Biodegradable edible zein microfibers were prepared using acetic acid as solvent. Uniform and beadfree zein fibers could be obtained by changing the solution concentration, the electro spinning voltage, the solution feed rate and the distance between needle tip and collector. The solution concentration at three levels: 22, 26 and 30 w/v %, the electro spinning voltage at three levels: 10, 20 and 30 kV, the solution feed rate at three levels: 4, 8 and 12 ml/h and the distance between needle tip and collector at three levels: 10, 15 and 20 cm were studied. Central composite design (CCD) was utilized to study the effect of electro spinning parameters of zein solution and the data were analyzed using response surface methodology (RSM). According to results of this research, the solution concentration had significant influence (P<0.0001) on morphology and diameter of fibers. By increasing the solution concentration, uniform and bead-free fibers were obtained. As the solution concentration was increased, the fiber diameters were also increased. Furthermore, the electro spinning voltage had significant effect (P<0.0001) on fiber diameters. By increasing the electro spinning voltage, fiber diameters increased. The solution feed rate and the distance between needle tip and collector hadn’t significant influence on fiber diameters. In this research, effect of the solution concentration and processing parameters on zein fiber morphology were studied. Zein microfibers could be used in food industry in different uses like packaging and encapsulation.

Purpose: The objective of this study was to improve the permeability and water solubility rate of a poor water soluble drug, cyclosporine A (CsA). Methods: In order to improve the drug dissolution rate and oral bioavailability, electrospinning method was used as an approach to prepare. The fibers were evaluated for surface morphology, thermal characterizations, drug crystallinity, in vitro drug release and in vivo bioavailability studies. Results: Scanning electron microscope (SEM) results confirmed that the fibers were in microsize range and the size of the fibers was in the rang of 0. 2 to 2 micron. Differential scanning calorimetry (DSC) and powder X-ray diffractometry (XRPD) analysis ensured that the crystalline lattice of drug were weakened or destroyed in the fibers. The drug release was 15. 28%, 20. 67%, and 32. 84% from pure drug, fibers of formulation B, and formulation A, respectively. In vivo study results indicated that the bioavailability parameters of the optimized fiber formulation were improved and the maximum concentration (Cmax ) were significantly higher for fibers (3001 ng/mL) than for pure drug (2550 ng/mL). The dissolution rate of the formulations was dependent on the nature and ratio of drug to carriers. Conclusion: The physicochemical properties showed that the optimized mixture of polyethylene glycol (PEG) and povidone (PVP) fibers could be an effective carrier for CsA delivery. PEG and PVP fibers improved the absolute bioavailability and drug dissolution rate with appropriate physicochemical properties.

Objective(s): Folic acid is an essential vitamin, labile to hydrolysis in the acidic environment of the stomach with low water solubility and bioavailability. In order to solve these problems, enteric oral folic acid-loaded microfibers with a pH-sensitive polymer by electrospinning method were prepared. Materials and Methods: Electrospinning was performed at different folic acid ratios and voltages. Fibers were evaluated in terms of mechanical strength, acidic resistance, and drug release. Additionally, DSC (Differential Scanning Calorimetry), FTIR (Fourier-transform infrared spectroscopy), and XRD (X-ray diffraction) analyses were performed on the optimal formulation. Results: Drug ratio and voltage had a considerable effect on fibers’ entrapment efficiency, acid resistance, and mechanical strength. Based on the obtained results, the optimum formulation containing 1. 25% of the drug/polymer was prepared at 18 kV. The entrapment efficiency of the optimal sample was above 90% with an acid resistance of higher than 70%. The tensile test confirmed the high mechanical properties of the optimum microfiber. DSC and XRD tests indicated that folic acid was converted to an amorphous form in the fiber structure and the FTIR test confirmed the formation of a chemical bond between the drug and the polymer. The release of the drug from the optimal fiber was about 90% in 60 min. Conclusion: In conclusion, the optimal formulation of folic acid with proper mechanical properties can be used as a candidate dosage form for further bioavailability investigations.

Lycopene is a carotenoid pigment with some special health attributes, which have attracted many researchers’ attention as a valuable ingredient. The stability of many bioactive compounds is limited due to various physicochemical and physiological processes. For this purpose, the application of different encapsulation methods for controlled release and improved stability of bioactive compounds is of great importance. In this study, the effect of various solution concentrations (15, 20, 25, 30 and 35 %w/v) on the production of zein fibers was studied. The optimized concentration was then, applied for the encapsulation process of lycopene at two levels (0. 05, 0. 075 %w/w). The physical and chemical properties of lycopenecontaining zein fibers and the profile of lycopene release in three phases of gastrointestinal (GI) tract (mouth, stomach and small intestine) were investigated. The results of scanning electron microscopy (SEM) showed that uniform, homogeneous and bead-free fibers were obtained at the optimum conditions. The lycopene loading efficiency was measured between 85. 68-88. 07%. The results of FTIR test indicate that the physical entrapment of lycopene in zein microfibers was successfully occurred. In addition, controlled and stable release of lycopene in the GI simulated system which shows its appropriate bioaccessibility was observed. Encapsulation using zein electrospun microfiber has the potential to serve as a targeted delivery system for lycopene. The use of this method is therefore, recommended for the encapsulation of lycopene in the food industry.

