Abstract：
The use of traditional Ag-based antibacterial agents is usually accompanied by uncontrollable silver release, which makes it difficult to find a balance between antibacterial performance and biosafety. Herein, we prepared a core-shell system of ZIF-8-derived amorphous carbon-coated Ag nanoparticles (Ag@C) as an ideal research model to reveal the synergistic effect and structure-activity relationship of the structural transformation of carbon shell and Ag core on the regulation of silver release behavior. It is found that Ag@C prepared at 600 °C (AC6) exhibits the best ion release kinetics due to the combination of relatively simple shell structure and lower crystallinity of the Ag core, thereby exerting stronger antibacterial properties (>99.999 %) at trace doses (20 μg mL-1) compared with most other Ag-based materials. Meanwhile, the carbon shell prevents the metal Ag from being directly exposed to the organism and thus endows AC6 with excellent biocompatibility. In animal experiments, AC6 can effectively promote wound healing by inactivating drug-resistant bacteria while regulating the expression of TNF-α and CD31. This work provides theoretical support for the scientific design and clinical application of controllable ion-releasing antibacterial agents.
摘要：
传统Ag基抗菌剂的使用通常伴随着无法控制的银释放，这使得很难在抗菌性能和生物安全性之间找到平衡。在这里，我们制备了ZIF-8衍生的无定形碳包覆Ag纳米颗粒（Ag@C）的核-壳体系作为理想的研究模型，以揭示碳壳和Ag核的结构转变对银释放行为的调节作用和构效关系。发现在600°C（AC6）下制备的Ag@C表现出最佳的离子释放动力学，这是由于相对简单的壳结构和Ag核的较低结晶度的结合，从而与大多数其他Ag基材料相比,在痕量剂量(20μgmL-1)下发挥更强的抗菌性能(>99.999%)。同时,碳壳可防止金属Ag直接暴露于生物体，从而赋予AC6优异的生物相容性。在动物实验中,AC6可通过灭活耐药菌有效促进创面愈合,同时调节TNF-α和CD31的表达。该工作为可控离子释放抗菌剂的科学设计和临床应用提供了理论支持。
