Antibacterial Nanofibrous Mat of Pullulan/Cinnamaldehyde-Cyclodextrin Inclusion Complexes as a Potential Cloth Mask Layer with Long-Term Storage Stability and Facile Disposal Property

Abstract

There is an ongoing rise in global plastic waste because of the mass production and vast consumption of surgical face masks during the COVID-19 outbreak. This problem leads to a crucial need for alternative face coverings which can eliminate environmental concerns. Using cloth masks can be a sustainable solution if combined with a functional filtering layer. In this study, electrospun nanofibrous mats (NM) were generated using a renewable biopolymer; pullulan by the incorporation of cyclodextrin inclusion complexes (γCD-IC) of naturally occurring essential oil compound; trans-cinnamaldehyde (CAH). Pullulan/CAH-γCD-IC NM was readily inserted into a cloth mask due to its free-standing and foldable features and achieved higher loading efficiency (∼62%) than pullulan/CAH NM (∼10%). Here, pullulan/CAH-γCD-IC NM showed substantial and better antibacterial activity, long-term storage stability, and thermal stability due to inclusion complexation. Pullulan/ CAH-γCD-IC NM was also obtained with promising properties of pore size (∼390 nm) and water vapor permeability (∼890 g/m 2 /day). The water solubility of pullulan/CAH-γCD-IC NM ensured fast and easy disposal without potential environmental loading, thanks to the biocompatibility of components. Briefly, pullulan/CAH-γCD-IC NM can create an attractive alternative as a functional layer that can be combined with the cloth mask.