Biopolymers

Biopolymeric continuous core-sheath fibres, with an inner core of chitosan and alginate as the sheath, were fabricated for the first time without using a template via a novel wet-spinning process. We hereby present the necessary conditions to achieve optimal properties of the chitosan-alginate core-sheath fibre in a one-step spinning process. Stereomicroscope image in Fig. 1 demonstrate the monofilament bicomponent fibre of chitosan/alginate. SEM images in Fig. 2 also clearly show the cylinder shaped porous structure of the chitosan fibre covered with alginate. Coaxial fibres of chitosan/alginate exhibit a 260% increase in ultimate stress and more than 300% enhancement in the Young’s modulus compared to its alginate counterpart. The swelling ratio of as-prepared fibres has been investigated in Simulated Biological Fluid (SBF). The release behaviour from as-spun fibres in SBF been has also determined. The release profile indicated that the coaxial fibres have the ability to release the drug in a much slower rate than the alginate fibres. The core-sheath biofibres have shown to be cytocompatible to living cells in cell culture studies. They also demonstrated the ability to be woven into 3D structures. These results confirm that they are likely to find applications such as tissue scaffolds and drug delivery.