Polycaprolactone/chitosan core-shell nanoparticles for the acceleration of second-degree burn healing in CD1 mice

Burn injuries are a major global health problem, and finding treatments for them is critical. Therefore, we aimed to design a drug delivery formulation for tea-tree oil comprising polycaprolactone/chitosan core-shell nanoparticles in order to accelerate the wound healing process in second-degree burns induced in CD1 mice. The present work is a continuation of our previously reported results on the antimicrobial and anti-inflammatory activity of the suggested nanomaterial. The nanoparticles (NPs) were optimized and characterized using FTIR spectroscopy, electron microscopy, dynamic light scattering, and zeta potential measurement. The investigations revealed that the best NP composition is 2 : 1 (PCL/CS, w/w), which showed an average particle size of 10.1 nm and a spherical core-shell structure. The nano-formulation was applied to burnt CD1 mice and showed a significant improvement in healing rate (21 days). Immunological analyses showed a significant increase in IL-13 and TNF-α levels. The immune response was enhanced in the early stages of burns, as revealed by the presence of CD8⁺ T-cell subsets being more than the CD4⁺ T-cells. Histological examination of burn areas showed healthy skin with a normal epidermal layer, newly formed blood capillaries, no scar formation, and apparently healthy hair follicles. TTO-loaded PCL/CS NPs provide a novel nanomaterial-based treatment for second-degree burns that can accelerate the wound healing process and prevent skin deformations via inducing tissue regeneration.