Zein Nanofibers Research Articles

Biomimetic mineralization of zein/calcium phosphate nanocomposite nanofibrous mats for bone tissue scaffolds

Biomimetic mineralization process has been extended to bio-inspired bone-like calcium phosphate coatings on biodegradable polymer substrates. The objective of the current work is to synthesize zein/calcium phosphate nanocomposite nanofibrous scaffolds by the biomimetic mineralization process for bone tissue engineering. After incubation in 10 times concentrated simulated body fluid for 2 hours, the surface of electrospun zein nanofibers was uniformly coated with plate-like calcium phosphate nanosheets which attach to fibers and preserve the fibrous morphology of electrospun zein fibers. The crystalline phases in the composite are hydroxyapatite and dicalcium phosphate dihydrate. The biological in vitro cell culture with adipose-derived stem cells demonstrated that mineralized electrospun zein scaffolds can improve specific biological functions like adhesion, spread and proliferation resulting from the retained fibrous morphology and bioactive environment provided by calcium phosphate minerals. This study has demonstrated that mineralization of electrospun zein fibers provides a simple platform to fabricate a new biomimetic scaffold for bone tissue engineering, which can recapitulate both the morphology of the extracellular matrix and the composition of the bone.

Electrospinning of zein/tannin bio-nanofibers

In order to investigate the incorporation of tannin from barbatimão bark in zein nanofibers obtained by electrospinning, it was studied the effect of addition of different contents of tannin in the properties of zein nanostructured membranes and their relationship with fiber morphology. It was confirmed the interaction occurring between the tannin and zein by thermal and microscopy analysis. Addition of tannins increased the glass transition temperature of the nanofibers, suggesting higher energy input for processing for example. SEM micrographs provided evidence of a homogeneous structure for the nanostructured membranes. X-ray analysis showed the presence of zein crystals in the nanofibers. This ongoing research confirms the possibility of incorporation of barbatimão tannin in the production of bio-nanofibers that will be studied for multi-purpose applications.

Colon-targeted drug delivery from core-sheath nanofibers prepared using a modified coaxial electrospinning process

In this paper, we report for the first time the use of a Teflon-coated spinneret for electrospinning processes. Polyvinylpyrrolidone (PVP) and zein were explored as filament-forming polymers, and electrospinning undertaken using both Teflon-coated tubing and traditional stainless steel tubing as spinnerets. Scanning electron microscope observations demonstrated that both the PVP and zein nanofibers produced using the Teflon-coated spinneret are narrower than those from the stainless steel equivalent. Electrospinning using a Teflon-coated spinneret resulted in smaller interfacial drawing forces counteracting the electrical forces on the spinning fluids. The Teflon-coated material thus takes advantage of the electrical forces more efficaciously than the steel analog. A molecular mechanism rationalizing the influence of the spinneret surface on electrospinning is proposed.

Co-Electrospinning with Ethanol Aqueous Solution for Preparing High Quality Zein Nanofibers

Co-Electrospinning with Ethanol Aqueous Solution for Preparing High Quality Zein Nanofibers

Electrospinning using a Teflon-coated spinneret

In this paper, we report for the first time the use of a Teflon-coated spinneret for electrospinning processes. Polyvinylpyrrolidone (PVP) and zein were explored as filament-forming polymers, and electrospinning undertaken using both Teflon-coated tubing and traditional stainless steel tubing as spinnerets. Scanning electron microscope observations demonstrated that both the PVP and zein nanofibers produced using the Teflon-coated spinneret are narrower than those from the stainless steel equivalent. Electrospinning using a Teflon-coated spinneret resulted in smaller interfacial drawing forces counteracting the electrical forces on the spinning fluids. The Teflon-coated material thus takes advantage of the electrical forces more efficaciously than the steel analog. A molecular mechanism rationalizing the influence of the spinneret surface on electrospinning is proposed.

Coaxial Electrospinning with Ethanol Aqueous Solution for Preparing High Quality Zein Nanofibers

A modified coaxial electrospinning process is developed for producing thinner zein nanofibers. With ethanol aqueous solutions as sheath fluids, high quality zein nanofibers have been successfully generated using the modified process. Electron scanning microscope results demonstrate that the nanofibers have better quality than those produced by a single fluid electrospinning in terms of nanofiber diameters and their distributions. The former has an average diameter of 1230±340 nm while the later 420±140 nm under a sheath-to-core flow rate ratio of 0.267. The mechanism is proposed that an appropriate ethanol aqueous solution surrounding the core zein jet helps to retain it in a fluid state to experience a longer time and more stable electrical drawing, with little adverse influence on the zein chain entanglements in the core fluid jets and thus its electrospinnability. The modified coaxial electrospinning process described here extends the capability of electrospinning process and opens a new way to obtain thinner nanofibers of macromolecules with fine structural uniformity.

