Average Diameter Of Nanofibers Research Articles

Fabrication and characterization of novel electrospun nanofibers based on grass pea (Lathyrus sativus L.) protein isolate loaded with sumac (Rhus coriaria L.) extract

In this study, sumac extract was utilized as an active ingredient and combined with grass pea protein isolate and polyvinyl alcohol to produce novel active nanofiber mats using an electrospinning technique. First, nanofiber mats were fabricated by different ratios (100:0, 90:10, 70:30, 50:50, 30:70, 10:90, 0:100) of grass pea protein isolate and polyvinyl alcohol. The characterization of nanofiber mats revealed that the nanofibers with a polymer ratio of 50:50 had appropriate mechanical properties and presented a fibrous and uniform morphology. Therefore, the 50:50 polymer solution ratio was selected to produce active nanofibers by adding different amounts (0%, 2%, and 4% (w/v)) of sumac extract. The average diameters of nanofibers decreased from 150 ± 31 to 122 ± 25, and 105 ± 19 nm, by increasing the concentration of sumac extract. Based on the SEM results, the electrospun nanofibers exhibited a bead-free and smooth surface. The FTIR and XRD analyses indicated the presence of intermolecular hydrogen bonds between the components. The antioxidant activity of the nanofibers was confirmed by DPPH analysis and ranged between 3.33% and 68.75%. Additionally, the antimicrobial test results indicated that the nanofibers with the highest sumac concentration (4%) displayed inhibitory activity against Staphylococcus aureus, resulting in an inhibition zone of 10 mm. The optimal treatment of this study was grass pea protein isolate: polyvinyl alcohol ratio of 50:50 containing 4% sumac extract which can be used as a natural antimicrobial and antioxidant agent.

Enhanced wound healing properties of biodegradable PCL/alginate core-shell nanofibers containing Salvia abrotanoides essential oil and ZnO nanoparticles

Electrospun nanofibrous membranes, with their unique structural features, can potentially enhance wound healing through controlled delivery of active agents. Here, an innovative porous nanofibrous membrane was developed as a dressing patch with antibacterial and anti-inflammatory functionalities for cutaneous wound healing. Zinc oxide nanoparticles (ZnO NPs) and Salvia abrotanoides essential oil (SAEO) were incorporated into sodium alginate, which served as the shell. Poly(ε-caprolactone) was used as the core of coaxial electrospun wound dressing nanofibers (PCL/SA@ZnO/SAEO). With the addition of ZnO NPs and SAEO, the average diameter of nanofibers was 187 ± 51 nm, with improved tensile strength (4.7 ± 0.4 MPa), elongation at break (32.9 ± 2.1), and elastic modulus (21.4 ± 2.0). Concurrent application of ZnO NPs and SAEO increased antimicrobial activity against Staphylococcus aureus and Escherichia coli and promoted the proliferation, attachment, and viability (>90 %) of L929 cells. The PCL/SA@ZnO/SAEO scaffold accelerated the healing time with total wound healing over 14 days in mouse models carrying full-thickness wounds compared to the nanofibrous scaffold without additives. Histopathological examinations demonstrated better tissue regeneration, i.e., enhanced collagen deposition, improved re-epithelialization, and neovascularization, and increased quantity of hair follicles. Moreover, the chicken chorioallantoic membrane assay confirmed the synergistic angiogenic effects of SAEO and ZnO NPs. Finally, the in vitro and in vivo results proposed the bioactive core-shell nanofibers synthesized as encouraging wound dressing materials for hastening the healing of cutaneous wounds.

