Mussel-Inspired Self-Healing Double-Cross-Linked Hydrogels by Controlled Combination of Metal Coordination and Covalent Cross-Linking
Mussel-Inspired Self-Healing Double-Cross-Linked Hydrogels by Controlled Combination of Metal Coordination and Covalent Cross-Linking
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DOI：
10.1021/acs.biomac.7b01249
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发表时间：
2018-05-01
影响因子：
6.2
通讯作者：
Birkedal, Henrik
中科院分区：
文献类型：
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作者：
Andersen, Amanda;Krogsgaard, Marie;Birkedal, Henrik
贻贝水凝胶通过可逆的儿茶酚-金属配位键结合在一起，由于其有吸引力的自愈合、粘弹性和粘附性以及pH响应性，最近引起了极大的关注。这些系统中的主要挑战是协调在空气中的碱性条件下发生的儿茶酚氧化的程度，并且对上述性质具有很大影响，因为它将不可逆的共价交联引入到系统中，这使水凝胶变硬，但消耗自修复所需的儿茶酚。在此，我们提出了一种基于儿茶酚的水凝胶设计，其允许控制氧化共价交联的程度。通过将可氧化的儿茶酚类似物单宁酸添加到抗氧化水凝胶构建体中来构建具有可调刚度的双交联水凝胶，所述抗氧化水凝胶构建体通过1-（2 '-羧乙基）-2-甲基-3-羟基-4-吡啶酮的二羟基官能团与三价金属离子的配位而保持在一起。通过改变鞣酸的量，可以针对给定的应用定制水凝胶刚度，同时保留水凝胶的配位化学组分的自修复能力。
Mussel-inspired hydrogels held together by reversible catecholato-metal coordination bonds have recently drawn great attention owing to their attractive self-healing, viscoelastic and adhesive properties together with their pH-responsive nature. A major challenge in these systems is to orchestrate the degree of catechol oxidation that occurs under alkaline conditions in air and has a great impact on the aforementioned properties because it introduces irreversible covalent cross-links to the system, which stiffens the hydrogels but consume catechols needed for self-healing. Herein, we present a catechol-based hydrogel design that allows for the degree of oxidative covalent cross-linking to be controlled. Double cross-linked hydrogels with tunable stiffness are constructed by adding the oxidizable catechol analogue, tannic acid, to an oxidation-resistant hydrogel construct held together by coordination of the dihydroxy functionality of 1-(2'-carboxyethyl)-2-methyl-3-hydroxy-4-pyridinone to trivalent metal ions. By varying the amount of tannic acid, the hydrogel stiffness can be customized to a given application while retaining the self-healing capabilities of the hydrogel's coordination chemical component.