High barrier polyhydroxyalcanoate food packaging film by means of nanostructured electrospun interlayers of zein

In this work, multilayer structures based on polyhydroxybutyrate-co-valerate with a valerate content of 12% (PHBV12) containing a high barrier interlayer of electrospun zein nanofibers were developed. It was observed that the method used for the preparation of the outer PHBV12 layers affected their functional properties, since mechanical resistance increased and water vapour permeability and transparency decreased in the multilayer containing outer layers prepared by compression-moulding to a higher extent than for their counterparts obtained by casting. The addition of zein interlayer produced minimum changes in mechanical and optical film properties while the incorporation of the zein nanostructured interlayers significantly improved oxygen barrier properties of the multilayer films prepared by both processing technologies. However, the effect of the interlayer on the water vapour and limonene permeability depended on zein content. Thus, this approach provides an innovative way to develop fully renewable microbial biopolyester-based multilayer structures with enhanced barrier performance of significant interest in food packaging applications.

Linear drug release membrane prepared by a modified coaxial electrospinning process

This study investigated a novel type of drug-delivery membrane prepared by a modified coaxial electrospinning process. Using 1% (w/v) unspinnable zein solution as sheath fluid, the coaxial electrospinning process can be smoothly conducted to generate ketoprofen (KET)-loaded zein nanofibers coated with a thin layer of blank zein. Scanning electron microscopy and transmission electron microscopy images demonstrated that the nanofibers had a ribbon morphology with a smooth surface, as well as average diameters of 860±210nm (coating thickness of ca. 20nm) and 680±140nm (coating thickness of ca. 30nm) at sheath-to-core flow rate ratios of 0.11 and 0.25, respectively. X-ray diffraction and differential scanning calorimetry verified that KET presented an amorphous state in all nanofibers. Attenuated total reflectance Fourier transform infrared spectroscopy demonstrated that zein had good compatibility with KET because of hydrogen bonding. In vitro dissolution tests showed that the nanofibers coated with blank zein did not exert any initial burst release effect, and can enable linear drug release over a period of 16h via a diffusion mechanism. The modified coaxial electrospinning process can provide new approaches to the development of nanofiber membranes with improved structural characteristics and performance.

Electrospun zein nanofibers incorporating cyclodextrins

Zein nanofibers containing cyclodextrins (zein/CD) were produced via electrospinning. Three types of CDs (α-CD, β-CD and γ-CD) having 10%, 25% and 50% (w/w) were individually incorporated into zein nanofibers. SEM imaging elucidated that the morphologies of the electrospun zein/CD nanofibers depended on the CD type and weight percentage. The incorporation of CDs in zein improved the electrospinnability and bead-free nanofibers were obtained at lower zein concentrations. Zein/CD nanofibers having fiber diameters ∼100–400nm were obtained depending on the zein concentrations, types and weight percentages of CD. XRD studies revealed that CDs were mostly distributed without forming crystalline aggregates for zein/CD nanofibers containing lower weight percentage of CDs. The surface analyses of zein/CD nanofibers by ATR-FTIR and XPS indicated that some of the CDs were present on the fiber surface. Thermal analyses showed that zein/β-CD nanofibers have shown higher glass transition temperatures and higher degradation temperature with increasing CD content.

Hybrid fluorescent curcumin loaded zein electrospun nanofibrous scaffold for biomedical applications

Nanomedicine utilizes engineered nanodevices and nanostructures for monitoring, repair, construction and control of human biological systems at the molecular level. In this study, we investigated the feasibility and potential of zein nanofiber as a delivery vehicle for curcumin in biomedical applications. By optimizing the electrospinning parameters, ultrafine zein fluorescence nanofibers containing curcumin were developed with interconnected fibrous networks. We found that these nanofibers show an increase in fluorescence due to the incorporation of curcumin. The morphology and material properties of the resulting multifunctional nanofiber including the surface area were examined by a field emission-scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and confocal microscopy. The surface area and pore size were characterized by N2 adsorption–desorption isotherm. SEM and fluorescence images showed that the uniform fibers with smooth surface had an average diameter of about 310 nm. An in vitro degradation study showed significant morphological changes. The in vitro evaluations suggested that the curcumin incorporated zein nanofibers showed sustained release of curcumin and maintained its free radical scavenging ability. It provides an attractive structure for the attachment and growth of fibroblast as cell culture surfaces. The results demonstrate that the curcumin loaded zein nanofiber could be a good candidate for soft tissue engineering scaffolds and has the potential for further applications in drug delivery system.

Effect of Ethanol/water Solvent Ratios on the Morphology of Zein Nanofiber Mats and their Wettability

Zein is a hydrophobic protein produced from maize and has great potential in a number of industrial applications, such as food, food coating and food packaging. To obtain suitable electrospinning conditions for thinner and uniform zein nanofiber mats, a series of experiments was conducted on various volume ratios (v/v) of ethanol/water solutions with different zein concentrations. The prepared zein nanofiber mats were characterized by field emission scanning electron microscopy and contact angle measurements. Uniform zein fibers with a average diameter in the nanometer scale (300~500 nm) could be prepared from 30 wt.% zein in 7/3 (v/v) ethanol/water solutions.

Biodegradable nanofibrous membrane of zein/silk fibroin by electrospinning

AbstractBACKGROUND: 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 and crosslinking of zein nanofiber mats

AbstractElectrospinning 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 zein‐dependent 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 μm. Zein nanofiber mats were crosslinked by hexamethylene diisocyanate (HDI). The tensile strength of the crosslinked electrospun zein nanofiber mats was increased significantly. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103:380–385, 2007