Immunomodulatory Activity of Electrospun Polyhydroxyalkanoate Fiber Scaffolds Incorporating Olive Leaf Extract

Olive tree is a well-known source of polyphenols. We prepared an olive leaf extract (OLE) and characterized it via high performance liquid chromatography (HPLC) analysis. OLE was blended with different polyhydroxyalkanoates (PHAs), namely, poly(hydroxybutyrate-co-hydroxyvalerate) (PHBHV) polyhydroxybutyrate/poly(hydroxyoctanoate-co-hydroxydecanoate) (PHB/PHOHD), to produce fiber meshes electrospinning: OLE/PHBV OLE/ respectively. An 80–90% (w/w%) release the main polyphenols from OLE/PHA fibers occurred in 24 h, burst first 30 min. produced were assayed using human dermal keratinocytes (HaCaT cells) evaluate expression panel cytokines involved inflammatory process innate immune response, such as antimicrobial peptide beta defensin 2 (HBD-2). Fibers containing able decrease pro-inflammatory at 6 h up h. All PHA allowed early downregulation which suggestive strong anti-inflammatory activity exerted by fibers. Differently pure OLE, PHB/PHOHD (both without OLE) upregulated HBD-2. Our results showed that are suitable decreasing incorporation may enable indirect antibacterial properties, essential wound healing tissue regeneration.