Stabilization of a Nutraceutical Omega-3 Fatty Acid by Encapsulation in Ultrathin Electrosprayed Zein Prolamine

Abstract: Docosahexaenoic acid (DHA) is a long chain polyunsaturated fatty acid of the omega-3 series (ω-3), which exerts strong positive influences on human health. The target of this study was the stabilization by encapsulation of this bioactive ingredient in zein ultrathin capsules produced by electrospraying. The zein ultrathin DHA encapsulation was observed by ATR-FTIR spectroscopy to be more efficient against degradation under both ambient conditions and in a confined space (so-called headspace experiment). In the latter case, that more closely simulates a sealed food packaging situation, the bioactive DHA was considerably more stable. By fitting the degradation data to a specific auto-decomposition food lipids kinetic model, it was seen that the encapsulated ω-3 fatty acid showed a 2.5-fold reduction in the degradation rate constant and also had much higher degradation induction time. Moreover, the ultrathin zein-DHA capsules resulted to be more stable across relative humidity and temperature. Finally, headspace analysis by gas chromatography coupled with mass spectrometry showed that the presence of 3 main flavor-influencing aldehydes in the headspace was much lower in the zein encapsulated DHA, suggesting that the encapsulated bioactive also releases much less off-flavors. Electrosprayed ultrathin capsules of zein are shown to exhibit potential in the design of novel functional foods or bioactive packaging strategies to enhance the stability of functional ingredients. Practical Application : This article presents a novel methodology for the stabilization by encapsulation of omega 3 nutraceuticals via electrospraying and has potential application in the development of functional foods.     

Production and properties of electrosprayed sericin nanopowder

Abstract

Sericin is a proteinous substrate that envelops fibroin (silk) fiber, and its recovery provides significant economical and social benefits. Sericin is an antibacterial agent that resists oxidation and absorbs moisture and UV light. In powder form, sericin has a wide range of applications in food, cosmetics and drug delivery. Asides from other techniques of producing powder, such as precipitation and spray drying, electrospraying can yield solid nanoparticles, particularly in the submicron range. Here, we report the production of sericin nanopowder by electrospraying. Sericin sponge was recovered from Bombyx mori cocoons through a high-temperature, high-pressure process, followed by centrifugation and freeze drying of the sericin solution. The electrospraying solution was prepared by dissolving the sericin sponge in dimethyl sulfoxide. We demonstrate that electrospraying is capable of producing sericin nanopowder with an average particle size of 25 nm, which is by far smaller than the particles produced by other techniques. The electrosprayed sericin nanopowder consists of small crystallites and exhibits a high moisture absorbance.     

Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning–electrospraying hybrid process for use in protective applications

Abstract

ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99%) against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95%) against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning–electrospraying hybrid process are promising material candidates for protective applications.     

Electrosprayed synthesis of red-blood-cell-like particles with dual modality for magnetic resonance and fluorescence imaging

Red blood cells (RBCs) are able to avoid filtration in the spleen to prolong their half-time in the body because of their flexibility and unique shape, or a concave disk with diameter of some 10 μm. In addition, they can flow through capillary blood vessels, which are smaller than the diameter of RBCs, by morphing into a parachute-like shape. In this study, flexible RBC-like polymer particles are synthesized by electrospraying based on electrospinning. Furthermore, magnetite nanoparticles and fluorescent dye are encapsulated in the particles via in situ hydrolysis of an iron-organic compound in the presence of celluloses. The superparamagnetic behavior of the particles is confirmed by low-temperature magnetic measurements. The particles exhibited not only a dark contrast in magnetic resonance imaging (MRI), but also effective fluorescence. The RBC-like particles with flexibility are demonstrated to have a dual-modality for MRI and fluorescence imaging.     

Micro-patterned hydroxyapatite/silk fibroin coatings on Mg--Zn--Y--Nd--Zr alloys for better corrosion resistance and cell behavior guidance

In this study, a micro-patterned hydroxyapatite/silk fibroin (HA-SF) coating was firstly fabricated on the surface of Mg–Zn–Y–Nd–Zr alloy by template-assisted electrospraying technique coupling with spin coating technique. Two types of micro-patterns were achieved with high contour accuracy, namely HA-SF(line-pattern) and HA-SF(dot-pattern). The microstructure, composition, surface wettability and corrosion behaviors of the coatings were investigated by SEM, EDS, FTIR, XRD, water contact angle and potentiodynamic polarization test. The results revealed the hydrophilic nature of coatings and two orders of magnitude reduction of corrosion density (i_corr) as compared with that of the substrate. All the micro-patterned surfaces promoted the attachment of MC3T3-E1 cells with visible filopodia after 1 d incubation. In addition, coatings with line pattern exhibited the superior guidance to cell migration as compared to dot pattern, and the preference of cell attachment in the convex zone was observed. In summary, the obtained micro-patterned HA-SF coatings possessed the remarkably improvement of anticorrosion ability and good efficacy in guidance of cell attachment and alignment, which can serve as a promising strategy for cellular response modulation at the interface of magnesium-based implants and bone.     

Fabrication and characterization of dual drug-loaded poly (lactic-co-glycolic acid) fiber-microsphere composite scaffolds

The purpose of this work is to develop dual drug-loaded poly (lactic-co-glycolic acid) (PLGA) fiber-microsphere composite scaffolds with desired morphologies and dual drug loading properties, and to investigate the release kinetics of the dual drugs, both hydrophobic and hydrophilic, from the composite scaffolds. In this study, simvastatin (SIM) and bovine serum albumin (BSA) were used as model drugs, which were incorporated into the composite scaffolds by performing electrospinning and emulsion electrospraying simultaneously. The optimum condition for electrospraying (solution concentration: 0.06?g/mL; applied voltage: 15?kV; and flow rate: 0.6?mL/h) has been obtained to prepare PLGA microspheres. The release rate of SIM and BSA from the composite scaffolds fit the first order kinetics and the Higuchi model, respectively. The results indicated that fiber-microsphere composite scaffolds had the ability to load two types of drug, suggesting the scaffolds have great potential in the field of tissue engineering and combined therapies.     

铝合金纳米镀层等离子弧扫描强化研究

利用高速电喷镀技术与等离子弧扫描强化工艺相结合制备出了等离子弧强化纳米复合TiN镀层。研究表明,等离子弧扫描强化后镀层与基体的结合强度提高,镀层的硬度增加,抗腐蚀性能有所改善。