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.