The effect of active ingredient-containing chitosan/polycaprolactone nonwoven mat on wound healing: in vitro and in vivo studies.

The use of an electrospun polycaprolactone (PCL) nonwoven mat that is coated with a layer of chitosan (CS) containing active ingredient [tea tree oil (TTO)] represents an effective strategy for producing functional dressings. CS-coated porous PCL nonwoven mat (CS3/PCLNM) with various concentrations of active ingredients were produced and investigated. In vitro, active ingredient-containing CS3/PCLNM is effective in inhibiting the formation of nitrite and the growth of Staphylococcus aureus. Both active ingredient TTO and CS have been proven to reach their maximum amount of releases within 24 h of contact with water-based environment. In vivo, full-thickness skin removal (1.2 cm × 1.2 cm) was performed on the back of the C57BL6/J mice in noninfected and infected animal models. Four groups of functional dressings were tested in this work including Tegderm™, PCLNM, CS3/PCLNM, and 100 μL TTO-CS3/PCLNM. After 7 days post-treatment, the bacterial levels were found to be significantly lower in both CS3/PCLNM and 100 μL TTO-CS3/PCLNM-treated groups than in the control group (81.6 ± 18.1% and 93.7 ± 9.57% of reductions in the bacterial load in the pus relative to the control group, respectively). Additionally, based on the histological analyses, the 100 μL TTO-CS3/PCLNM-treated group outperformed all other groups in wound healing.