Continuous Nanofiber Bundle Production Using Helical Spinnerets with Different Configurations in Needleless Electrospinning

This study investigates the production of continuous nanofiber bundles using needleless electrospinning with a focus on helical spinneret configurations. It delves into the effects of spinneret diameter, pitch length, and thickness on nanofiber bundle characteristics, employing polyacrylonitrile as the polymer. The research highlights the significant impact of these parameters on the nanofiber morphology, bundle width, productivity, and deposition properties of nanofiber bundles. Scanning electron microscopy imaging, bundle depositions analyses, and electric field modeling with COMSOL Multiphysics are applied for the nanofiber bundles electrospun by helical spinnerets. As the diameter of the spinneret increases, productivity, bundle width, deposition ratio, deposition intensity, and deposition homogeneity are increased significantly. Additionally, an increase in spinneret thickness leads to a decrease in average nanofiber diameter. Specifically, increasing the spinneret diameter from 30 to 50 mm, pitch length from 20 to 40 mm, and reducing thickness from 3 to 1 mm increases productivity by 170%, 72%, and 32%, respectively. As a result of practical and modeling studies on helical spinnerets, the optimized parameters are determined as 1 mm thickness, 40 mm pitch length, and 50 mm diameter.

Novel Electrospun Gelatin Nanofibers Loaded with Purple Potato Anthocyanin and Syringic Acid for Multifunctional Food Packaging.

In this study, a series of novel nanofibers based on gelatin (GA) loading with purple potato anthocyanin (PPA) and syringic acid (SA) were obtained by electrospinning technology. The effects of SA on mechanical properties, thermal stability, antioxidant capacity, and antimicrobial activity of the GA/PPA nanofibers were systematically characterized. The scanning electron microscopy observation results revealed a smooth surface on the nanofibers. The incorporation of SA enhanced the viscosity of the electrospun solutions, and it increased the average diameter of nanofibers from 0.17 μm to 0.28 μm. The tensile strength and thermal stability of the obtained nanofibers were enhanced with the addition of a suitable level of SA (1.5%, w/v), which strengthened the intermolecular interaction. The GA/PPA/SA nanofibers presented over 80% antioxidant capacity and strong antibacterial activity against E. coli and S. aureus. Meanwhile, the sensitivity responses of nanofibers to NH3 revealed that GA/PPA/SA II nanofibers (1.5% w/v SA) presented good sensitivity of colorimetric behavior to ammonia. A pork spoilage test was performed to evaluate practical application of the nanofibers, and an obvious color change (dark purple to green) was observed. These results indicated GA/PPA/SA II nanofibers can be utilized as an active and intelligent multipurpose packaging material to preserve and track the freshness of pork.

Characterization Electrospun Nanofibers Based on Cellulose Triacetate Synthesized from Licorice Root Cellulose

Cellulose triacetate (CTA) nanofibers were formed by electrospinning using two binary solvent systems: methylene chloride/ethanol and chloroform/acetone. Previously, licorice root cellulose (LRC) with a degree of polymerization (DP) of 710 was extracted from licorice root waste by alkaline treatment and hydrogen peroxide bleaching at high temperatures. Then CTA with a degree of substitution (DS) of 2.9 and an average molecular weight of 175 kDa was synthesized from LRC using acetic acid and acetic anhydride, sulfuric acid was as a catalyst. The influence of the electrospinning process and various solvent systems on the morphology and structure of nanofibers is studied. The structure and morphology of the nanofibers were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), and the sorption characteristics were also investigated. The results showed that the morphology and structure of nanofibers depended on the solvent mixture used. The average diameters of the CTA nanofibers with grooved morphology varied 200-700 nm (solvent methylene chloride/ethanol) and the dumbbell-shaped (flat ribbon) CTA nanofibers in a wide range from 200 nm to 4 mkm (solvent chloroform/acetone).

