Catechin Encapsulated Antioxidant Electrospun Nanofibers: A Comparative Study between Cyclodextrin Complex Nanofibers and Poly(vinyl alcohol) Nanofibers

Catechin is a plant polyphenol with a strong antioxidant effect. However, its use is limited due to its poor water solubility and sensitivity to light and oxygen. Here, catechin could be solubilized by inclusion complexation with cyclodextrin (CD) (CD-IC), and their solutions were electrospun into fibers in the presence and absence of poly(vinyl alcohol) (PVA) to compare the stabilization of catechin for its antioxidant activity. The antioxidant activity of catechin/CD IC nanofibers was also compared to that of the powder form. Scanning electron microscopy (SEM) analysis revealed the production of bead-free nanofibers. The successful incorporation of catechin into nanofibers was confirmed by Fourier-transform infrared spectroscopy (FTIR) analysis of catechin C＝C bond stretching. Likewise, ¹H NMR spectroscopic analysis revealed the characteristic aromatic protons of catechin. The formation of inclusion complexes was confirmed by X-ray diffraction (XRD) and dissolution testing by the disappearance of crystalline peaks and rapid fiber dissolution, respectively. Finally, antioxidant testing demonstrated the higher antioxidant activity of polymer-free CD-IC nanofibers.