Department of Biomass Chemistry and Engineering, Sichuan University, Chengdu, 610065, P. R. China.
National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu, 610065, P. R. China.
Chem Biodivers. 2020 Mar;17(3):e1900734. doi: 10.1002/cbdv.201900734. Epub 2020 Feb 20.
Biofilm is the crucial reason of clinical infections. Herein, green tea based polyphenol (catechin) and rare earth (RE) metal ions were employed for the preparation of catechin-RE complexes with significant anti-biofilm properties. The complexes were characterized by FT-IR, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and dynamic light scattering (DLS), which suggested that catechin coordinated with RE through its ortho phenolic hydroxy groups. The prepared catechin-RE showed significant effects in anti-biofilm growth against P. aeruginosa (Gram-negative bacteria), S. sciuri (Gram-positive bacteria), and A. niger (fungi), which significantly exceeded the utilization of catechin or RE . Morphological observations indicated that catechin supplied cell affinity to transfer RE and helped to damage cell membrane, which act as a carrier to exert cytotoxicity of RE to realize anti-biofilm. Differential gene expression analysis described gene expression changes induced by catechin-RE, including 56, 272 and 2160 downregulated genes for P. aeruginosa, S. sciuri and A. niger, respectively, which suggested critical changes in cellular metabolism, growth and other processes. These results illustrate the outstanding superiority of catechin-RE complexes in anti-infection aspect, i. e., the green tea based rare earth complexes are promising candidates for anti-biofilm applications to address serious challenges in the prevention of multiple infections.
生物膜是临床感染的关键原因。在此，采用绿茶多酚（儿茶素）和稀土（RE）金属离子，制备具有显著抗生物膜性能的儿茶素-RE 配合物。通过傅里叶变换红外光谱（FT-IR）、拉曼光谱、X 射线光电子能谱（XPS）和动态光散射（DLS）对配合物进行了表征，结果表明儿茶素通过邻位酚羟基与 RE 配位。所制备的儿茶素-RE 对铜绿假单胞菌（革兰氏阴性菌）、松鼠葡萄球菌（革兰氏阳性菌）和黑曲霉（真菌）的抗生物膜生长具有显著效果，明显优于儿茶素或 RE 的利用。形态观察表明，儿茶素提供了细胞亲和力来转移 RE，并有助于破坏细胞膜，作为载体发挥 RE 的细胞毒性，实现抗生物膜。差异基因表达分析描述了儿茶素-RE 诱导的基因表达变化，分别为铜绿假单胞菌、松鼠葡萄球菌和黑曲霉的 56、272 和 2160 个下调基因，这表明细胞代谢、生长和其他过程发生了关键变化。这些结果说明了儿茶素-RE 配合物在抗感染方面的突出优势，即基于绿茶的稀土配合物是抗生物膜应用的有前途的候选物，可解决预防多种感染的严峻挑战。
