Fabrication and Characterization of Electrospun Chitosan Nanofibers Formed via Templating with Polyethylene Oxide

Abstract

Chitosan is an abundantly common, naturally occurring, polysaccharide biopolymer. Its biocompatible, biodegradable, and antimicrobial properties have led to significant research toward biological applications such as drug delivery, artificial tissue scaffolds for functional tissue engineering, and wound-healing dressings. For applications such as tissue scaffolding, formation of highly porous mats of nanometer-sized fibers, such as those fabricated via electrospinning, may be quite important. Previously, strong acidic solvents and blending with synthetic polymers have been used to achieve electrospun nanofibers containing chitosan. As an alternative approach, in this work, polyethylene oxide (PEO) has been used as a template to fabricate chitosan nanofibers by electrospinning in a core-sheath geometry, with the PEO sheath serving as a template for the chitosan core. Solutions of 3 wt % chitosan (in acetic acid) and 4 wt % PEO (in water) were found to have matching rheological properties that enabled efficient core-sheath fiber formation. After removing the PEO sheath by washing with deionized water, chitosan nanofibers were obtained. Electron microscopy confirmed nanofibers of approximately 250 nm diameter with a clear core-sheath geometry before sheath removal, and chitosan nanofibers of approximately 100 nm diameter after washing. The resultant fibers were characterized with IR spectroscopy and X-ray diffraction, and the mechanical and electrical properties were evaluated.

Transient charge-masking effect of applied voltage on electrospinning of pure chitosan nanofibers from aqueous solutions

“…However, the chitosan content and hence the properties of the blended fiber are limited unless the added component is removed after deposition. One of the proposed methods for obtaining pure chitosan nanofibers involves the removal of the poly(ethylene oxide) sheath in the core-sheath electrospinning of chitosan with poly(ethylene oxide) [9]. However, the resultant mat was too fragile even for its mechanical properties to be measured.…”

Synthetic/Biopolymer Nanofibrous Composites as Dynamic Tissue Engineering Scaffolds

“…These studies all illustrate that either soluble or unstable encapsulates can be stabilized by the presence of the sheath, and that the properties of release are controlled by both core and shell properties. Chitosan is particularly well suited to this technology because of the difficulty in spinning pure solutions, while being a potentially valuable encapsulant [167]. Due to their general success so far, future studies will undoubtedly continue to utilize synthetic sheaths such as PLLA and PCL to protect and facilitate spinning of biopolymer core components such as chitosan, silk, and gelatin or soluble core polymers such as PVA or PEO.…”

Coaxial nanofibers containing TiO2 in the shell for water treatment applications

“…Unspinnable materials such as drugs, enzymes, etc. could be electrospun as the core of a fiber-forming polymer [3][4][5][6]. Nanofibers encapsulating epoxy within a polymeric shell were found to be suitable for self-healing applications [7].…”

“…Nanofibers encapsulating epoxy within a polymeric shell were found to be suitable for self-healing applications [7]. Biocompatible nanofibers with improved mechanical properties [8], hollow nanofibers [9], nanofibers from unspinnable polymers [5,10] could be electrospun. Coaxial nanofibers encapsulating bio-based phase change material (bio-PCM) exhibited balanced thermal storage and releasing properties for thermo-regulating functions [11].…”