To meet the progressive requirements of advanced engineering materials with superior physicochemical performances, self-healing and injectable hydrogels (AD hydrogels) based on agarose with pH-response were prepared through dynamic covalent Schiff-base linkages by simply mixing nontoxic agarose–ethylenediamine conjugate (AG-NH₂) and dialdehyde-functionalized polyethylene glycol (DF-PEG) solutions. The self-healing and injectable capabilities of the hydrogels without any external stimulus are ascribed to dynamic covalent Schiff-base linkages between the aldehyde groups of DF-PEG and amine groups on AG-NH₂ backbone. It is demonstrated that the AD hydrogels possess interconnected porous morphologies, rapid gelation time, excellent deformability, and good mechanical strength. The incorporated Schiff’s base imparts the hydrogels to the remarkable tissue adhesiveness. In vivo hemostatic tests on rabbit liver demonstrate that the hydrogels are able to stanch the severe trauma effectively. Compared with the conventional gauze treatment, the total amount of bleeding sharply declined to be (0.19 ± 0.03) g, and hemostasis time was strikingly shorter than 10 s after treating with AD hydrogels. In summary, the self-healing ability, cytocompatibility, and adhesion characteristic of the pH-responsive hydrogels make them promising candidates for long-lived wound dressings in critical situations.

中文翻译：

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快速形成的可自我修复的基于琼脂糖的水凝胶，用于组织粘合剂和潜在的伤口敷料

为了满足具有优异理化性能的先进工程材料的发展要求，只需将无毒琼脂糖-乙二胺共轭物（AG）混合，就可以通过动态共价席夫碱键制备基于琼脂糖和pH响应的自修复和可注射水凝胶（AD水凝胶）。 -NH ₂）和二醛官能化的聚乙二醇（DF-PEG）溶液。在没有任何外部刺激的情况下，水凝胶的自我修复和可注射能力归因于DF-PEG的醛基与AG-NH ₂上的胺基之间的动态共价席夫碱键骨干。证明了AD水凝胶具有相互连接的多孔形态，快速的胶凝时间，优异的可变形性和良好的机械强度。掺入的席夫氏碱使水凝胶具有出色的组织粘合性。在兔肝上进行的体内止血测试表明，水凝胶能够有效地止住严重的创伤。与常规纱布治疗相比，用AD水凝胶治疗后的出血总量急剧下降至（0.19±0.03）g，止血时间明显短于10 s。总之，pH响应水凝胶的自我修复能力，细胞相容性和粘附特性使其成为在关键情况下长寿命伤口敷料的有希望的候选者。