Convenient Fabrication of Electrospun Prolamin Protein Delivery System with Three-Dimensional Shapeability and Resistance to Fouling

It has been newly discovered that by simply altering the applied voltage, the resultant electrospun prolamin protein fabrics can rapidly (within 30 s) form either flat sheets or self-rolled tubes when immersed in water. This phenomenon opens up many potential biomedical applications for drug delivery. The morphology and structure of both dry and wet fibers were characterized in detail. The hordein/zein fibers fabricated at relatively lower voltage were stabilized by the preaggregated nanoscale hydrophobic domains and exhibited restricted swelling while maintaining a flat sheet shape with minimal changes to secondary structure when immersed in water. By applying a higher voltage, we triggered a greater bending instability during the electrospinning process, and the hordein/zein network structure generated could rapidly relax in an aqueous environment. This increased mobility of molecular chains allowed the uneven aggregation of hydrophobic dopants, which catalyzed the self-rolling of the aligned fibers. Sessile drop measurements even showed a reduction in the contact angle from 106 to 39° for the fibers with 50% zein prepared at raised voltage, indicating the conversion of surface properties caused by the relaxation. All the fibers demonstrated low toxicity in human primary dermal fibroblast cell culture. Moreover, the electrospun fabrics exhibited a strong resistance to protein adsorption and cell attachment, and the release experiment indicated that both three-dimensional porous structures could serve as a carrier for controlled release of incorporated bioactive compounds into phosphate-buffered saline. Therefore, these electrospun prolamin protein fabrics represent an ideal and novel platform to develop nonadherent drug delivery systems for wound dressing and other biomedical applications.