Tyler Bonnie J, Hook Andrew, Pelster Andreas, Williams Paul, Alexander Morgan, Arlinghaus Heinrich F
Physikalisches Institut, University of Münster, 48159 Münster, Germany.
School of Pharmacy, University of Nottingham, NG7 2RD Nottingham, United Kingdom.
Biointerphases. 2017 May 23;12(2):02C412. doi: 10.1116/1.4984011.
Catheter associated urinary tract infections are the most common health related infections worldwide, contributing significantly to patient morbidity and mortality and increased health care costs. To reduce the incidence of these infections, new materials that resist bacterial biofilm formation are needed. A composite catheter material, consisting of bulk poly(dimethylsiloxane) (PDMS) coated with a novel bacterial biofilm resistant polyacrylate [ethylene glycol dicyclopentenyl ether acrylate (EGDPEA)-co-di(ethyleneglycol) methyl ether methacrylate (DEGMA)], has been proposed. The coated material shows excellent bacterial resistance when compared to commercial catheter materials, but delamination of the EGDPEA-co-DEGMA coatings under mechanical stress presents a challenge. In this work, the use of oxygen plasma treatment to improve the wettability and reactivity of the PDMS catheter material and improve adhesion with the EGDPEA-co-DEGMA coating has been investigated. Argon cluster three dimensional-imaging time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been used to probe the buried adhesive interface between the EGDPEA-co-DEGMA coating and the treated PDMS. ToF-SIMS analysis was performed in both dry and frozen-hydrated states, and the results were compared to mechanical tests. From the ToF-SIMS data, the authors have been able to observe the presence of PDMS, silicates, salt particles, cracks, and water at the adhesive interface. In the dry catheters, low molecular weight PDMS oligomers at the interface were associated with poor adhesion. When hydrated, the hydrophilic silicates attracted water to the interface and led to easy delamination of the coating. The best adhesion results, under hydrated conditions, were obtained using a combination of 5 min O plasma treatment and silane primers. Cryo-ToF-SIMS analysis of the hydrated catheter material showed that the bond between the primed PDMS catheter and the EGDPEA-co-DEGMA coating was stable in the presence of water. The resulting catheter material resisted Escherichia coli and Proteus mirabilis biofilm colonization by up to 95% compared with uncoated PDMS after 10 days of continuous bacterial exposure and had the mechanical properties necessary for use as a urinary catheter.
导尿管相关尿路感染是全球最常见的与健康相关的感染，对患者的发病率和死亡率有重大影响，并增加了医疗成本。为了降低这些感染的发生率，需要能够抵抗细菌生物膜形成的新材料。有人提出了一种复合导管材料，它由涂有新型抗细菌生物膜聚丙烯酸酯[乙二醇二环戊烯基醚丙烯酸酯（EGDPEA）-共-二（乙二醇）甲醚甲基丙烯酸酯（DEGMA）]的本体聚二甲基硅氧烷（PDMS）组成。与商用导管材料相比，这种涂层材料表现出优异的抗菌性能，但在机械应力下EGDPEA-共-DEGMA涂层的分层是一个挑战。在这项工作中，研究了使用氧等离子体处理来改善PDMS导管材料的润湿性和反应性，并提高与EGDPEA-共-DEGMA涂层的附着力。氩簇三维成像飞行时间二次离子质谱（ToF-SIMS）已被用于探测EGDPEA-共-DEGMA涂层与处理后的PDMS之间的埋藏粘合界面。在干燥和冷冻水合状态下都进行了ToF-SIMS分析，并将结果与机械测试进行了比较。根据ToF-SIMS数据，作者能够观察到粘合界面处存在PDMS、硅酸盐、盐颗粒、裂缝和水。在干燥的导管中，界面处的低分子量PDMS低聚物与附着力差有关。水合时，亲水性硅酸盐将水吸引到界面，导致涂层容易分层。在水合条件下，使用5分钟的氧等离子体处理和硅烷底漆的组合可获得最佳附着力结果。对水合导管材料的低温ToF-SIMS分析表明，在有水的情况下，涂底漆的PDMS导管与EGDPEA-共-DEGMA涂层之间的键是稳定的。在连续细菌暴露10天后，所得导管材料与未涂层的PDMS相比，对大肠杆菌和奇异变形杆菌生物膜定植的抵抗力高达95%，并具有用作导尿管所需的机械性能。