Impact of concentration and aging time of pea starch‐based polymeric solutions on the fabrication of electrospun nanofibers

AbstractPolymer concentration and aging time of polymeric solutions are crucial factors that can influence their viscosity, playing an essential role in the fabrication of electrospun nanofibers. Based on this, herein we evaluated the impact of aging time (24 and 48 h) and pea starch concentration (10%, 20%, and 30%, wt/vol) on the polymeric solutions to produce electrospun nanofibers. Solutions were evaluated by rheology, electrical conductivity, and degree of substitution. The nanofibers were analyzed by morphology, size distribution, chemical nature, and thermal properties. The degree of substitution of starches varied from 1.17 to 1.56. Overall, electrical conductivity decreased with increasing starch concentration and aging time of the polymeric solutions. The use of 10% starch displayed a transition from capsules to fibers, while 20% and 30% starch were able to manufacture homogenous, cylindrical, and random nanofibers with diameters varying from 89 to 373 nm. A significant impact of viscosity was not observed; on the other hand, aging time increased the average diameter of nanofibers. Besides, the fabricated nanofibers showed a lower decomposition temperature than raw starch. The fabricated nanofibers have great potential as wall materials for the encapsulation of different compounds and applications in the biomedical and food sectors.

Comparative Study of Electrospinning Parameters for Production of Polylactic Acid and Polycaprolactone Nanofibers Based on Design of Experiment

In terms of applications, the diameter of nanofibers is one of their most important characteristics. This size is influenced by various process parameters, such as: the concentration, the distance between the needle and the collector, volume flow, etc. In this study, we compared the average diameter of nanofibers made from two different polymers, polycaprolactone and polylactic acid.We investigated the impact of various parameters on the production of nanofibers from polycaprolactone and polylactic acid using the electrospinning technique. We employed a factorial experiment design model to characterize this versatile and efficient fibre fabrication method. By considering the effects of voltage, concentration, distance between the pin and the collector, and flow rate, we established a mathematical model to describe the process. The diameters and morphologies of the resulting fibers were analyzed and compared to each other using SEM analysis. Our findings revealed that, among the studied parameters, concentration had the most significant impact on the diameter of the polymer fibers.

Enhancing wearable humidity sensing with conductive PANi-Coated polyurethane nanofibers

This study presents a flexible nanofibrous humidity sensor for wearable applications and smart textiles. The methodology involved fabricating polyurethane (PU) nanofibers via electrospinning, followed by polyaniline (PANi) coating under varied synthesis conditions. Scanning electron microscopy (SEM) analysis revealed consistent diameter uniformity in the prepared PU nanofibers. Moreover, an increase in average nanofiber diameter (305 to 539 nm) was observed with rising polymer solution concentration (7% to 9%). Fourier-transform infrared spectroscopy (FT-IR) confirmed the physical presence of PANi on PU nanofiber surfaces without inducing structural changes. Additionally, the strength of PU nanofibrous samples, with or without PANi coating, increased proportionally with higher PANi and PU polymer concentrations. Electrical conductivity was measured using a four-point device, and surface resistance was assessed across varying humidity levels to study humidity’s impact on samples. Results exhibited a linear relationship between surface electrical resistance and relative humidity changes. Furthermore, the PU and PU/PANi nanofibers exhibit contact angles of 113° and 133°, respectively. The PANi-coated sample is more hydrophobic compared to the uncoated sample. In conclusion, these findings underscore the potential of the developed sensor as a responsive tool for monitoring humidity fluctuations in diverse applications.

Central Composite Design and Response Surface Methodology for Optimizing the Diameter of Electrospun Polyamide-6,6 Nanofiber Mat

