Fabrication and characterization of electrospun gelatin nanofibers crosslinked with oxidized phenolic compounds

In this study, the ability of oxidized phenolic compounds of tannic, gallic, ferulic and caffeic acids to crosslink gelatin (G) was investigated. The electrospun crosslinked gelatin nanofibers were assessed in terms of gelatin solution properties, fiber morphology, thermal properties, FTIR spectra, XRD pattern and antioxidant activity. Tannic acid showed the most crosslinking activity towards gelatin (13.3 vs 7.44, 4.65, and 3.45% for caffeic, gallic and ferulic, respectively). Crosslinking enhanced roughly electrical conductivity of gelatin solution while the surface tension and viscosity, reduced. According to scanning electron microscopy (SEM) results, the fibrous structure of crosslinked gelatin nanofibers didn't change while their diameter increased to the highest value of 280 nm for gelatin-tannic. Gelatin-gallic sample showed the highest total phenolic content (86.3 mg gallic acid equivalent/g) and antioxidant activity (86.5%). Surprisingly, from differential scanning calorimetry (DSC) curves, it was found that crosslinking led to the reduction of thermal stability of gelatin nanofibers. (C) 2017 Elsevier B.V. All rights reserved.