Strain-Stiffening Hydrogels with Dynamic, Secondary Cross-Linking
Strain-Stiffening Hydrogels with Dynamic, Secondary Cross-Linking
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具有动态二次交联的应变硬化水凝胶
DOI：
10.1021/acs.langmuir.2c03117
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发表时间：
2023
期刊：
影响因子：
3.9
通讯作者：
Peyton, Shelly R.
中科院分区：
文献类型：
--
作者：
Sonu, K. P.;Zhou, Le;Biswas, Santidan;Klier, John;Balazs, Anna C.;Emrick, Todd;Peyton, Shelly R.
水凝胶是水膨胀的，典型的软网络，可用作生物材料和其他生物技术领域。水凝胶网络能够感知和响应外部扰动，如光、温度、pH值或力，在需要按需交联或动态变化的广泛应用中是有用的。到目前为止，尽管机械载体被描述为应变敏感反应基团，但将这种类型的力响应性嵌入水凝胶尚未得到证实。在这里，我们合成了多功能聚合物，将亲水性两性离子与永久交联的烯烃和动态交联的二硫化物结合在一起。从这些聚合物中，我们创造了含有不可逆的强巯基交联和可逆的二硫交联的水凝胶，它们在应变下变硬，在压缩下的模量增加了数百kPa。我们研究了聚合物组成的变化，并使用本构模型来确定如何平衡巯基与二硫交联的数量，以创建最大的力响应网络。这些应变硬化水凝胶代表了潜在的生物材料，它们受益于组织工程等新兴应用领域所需的机械反应行为。
Hydrogels are water-swollen, typically soft networks useful as biomaterials and in other fields of biotechnology. Hydrogel networks capable of sensing and responding to external perturbations, such as light, temperature, pH, or force, are useful across a wide range of applications requiring on-demand cross-linking or dynamic changes. Thus far, although mechanophores have been described as strain-sensitive reactive groups, embedding this type of force-responsiveness into hydrogels is unproven. Here, we synthesized multifunctional polymers that combine a hydrophilic zwitterion with permanently cross-linking alkenes, and dynamically cross-linking disulfides. From these polymers, we created hydrogels that contain irreversible and strong thiol–ene cross-links and reversible disulfide cross-links, and they stiffened in response to strain, increasing hundreds of kPa in modulus under compression. We examined variations in polymer composition and used a constitutive model to determine how to balance the number of thiol–ene vs disulfide cross-links to create maximally force-responsive networks. These strain-stiffening hydrogels represent potential biomaterials that benefit from the mechanoresponsive behavior needed for emerging applications in areas such as tissue engineering.