Chen Chueh-Pin, Chen Yee-Chun, Chang Po-Han, Tsai Tsuimin, Chen Chin-Tin
Department of Surgery, National Taiwan University College of Medicine, Taipei 100, Taiwan.
Int J Mol Sci. 2013 Apr 3;14(4):7445-56. doi: 10.3390/ijms14047445.
Drug-resistant Candida infection is a major health concern among immunocompromised patients. Antimicrobial photodynamic inactivation (PDI) was introduced as an alternative treatment for local infections. Although Candida (C.) has demonstrated susceptibility to PDI, high doses of photosensitizer (PS) and light energy are required, which may be harmful to eukaryotic human cells. This study explores the capacity of chitosan, a polycationic biopolymer, to increase the efficacy of PDI against C. albicans, as well as fluconazole-resistant clinical isolates in planktonic or biofilm states. Chitosan was shown to effectively augment the effect of PDI mediated by toluidine blue O (TBO) against C. albicans that were incubated with chitosan for 30 min following PDI. Chitosan at concentrations as low as 0.25% eradicated C. albicans; however, without PDI treatment, chitosan alone did not demonstrate significant antimicrobial activity within the 30 min of incubation. These results suggest that chitosan only augmented the fungicidal effect after the cells had been damaged by PDI. Increasing the dosage of chitosan or prolonging the incubation time allowed a reduction in the PDI condition required to completely eradicate C. albicans. These results clearly indicate that combining chitosan with PDI is a promising antimicrobial approach to treat infectious diseases.
耐药念珠菌感染是免疫功能低下患者的主要健康问题。抗菌光动力灭活（PDI）作为一种局部感染的替代治疗方法被引入。尽管念珠菌已显示出对PDI敏感，但需要高剂量的光敏剂（PS）和光能，这可能对真核人类细胞有害。本研究探讨了壳聚糖（一种聚阳离子生物聚合物）增强PDI对白色念珠菌以及浮游或生物膜状态下耐氟康唑临床分离株的疗效的能力。结果表明，壳聚糖能有效增强甲苯胺蓝O（TBO）介导的PDI对白色念珠菌的作用，即在PDI后将白色念珠菌与壳聚糖孵育30分钟。低至0.25%浓度的壳聚糖就能根除白色念珠菌；然而，未经PDI处理时，壳聚糖单独在孵育30分钟内未显示出显著的抗菌活性。这些结果表明，壳聚糖仅在细胞被PDI损伤后增强了杀菌效果。增加壳聚糖剂量或延长孵育时间可降低完全根除白色念珠菌所需的PDI条件。这些结果清楚地表明，壳聚糖与PDI联合是一种治疗传染病的有前景的抗菌方法。