Electrospinning is a well-established technique for creating submicron polymer fibers to create distinctive functional nanostructures. Electrospinning parameters including solution concentration, tip-to-collector distance and applied voltage are adjusted to produce nonwovens with variable fiber diameter distributions. This research on the response surface methodology (RSM) is being used to model the diameter of a polyamide-6,6 (PA-6,6) nanofiber mat. The experiments were designed using central composite design (CCD) and RSM, which evaluated the interactions between the operating variables (polymer concentration, applied positive voltage, needle tip to collector distance and spinning angle) on the diameter of the PA-6,6 nanofiber. The average nanofiber diameter increased as the concentration of the PA-6,6 polymer solution increased. The model’s strong regression coefficient ([Formula: see text]) reveals that it did a desirable of predicting the diameter of PA-6,6 fibers. The experimental findings and predicted fiber diameters were in good agreement. The results demonstrate that the optimization of electrospinning process to produce the smallest nanofibers and narrowest diameter distribution ([Formula: see text]) combined effects of 10% polymer concentration, 21[Formula: see text]kV applied positive voltage, 18[Formula: see text]cm needle tip to collector distance and 60[Formula: see text] spinning angle are substantial interacting effects that have an impact on the surface response nanofibers. The results of the research and several mathematical models will offer useful guidelines for choosing parameter settings for electrospinning PA-6,6 to achieve the required fiber diameter. By saving time, effort and money more effectively, this research will expand the field of investigation for the quality of electrospun nanofibers.

Mapping the Influence of Solvent Composition over the Characteristics of Polylactic Acid Nanofibers Fabricated by Electrospinning

AbstractThis study investigated the solubility of poly(lactic acid) (PLA) in various solvents (to achieve an 8 % (w/v) polymer solution) and its impact on the morphology of electrospun PLA nanofibers. Several solvents, such as dichloromethane (DCM), chloroform (CHL), tetrahydrofuran (THF), acetone (AC), acetonitrile (ACTNR), dimethylformamide (DMF), dimethylacetamide (DMAc), ethylene glycol (ETGLY), distilled water (WATER), methanol (MEOH), formic acid (FA), and n‐hexane (NHX) were used in their pure and binary forms at several ratios (4 : 1, 2 : 1, 1 : 1, 1 : 2, 1 : 3, and 1 : 4). The study aims to explore the correlation between PLA solubility and its electrospinnability using solvents mapped from the Teas graph across different parameter zones and chemical groups. Hansen solubility parameters, including dispersion cohesion fractional solubility parameter (fd), the polar cohesion fractional solubility parameter (fp) was employed to identify the most effective solvents for PLA dissolution. Teas graph analysis highlighted a correlation between PLA solubility and solvent proximity to Hansen solubility parameters. Additionally, the solubility time varied between 1 hour and 24 hours. Polar solvents such as DCM, CHL, THF, ACTNR, and FA were able to dissolve 8 % (w/v) of PLA at different times, but only very high and effective dissolution of PLA was achieved in pure DCM and CHL whereas FA dissolved PLA in 24 hours, which resulted in the slowest solubility rate. Several structures of nanofibers, such as smooth, heterogenous, porous, fibrous, and beaded, were observed and discussed accordingly in terms of solvent type and ratio. The average nanofiber diameter ranged between 0.18 μm and 3.81 μm. Moreover, physical tests, including surface tension, density, viscosity, and conductivity, were conducted on solvent systems and CHL displayed higher viscosity, while ACTNR had the lowest viscosity and highest conductivity among pure solvents. According to the results of our study, it is possible to design further studies with the aim of deciding which solvents or binary forms should be applied to dissolve PLA within a certain time. The desired structure can be easily arranged to be used as a filter, biomimicking tissue environment, drug delivery system, or extra.

Facile synthesis of co-axially electrospun Co-C nanofibers and their ferromagnetic behavior

