Preparation and performance evaluations of electrospun poly(ε-caprolactone), poly(lactic acid), and their hybrid (50/50) nanofibrous mats containing thymol as an herbal drug for effective wound healing

The use of herbal drugs as biocompatible and nontoxic drugs without special side effects in wound dressings are highly favored compared to that of chemical and synthetic drugs. In this study, the properties and performance of electrospun poly(epsilon-caprolactone) (PCL), poly(lactic acid) (PLA), and their 50/50 hybrid nanofibrous mats containing the herbal drug thymol (1.2% v/v) as wound dressings were investigated. The optimized solution concentrations of PCL (12% w/v) and PLA (3% w/v) in chloroform/dimethylformamide (7:3) for electrospinning were determined with viscometry and scanning electron microscopy studies to obtain smooth and beadless nanofibers. The results of the drug-release behavior along with swelling tests showed that the electrospun 50/50 PCL/PLA hybrid nanofibers had the highest level of drug release (approximate to 72%) compared with the PCL and PLA nanofibrous samples. The release kinetics of thymol from PCL, PLA, and 50/50 PCL/PLA hybrid nanofibrous mats were studied by the Peppas equation and the zero-order, first-order, Higuchi, and HixonCrowell models. Antibacterial evaluations showed that the electrospun 50/50 PCL/PLA hybrid nanofibrous samples containing thymol had satisfactory effects on Staphylococcus aureus compared with Escherichia coli bacteria during the treatment periods. In vivo rat wound-healing and histological performance observations of thymol-loaded 50/50 PCL/PLA nanofibrous mats, the commercial wound dressing Comfeel Plus, and gauze bandages (control) after 14-day post-treatment periods were evaluated. The results reveal that the electrospun 50/50 PCL/PLA hybrid nanofibers containing thymol had a remarkable wound-closure percentage of about 92.5% after a period of 14 days. Finally, the crystallinity and thermal behavior of the electrospun 50/50 PCL/PLA hybrid nanofibrous mats with and without thymol were studied by differential scanning calorimetry. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 129: 756-766, 2013