Yang Sandy, Tran Clara, Whiteley Gregory S, Glasbey Trevor, Kriel Frederik H, McKenzie David R, Manos Jim, Das Theerthankar
Department of Infectious Diseases and Immunology, School of Medical Science, The University of Sydney, Camperdown 2006, Australia.
School of Physics, The University of Sydney, Camperdown 2006, Australia.
Langmuir. 2020 Nov 3;36(43):13023-13033. doi: 10.1021/acs.langmuir.0c02414. Epub 2020 Oct 20.
Biofilm formation and antimicrobial resistance at surgical implant sites result in high morbidity and mortality. Identifying novel molecules that inhibit biofilm formation to coat surgical biomaterials is essential. One such compound is -acetylcysteine (NAC), a potent antioxidant precursor for glutathione, necessary in mammalian cells and known to disrupt/prevent biofilms. In this study, NAC was covalently immobilized onto functionalized polyvinyl chloride surfaces using plasma immersion ion implantation (PIII) treatment that achieves covalent binding without the need for linker groups. NAC immobilization was characterized using water contact angles, Fourier-transform infrared, and X-ray photoelectron spectroscopy techniques. Bacterial viability and biofilm formation on NAC surfaces were assessed using resazurin assays, phase contrast microscopy, and colony counting experiments. Effect of NAC on bacterial polysaccharide production and DNA cleaving was investigated using the phenol-sulfuric acid method and the Qubit fluorometer. Surface thermodynamics between the NAC coating and bacterial cells were measured using the Lewis acid-base method. Surface characterization techniques demonstrated superficial changes after PIII treatment and subsequent covalent NAC immobilization. NAC-coated surfaces significantly reduced biofilm viability and the presence of Gram-negative and Gram-positive bacteria. NAC also decreased polysaccharide production and degraded DNA. This led to unfavorable conditions for biofilm formation on NAC-coated surfaces, as demonstrated by surface thermodynamic analysis. NAC-coated surfaces showed no cytotoxicity to human fibroblast cells. This study has successfully utilized NAC as an antibiofilm coating, which may pave the way for improved prophylactic coatings on medical implant devices in the future.
手术植入部位的生物膜形成和抗菌耐药性会导致高发病率和死亡率。识别能够抑制生物膜形成的新型分子以包覆手术生物材料至关重要。一种这样的化合物是N-乙酰半胱氨酸（NAC），它是谷胱甘肽的一种强效抗氧化前体，在哺乳动物细胞中是必需的，并且已知能破坏/预防生物膜。在本研究中，使用等离子体浸没离子注入（PIII）处理将NAC共价固定在功能化聚氯乙烯表面，该处理无需连接基团即可实现共价结合。使用水接触角、傅里叶变换红外光谱和X射线光电子能谱技术对NAC的固定进行了表征。使用刃天青测定法、相差显微镜和菌落计数实验评估了NAC表面上细菌的活力和生物膜形成。使用苯酚-硫酸法和Qubit荧光计研究了NAC对细菌多糖产生和DNA裂解的影响。使用路易斯酸碱法测量了NAC涂层与细菌细胞之间的表面热力学。表面表征技术证明了PIII处理及随后的NAC共价固定后表面发生的变化。NAC包覆的表面显著降低了生物膜活力以及革兰氏阴性和革兰氏阳性细菌的存在。NAC还减少了多糖产生并降解了DNA。如表面热力学分析所示，这导致在NAC包覆的表面上形成生物膜的条件不利。NAC包覆的表面对人成纤维细胞无细胞毒性。本研究成功地将NAC用作抗生物膜涂层，这可能为未来改进医疗植入装置的预防性涂层铺平道路。
