Key Laboratory of Optoelectronic Chemical Materials and Devices, Ministry of Education, School of Chemical and Environmental Engineering , Jianghan University , Wuhan , 430056 , P R China.
Institute for Bioscience and Biotechnology Research , University of Maryland , 4291 Fieldhouse Drive, Plant Sciences Building , College Park , Maryland 20742 , United States.
Biomacromolecules. 2018 Aug 13;19(8):3502-3514. doi: 10.1021/acs.biomac.8b00809. Epub 2018 Jul 6.
Recent studies showed that melanin-mimetic catechol-chitosan films are redox-active and their ability to exchange electrons confers pro-oxidant activities for the sustained, in situ generation of reactive oxygen species for antimicrobial bandages. Here we electrofabricated catechol-chitosan films, demonstrate these films are redox-active, and show their ability to exchange electrons confers sustained radical scavenging activities that could be useful for protective coatings. Electrofabrication was performed in two steps: cathodic electrodeposition of a chitosan film followed by anodic grafting of catechol to chitosan. Spectroelectrochemical reverse engineering methods were used to characterize the catechol-chitosan films and demonstrate the films are redox-active and can donate electrons to quench oxidative free radicals and can accept electrons to quench reductive free radicals. Electrofabricated catechol-chitosan films that were peeled from the electrode were also shown to be capable of donating electrons to quench an oxidative free radical, but this radical scavenging activity decayed upon depletion of electrons from the film (i.e., as the film became oxidized). However, the radical scavenging activity could be recovered by a regeneration step in which the films were contacted with the biological reducing agent ascorbic acid. These results demonstrate that catecholic materials offer important redox-based and context-dependent properties for possible applications as protective coatings.
最近的研究表明，黑色素模拟儿茶酚壳聚糖薄膜具有氧化还原活性，其电子交换能力赋予了它们持续原位产生活性氧物种的促氧化剂活性，可用于抗菌绷带。在这里，我们电化学制备了儿茶酚壳聚糖薄膜，证明了这些薄膜具有氧化还原活性，并表明其电子交换能力赋予了持续的自由基清除活性，这对于保护性涂层可能是有用的。电化学制备分两步进行：壳聚糖膜的阴极电沉积，然后是儿茶酚到壳聚糖的阳极接枝。光谱电化学反向工程方法用于表征儿茶酚壳聚糖薄膜，并证明这些薄膜具有氧化还原活性，可以向氧化自由基供电子，也可以向还原自由基接受电子。从电极上剥离下来的电化学制备的儿茶酚壳聚糖薄膜也被证明能够向氧化自由基供电子，但随着薄膜中电子的耗尽（即，当薄膜被氧化时），这种自由基清除活性会衰减。然而，通过与生物还原剂抗坏血酸接触的再生步骤，可以恢复自由基清除活性。这些结果表明，儿茶酚类材料具有重要的氧化还原特性和上下文相关特性，可能适用于保护性涂层。