To prevent a potential energy crisis in the near future, it is necessary to develop high-performance energy storage devices, such as supercapacitors (SCs). In this study, we fabricated a thin film of a new redox catalyst, catocene, on a carbon microfiber electrode (Cat/CMF) using a self-assembled method. We then investigated its electrochemical behaviour in an aqueous sodium sulfate electrolyte. Different techniques were used to evaluate the surface quality of the thin film and its iron content, including scanning electron microscopy (SEM), laser-induced breakdown spectroscopy (LIBS), and attenuated total reflection infrared spectroscopy (ATR). The efficiency and specific capacity of the electrodes were then assessed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD) methods in a three-electrode system. Electrochemical tests revealed that the redox processes are diffusion-controlled, exhibiting battery-like behaviour. The cathodic transfer coefficient is close to 0.48, and the charge transfer resistance of the modified electrode is improved up to 23 times compared to the bare electrode. At a current density of 0.55 A/g, the specific capacity of the Cat/CMF electrode is 39.76 F/g. At a current density of 0.83 A/g, the catocene thin film exhibits a supercapacitance behaviour with an energy density of 2.5 Wh/kg and a power density of 373.8 W/kg.

Objective: The incidence of heart valve disease is increasing worldwide and the number of heart valve replacements is expected to increase in the future. By mimicking the main tissue structures and properties of heart valve, tissue engineering offers new options for the replacements. Applying an appropriate scaffold in fabricating tissue-engineered heart valves (TEHVs) is of importance since it affects the secretion of the main extracellular matrix (ECM) components, collagen 1 and elastin, which are crucial in providing the proper mechanical properties of TEHVs.Materials and Methods: Using real-time polymerase chain reaction (PCR) in this experimental study, the relative expression levels ofCOLLAGEN 1 and ELASTIN were obtained for three samples of each examined sheep mitral valvular interstitial cells (MVICs) -seeded onto electrospun poly (glycerol sebacate) (PGS) -poly (e-caprolactone) (PCL) microfibrous, gelatin and hyaluronic acid based hydrogel-only and composite (PGS-PCL/hydrogel) scaffolds. This composite has been shown to create a synthetic three-dimensional (3D) microenvironment with appropriate mechanical and biological properties for MVICs.Results: Cell viability and metabolic activity were similar among all scaffold types. Our results showed that the level of relative expression of COLLAGEN 1 and ELASTIN genes was higher in the encapsulated composite scaffolds compared to PGS-PCL-only and hydrogel- only scaffolds with the difference being statistically significant (P<0.05).Conclusion: The encapsulated composite scaffolds are more conducive to ECM secretion over the PGS-PCL-only and hydrogel-only scaffolds. This composite scaffold can serve as a model scaffold for heart valve tissue engineering.

Hypothesis: Since naturally hydrophobic surface of polystyrene (PS) substrate is unsuitable for cell adhesion, grafting hydrophilic and biocompatible poly(2-hydroxyethyl methacrylate) (PHEMA) chains through surface-initiated atom transfer radical polymerization (SI-ATRP) can alter the surface properties and enhance the cell behavior Methods: Hydroxyl functional groups were introduced through ultraviolet/ozone (UVO) irradiation at a distance of 3 cm. Next, an initiator layer was deposited on the surface, which facilitated PHEMA grafting via SI-ATRP, conducted across various polymerization durations (2, 4, and 6 h) Findings: The intensity of carbonyl and hydroxyl peaks in ATR-FTIR spectra increased with increasing UVO irradiation time up to 15 min, where water contact angle (WCA) was about 12°. WCA of PHEMA-modified surface decreased from 56 to 48° as polymerization time increased from 2 to 6 h, and the peaks related to hydroxyl and carbonyl groups in ATR-FTIR analysis became stronger. A thin and relatively uniform PHEMA layer with a thickness of about 90-110 nm was observed for the PS substrate pretreated for 15 min and subsequently polymerized with HEMA for 6 h NIH3T3 cell viability on PHEMA-modified surfaces at polymerization times of 2, 4 and 6 h, with a pretreatment for 15 min, was 300, 250 and 225%, respectively. The cell-covered area percentages of the pristine and the PHEMA-modified PS surfaces at polymerization times of 2 and 6 h were 27%, 75%, and 62%, respectively. Most cells on the virgin PS surface exhibited a flat morphology, while a smaller subset displayed a spindle-shaped form. On the modified surfaces, the cells had a spherical shape differed from the natural shape of fibroblast cells. However, cell alignment on the modified surfaces was different from the natural alignment of cells on tissue culture PS dishes, being elongated and spindle-shaped

In this paper, a new algebraic closure model for the DNS of turbulent drag reduction in a channel flow using microfiber additives is presented. This model is an extension of an existing model and cures some the shortcomings of the old model. In the proposed model, using the velocity correlation tensor in the modeling process, more physical conditions of the flow field are taken into account. With this, some of the shortcomings of other models are cured. The proposed model is used to directly simulate turbulent drag reduction in a horizontal channel flow under the action of a constant pressure gradient. For this purpose, time-dependent, three-dimensional Navier-Stokes equations for the incompressible flow of a non-Newtonian fluid are numerically solved. Statistical quantities of obtained by the new model are compared with the results of previous simulations. The good agreement between the results demonstrates the proper accuracy of the new model. Especially, the root-mean-square of velocity fluctuations in the streamwise direction is predicted with high accuracy as compared to previous models. Other statistical quantities are also computed with appropriate accuracy. This model is capable of prediction all properties of a microfiber-induced drag-reduced flow.