Novel zein‐based electrospun fibers with the water stability and strength necessary for various applications

Abstract

BACKGROUND: Some of the problems with electrospun zein fiber are that it has very low tenacities in the dry and wet states and that mats of the fiber become films when immersed in water. The fibers are therefore unusable for various applications despite their good biocompatibility and biodegradability. This research was conducted to overcome these problems by electrospinning novel fibers containing various concentrations of zein, citric acid (CA) and sodium hypophosphite monohydrate (SHP) and by crosslinking the zein with CA and with SHP serving as a catalyst. RESULTS:The CA-crosslinked electrospun zein fiber has as much as 10-fold greater wet tenacity and 15-fold greater dry tenacity than regular electrospun zein fiber. The average diameter of these fibers is 451 nm, which is the smallest diameter ever reported for zein-based electrospun fiber. A mat of this fiber retains its fibrous structure when immersed in water, and the fiber retains about 70% of its tenacity after 16 days at 50 • C and 90% relative humidity. CONCLUSION:The high dry and wet tenacities, good water stability and small diameter of the novel CAcrosslinked electrospun zein fiber make it attractive for biomedical and other applications that expose zein to water or that require high surface area.

Cytocompatible cross-linking of electrospun zein fibers for the development of water-stable tissue engineering scaffolds

“…Electrospun zein fibers were also prepared using our previous method of cross-linking zein using citric acid in the presence of SHP as catalyst in order to evaluate the effect of SHP on cells [32]. The zein solution was aged for 48 h at 50 wt.% with 6.0 wt.% (on weight of zein) citric acid and 3.3 wt.% (on weight of zein) SHP (Sigma-Aldrich, Inc.).…”

“…After being diluted to 26 wt.% with 70 wt.% ethanol, the zein solution was electrospun under the same conditions to produce samples XL-L, XL-M, and XL-H. The fibers obtained were cross-linked at 150 °C for 30 min (the optimized conditions in our previous research [32]). …”

“…Since the electrospun fibers were unstable and became film-like when immersed in the cross-linking solution, this wet cross-linking method was unsuitable for the modification of electrospun protein mats. In similar research on cross-linking plant proteins, micro-and nano-scale zein fibers were cross-linked using citric acid as the cross-linking agent and sodium hypophosphite monohydrate (SHP) as the catalyst and cross-linking was carried out in the dry state at high temperature (150-175 °C) [31,32]. However, the catalyst SHP was reported to be cytotoxic [33,34] and hence not suitable to cross-link electrospun fibers used for biomedical applications.…”

Electrospun starch acetate nanofibers: Development, properties, and potential application in drug delivery

“…98/2 and 95/5 (v/v)) was high, leading to beaded SA nanofibers as observed in another study. 18 On the other hand, low formic acid-to-water ratio solvent systems (e.g. 85/15 (v/v)) has a low vaporization rate, resulting in the collection of the non-solidified fibers on the collector.…”

“…The tenacity of SA nanofibers was measured according to the method reported by Xu et al 18 After being conditioned, the cross-sectional area of the SA nanofibers' mat was calculated by Eq. 2 using the weight, density and the length of the mat.…”