Effect of polymer solution properties on the formation and morphology of chitosan / polyvinyl alcohol nanofibers by electrospinning

Electrospinning is an old technique established for the preparation of submicron polymeric fibers. Recently, electrospun nanofibers have shown several medical and pharmaceutical advantages due to their extremely small diameter and high porosity. They can imitate the extra cellular matrix (ECM), utilized as wound healing and protective dressing. Chitosan is one of the important biomaterials which has shown wound healing and antimicrobial properties. The main purpose of this study is to investigate the effect of solution properties of chitosan such as concentration, viscosity on nanofiber formation and morphology. Chitosan solutions (2 and 3% w/v), with three different molecular weights prepared in 2% acetic acid. The solutions mixed with a 10% w/v polyvinyl alcohol solution (1:1 ratio) and analyzed for their viscosity. Nanofibers prepared with electrospinning technique and the morphology and diameter of resulting nanofibers were tested by scanning electron microscopy (SEM) and image analysis. Possible physicochemical interactions between PVA and chitosan also evaluated by FTIR and DSC analysis. The results showed that the PVA solution has the highest viscosity and addition of chitosan decreases its viscosity. Eelectrospinning of chitosan solution by itself was impossible but addition of PVA could facilitate the process. SEM analysis revealed that PVA solution results in smooth fibers which were comparatively large in diameter. Increasing chitosan decreased the nanofibers diameter and caused the formation of beaded structures. The results indicated that Chitosan with <500cp viscosity seems to produce more uniform nanofibers.