Department of Bioengineering, University of California, Los Angeles, Los Angeles, California 90095, United States.
California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States.
ACS Appl Mater Interfaces. 2021 Sep 1;13(34):40290-40301. doi: 10.1021/acsami.1c10048. Epub 2021 Aug 19.
Hydrogel patches with high toughness, stretchability, and adhesive properties are critical to healthcare applications including wound dressings and wearable devices. Gelatin methacryloyl (GelMA) provides a highly biocompatible and accessible hydrogel platform. However, low tissue adhesion and poor mechanical properties of cross-linked GelMA patches (., brittleness and low stretchability) have been major obstacles to their application for sealing and repair of wounds. Here, we show that adding dopamine (DA) moieties in larger quantities than those of conjugated counterparts to the GelMA prepolymer solution followed by alkaline DA oxidation could result in robust mechanical and adhesive properties in GelMA-based hydrogels. In this way, cross-linked patches with ∼140% stretchability and ∼19 000 J/m toughness, which correspond to ∼5.7 and ∼3.3× improvement, respectively, compared to that of GelMA controls, were obtained. The DA oxidization in the prepolymer solution was found to play an important role in activating adhesive properties of cross-linked GelMA patches (∼4.0 and ∼6.9× increase in adhesion force under tensile and shear modes, respectively) due to the presence of reactive oxidized quinone species. We further conducted a parametric study on the factors such as UV light parameters, the photoinitiator type (., lithium phenyl-2,4,6-trimethylbenzoylphosphinate, LAP, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, Irgacure 2959), and alkaline DA oxidation to tune the cross-linking density and thereby hydrogel compliance for better adhesive properties. The superior adhesion performance of the resulting hydrogel along with cytocompatibility demonstrated its potential for use in skin-attachable substrates.
具有高韧性、拉伸性和粘附性能的水凝胶贴片对于医疗保健应用至关重要，包括伤口敷料和可穿戴设备。明胶甲基丙烯酰（GelMA）提供了一个高度生物相容和易于使用的水凝胶平台。然而，交联 GelMA 贴片的低组织粘附性和较差的机械性能（例如脆性和低拉伸性）一直是限制其在伤口密封和修复中应用的主要障碍。在这里，我们表明，在 GelMA 预聚物溶液中添加比共轭物多的多巴胺（DA）部分，然后进行碱性 DA 氧化，可以在 GelMA 基水凝胶中产生强大的机械和粘附性能。通过这种方式，交联贴片的拉伸性约为 140%，韧性约为 19000 J/m，与 GelMA 对照相比分别提高了约 5.7 倍和 3.3 倍。在预聚物溶液中进行的 DA 氧化被发现对交联 GelMA 贴片的粘附性能起着重要作用（在拉伸和剪切模式下，粘附力分别增加了约 4.0 倍和 6.9 倍），这是由于存在反应性氧化醌类物质。我们进一步对 UV 光参数、光引发剂类型（例如，二苯甲酮，LAP，2-羟基-4'-(2-羟基乙氧基)-2-甲基苯丙酮，Irgacure 2959）和碱性 DA 氧化等因素进行了参数研究，以调节交联密度，从而调节水凝胶顺应性，以获得更好的粘附性能。所得水凝胶的优异粘附性能和细胞相容性表明其在可附着于皮肤的基底中的应用潜力。
