Carboxymethyl chitosan-based electrospun nanofibers with high citral-loading for potential anti-infection wound dressings.

As a natural antibacterial agent with pleasant fragrance, citral possesses low aqueous solubility. To improve citral loading in hydrophilic nanofiber, Pickering emulsion electrospinning strategy was proposed for anti-infection dressing development. The in-situ aggerated β-cyclodextrin-citral inclusion complex particles (βCPs) were used as emulsion stabilizers, while citral and carboxymethyl chitosan (CMCS)/polyvinyl alcohol (PVA) mixed solutions were used as the inner "dispersed oil phase" and outer "continuous water phase", respectively. The results of electronic microscope investigation shown βCPs possessed regular cube appearances with a size of 5.5 ± 2.2 μm, which might improve the emulsion storage stability based on visual investigation. Moreover, randomly oriented and bead-on-string nanofibers with βCPs uniformly distributed could be obtained under optimized compositions and electrospinning parameters. Despite volatilization during electrospinning, nanofibers with high citral loading possessed good antibacterial performance against Staphylococcus aureus and Escherichia coli. In vitro hemolysis test indicated that nanofibers were hemocompatible. In addition, both fiber matrix and citral could promote the proliferation of mouse fibroblast cells. And the permeability of the fibers was adjustable. Thus, CMCS/PVA/βCPs/citral nanofibers could potentially protect wound from infection. In summary, CMCS/PVA/βCPs/citral nanofibers seemed to be promising alternatives to conventional wound dressings.