Influence of K+ and Na+ ions on the degradation of wet-spun alginate fibers for tissue engineering

A synthetic type of wet-spun alginate fibers were immersed in simulated body fluid(SBF) composed of K+, Na+, and Ca2+ cations with various concentrations. Experimental measurements revealed that Na+ had a greater impact on degradability than that of K+ ion. The finding was further confirmed by the characterization of mass loss, ICP, XRD, and theoretical analyses. The degradation process and mechanism were demonstrated through the research on swelling behavior and mass loss. Besides, the wet-spun alginate fibers were characterized by FT-IR, XRD, and SEM. The results showed that the degradation mechanism could be attributed to the ion-exchange between Ca2+ of the synthetic alginate fibers and Na+, K+ of the solutions under the osmotic pressure. The synthetic fibers were swelled and then degraded faster with the presence of Na+ ion presented greater influence on degradability compared with K+ ion. The degradation results of a mechanical rupture of fibers due to excessive water uptake without the occurrence of any chemical changes in the spun alginates structure. (C) 2016 Wiley Periodicals, Inc.