We describe a simple co-axial electrospinning approach followed by a carbonisation process to create cobalt-carbon (Co-C) nanofibers that are then thoroughly analysed using various techniques. X-ray diffraction measurements showed the creation of pure crystalline cobalt with face-centered cubic (fcc) structure, and average crystallite size was determined using the Debye–Scherrer formula. The average crystallite size has been calculated to be in the range of 10 − 15 nm. According to the Raman investigation, all Co-C nanofibers have an amorphous carbon structure with little graphitic behaviour. Field emission scanning electron microscopy was used to determine the shape and average diameter of electrospun nanofibers. The field-dependent magnetic characterisation demonstrated a satisfactory ferromagnetic behaviour with maximum saturation magnetisation values of 10, 10.2, and 11.2 emu/g for Co12.5-C sample at 300, 100, and 5 K, respectively. Compared to bulk cobalt, the produced Co-C nanofibers have a high coercivity value. With average crystallite size, the coercivity varies. Again, magnetisation versus temperature measurements have supported the existence of ferromagnetism because there is no evidence of blocking temperature or any transitional behaviour below 300 K. As a result, applications for microwave absorption, catalysis, and several magnetic recording devices can benefit from the coupling of ferromagnetic properties with carbon nanofiber materials.

Lactosporin loaded electrospun nanofibrous membrane: Novel antibacterial and wound dressing patch

IntroductionAny disruption in the cohesion of skin tissue is called a skin ulcer. If the skin lesion is a superficial lesion, it heals easily. But some wounds, such as diabetic wounds, bedsores, and burns, are difficult to heal and are often associated with infection. Therefore, one of the new methods used to treat such wounds is skin patch. MethodIn this study, partly purified lactosporin (LP), as novel postbiotic, was extracted from Bacillus coagulans, and its antibacterial properties against six bacterial species, namely Escherichia coli, Micrococcus Luteus, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermis, and Klebsiella pneumonia were investigated. An electrospun nanofibrous membrane (NFM) containing LP was electrospun based on the three polymers including hyaluronic acid (HA), chitosan, and polyvinyl alcohol (PVA) and its potential for biomedical applications was analized. The morphological characteristics, hydrophilic properties, cytotoxicity, and wound healing potential of LP-loaded NFMs were investigated. ResultsIt was revealed that extracted LP includes supperior antibacterial properties, which is beneficial for developing wound dressing patches. The results showed fabricated composite NFMs are bead-free and uniform. The average diameter of uncross-linked and cross-linked nanofibers are 281 ± 10 nm and 359 ± 51 nm, respectively. These NFMs are hydrophilic in both cross-linked and uncross-linked forms and the contact angles of them were 39 and 13°, respectively. These NFMs were also tested for cytotoxicity by the MTT assay and were found to be non-toxic. ConclusionThese results indicate that HA/CS/PVA/LP NFM could act as an efficient antibacterial and multifunctional wound dressing patch.

Dual therapeutic approach: Biodegradable nanofiber scaffolds of silk fibroin and collagen combined with silver and gold nanoparticles for enhanced bacterial infections treatment and accelerated wound healing

The development of novel multifunctional wound healing materials based on natural bioactives has garnered significant interest in recent years due to their ability to stimulate the healing process and alleviate problems associated with standard wound dressings. In the presented work, a bimetallic combination of silver (Ag) and gold (Au) nanoparticles incorporated into silk fibroin (SF) and collagen (CL) composite nanofiber (CNF) using the electrospinning technique. The physicochemical investigations confirmed the successful integration of Ag and Au nanoparticles sizes of approximately 6.76 nm and 9.75 nm, with an average nanofiber diameter of 189.46 ± 108.73 nm. The evaluation of composite nanofiber treated in the in vitro antibacterial tests zone of inhibition value S. aureus (17 mm) and E. coli (18 mm). Additionally, we analyzed the cell proliferation study using NIH3T3 fibroblast cell line treated with the composite nanofiber material. The SF/CL/Ag–Au composite nanofiber exhibited the highest level of cell proliferation compared to other matrices. This increased cell proliferation offers significant advantages in wound healing applications. Furthermore, in vivo study on wound healing activity in Sprague-Dawley rats demonstrated a remarkable healing percentage of 98.85%. These findings collectively highlight the promising potential of the SF/CL/Ag–Au composite nanofiber in promoting accelerated wound healing. The composite nanofibers demonstrated remarkable hemocompatibility of erythrocyte lysis percentages varying between 1.5% and 3.9%. Besides, swelling tests revealed that the material can absorb exudates from wound sites, facilitating tissue regeneration and cell adhesion. Finally, this research highlights the potential of the SF/CL/Ag–Au composite nanofiber excellent antibacterial activity, highest biocompatibility, enhanced wound healing, and highly suitable for various biomedical applications.

