In this study, alginate (AL) fibers were electrospun and coagulated with chitosan (ChS) and ethanol using a single spinneret. These fibers exhibited a core-sheath structure that was revealed using a confocal laser scanning microscope (CLSM) and fluorescence-labeled polymers. The resulting fibers were examined using a field emission scanning electron microscope (FESEM) for the fiber size and morphology. The average diameter of the fibers ranged from 600 to 900 nm depending on the electrospinning parameters. To mimic the stability of alginate fibers in physiological fluids, the release of alginate from these fibers in normal saline was also tested. The results demonstrated that the core-sheath structure of alginate fiber can greatly reduce the degradation by 40% for 3 d in physiological environment. (C) 2011 Elsevier Ltd. All rights reserved.