Electrospun nanofibers for localized drug release of a neuroprotective natural extract of Usnea ghattensis

This research is based on the incorporation of the methanolic extract of the Usnea ghattensis into poly (caprolactone) (PCL) nanofibers (NFs) to investigate the capacity in reducing reactive oxygen species (ROS). PCL-NFs were fabricated by the electrospinning technique and are investigated as potential dressing material focused on the release of usnic acid (PCL-USNIC NFs), and its encapsulation efficiency and kinetic release were analyzed by high performance liquid chromatography (HPLC). This investigation was performed by analyzing the usnic acid concentration as a function of the distance from the mat center point. The kinetic release analysis is also developed with the usnea ghattensis extract (PCL-USNEA NFs), performing a metabolomic analysis of the released molecules as a function of time by nuclear magnetic resonance (NMR). Usnic acid was revealed as the most relevant compound together with other molecules, such as sucrose, mannitol, arabitol or glycerol that generate a positive matrix effect on the release of usnic acid. Finally, we analize the cytotoxicity and the neuroprotective effect of PCL-USNEA and PCL-USNIC NFs using a human neuroblastoma cell line model. Negligible toxicity was appreciated for both polymeric systems, showing high protective effects in presence of highly oxidative environment (e.g. in presence of H₂O₂).