Metal-Organic Framework (MOFs) tethered to cotton fibers display antimicrobial activity against relevant nosocomial bacteria

Abstract

Despite antibiotic treatments, bacteria remain outstanding etiological agents of hospital-acquired infections. This work assessed the antimicrobial activity of copper, zinc, and aluminum Metal-Organic framework (MOFs) immobilized onto cotton fibers against nosocomial bacteria. The MOF systems were synthesized over cotton carboxymethylated fibers (CMCs) through a friendly environmental insitu method. SEM and XRD analyses showed that MOFs uniformly anchored on cotton fibers were resistant to sterilization by autoclaving processes.On the other hand, using the ASTM E2149-13a method, it was observed that all the MOF systems exhibited antibacterial activity against Escherichia coli ATCC25922TM, Staphylococcus aureus ATCCR6538TM and Klebsiella pneumoniae ATCCR13882TM. In general, Gram-negative bacteria were the most susceptible to the cellulose-MOF systems; in fact, the cotton-Cu-MOF (MOF-199) displayed antimicrobial activity greater than 99% against Gram-negative bacteria in less than 5 min. On the other hand, the cotton-Zn-MOFs (MOF-74 and MOF-5) systems inhibited the growth of E. coli and K. pneumonia, displaying a bacterial growth inhibition range between 80% and 99.9%. In addition, the cotton-Al-MOF (MIL-53) exhibited a greater spectrum of antibacterial activity, indeed inhibited the growth of S. aureus (Gram-positive), K. pneumoniae, and E. coli (Gram-negative) at 50.2%, 53.6%, and 93.4%, respectively. Noteworthy, the antibacterial activity of Al+3 based MOFs has not been reported previously. All these results expand the potential of cellulose-MOF systems as attractive materials in the production of antibacterial fabrics, especially for hospital environments.