Nanofibers incorporating natural aryl polyene pigment from Chryseobacterium sp. kr6 as an innovative antioxidant platform

Microbial pigments have emerged as sustainable and functional alternatives to synthetic dyes, owing to their natural origin, structural diversity, and bioactivity. In this study, an aryl polyene pigment from Chryseobacterium sp. kr6 was successfully incorporated into electrospun poly(ε-caprolactone) (PCL) nanofibers. Scanning electron microscopy confirmed the formation of homogeneous nanofibers, with increased pigment content leading to thicker fibers and broader diameter distribution. Infrared analyses revealed non-covalent interactions, primarily hydrogen bonding, between pigment functional groups and the PCL matrix. Thermal analyses showed a minor reduction in crystallinity and thermal stability upon pigment addition, consistent with physical confinement within the amorphous regions of PCL. Mechanical testing revealed a decrease in stiffness and tensile strength in nanofibers containing pigment. Notably, the pigment retained its antioxidant activity after electrospinning achieving around 58.8% ABTS radical-scavenging (1273 μM Trolox). Electrospinning is a viable strategy for encapsulating bacterial pigments into nanofibers, enabling the development of functional eco-friendly materials.