Govindan Sreejith, Ghosh Rudra Nath, Basavakumar Roopa Vaidehi, Joseph Ann Treasa, Gupta Ashutosh, Moorkoth Sudheer, Namboothiri Pramod K, Peter Mathew
Department of Basic Medical Sciences, Manipal, Manipal Academy of Higher Education, Madhav Nagar, Manipal, Karnataka 576104, India.
Department of Biomedical Engineering, Manipal Institute of Technology, Manipal, Manipal Academy of Higher Education, Manipal, Madhav Nagar, Manipal, Karnataka 576104, India.
ACS Omega. 2025 May 23;10(21):21334-21349. doi: 10.1021/acsomega.4c11412. eCollection 2025 Jun 3.
Bacterial resistance to antimicrobial agents is a serious problem encountered all over the world. With the misuse of antimicrobial agents for the treatment of human and animal diseases, large quantities of these agents find their way into our environment, polluting water and soil. Further, with industrialization and urbanization, several organic dyes are used as colorants for products. The waste products from such manufacturing processes find their way into our environment, especially in the less developed world. There is an urgent need to remediate the effects of organic dyes and develop a new class of materials that can tackle the effects of antimicrobial resistance. In this regard, the research in this paper pertains to the development of zinc imidazolate metal-organic framework (ZIF-L) nanoparticles and evaluation of their antimicrobial effects on both standard and clinically isolated strains of Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa). Further, in this work, we evaluated the removal of organic dyes using ZIF-L and Ag/ZIF-L nanoparticles. The synthesized nanoparticles were characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), thermal gravimetric analysis (TGA), UV-visible absorption spectroscopy, and band-gap energy analysis. The results for the antibacterial study showed that Ag/ZIF-L nanoparticles were superior to ZIF-L against S. aureus and P. aeruginosa strains tested, where the minimum bactericidal concentration (MBC) of Ag/ZIF-L was 2.5 mg/mL, whereas the MBC of ZIF-L was more than 10 mg/mL. In the case of E. coli strains, ZIF/L showed a better MBC value of less than 1.25 mg/mL, whereas for Ag/ZIF-L it was more than 1.25 mg/mL. Further, Ag/ZIF-L nanoparticles coated on a face mask and cotton gauze demonstrated superior antimicrobial activity compared to uncoated gauze and mask, whereas the Ag/ZIF-L-coated mask and gauze showed the zone of inhibition (ZOI) for all of the bacteria with P. aeruginosa having a higher ZOI value than S. aureus and E. coli. For quantification of the removal of organic dyes, ZIF-L and Ag/ZIF-L nanoparticles showed complete methylene blue dye removal from the solution at 150 min in the presence of sunlight. Under dark conditions, only 83% dye was removed by Ag/ZIF-L and 65% by ZIF-L. The results show that ZIF-L metal-organic frameworks have the potential to be used for clinical and environmental remediation applications.
细菌对抗菌剂的耐药性是全球面临的一个严重问题。随着抗菌剂在人类和动物疾病治疗中的滥用，大量此类药剂进入我们的环境，污染水和土壤。此外，随着工业化和城市化进程，几种有机染料被用作产品的着色剂。此类制造过程产生的废品进入我们的环境，在欠发达地区尤为如此。迫切需要修复有机染料造成的影响，并开发一类能够应对抗菌耐药性影响的新型材料。在这方面，本文的研究涉及咪唑锌金属有机框架（ZIF-L）纳米颗粒的开发及其对金黄色葡萄球菌、大肠杆菌和铜绿假单胞菌的标准菌株及临床分离菌株的抗菌效果评估。此外，在这项工作中，我们评估了ZIF-L和Ag/ZIF-L纳米颗粒对有机染料的去除效果。使用傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、扫描电子显微镜（SEM）、能量色散X射线光谱（EDS）、热重分析（TGA）、紫外可见吸收光谱和带隙能量分析对合成的纳米颗粒进行了表征。抗菌研究结果表明，在测试的金黄色葡萄球菌和铜绿假单胞菌菌株上，Ag/ZIF-L纳米颗粒的抗菌效果优于ZIF-L，其中Ag/ZIF-L的最低杀菌浓度（MBC）为2.5 mg/mL，而ZIF-L的MBC超过10 mg/mL。对于大肠杆菌菌株，ZIF/L的MBC值表现更好，小于1.25 mg/mL，而Ag/ZIF-L的MBC值则超过1.25 mg/mL。此外，涂覆在口罩和纱布上的Ag/ZIF-L纳米颗粒相比未涂覆的纱布和口罩表现出卓越的抗菌活性，而涂覆Ag/ZIF-L的口罩和纱布对所有细菌均显示出抑菌圈（ZOI），其中铜绿假单胞菌的抑菌圈值高于金黄色葡萄球菌和大肠杆菌。为了量化有机染料的去除效果，ZIF-L和Ag/ZIF-L纳米颗粒在阳光下150分钟时可将溶液中的亚甲基蓝染料完全去除。在黑暗条件下，Ag/ZIF-L仅去除83%的染料，ZIF-L仅去除65%的染料。结果表明，ZIF-L金属有机框架有潜力用于临床和环境修复应用。
