Development of antiviral electrospun PET nanofabric functionalized with β-cyclodextrin encapsulated thymol

The development of advanced personal protective equipment necessitates materials that combine high filtration efficiency with active pathogen neutralization. In this study, a novel bioactive nonwoven filter was successfully fabricated from polyethylene terephthalate (PET) via solution electrospinning. Systematic optimization of electrospinning parameters revealed that a 15 wt% PET concentration and a 2.5 mL/h flow rate yielded highly uniform nanofibers with an average diameter of 540 nm. To impart antimicrobial properties, thymol, in its pure form and encapsulated within β-cyclodextrin (β-CD), was incorporated into the PET matrix. Encapsulation achieved 75% efficiency, significantly modulating the release profile of the active agent. While pure thymol showed a rapid burst release within one day, the β-CD encapsulated thymol (2:1 β-CD to thymol mass ratio) exhibited a sustained, controlled release extending beyond 7 days. Based on the headspace release measurement methodology, the PET mat containing 25 wt% thymol demonstrated superior performance, reaching total released thymol concentrations of 57.7 mg/L at 25°C and 63.5 mg/L at 37°C over a 40-day period, accumulated in the headspace gas. Biological assays confirmed that the PET-thymol 25 wt% sample possessed remarkable antibacterial activity, significantly inhibiting E. coli and S. aureus within 6 h. Furthermore, the material achieved a 2.5-log reduction in human coronavirus 229E titers after only 2 h of contact. These findings highlight the potential of PET–β-CD–thymol electrospun fabrics as multifunctional, recyclable, and highly effective materials for next-generation protective face masks and biomedical filtration applications.