Electrospun polycaprolactone nanofibers functionalized with Achillea millefolium extract yield biomaterial with antibacterial, antioxidant and improved mechanical properties

In this study, polycaprolactone (PCL), as a biocompatible polymer was functionalized by addition of medicinal plant extract- Achillea millefolium L. (yarrow). Nanofiber mats were fabricated from PCL solutions containing dry yarrow extract in four concentrations (5%, 10%, 15%, and 20% relative to the weight of the polymer) by using blend electrospinning method. The nanofibers were characterized for their biological, mechanical and drug release behavior. In vitro release of yarrow polyphenols from the electrospun PCL nanofibers over a period of 5 days showed the release of up to 98% of the total loaded polyphenols. The released polyphenols retained its antioxidant activity, which was determined by DPPH assay. Electrospun PCL/yarrow nanofiber mats exhibited the antibacterial effect against Staphylococcus aureus, but had no effect on the growth of Pseudomonas aeruginosa. All PCL/yarrow nanofiber mats had improved mechanical properties compared to the neat PCL nanofibers, as evident by an increase in Young's modulus of elasticity (up to 5.7 times), the tensile strength (up to 5.5 times), and the strain at break (up to 1.45 times). Based on our results, yarrow-loaded PCL nanofiber mats appeared to be multi-functional biomaterials suitable for the production of catheter-coating materials, patches, or gauzes with antibacterial and antioxidant properties