Nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) was successfully used to cross-link complementary tetrazole and maleimide chitosan derivatives into hydrogel networks using irradiation. The photo-click reaction resulted in the formation of robust fluorescent hydrogels with an emission signal at around 530 nm. The degree of cross-linking and the resulting hydrogel properties such as pH sensitivity and swelling were influenced by the tetrazole/maleimide ratio and the length of irradiation. Interestingly, rheological studies demonstrated self-healing character of the novel hydrogels as indicated by instantaneous recovery of the storage modulus to the initial values under different oscillatory strains without any additional external trigger. Finally, in addition to their photo-tuneable and self-healing properties, the novel chitosan hydrogels were also found to be biocompatible and susceptible to in vitro enzymatic degradation, making them suitable for design of traceable biomaterials for biomedical applications.

中文翻译：

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具有自愈能力的生物相容性荧光壳聚糖水凝胶的光驱动组装

腈亚胺介导的四唑-烯环加成（NITEC）已成功用于通过辐照将互补的四唑和马来酰亚胺壳聚糖衍生物交联到水凝胶网络中。光点击反应导致形成坚固的荧光水凝胶，其发射信号在530 nm附近。交联度和所得的水凝胶性质（例如pH敏感性和溶胀度）受四唑/马来酰亚胺比率和照射时间的影响。有趣的是，流变学研究证明了新型水凝胶的自修复特性，这是通过在不同振荡应变下将储能模量瞬时恢复至初始值所表明的，而没有任何其他外部触发因素。最后，除了具有光可调和自我修复的特性外，体外酶促降解，使其适合用于生物医学应用的可追溯生物材料的设计。