Xiangya School of Pharmaceutical Sciences, Central South University, Changsha, Hunan, 410013, China.
Institute of Analytical Chemistry and Instrument for Life Science, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
Small. 2024 Feb;20(8):e2307220. doi: 10.1002/smll.202307220. Epub 2023 Oct 12.
Systematic management of infected wounds requires simultaneous antiinfection and wound healing, which has become the current treatment dilemma. Recently, a multifunctional silver nanoclusters (AgNCs)-based hydrogel dressing to meet these demands is developed. Here a diblock DNA with a cytosine-rich fragment (as AgNCs template) and a guanine-rich fragment (to form G-quadruplex/hemin DNAzyme, termed G4/hemin) is designed, for G4/hemin functionalization of AgNCs. Inside bacteria, G4/hemin can not only accelerate the oxidative release of Ag from AgNCs but also generate reactive oxygen species (ROS) via catalase- and peroxidase-mimic activities, which enhance the antibacterial effect. On the other hand, the AgNCs exhibit robust anti-inflammatory and antioxidative activities to switch M1 macrophages into M2 phenotype, which promotes wound healing. Moreover, the hemin is released to upregulate the heme oxygenase-1, an intracellular enzyme that can relieve oxidative stress, which significantly alleviates the cytotoxicity of silver. As a result, such silver-based dressing achieves potent therapeutic efficacy on infected wounds with excellent biosafety.
感染性伤口的系统管理需要同时进行抗感染和伤口愈合，这已成为当前的治疗难题。最近，开发了一种基于多功能银纳米簇（AgNCs）的水凝胶敷料来满足这些需求。在这里，设计了一种带有富含胞嘧啶片段（作为 AgNCs 模板）和富含鸟嘌呤片段（形成 G-四链体/血红素 DNA 酶，称为 G4/血红素）的两亲 DNA，用于 G4/血红素功能化 AgNCs。在细菌内部，G4/血红素不仅可以加速 AgNCs 中 Ag 的氧化释放，还可以通过过氧化物酶和过氧化氢酶模拟活性产生活性氧（ROS），从而增强抗菌作用。另一方面，AgNCs 表现出强大的抗炎和抗氧化活性，将 M1 巨噬细胞转化为 M2 表型，从而促进伤口愈合。此外，血红素被释放以上调血红素加氧酶-1，这是一种细胞内酶，可缓解氧化应激，从而显著减轻银的细胞毒性。因此，这种基于银的敷料在具有优异生物安全性的感染性伤口上实现了强大的治疗效果。
