Elastic Nanofibrous Membranes for Medical and Personal Protection Applications: Manufacturing, Anti-COVID-19, and Anti-Colistin Resistant Bacteria Evaluation

Herein, in the present work two series of thermoplastic polyurethane (TPU) nanofibers were manufactured using the electrospinning techniques with ZnO and CuO nanoparticles for a potential use as an elastic functional layer in antimicrobial applications. Percentages of 0%, 2 wt%, and 4 wt% of the nanoparticles were used. The morphological characterization of the electrospun TPU and TPU/NPs composites nanofibers were observed by using scanning electron microscopy to show the average fiber diameter and it was in the range of 90-150 nm with a significant impact of the nanoparticle type. Mechanical characterization showed that TPU nanofiber membranes exhibit excellent mechanical properties with ultra-high elastic properties. Elongation at break reached up to 92.5%. The assessment of the developed nanofiber membranes for medical and personal protection applications was done against various colistin resistant bacterial strains and the results showed an increment activity by increasing the metal oxide concentration up to 83% reduction rate by using TPU/ZnO 4% nanofibers against K. pneumoniae strain 10. The bacterial growth was completely eradicated after 8 and 16 h incubation with TPU/ZnO and TPU/CuO nanofibers, respectively. The nanofibers SEM study reveals the adsorption of the bacterial cells on the metal oxides nanofibers surface which led to cell lysis and releasing of their content. Finally, in vitro study against Spike S-protein from SARS-CoV-2 was also evaluated to investigate the potent effectiveness of the proposed nanofibers in the virus deactivation. The results showed that the metal oxide concentration is an effective factor in the antiviral activity due to the observed pattern of increasing the antibacterial and antiviral activity by increasing the metal oxide concentration; however, TPU/ZnO nanofibers showed a potent antiviral activity in relation to TPU/CuO.

Automated summary

In this study, TPU nanofibers containing ZnO and CuO nanoparticles were manufactured using electrospinning techniques, showing excellent mechanical properties and antimicrobial/antiviral activity. Among them, TPU/ZnO nanofibers exhibited potent antiviral activity.