State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China.
Department of Pharmacy, West China Hospital, Sichuan University, Chengdu 610041, China; Department of Pharmacy, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center of Biotherapy, Chengdu 610041, China.
Colloids Surf B Biointerfaces. 2020 Jul;191:111009. doi: 10.1016/j.colsurfb.2020.111009. Epub 2020 Apr 12.
The antibiotics-independent antimicrobial activity of graphene oxide (GO) is of great importance since antibiotic therapy is facing great challenges from drug resistance. However, the relations of GO size with its antimicrobial activity and how the size regulates the antibacterial mechanisms are still unknown. Herein, we fabricated four GO suspensions with different sizes and demonstrated the parabolic relationship between GO size and its antibacterial activity against the Gram-positive cariogenic bacterium Streptococcus mutans. More interestingly, we found out how GO size regulated the nano-bio interaction-based physical antibacterial mechanisms. Increasing the size reduced the cutting effect but enhanced the cell entrapment effect, and vice versa. In conclusion, GO size affects its edge density and lateral dimension, further regulates its physical antibacterial mechanisms in different orientations and ultimately determines its activity. These findings provide a deep understanding of GO antibacterial property and may guide the design and development of GO for clinical use.
氧化石墨烯（GO）具有抗生素非依赖性的抗菌活性，这一点非常重要，因为抗生素疗法正面临着耐药性带来的巨大挑战。然而，GO 的尺寸与其抗菌活性之间的关系，以及尺寸如何调节抗菌机制，目前仍不清楚。在此，我们制备了四种具有不同尺寸的 GO 悬浮液，并证明了 GO 尺寸与其对革兰氏阳性致龋菌变形链球菌的抗菌活性之间呈抛物线关系。更有趣的是，我们发现了 GO 尺寸如何调节基于纳米-生物相互作用的物理抗菌机制。增加尺寸会降低切割作用，但会增强细胞捕获作用，反之亦然。总之，GO 的尺寸会影响其边缘密度和横向尺寸，进一步以不同的方向调节其物理抗菌机制，最终决定其活性。这些发现为 GO 的抗菌特性提供了更深入的了解，并可能为 GO 的临床应用设计和开发提供指导。
