Preparation of Chondroitin Sulfate/Chitosan Composite Fibers by Spinning from Aqueous Solution Interfaces

We developed processes to obtain water-insoluble fibers from polyion complexes (PIC) of chondroitin sulfate C (CS) and chitosan (CHI) by utilizing interface-spinning methods. A CS solution was gently placed on a CHI solution, which resulted in formation of films made of PIC at the solution interfaces. Fibers were spun by withdrawing the films from the interfaces, then dried by passing through an acetone bath and finally rolled up. We evaluated-the morphology and strength of the prepared fibers. Several meters-long CS/CHI composite fibers having several tens of micrometers diameter were successfully obtained through this process. Interestingly, it was found that tensile strength increased as the molecular weight of CHI increased. Swelling-stretching treatment made these fibers denser and stronger than before treatment. The experimental results revealed that these fibers made of CS/CHI had mechanical properties sufficient for structural materials.