Citric acid crosslinked chitosan/poly(ethylene oxide) composite nanofibers fabricated by electrospinning and thermal treatment for controlled drug release

A nontoxic multicarboxylic acid (critic acid) was incorporated into the chitosan/poly(ethylene oxide) composite nanofibers by electrospinning. Critic acid was used to crosslink the chitosan molecules inside the composite nanofibers at elevated temperature, which were characterized by FT-IR and XPS analyses. By increasing the critic acid loading and annealing temperature, the solvent resistance and mechanical properties of these composite nanofibers could be significantly improved. Aspirin, a model drug, has been incorporated into the composite nanofibers and the corresponding drug release performances in PBS solution were evaluated. With the increasing of annealing temperature, the drug release rate of the composite nanofibers was decreasing, which could be ascribed to the reduced swelling ratio and concentration of free volume holes in composite nanofibers. Moreover, the cumulative released aspirin amount in certain release time could be finely tuned by adjusting the initial aspirin loading in the composite nanofibers.