Appenroth Julia, Moreno Ostertag Laila, Imre Alexander M, Valtiner Markus, Mears Laura L E
Institute of Applied Physics, Vienna University of Technology, 1040 Vienna, AustriaCEST Centre for Electrochemistry and Surface Technology GmbH, Viktor-Kaplan-Strasse 2 Bauteil A, 2700 Wr. Neustadt, Austria.
Biointerphases. 2021 Dec 30;16(6):061002. doi: 10.1116/6.0001609.
Catechol reaction mechanisms form the basis of marine mussel adhesion, allowing for bond formation and cross-linking in wet saline environments. To mimic mussel foot adhesion and develop new bioadhesive underwater glues, it is essential to understand and learn to control their redox activity as well as their chemical reactivity. Here, we study the electrochemical characteristics of functionalized catechols to further understand their reaction mechanisms and find a stable and controllable molecule that we subsequently integrate into a polymer to form a highly adhesive hydrogel. Contradictory to previous hypotheses, 3,4-dihydroxy-L-phenylalanine is shown to follow a Schiff-base reaction whereas dopamine shows an intramolecular ring formation. Dihydrocaffeic acid proved to be stable and was substituted onto a poly(allylamine) backbone and electrochemically cross-linked to form an adhesive hydrogel that was tested using a surface forces apparatus. The hydrogel's compression and dehydration dependent adhesive strength have proven to be higher than in mussel foot proteins (mfp-3 and mfp-5). Controlling catechol reaction mechanisms and integrating them into stable electrochemically depositable macroscopic structures is an important step in designing new biological coatings and underwater and biomedical adhesives.
儿茶酚反应机制构成了海洋贻贝粘附的基础，使其能够在潮湿的盐水环境中形成化学键并进行交联。为了模拟贻贝足部的粘附并开发新型水下生物粘合剂，了解并学会控制其氧化还原活性以及化学反应性至关重要。在此，我们研究功能化儿茶酚的电化学特性，以进一步了解其反应机制，并找到一种稳定且可控的分子，随后将其整合到聚合物中以形成高粘性水凝胶。与先前的假设相反，结果表明3,4-二羟基-L-苯丙氨酸遵循席夫碱反应，而多巴胺则呈现分子内环化。二氢咖啡酸被证明是稳定的，并被取代到聚（烯丙胺）主链上，通过电化学交联形成一种粘合剂水凝胶，该水凝胶使用表面力仪进行了测试。已证明该水凝胶的压缩和脱水依赖性粘附强度高于贻贝足部蛋白质（mfp-3和mfp-5）。控制儿茶酚反应机制并将其整合到稳定的可电化学沉积宏观结构中，是设计新型生物涂层以及水下和生物医学粘合剂的重要一步。