Nanofibrous polyelectrolyte complex incorporated BSA-alginate composite bioink for 3D bioprinting of bone mimicking constructs

Although several bioinks have been developed for 3D bioprinting applications, the lack of optimal printability, mechanical properties, and adequate cell response has limited their practical applicability. Therefore, this work reports the development of a composite bioink consisting of bovine serum albumin (BSA), alginate, and self-assembled nanofibrous polyelectrolyte complex aggregates of gelatin and chitosan (PEC-GC). The nanofibrous PEC-GC aggregates were prepared and incorporated into the bioink in varying concentrations (0 % to 3 %). The bioink samples were bioprinted and crosslinked post-printing by calcium chloride. The average nanofiber diameter of PEC-GC was 62 ± 15 nm. It was demonstrated that PEC-GC improves the printability and cellular adhesion of the developed bioink and modulates the swelling ratio, degradation rate, and mechanical properties of the fabricated scaffold. The in vitro results revealed that the bioink with 2 % PEC-GC had the best post-printing cell viability of the encapsulated MG63 osteosarcoma cells and well oragnized stress fibers, indicating enhanced cell adhesion. The cell viability was >90 %, as observed from the MTT assay. The composite bioink also showed osteogenic potential, as confirmed by the estimation of alkaline phosphatase activity and collagen synthesis assay. This study successfully fabricated a high-shape fidelity bioink with potential in bone tissue engineering.

Fabrication of electrostatic-induction-assisted solution blowing spinning nanofibers and its mechanism

Commonly used nanofiber fabrication technologies have many shortcomings: the yield of electrospinning is low, solution blowing spinning (SBS) and its improved technologies have problems with large fiber diameter, non-uniform nanofiber diameter and poor receiving aggregation of nanofibers on receiver. A nanofiber fabrication technology called electrostatic-induction-assisted solution blowing spinning (ESBS), which overcomes these disadvantages, was developed in this paper. This technology utilizes the joint action of electrostatic force and airflow stretching force to stretch the jet to fabricate nanofibers. The grounding of the blunt needle realizes the directional migration and dynamic circulation of charges in the ESBS microscopic system. Compared with traditional SBS, the average diameter and diameter standard deviation of ESBS nanofibers can be reduced by 44 % and 80.8 %, respectively, and the fiber cover rate can be increased by 329.7 %. In contrast to the cylindrical-electrode-assisted solution blowing spinning, the mean diameter and diameter standard deviation of ESBS nanofibers can be reduced by 34.6 % and 68.1 %, respectively, and the fiber cover rate can be increased by 305 %. The microcosmic fabrication mechanism of ESBS nanofibers—“the theory of separation and directional transfer of charges” was proposed and verified. ESBS nanofibers with single-needle injection speed up to 200 μl/min (far exceeding the 4–10 μl/min injection speed of conventional electrospinning) were successfully fabricated to prove that this technology has great industrial potential. ESBS nanofibers with small and uniform diameter, high yield, and good receiving aggregation of fibers on receiver have bright application prospects in many fields.

