Cao Yi/Wang Wei/Xue Bin of Nanjing University published in "German Yinghua": Strong, Reversible Covalent Double Network Hydrogel

Many biological tissues, such as tendons, cartilage, and blood vessels, have excellent mechanical properties, can withstand large deformations without breaking, and can quickly recover their mechanical properties when the mechanical load is released
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However, many synthetic soft materials, such as hydrogels, have low mechanical strength, poor toughness, and limited recoverability
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At present, it is still a challenge how to make synthetic and strong hydrogels to simulate the complex energy dissipation and recovery mechanisms of biological tissues
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Recently, Professor Wang Wei, Professor Cao Yi, and Dr.
Xue Bin of Nanjing University used a force-coupled enzyme reaction to convert a strong covalent peptide bond into a reversible bond
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Based on this concept, we designed double network hydrogels (DN hydrogels) to achieve high mechanical strength and reversible mechanical recovery
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Specifically, the researchers discovered a peptide ligase, sortase A (SrtA), that promotes the proteolysis of peptides under external force
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Peptide bonds can be reconnected by the same enzyme in the absence of external forces, which allows the sacrificial network in double-network hydrogels to be reversibly ruptured and rebuilt
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This work demonstrates a general approach to precisely control the mechanical and dynamic properties of hydrogels at the molecular level
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The related work was published in the latest issue of "Angewandte Chemie International Edition" under the title of "Strong and Reversible Covalent Double Network Hydrogel Based on Force-coupled Enzymatic Reactions"
.