Fabrication of sonicated chitosan nanofiber mat with enlarged porosity for use as hemostatic materials

•CS nanofiber mat with enlarged porosity and thickness achieved using sonication.•The BCI value for the sonicated CS nanofiber mat was lower than for other samples.•Sonicated CS nanofiber mats had decreased water absorption time and contact angle.•Cell viability on the sonicated mat was higher than non-sonicated mat. Electrospinning of pure chitosan was employed to obtain a nanofibrous hemostatic material. Owing to the water-solubility of the resulting acidic chitosan nanofibers, the optimum neutralization conditions were identified by testing various alkaline solutions, so that an insoluble material could be achieved. The pore size and thickness of the neutralized chitosan nanofibers mat could be controlled using ultra-sonication. The porosity of the chitosan mat was increased from 79.9% to 97.2% with ultra-sonication treatment for 1min, and the water absorption time decreased from 110s to 9s. The blood clotting efficiency measured for the sonicated chitosan nanofiber mat was 1.35- and 3.41-fold better than the efficiencies of the Surgicel® and chitosan sponge, respectively. In addition, the proliferation of normal human dermal fibroblasts on the sonicated nanofiber mat was found to be 1.4-fold higher than that on the non-sonicated material after 7 days of culture.