Fabrication and application of coaxial polyvinyl alcohol/chitosan nanofiber membranes

It is difficult to fabricate chitosan-wrapped coaxial nanofibers, because highly viscous chitosan solutions might hinder the manufacturing process. To overcome this difficulty, our newly developed method, which included the addition of a small amount of gum arabic, was utilized to prepare much less viscous chitosan solutions. In this way, coaxial polyvinyl alcohol (PVA)/chitosan (as core/shell) nanofiber membranes were fabricated successfully by coaxial electrospinning. The core/shell structures were confirmed by TEM, and the existence of PVA and chitosan was also verified using FT-IR and TGA. The tensile strength of the nanofiber membranes was increased from 0.6-0.7 MPa to 0.8-0.9 MPa after being crosslinked with glutaraldehyde. The application potential of the PVA/chitosan nanofiber membranes was tested in drug release experiments by loading the core (PVA) with theophylline as a model drug. The use of the coaxial PVA/chitosan nanofiber membranes in drug release extended the release time of theophylline from 5 minutes to 24 hours. Further, the release mechanisms could be described by the Korsmeyer-Peppas model. In summary, by combining the advantages of PVA and chitosan (good mechanical strength and good biocompatibility respectively), the coaxial PVA/chitosan nanofiber membranes are potential biomaterials for various biomedical applications.