先前已经报道,石墨烯氧化物/铜纳米衍生物(GO/Cu)-并入的壳聚糖/透明质酸支架可能是用于管理感染的伤口愈合的有前途的伤口敷料。本研究的目的是深入探索潜在的抗菌机制和协同成骨活性,以及GO/Cu纳米复合材料的体内抗感染行为,使他们成为建立植入式生物材料修复感染骨缺损的可能候选人。通过对膜完整性的检测,探讨了纳米复合材料的抗菌机理,氧化应激,和代谢酶活性。然后,证实了与骨髓间充质干细胞(rBMSCs)的细胞相容性和成骨潜能,并建立大鼠皮下细菌感染模型,验证纳米复合材料的体内抗感染性能和生物安全性。发现三磷酸腺苷的泄漏,蛋白质,减少细菌细胞中的糖,指示细菌膜的渗透性受损,并促进响应氧化应激的活性氧和无序代谢酶活性的产生是GO/Cu纳米复合材料协同抗菌作用的可能分子机制。此外,在GO/Cu纳米复合材料(质量比=2:1)中发现与rBMSCs具有良好的细胞相容性并促进成骨分化,这也表现出令人满意的体内抗感染性能,减少炎症,和可接受的生物安全性。根据我们的结果,受损的细菌膜,增加ROS产量,关键酶代谢紊乱是GO/Cu纳米复合材料引起的细菌杀伤事件的主要抗菌机制,还显示出增强的成骨活性,体内抗感染能力,和可接受的细胞相容性和生物安全性。因此,GO/Cu(2:1)纳米复合材料是改善当前用于对抗细菌污染的骨缺损的骨替代物的生物学性能的潜在策略。
It has been previously reported that graphene oxide/copper nanoderivative (GO/Cu)-incorporated chitosan/hyaluronic acid scaffolds might be promising wound dressings for the management of infected wound healing. The aim of the present research is to deeply explore the potential antimicrobial mechanisms and synergistic osteogenic activity, as well as the in vivo anti-infective behavior of GO/Cu nanocomposites, making them possible candidates for establishing implantable biomaterials for the repair of infected bone defects. The antibacterial mechanisms of the nanocomposites were explored through the examination of membrane integrity, oxidative stress, and metabolic enzyme activities. Then, the cytocompatibility with bone mesenchymal stem cells (rBMSCs) and osteogenic potential were confirmed, and a subcutaneous bacterial infection model in rats was also established to verify the in vivo anti-infective property and
biosafety of the nanocomposites. It was found that leakage of adenosine triphosphate, proteins, and reducing sugars from the bacterial cells, indicative of damaged permeability of bacterial membranes, and promoted production of reactive oxygen species and disordered metabolic enzyme activities in response to oxidative stress were possible molecular mechanisms responsible for the synergistic antibacterial effects of the GO/Cu nanocomposites. Additionally, good cytocompatibility with rBMSCs and promoted osteogenic differentiation were found in GO/Cu nanocomposites (mass ratio = 2:1), which also demonstrated satisfactory in vivo anti-infective performance, reduced inflammation, and acceptable
biosafety. Based on our results, damaged bacterial membranes, increased ROS production, and disorders of crucial enzyme metabolism were the main antibacterial mechanisms involved in the bacterium-killing events caused by the GO/Cu nanocomposites, which also showed enhanced osteogenic activity, in vivo anti-infective capability, and acceptable cytocompatibility and
biosafety. Therefore, GO/Cu (2:1) nanocomposites are a potential strategy for improving the biological performance of current bone substitutes used for combating bacterial-contaminated bone defects.