溴化壳聚糖抗菌敷料的电化学制备及性能

采用电化学两步法快速制备了一种含溴胺结构的自支持壳聚糖抗菌敷料（Chit-Br）。利用场发射扫描电子显微镜（SEM）、能谱仪（EDS）、衰减全反射红外光谱（FTIR-ATR）、碘量滴定、抗菌实验对溴化壳聚糖膜的结构、溴胺（N—Br）含量及抗菌性能进行了表征。结果表明：壳聚糖可通过电极反应原位生成溴化试剂而被溴化，溴化过程同时伴随着对糖单元的氧化。当阳极电量为4.0~20.5 C时，所制备的Chit-Br膜中的N—Br含量无显著差异。溴化壳聚糖膜对大肠杆菌和金黄色葡萄球菌均具有优异的抗菌性能，通过破坏细菌表面结构导致细菌死亡。

Electrochemical Fabrication and Properties of Brominated Chitosan Antimicrobial Dressing

Brominated chitosan wound dressing (Chit-Br) with high antimicrobial activity was fabricated by a two-step electrochemical method, which involved a cathodic electrodeposition of pristine chitosan film (Chit) triggered by a localized region of high pH and an anodic bromination of the deposited film in the presence of bromides. The generated brominated chitosan could be peeled from the electrode to get a free-standing film. The structure and incorporated active N-Br content of Chit-Br were characterized via SEM, EDS, FTIR-ATR and iodometric titration. In vitro antimicrobial activities of Chit-Br films were evaluated via antibacterial experiments using E. coli and S. aureus as model pathogens. Results showed that chitosan could be brominated by bromides in-situ generated from electrode reactions, and the bromination was accompanied with oxidation on sugar units. In the test range, N-Br contents of Chit-Br films brominated by varying anodic charges had no statistical difference. Chit-Br films had excellent antimicrobial activities and could kill bacteria by destroying their surface structures.