Department of Mechanical Engineering and Munich School of Bioengineering, Technical University of Munich, 85748 Garching, Germany.
Woehlk Contactlinsen GmbH, 24232 Schönkirchen, Germany.
ACS Appl Mater Interfaces. 2020 Jun 24;12(25):28024-28033. doi: 10.1021/acsami.0c06847. Epub 2020 Jun 9.
A stable, good coverage of the corneal tissue by the tear film is essential for protecting the eye. Contact lenses, however, constitute a foreign body that separates the tear film into two thinner layers, which are then more vulnerable toward disruption. This effect is even more pronounced if the contact lenses possess an insufficient surface wettability, which, in addition to friction, is suggested to be linked to discomfort and damage to the ocular surface. In this study, we establish covalent surface coatings with mucin macromolecules to overcome this issue for pure silicone contact lenses. This material class, which outperforms state-of-the-art silicone hydrogels in terms of oxygen permeability, is not yet used for commercial contact lens applications, which is due to its strongly hydrophobic surface characteristics. The applied process stably attaches a transparent mucin layer onto the contact lenses and thereby establishes hydrophilic surfaces that not only prevent lipid adsorption but also interact very well with liquid environments. Most importantly, however, we show that those mucin coatings are indeed able to prevent wear formation on corneal tissue that is subjected to the tribological stress applied by a contact lens. Our results open up great possibilities for a variety of hydrophobic materials that are, to date, not suitable for a contact lens application. Furthermore, the ability of mucin coatings to reduce wear in a tissue/synthetic material contact might be also beneficial for other biomedical applications.
泪膜稳定且充分覆盖角膜组织对于保护眼睛至关重要。然而，隐形眼镜是一种异物，会将泪膜分成两层更薄的膜，从而更容易破裂。如果隐形眼镜的表面润湿性不足，这种情况会更加明显，因为这不仅会增加摩擦，还会导致眼部不适和损伤。在这项研究中，我们为纯硅胶隐形眼镜建立了具有粘蛋白大分子的共价表面涂层，以克服这个问题。这种材料在氧气透过率方面优于最先进的硅胶水凝胶，但尚未用于商业隐形眼镜应用，这是因为其具有强烈的疏水性表面特性。所应用的工艺可将透明的粘蛋白层稳定地附着在隐形眼镜上，从而建立亲水表面，不仅可以防止脂质吸附，还可以与液体环境很好地相互作用。但最重要的是，我们表明，这些粘蛋白涂层确实能够防止在接触镜施加的摩擦学应力下磨损角膜组织。我们的研究结果为各种疏水材料开辟了广阔的可能性，这些材料目前不适用于隐形眼镜应用。此外，粘蛋白涂层在组织/合成材料接触中减少磨损的能力对于其他生物医学应用也可能有益。
