Bochum and Munich, Germany From the Department for Plastic Surgery, Burn Center, BG University Hospital Bergmannsheil, Ruhr University Bochum, and the Department of Oral and Maxillofacial Surgery, Klinikum Rechts der Isar, TU Munich.
Plast Reconstr Surg. 2011 May;127(5):1838-1846. doi: 10.1097/PRS.0b013e31820cf29a.
Wound infections caused by multidrug-resistant bacteria are a major issue in wound care. An occlusive dressing delivering an antimicrobial agent to the wound may be advantageous. The objective of this study was to evaluate an occlusive silk membrane loaded with colistin to establish an effective antimicrobial wound dressing against Gram-negative bacteria in vitro and in vivo.
ST-silk protein membranes (thickness, 100 μm; pore size, <100 nm) were loaded with log-scale colistin dilutions (0.027 to 270 mg/ml) and tested in a modified microbroth dilution assay against Pseudomonas aeruginosa (American Type Culture Collection 27853). A rat burn infection model was used to demonstrate the antimicrobial activity of ST-silk membranes loaded with 270 mg/ml colistin. Finally, a porcine wound infection model was used to study dose response (2.7, 27, and 270 mg/ml colistin loading concentration) in a time-dependent manner (0, 2, 4, and 6 days).
The in vitro study demonstrated a concentration-dependent antimicrobial effect against P. aeruginosa, with complete elimination at the highest loading concentrations (2.7, 27, and 270 mg/ml). All colistin membranes demonstrated lower colony-forming unit counts compared with the corresponding phosphate-buffered saline or carrier controls. The rat burn infection model demonstrated a colony-forming unit reduction of greater than 3 log-scales for the colistin-loaded ST-silk membranes after 3 days. On average, the wounds' colony-forming unit quantity remained at greater than 1000 during the entire follow-up of 6 days, apart from three wounds where complete bacterial clearance was observed.
This study demonstrates that occlusive ST-silk membranes loaded with an antimicrobial agent may be an effective dressing for infected wounds.
由耐药菌引起的伤口感染是伤口护理的一个主要问题。局部使用载有抗菌剂的密闭性敷料可能会更具优势。本研究的目的是评估一种载有黏菌素的密闭性丝质膜，以建立一种针对革兰氏阴性菌的有效抗菌性伤口敷料，在体外和体内进行评估。
ST-丝质蛋白膜（厚度 100μm；孔径<100nm）用对数级别的黏菌素稀释液（0.027 至 270mg/ml）负载，并用改良的微量肉汤稀释法对铜绿假单胞菌（美国典型培养物保藏中心 27853 号）进行测试。使用大鼠烧伤感染模型来证明载有 270mg/ml 黏菌素的 ST-丝质膜的抗菌活性。最后，使用猪伤口感染模型来研究剂量反应（2.7、27 和 270mg/ml 黏菌素负载浓度）在时间依赖性（0、2、4 和 6 天）方面的情况。
体外研究显示出对铜绿假单胞菌的浓度依赖性抗菌效果，在最高负载浓度（2.7、27 和 270mg/ml）下完全消除。所有黏菌素膜的菌落形成单位计数均低于相应的磷酸盐缓冲盐水或载体对照。大鼠烧伤感染模型表明，在 3 天内，载有黏菌素的 ST-丝质膜的菌落形成单位减少了 3 个对数级。平均而言，除了三个观察到完全清除细菌的伤口外，在整个 6 天的随访期间，伤口的菌落形成单位数量一直保持在 1000 以上。
本研究表明，载有抗菌剂的密闭性 ST-丝质膜可能是感染伤口的有效敷料。