Large-scale fabrication of nanofibers by tiny-needle-spaced electrostatic-induction-assisted solution blowing spinning

In this paper, a technology and device for large-scale fabrication of nanofibers called tiny-needle-spaced electrostatic-induction-assisted solution blowing spinning (TESBS) was developed. The airflow stretching force is used as the initial driving force for jet formation in TESBS, which avoids the electric field interference existing in the jet formation stage of multi-needle electrospinning(MES). The addition of an induced electric field in TESBS solves the problem of mutual merging of jets in multi-needle solution blowing spinning (MSBS). The needle spacing of TESBS can be as small as 1 mm, which is much smaller than MES (100 mm) and MSBS (3 mm). The substantial reduction in needle spacing can increase the arrangement density of blunt needles, thereby increasing the output of nanofibers. Compared with MSBS, the average diameter and diameter standard deviation of TESBS nanofibers can be reduced by 52.6% and 78.7%, respectively. Compared with MES, the uniformity of the TESBS nanofiber web has been significantly improved. The formula for the critical needle spacing to ensure that the TESBS jets do not merge with each other was derived. The output of 15-needle TESBS can reach as high as 3 ml/min. The average diameter of TESBS nanofibers decreases with the decrease in injection speed or the increase in voltage. The distance between the needle and the receiver has little effect on the average fiber diameter. TESBS nanofibers with good quality and high yield have broad and bright application prospects in many fields.

Innovative Electrospun Nanofiber Mats Based on Polylactic Acid Composited with Silver Nanoparticles for Medical Applications.

Nanofibers are some of the most attractive materials that can modify functionalities for developing new kinds of specific applications and are mainly used as a biomedical material. Herein, we designed and prepared antibacterial nonwoven fiber mats of PLA and PLA composited with Ag nanoparticles by electrospinning. The effects of varying filler contents on their chemical, surface morphology, thermal, water absorbency, and antibacterial properties were investigated using FTIR, SEM/EDS, DSC, swelling ratio, and qualitative and quantitative antibacterial tests. FTIR and EDS spectra indicated that Ag nanoparticles were incorporated in the PLA without chemical bonding. SEM revealed that the average diameter of the PLA nanofibers containing the Ag nanoparticles was more significant than those without those particles. In addition, fiber diameters are proportional to the amount of Ag nanoparticle contents. DSC indicated that the Ag nanoparticles can be incorporated within the PLA matrix without strongly affecting their thermal properties. Moreover, the crystallinity of the composite nonwoven fiber mats was higher than those of fiber mats in the neat PLA. However, TGA revealed that the loaded Ag can improve the thermal stability of the PLA electrospun fiber mats. Accordingly, the antibacterial activities revealed that all the composite nanofiber mats exhibited excellent resistance against S. aureus and E. coli bacterial strains. In addition, in the cell toxicity study, all produced hybrids of nonwoven fiber mats induced a reduction in cell viability for the L929 fibroblast cells. Our results suggest that the designed and prepared nonwoven fiber mats may have good potential for use in the biomedical field, particularly in wound dressing applications.

INVESTIGATION OF THE IMPACT OF DIFFERENT PARAMETERS ON THE MORPHOLOGY OF ELECTROSPUN POLYURETHANE NANOFIBERS

In this research, nonwoven nanofiber mats were prepared using the electrospinning method for the solution of polyurethane polymer dissolved in acetic acid. Effects of solution concentration, solution flow rate, as well as high voltage on the morphonology and wettability of the prepared nanofibers were studied. Nanofiber morphology was investigated through the analysis of scanning electron microscopy (SEM) micrographs using ImageJ software, while the wettability of the nanofiber mat surfaces was studied through the measurement of the contact angle. Results revealed that when the concentration of the solution was changed from 8wt% to 12wt%, the average nanofiber diameter showed a significant increase from 0.326 µm to 0.380 µm, while the contact angle increased from 39 degrees to 79 degrees. Results also showed that when the applied high voltage was changed from 10 KV to 25 KV, the average nanofiber diameter decreased and then increased within the range of 0.380 to 0.497 µm and that the contact angle was increased from 81 degrees to 108 degrees showing an obvious switching from hydrophilic towards hydrophobic surface. When the syringe pump flow rate was changed from 0.012 ml/min to 0.02 ml/min, morphology measurements showed that the average nanofiber diameter showed a significant increase from 0.351 µm to 0.456 µm, and the surface contact angle was also increased from 43 degrees to 98 degrees. Finally, the results of Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction analysis (XRD) tests showed that the electrospun polyurethane polymer material used in this work was not changed during the electrospinning process.

