Electrospinning processing can be applied to fabricate fibrous polymer mats composed of fibers whose diameters range from several microns down to 100 nm or less. In this article, we describe how electrospinning was used to produce zein nanofiber mats and combined with crosslinking to improve the mechanical properties of the as-spun mats. Aqueous ethanol solutions of zein were electrospun, and nanoparticles, nanofiber mats, or ribbonlike nanofiber mats were obtained. The effects of the electrospinning solvent and zein concentration on the morphology of the as-spun nanofiber mats were investigated by scanning electron microscopy. The results showed that the morphologies of the electrospun products exhibited a zeindependent concentration. Optimizing conditions for zein produced nanofibers with a diameter of about 500 nm with fewer beads or ribbonlike nanofibers with a diameter of approximately 1-6 mm. Zein nanofiber mats were crosslinked by hexamethylene diisocyanate (HDI). The tensile strength of the crosslinked electrospun zein nanofiber mats was increased significantly.

BACKGROUND: Electrospinning of natural polymers offers a promising approach to generate nanofibers with a similar fibrillar structure to that of native extracellular matrix. In the present work, zein/silk fibroin (SF) blends were electrospun with formic acid as solvent to fabricate bicomponent nanofibrous scaffolds for biomedical applications.RESULTS: The zein/SF electrospun nanofibers had a smaller diameter and narrower diameter distribution than pure zein nanofibers, and the average diameter gradually decreased from 265 to 230 nm with increasing SF content in the blend. The predominant presence of α‐helix zein structure and random coil form of silk I in blend fibrous membranes was confirmed from Fourier transform infrared spectral and wide‐angle X‐ray diffraction data, while conversion to the β‐sheet structure of SF was also detected. The tensile strength of the zein/SF fibrous membranes was improved as the content of SF in the blend fibers increased. A preliminary study of in vitro degradation and cytotoxicity evaluated by MTT assay indicated that biodegradable zein/SF fibrous membranes did not induce cytotoxic effects in an L929 mouse fibroblast system.CONCLUSION: Biodegradable zein/SF fibrous membranes with good mechanical properties and cytocompatibility combine the beneficial characteristics of the individual components and may be useful for biomedical applications. Copyright © 2009 Society of Chemical Industry

Electrospinning of biopolymers, such as proteins and polysaccharides, has recently attracted much attention for the fabrication of scaffolds for tissue engineering. In this report, zein/hyaluronic acid (HA) blend fibrous membranes were electrospun and characterized. To facilitate the compatibility of zein and HA, poly(vinyl pyrrolidone) (PVP) was introduced into aqueous ethanol solutions of the blend. A series of zein/HA/PVP blend fibrous membranes with different volume ratios were successfully electrospun. The effect of blend composition on the morphology of electrospun fibrous membranes was investigated by scanning electron microscopy. The average diameter of blend fibers increased with increasing the content of zein component. The electrospun zein/HA/PVP fibrous membranes were then cross-linked by methylene diphenyl diisocyanate (MDI). The morphology of the cross-linked zein/HA/PVP fibrous membranes changed slightly compared with un-cross-linked membranes. Tensile tests demonstrated that the mechanical properties of the zein/HA/PVP fibrous membranes were improved by cross-linking.

ABSTRACT:The continuous nanofiber yarns of poly(Llactide) (PLLA)/nano-b-tricalcium phosphate (n-TCP) composite are prepared from oppositely charged electrospun nanofibers by conjugate electrospinning with coupled spinnerets. The morphology and mechanical properties of PLLA/n-TCP nanofiber yarns are characterized by scanning electron microscope, transmission electron microscope, and electronic fiber strength tester. The results show that PLLA/n-TCP nanofibers are aligned well along the longitudinal axis of the yarn, and the concentration of PLLA plays a significant role on the diameter of the nanofibers. The thicker yarn of PLLA/n-TCP composite with the weight ratio of 10/1 has been produced by multiple conjugate electrospinning using three pairs of spinnerets, and the yarn has tensile strength of 0.31cN/dtex. A preliminary study of cell biocompatibility suggests that PLLA/n-TCP nanofiber yarns may be useable scaffold materials.

in Wiley InterScience (www.interscience.wiley.com).ABSTRACT: Zein and zein/poly-L-lactide (PLLA) nanofiber yarns were prepared by conjugate electrospinning using coupled spinnerets applied with two high electrical voltages of opposite polarities in this article. Structure and morphology of zein yarns were investigated by SEM and Xray diffraction. The results showed that zein yarn consisted of large quantity of fibers with diameters ranging from several hundreds nanometers to a few microns, and zein concentration played a significant role on the diameter of nanofibers in yarns. To improve mechanical property of nanofiber yarns, PLLA was then incorporated with zein. Zein/PLLA composite nanofiber yarns conjugate electrospun from solution with concentration of 7.5% (zein, w/v)/ 7.5% (PLLA, w/v) exhibited tensile strength of 0.305 AE 0.014 cN/dtex. The composite yarns showed better nanofiber alignment along the longitudinal axis.