Key Laboratory for Ultrafine Materials of Ministry of Education, The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
Key Laboratory for Ultrafine Materials of Ministry of Education, The State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China.
Biomaterials. 2018 Apr;162:109-122. doi: 10.1016/j.biomaterials.2017.12.027. Epub 2018 Jan 2.
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 O 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.
开放性伤口和烧伤容易感染，因此人们仍然非常有兴趣开发安全有效的机制，为伤口敷料提供抗菌活性。我们报告了一种仿生伤口敷料，用于原位和持续产生活性氧（ROS）。具体来说，我们制备了一种儿茶酚修饰的壳聚糖膜，模拟了昆虫对感染的免疫反应中产生的黑色素胶囊的特征。我们使用电化学反向工程方法证明，这种儿茶酚-壳聚糖膜具有氧化还原活性，可以被反复氧化和还原。体外测试表明，该膜可以催化电子从生理还原剂抗坏血酸向 O 的转移，从而持续产生 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菌实验表明，还原态的儿茶酚-壳聚糖膜抑制细菌生长并减轻切口感染。用小鼠模型进行的开放性伤口愈合实验表明，儿茶酚-壳聚糖膜抑制伤口部位的细菌种群，减少炎症并促进伤口愈合。我们设想这种仿生方法可以持续、局部和原位产生 ROS，为伤口管理提供新的机会，防止病原体感染，甚至可能利用 ROS 介导的伤口愈合机制。
