Laboratory for Nanomedicine Research, Division of Engineering, Brown University, Providence, Rhode Island, USA.
J Biomed Mater Res B Appl Biomater. 2011 Jul;98(1):1-7. doi: 10.1002/jbm.b.31821. Epub 2011 May 18.
Patients on mechanical ventilators for extended periods of time are faced with a high probability of developing ventilator associated pneumonia. Although this has been mostly addressed through the re-engineering of endotracheal tubes (ETTs) with antimicrobial materials, such material coatings may easily delaminate during use. However, the potential exists to apply nanotechnology to the ETT to avoid delamination but implement antibacterial properties. Selecting a protocol to evaluate in vitro material for anti-infection is difficult, partially due to the existence of conflicting reported methods of analysis. In this study, the susceptibility of conventional and nanorough polymeric materials to bacterial biofilm growth were evaluated. After creating nanorough polyvinyl chloride (PVC) ETTs, Pseudomonas aeruginosa biofilms were then grown on sample surfaces during a 24-h culture. Biofilms were then removed and assayed from sample surfaces using a variety of techniques. Comparisons between the different techniques used for biofilm removal indicated that vortexing provided adequate removal of the biofilm from sample surfaces. Most importantly, a protocol following the vortexing method of biofilm and bacteria removal provided an ∼40% lower yield of colony forming units from nanorough PVC compared to conventional PVC. This suggests that Pseudomonas aeruginosa are less adherent on nanorough PVC than conventional PVC.
长时间使用机械呼吸机的患者极有可能患上呼吸机相关性肺炎。虽然这在很大程度上可以通过使用抗菌材料对气管内导管（ETT）进行重新设计来解决，但这些材料涂层在使用过程中可能很容易分层。然而，将纳米技术应用于 ETT 以避免分层并实现抗菌性能是有可能的。选择评估体外材料抗感染的方案具有一定难度，部分原因是存在相互矛盾的报告分析方法。在这项研究中，评估了常规和纳米粗糙聚合物材料对细菌生物膜生长的敏感性。在创建纳米粗糙聚氯乙烯（PVC）ETT 后，在 24 小时培养期间在样品表面上生长铜绿假单胞菌生物膜。然后从样品表面去除生物膜并使用各种技术进行分析。用于生物膜去除的不同技术之间的比较表明，涡旋足以从样品表面去除生物膜。最重要的是，与传统 PVC 相比，纳米粗糙 PVC 采用涡旋法去除生物膜和细菌的方案提供了约 40%的较低菌落形成单位产量。这表明铜绿假单胞菌在纳米粗糙 PVC 上的附着性低于传统 PVC。
