Although widely used as implantable materials due to their mechanical properties, metal devices show several disadvantages, such as the lack of cellular binding sites, antibacterial properties, or lubricant properties. To this end, the development of engineered surfaces through protein coatings has been largely investigated. Due to their natural origin and complex structure which allows the formation of hydrogels, mucins have been proposed and investigated as effective coatings for metallic implants. The present study evaluates the ability of porcine gastric mucin (PGM) to form stable coatings on a model metal surface, using three buffers with different pH values, ranging from acid to alkaline, as dispersion media. Considering its large number of hydroxyl groups and its ability to form hydrogen bonds with the protein, tannic acid (TA) was used as cross‐linker. In addition to coatings' thickness and elasticity assessed through Quartz Crystal Microbalance with Dissipation monitoring (QCM‐D), the study also evaluates the interactions between PGM and TA at various pH values of the dispersion media through DLS. The corroborated results show that the neutral pH allows the best interactions between PGM and TA leading to the formation of a stable, less elastic coating when compared with that obtained using as dispersion media the other two investigated buffers. Moreover, the hydrophilicity and mechanical properties of the dried coatings were assessed through contact angle measurements and nanoindentation, respectively.

中文翻译：

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基于粘胶鞣酸的涂层可组装多层。pH的影响

尽管由于其机械性能而被广泛用作可植入材料，但金属装置仍显示出若干缺点，例如缺少细胞结合位点，抗菌性能或润滑剂性能。为此，已经广泛研究了通过蛋白质涂层对工程表面的开发。由于它们的天然来源和允许水凝胶形成的复杂结构，已经提出并研究了粘蛋白作为金属植入物的有效涂层。本研究使用三种具有不同pH值（从酸到碱）的缓冲液作为分散介质，评估了猪胃粘蛋白（PGM）在模型金属表面上形成稳定涂层的能力。考虑到其大量的羟基和与蛋白质形成氢键的能力，单宁酸（TA）被用作交联剂。除了通过具有耗散监测的石英晶体微天平（QCM-D）评估涂层的厚度和弹性外，该研究还通过DLS评估了分散介质在各种pH值下PGM和TA之间的相互作用。证实的结果表明，与使用其他两种研究缓冲液作为分散介质获得的涂层相比，中性pH可使PGM和TA之间实现最佳相互作用，从而导致形成稳定的弹性较小的涂层。此外，分别通过接触角测量和纳米压痕评估干燥涂层的亲水性和机械性能。该研究还通过DLS评估了分散介质在各种pH值下PGM和TA之间的相互作用。证实的结果表明，与使用其他两种研究缓冲液作为分散介质获得的涂层相比，中性pH可使PGM和TA之间实现最佳相互作用，从而导致形成稳定的弹性较小的涂层。此外，分别通过接触角测量和纳米压痕评估干燥涂层的亲水性和机械性能。该研究还通过DLS评估了分散介质在各种pH值下PGM和TA之间的相互作用。证实的结果表明，与使用其他两种研究缓冲液作为分散介质获得的涂层相比，中性pH可使PGM和TA之间实现最佳相互作用，从而导致形成稳定的弹性较小的涂层。此外，分别通过接触角测量和纳米压痕评估干燥涂层的亲水性和机械性能。与使用其他两种缓冲液作为分散介质获得的涂层相比，弹性涂层的弹性较小。此外，分别通过接触角测量和纳米压痕评估干燥涂层的亲水性和机械性能。与使用其他两种缓冲液作为分散介质获得的涂层相比，弹性涂层的弹性较小。此外，分别通过接触角测量和纳米压痕评估干燥涂层的亲水性和机械性能。