pH-Sensitive ε-polylysine/polyaspartic acid/zein nanofiber membranes for the targeted release of polyphenols

In this work, zein nanofiber membranes loaded with ε-polylysine-polyphenol-polyaspartic acid were prepared using electrospinning for the controlled delivery of polyphenols. The loading efficiency (LE) and loading capacity (LC) of polyphenols in ε-polylysine/polyaspartic acid hydrogels were determined. Characterization of the films was carried out using water contact angle (WCA) measurement, thermal analysis (DSC/TG), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The study showed that the embedding rates of all samples reached more than 80%. The structural characterization results showed that the nanofiber membranes loaded with hydrophobic polyphenols were more stable and no new compounds formed during electrostatic spinning. The in vitro release study of phlorotannin, kaempferol and tannic acid indicated that about 62.35%, 63.51% and 73.65% of polyphenol release occurred at pH 6.8 for 8 h. The result of cytotoxicity assay in human colon cancer cells (HT-29) showed good biocompatibility of the zein nanofiber membranes. The investigation suggested that polyphenols can be successfully entrapped in the ε-polylysine-polyaspartic acid-zein nanofiber membranes for targeted delivery.