Surface coatings are extensively applied on biomedical devices to provide protection against biofouling and infections. However, most surface coatings prevent both bacteria and cells interactions with the biomaterials, limiting their uses as implants. Furthermore, damage to the surface such as scratches and abrasions can happen during transport and clinical usage, resulting in the loss of antibacterial property. In this work, we introduce an efficient method to fabricate stable anti-infective and self-healable multilayer coatings on stainless steel surface via a three-step procedue. Firstly, modified polyethyleneimine (PEI) and poly(acrylic acid) (PAA), both contain pendant furan groups, were deposited on the surface using Layer-by-Layer (LbL) self-assembly technique. Secondly, the polymer layers were cross-linked, via Diels-Alder cycloaddition, using a bismaleimide poly(ethylene glycol) linker, to enhance the stability of the coatings. Thirdly, the Diels-Alder adduct was utilised in the thiol-ene click reaction for post-modification of the coatings, which allowed for the grafting of antimicrobial poly(hexamethylene biguanide) (PHMB) and ε-poly(lysine) (EPL). The resultant multilayer coatings not only exhibited rapid self-healing property, with complete scratch closure within 30 min, but also demonstrated effective antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). In addition, biofouling of bovine serum albumin was found to be inhibited on the coated surfaces. Furthermore, these coatings showed no toxicity effect towards seeded osteoblastic cells (MC3T3-E1) and evidence of anti-inflamatory activity when tested against macrophage cell line U-937. Our coating method thus represents an effective strategy for the anti-infective protection of biomedical-devices having direct contact with tissues.

表面涂层广泛应用于生物医学设备，以提供针对生物污垢和感染的保护。然而，大多数表面涂层都阻止细菌和细胞与生物材料的相互作用，从而限制了其作为植入物的用途。此外，在运输和临床使用期间可能发生表面损伤，例如刮擦和擦伤，从而导致抗菌性能的损失。在这项工作中，我们介绍了一种有效的方法，可通过以下方法在不锈钢表面上制备稳定的抗感染和可自愈的多层涂层三个步骤。首先，使用逐层（LbL）自组装技术将均含有呋喃侧基的改性聚乙烯亚胺（PEI）和聚丙烯酸（PAA）沉积在表面上。其次，使用双马来酰亚胺聚（乙二醇）接头，通过Diels-Alder环加成使聚合物层交联，以增强涂层的稳定性。第三，将Diels-Alder加合物用于硫醇-烯点击反应，对涂料进行后改性，从而可以接枝抗菌聚六亚甲基双胍（PHMB）和ε-聚（赖氨酸）（EPL）。所得多层涂料不仅显示出快速的自修复性能，在30分钟内完全刮擦闭合，而且还显示出有效的抗菌活性大肠杆菌（E. coli）和金黄色葡萄球菌（S. aureus）。另外，发现牛血清白蛋白的生物结垢在包被的表面上被抑制。此外，这些涂层对接种的成骨细胞（MC3T3-E1）没有毒性作用，并且在针对巨噬细胞U-937进行测试时具有抗炎活性。因此，我们的包衣方法代表了一种与组织直接接触的生物医学设备的抗感染保护的有效策略。