Biointerface Engineering Group, IRIS, Faculty of SET, Swinburne University of Technology, 3122, Hawthorn, Victoria, Australia.
ACS Appl Mater Interfaces. 2015 Apr 15;7(14):7644-52. doi: 10.1021/acsami.5b00453. Epub 2015 Apr 1.
Electrospun materials have been widely investigated in the past few decades as candidates for tissue engineering applications. However, there is little available data on the mechanisms of interaction of bacteria with electrospun wound dressings of different morphology and surface chemistry. This knowledge could allow the development of effective devices against bacterial infections in chronic wounds. In this paper, the interactions of three bacterial species (Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) with electrospun polystyrene meshes were investigated. Bacterial response to meshes with different fiber diameters was assessed through a combination of scanning electron microscopy (SEM) and confocal microscopy. Experiments included attachment studies in liquid medium but also directly onto agar plates; the latter was aimed at mimicking a chronic wound environment. Fiber diameter was shown to affect the ability of bacteria to proliferate within the fibrous networks, depending on cell size and shape. The highest proliferation rates occurred when fiber diameter was close to the bacterial size. Nanofibers were found to induce conformational changes of rod shaped bacteria, limiting the colonization process and inducing cell death. The data suggest that simply tuning the morphological properties of electrospun fibers may be one strategy used to control biofilm formation within wound dressings.
在过去的几十年中，静电纺丝材料作为组织工程应用的候选材料得到了广泛的研究。然而，关于不同形态和表面化学的电纺伤口敷料与细菌相互作用的机制的数据很少。这方面的知识可能有助于开发针对慢性伤口细菌感染的有效装置。本文研究了三种细菌（大肠杆菌、铜绿假单胞菌和金黄色葡萄球菌）与聚苯乙烯静电纺丝网的相互作用。通过扫描电子显微镜（SEM）和共聚焦显微镜的组合评估了细菌对不同纤维直径的网的反应。实验包括在液体培养基中的附着研究，但也直接在琼脂平板上进行；后者旨在模拟慢性伤口环境。纤维直径被证明会影响细菌在纤维网络内增殖的能力，这取决于细胞的大小和形状。当纤维直径接近细菌大小时，增殖率最高。纳米纤维被发现会引起杆状细菌的构象变化，限制了定植过程并诱导细胞死亡。数据表明，只需调整静电纺丝纤维的形态特性，就可能成为控制伤口敷料内生物膜形成的一种策略。
