Tea tree oil-containing chitosan/polycaprolactone electrospun nonwoven mats: a systematic study of its anti-bacterial properties in vitro

This study demonstrates a facile and general method developed to prepare a free–standing chitosan/polycaprolactone nonwoven mat (CS/PCLNM) using an electrospinning system equipped with a metallic frame with an air gap. All nonwoven mats are composed of polycaprolactone microfibres coated with a layer of CS or tea tree oil containing–CS (TTO–CS/PCLNM). Four bacteria commonly associated with human skin flora infections or hospital–acquired infections were chosen as the targets for our in vitro anti–bacterial susceptibility testing (P. aeruginosa, M. luteus, S. pyogenes, and S. aureus). The bacteriostatsis ratios of the CS/PCLNM against abovementioned bacteria are −77.2%, −67.5%, 99.9%, and 86.4%, respectively. In addition, we find that the anti–bacterial ability of the CS/PCLNM is further promoted by incorporating a 100 μL of TTO in its CS overlayer. After TTO incorporation, the produced TTO–CS/PCLNM shows anti–bacterial ability against all four strains of bacteria (P. aeruginosa: 99.8%, M. luteus: 12.8%, S. pyogenes: 96.7%, and S. aureus: 99.9%). In conclusion, the TTO–CS/PCLNM exhibits broader anti–bacterial spectrum than that of the CS/PCLNM toward commonly seen skin flora.