Open wounds and burns are prone to infection and there remains considerable interest in developing safe and effective mechanisms to confer antimicrobial activities to wound dressings. We report a biomimetic wound dressing for the in situ and sustained generation of reactive oxygen species (ROS). Specifically, we fabricate a catechol-modified chitosan film that mimics features of the melanin capsule generated during an insect immune response to infection. We use an electrochemical reverse engineering approach to demonstrate that this catechol-chitosan film possesses redox-activities and can be repeatedly oxidized and reduced. In vitro tests demonstrate that this film catalyzes the transfer of electrons from physiological reductant ascorbate to O₂ for sustained ROS generation, and confers ascorbate-dependent antimicrobial activities. In vivo antimicrobial experiment with a rat subcutaneous model indicates the catechol-chitosan film at reduced state inhibits the bacterial growth and alleviates the infection of the incisions. Open wound healing tests with a mouse model indicate that the catechol-chitosan film suppresses the bacterial population at the wound site, induces less inflammation and promotes wound healing. We envision this biomimetic approach for the sustained, localized and in situ generation of ROS could provide new opportunities for wound management by protecting against pathogen infection and potentially even enlisting ROS-mediated wound healing mechanisms.

开放性伤口和烧伤易于感染，因此人们对开发安全有效的机制以赋予伤口敷料以抗菌作用的兴趣仍然很大。我们报告了仿生伤口敷料的活性氧（ROS）的原位和持续生成。具体来说，我们制作了儿茶酚修饰的壳聚糖薄膜，该薄膜模仿了昆虫对感染的免疫反应过程中产生的黑色素胶囊的功能。我们使用电化学逆向工程方法来证明该邻苯二酚-壳聚糖膜具有氧化还原活性，并且可以被反复氧化和还原。体外测试表明，该薄膜可催化电子从生理性抗坏血酸抗坏血酸向O ₂的转移持续产生ROS，并赋予抗坏血酸依赖性抗菌活性。用大鼠皮下模型进行的体内抗微生物实验表明，处于降低状态的邻苯二酚-壳聚糖膜可抑制细菌生长并减轻切口感染。小鼠模型的开放式伤口愈合测试表明，邻苯二酚-壳聚糖薄膜可抑制伤口部位的细菌繁殖，减少炎症并促进伤口愈合。我们设想这种仿生方法可用于持续，局部和原位产生ROS，通过防止病原体感染甚至潜在地利用ROS介导的伤口愈合机制，可以为伤口处理提供新的机会。