Synthesis and characterization of new electrospun medical scaffold-based modified cellulose nanofiber and bioactive natural propolis for potential wound dressing applications.

Recently, the design of polymer nanofibers using the electrospinning process has attracted much interest. Particularly the use of natural polymers has promoted many advantages in their biomedical applications. However, the combination of multiple natural polymers remains a great challenge in terms of electrospun production and applied performance. From this perspective, the current investigation highlights the study of the preparation of electrospun nanomaterial scaffolds based on combined natural polymers for improved wound healing performance. First, we have synthesized a crosslinked polymer by reacting microcrystalline cellulose (MC) and chitosan (CS) biopolymer via the intermediate of citric acid as a crosslinking agent. Then a natural propolis biomolecule was incorporated into the polymer network. Different MC/CS blend ratios of 90/10 and 70/30 were then used and various machine parameters were optimized to obtain nanofiber scaffolds with excellent strength and structures. SEM, IR, physicochemical, mechanical, and morpho-logical characterization were then performed. SEM evaluation revealed homogeneous and bead-free nanofibrous structures, with well-defined morphology and a random deposition that could accurately mimic the extracellular matrix of native skin. The calculated average nanofiber diameters for the MC/CS blend ratios at 90/10 and 70/30 were 431.4 and 441.2 nm, respectively. The results showed that when the chitosan amount increased, larger nanofibers with narrow diameter distribution appeared. The prepared nanomaterials had a significant and close water vapor permeability of about 1735.12 and 1698.52 g per m per day for the two blend ratios of 90/10 and 70/30, respectively. The examination of swelling behavior revealed a noteworthy enhancement in hydrophilicity, a necessary attribute for improved healing efficacy. FT-IR analysis confirmed the success and the stability of the chemical crosslinking reaction between the two biopolymers before nanofiber conception. Excellent mechanical properties were acquired, based on the chitosan content. Both developed nanofiber scaffolds exhibited high tensile strength and Young's modulus values. The incorporation of 30% chitosan versus 10% results in an increase in tensile strength of 11% and 14% in Young's modulus. Therefore, we could adjust the different mechanical properties simply by varying the mixing rate of the electrospun polymers. Using epithelial HepG2 cells, viability and kinetic cell adhesion assays were assessed to obtain biological evaluation. No cytotoxicity was observed and good cytocompatibility was confirmed. Functionalized nanofiber biomaterials with different MC/CS ratios substantiated significant bactericidal effectiveness against Gram-positive and Gram-negative bacterial culture strains. The novel functional electrospun wound dressing scaffold demonstrated effective and promising biomedical performance, healing both acute and chronic wounds.

Optimizing Electrospinning Parameters for Enhanced Diameter Control of Composite Nanofibers in Direct Methanol Fuel Cells (DMFCs)

This study investigates the impact of electrospinning parameters, particularly focusing on the applied voltage parameter, on the diameter of TCNFs composite nanofibers for application in direct methanol fuel cells (DMFCs). The electrospun nanofibers are comprehensively characterized using fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), Brunauer–Emmett–Teller (BET) analysis and electrochemical techniques of cyclic voltammetry (CV). The results revealed that the optimal applied voltage is 16 kV for TCNFs nanofiber, resulting in an average nanofiber diameter of 161.18 nm. Furthermore, the electrochemically characterized composite nanofibers of PtRu/TCNFs demonstrate exceptional performance, achieving a peak current density of 265.33 mAmgPtRu-1, surpassing PtRu/C by 3.35 times. The comprehensive analysis contributes valuable insights for tailoring nanofiber design to enhance electrocatalytic performance, paving the way for advancements in DMFC technology.