Department of Biological and Environmental Engineering , Cornell University , Ithaca , New York 14850 , United States.
Key Lab of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering , Tsinghua University , Beijing 100084 , China.
Langmuir. 2019 Feb 5;35(5):1927-1934. doi: 10.1021/acs.langmuir.8b03074. Epub 2018 Nov 29.
Reducing biofouling while increasing lubricity of inserted medical catheters is highly desirable to improve their comfort, safety, and long-term use. We report here a simple method to create thin (∼30 μm) conformal lubricating hydrogel coatings on catheters. The key to this method is a three-step process including shape-forming, gradient cross-linking, and swell-peeling (we label this method as SGS). First, we took advantage of the fast gelation of agar to form a hydrogel layer conformal to catheters; then, we performed a surface-bound UV cross-linking of acrylamide mixed in agar in open air, purposely allowing gradual oxygen inhibition of free radicals to generate a gradient of cross-linking density across the hydrogel layer; and finally, we caused the hydrogel to swell to let the non-cross-linked/loosely attached hydrogel fall off, leaving behind a surface-bound, thin, and mostly uniform hydrogel coating. This method also allowed easy incorporation of different polymerizable monomers to obtain multifunctionality. For example, incorporating an antifouling, zwitterionic moiety sulfobetaine in the hydrogel reduced both in vitro protein adsorption and in vivo foreign-body response in mice. The addition of a biocidal N-halamine monomer to the hydrogel coating deactivated both Staphylococcus aureus ( S. aureus) and Escherichia coli ( E. coli) O157:H7 within 30 min of contact and reduced biofilm formation by 90% compared to those of uncoated commercial catheters when challenged with S. aureus for 3 days. The lubricating, antibiofouling hydrogel coating may bring clinical benefits in the use of urinary and venous catheters as well as other types of medical devices.
减少生物污垢的同时增加插入式医用导管的润滑性，对于提高其舒适性、安全性和长期使用性非常重要。我们在此报告一种在导管上制备薄（约 30μm）且具有良好润湿性的水凝胶涂层的简单方法。该方法的关键是包括形状形成、梯度交联和溶胀-剥离三个步骤（我们将此方法标记为 SGS）。首先，我们利用琼脂的快速胶凝作用在导管上形成水凝胶层；然后，我们在空气中进行丙烯酰胺与琼脂的表面结合紫外交联，故意允许自由基的逐步氧抑制来生成水凝胶层中交联密度的梯度；最后，我们使水凝胶溶胀，让未交联/松散附着的水凝胶脱落，在表面留下一层结合紧密且大部分均匀的水凝胶涂层。这种方法还可以轻松地掺入不同的可聚合单体以获得多功能性。例如，在水凝胶中掺入抗污的两性离子磺酸基甜菜碱，可减少体外蛋白质吸附和体内异物反应。当将具有生物杀灭作用的 N-卤胺单体添加到水凝胶涂层中时，在与金黄色葡萄球菌（S. aureus）接触 30 分钟内可同时灭活金黄色葡萄球菌（S. aureus）和大肠杆菌（E. coli）O157：H7，与未涂层的商业导管相比，在金黄色葡萄球菌（S. aureus）挑战 3 天后，生物膜形成减少了 90%。这种具有润滑性和抗生物污垢的水凝胶涂层可能会给导尿管和静脉导管以及其他类型的医疗器械的使用带来临床益处。
