Characteristics, Controlled-release and Antimicrobial Properties of Tea Tree Oil Liposomes-incorporated Chitosan-based Electrospun Nanofiber Mats

In this paper, a notable chitosan/poly(ethylene oxide) nanofiber mats containing tea tree oil liposomes (TOL-CENs) were successfully fabricated using electrospinning process. The microstructures and morphology were characterized by scanning electron microscopy. The porosity, fluid absorbability, water vapor permeability and mechanical properties of nanofiber mats were also estimated by ethanol density method, gravimetric method, dish method and tensile test, respectively. Compared to the chitosan/poly(ethylene oxide) composite freeze-dried sponges containing tea tree oil liposomes, TOL-CENs had greater porosity, water absorption, breathability and better mechanical properties. In addition, the controlled-release properties and long-term bactericidal capability of the material were also assessed. From the analysis of the release kinetics and mechanism, it was found that the significant decreased terpinen-4-ol concentration gradient from liposomal surface to the outside of material was the key to the sustained terpinen-4-ol release in virtue of liposomal encapsulation. TOL-CENs exhibited long-term and more excellent microbicidal effects against Staphylococcus aureus, Escherichia coli and Candida albicans than chitosan/poly(ethylene oxide) nanofiber mats. The combination of tea tree oil liposomes and chitosan in nanofiber mats synergistically destroyed cell membrane, prevented cell adhesion and caused the irregular aggregation of cytoplasm, resulting in cell disintegration observed by transmission electron microscope. In summary, TOL-CENs had potential application value as a long-term antimicrobial nonwoven materials.