Rosmarinic acid-loaded electrospun nanofibers: In vitro release kinetic study and bioactivity assessment

This study seeks to develop a nanofibrous matrix containing rosmarinic acid (RosA), an herbal non-steroidal anti-inflammatory and antioxidant drug with low water solubility, for drug delivery applications. Neat and two types of RosA-loaded cellulose acetate (CA) mats varying in the initial content of RosA were electrospun. Microstructure of nanofibers, chemistry and physical state of RosA in nanofibers, RosA loading efficiency and RosA release in acetate buffer were investigated. To evaluate bioactivity of RosA-loaded nanofibers, their ability to inhibit protein denaturation was assayed as an indicator of anti-inflammatory properties and their antioxidant activity was determined by radical scavenging assay. The indirect cytotoxicity assay was used to find if there is a cytotoxic response to nanofibers. The homogeneous distribution of the drug within nanofibers through electrospinning led to high loading efficiency, low burst release and prolonged release of a large percentage of RosA over a period of 64h following Fickian diffusion mechanism. Nanofibers with higher RosA content exhibited anti-inflammatory activity comparable to ibuprofen, and higher antioxidant activity compared to nanofibers with lower RosA content. Additionally, extracts from nanofibers did not give any major harmful effect on cells. Sustained release of RosA, and bioactivity of RosA-loaded nanofibers confirmed the potential of the produced matrix as a drug delivery system.