Wu Jindan, Zhao Sufang, Xu Shuting, Pang Xiaoyu, Cai Guoqiang, Wang Jiping
MOE Key Laboratory of Advanced Textile Materials & Manufacturing Technology, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China.
J Mater Chem B. 2018 Dec 7;6(45):7462-7470. doi: 10.1039/c8tb02093k. Epub 2018 Oct 25.
The acidity of a microenvironment in infected sites was utilized as the trigger to manipulate the bacterial behavior on the surface. Multilayers composed of dopamine-anchored poly(acrylic acid) (PAA-dopa) and chitosan quaternary ammonium salt (Q-CS) were deposited onto a surface via the layer-by-layer (LBL) assembly technology. The multilayer was crosslinked through the reaction of catechol moieties. The surface charge of the multilayer reversibly shifted from positive to negative as the pH increased without influencing the chemical composition and wettability of the top layer. The precise manipulation of the surface charge, and therefore, the biological function was achieved by varying the acidity. The bactericidal efficiency increased 15 times for E. coli, while almost 90% dead S. aureus and 100% E. coli were released from the surface when the pH increased from 5.0 to 7.4. Therefore, the functional surface was regenerated, which is particularly essential during the long-term treatment of chronic wounds. This study presented a new adaptive material responding to microenvironment acidity of the infected sites for efficient and safe antibacterial therapies.
感染部位微环境的酸度被用作触发因素来操控表面的细菌行为。通过层层（LBL）组装技术将由多巴胺锚定的聚丙烯酸（PAA-dopa）和壳聚糖季铵盐（Q-CS）组成的多层膜沉积到表面上。多层膜通过儿茶酚部分的反应进行交联。随着pH值升高，多层膜的表面电荷可逆地从正变为负，而不影响顶层的化学成分和润湿性。通过改变酸度实现了对表面电荷以及生物功能的精确操控。当pH值从5.0增加到7.4时，大肠杆菌的杀菌效率提高了15倍，同时几乎90%的死亡金黄色葡萄球菌和100%的大肠杆菌从表面释放出来。因此，功能性表面得以再生，这在慢性伤口的长期治疗过程中尤为重要。本研究提出了一种新型的适应性材料，可响应感染部位的微环境酸度，用于高效安全的抗菌治疗。
