Department of Pharmaceutics and Biopharmaceutics, University of Marburg, 35037 Marburg, Germany.
Department of Pharmaceutics and Biopharmaceutics, University of Marburg, 35037 Marburg, Germany.
Mater Sci Eng C Mater Biol Appl. 2019 Oct;103:109749. doi: 10.1016/j.msec.2019.109749. Epub 2019 May 14.
Catheter related infections are causing one third of all blood stream infections. The mortality of those infections is very high and the gold standard for catheter related blood stream infections (CR-BSI) is still the removal of the catheter and systemic antibiotic therapy. There already exist some approaches to prevent the biofilm formation on catheter material, which are far from ideal. A new strategy to prevent bacterial colonization on catheter surfaces is the application of photodynamic therapy (PDT). Therefor the surface has to be modified with substances that can be activated by light, leading to the production of cell toxic reactive oxygen species (ROS). Only small concentrations of the so called photosensitizer (PS) are necessary, avoiding side effects in human therapy. Furthermore, there is no resistance development in PDT. In this study polyurethane (PUR) surfaces were coated with hypericin nanoformulations, leading to 4.3 log reduction in bacterial growth in vitro. The effect could be enhanced by the application of ultrasound. The combination of PDT with ultrasound therapy led to a synergistic effect resulting in a 6.8 log reduction of viable counts. This minimal invasive method requires only an optical fibre inserted in the catheter lumen and an ultrasound device. Thus the implementation in daily clinical practice is very simple.
导管相关感染导致了三分之一的血流感染。这些感染的死亡率非常高，导管相关血流感染（CR-BSI）的金标准仍然是去除导管和全身抗生素治疗。目前已经有一些方法可以防止导管材料上生物膜的形成，但还远不理想。预防细菌在导管表面定植的一种新策略是应用光动力疗法（PDT）。因此，表面必须用可以被光激活的物质进行修饰，从而产生细胞毒性的活性氧（ROS）。只需要非常低浓度的所谓光敏剂（PS），就可以避免人体治疗中的副作用。此外，PDT 不会产生耐药性。在这项研究中，聚氨酯（PUR）表面涂有金丝桃素纳米制剂，导致体外细菌生长减少 4.3 对数。应用超声波可以增强这种效果。PDT 与超声波治疗的联合应用产生协同作用，使活菌数减少 6.8 对数。这种微创方法只需要一根光纤插入导管腔和一个超声设备。因此，在日常临床实践中的实施非常简单。
