Quercetin-Loaded Polycaprolactone-Polyvinylpyrrolidone Electrospun Membranes for Health Application: Design, Characterization, Modeling and Cytotoxicity Studies.

Fibrous membranes of polycaprolactone (PCL)-polyvinylpyrrolidone (PVP) encapsulating 15% wt of quercetin are fabricated by a uniaxial electrospinning technique. Morphological analysis of the electrospun systems proved the fabrication of micrometric fibers (1.58 µm for PCL/PVP and 2.34 µm for quercetin-loaded membrane). The liquid retention degree of the electrospun membranes is evaluated by testing four different liquid media. The contact angle estimation is performed by testing three liquids: phosphate buffer solution, basic solution (pH = 13) and acidic solution (pH = 3), showing high hydrophobicity degree (contact angles > 90°) in all cases. The release of quercetin from the nanofibers in PBS (phosphate buffer solution) and pH = 3 medium, modeled through different models, shows the possibility of a fine tuning of drug release (up to 7 days) for the produced materials. The release profiles attained a plateau regime after roughly 50 h up to 82% and 71% for PBS and pH = 3 media, respectively. Then, since quercetin is known to undergo photooxidation upon UV radiation, release tests after different UV treatment times are carried out and compared with the untreated membrane, demonstrating that the release of the active drug changes from 82% for no-irradiated sample up to 57% after 10 h of UV exposure. The biology activity of released quercetin is evaluated on two human cell lines. The reported results demonstrate the ability of the quercetin-loaded membranes to reduce cell viability of human cell lines in two different conditions: direct contact between cells and quercetin-loaded membranes and cells treatment with culture medium previously conditioned with quercetin-loaded membranes. Therefore, the reported preliminary data confirm the possibility of applying the electrospun quercetin-loaded PCL-PVP membranes for health applications.