Average Diameter Of Nanofibers Research Articles

Electrospun microcrystalline cellulose/chitosan porous composite nanofibrous membranes modified by non-thermal plasma for gaseous formaldehyde adsorption

To develop a green and facile adsorbent for removing indoor polluted formaldehyde (HCHO) gas, the biomass porous nanofibrous membranes (BPNMs) derived from microcrystalline cellulose/chitosan were fabricated by electrospinning. The enhanced chemical adsorption sites with diverse oxygen (O) and nitrogen (N)-containing functional groups were introduced on the surface of BPNMs by non-thermal plasma modification under carbon dioxide (CO2) and nitrogen (N2) atmospheres. The average nanofiber diameters of nanofibrous membranes and their nanomechanical elastic modulus and hardness values decreased from 341 nm to 175–317 nm and from 2.00 GPa and 0.25 GPa to 1.70 GPa and 0.21 GPa, respectively, after plasma activation. The plasma-activated nanofibers showed superior hydrophilicity (WCA = 0°) and higher crystallinity than that of the control. The optimal HCHO adsorption capacity (134.16 mg g−1) of BPNMs was achieved under a N2 atmosphere at a plasma power of 30 W and for 3 min, which was 62.42 % higher compared with the control. Pyrrolic N, pyridinic N, CO and O–C=O were the most significant O and N-containing functional groups for the improved chemical adsorption of the BPNMs. The adsorption mechanism involved a synergistic combination of physical and chemical adsorption. This study provides a novel strategy that combines clean plasma activation with electrospinning to efficiently remove gaseous HCHO.

New discovery on the role of graphene nanoplates in enhancing the structural and electrical properties of carbon nanofibers

In this study, carbon nanofibers (CNFs) were successfully manufactured from special polyacrylonitrile (SPAN) copolymer/graphene nanoplates (GNPs) via an electrospinning process after that stabilization and carbonization approaches. The carbonization stage for stabilized SPAN/GNPs nanofibers was applied by heating the samples to 900 °C under an N2 inert atmosphere. The relationship of the GNPs concentration with morphological and structural properties of SPAN/GNPs composite nanofibers has been examined. The fineness and crystallinity of composite nanofiber increase with increasing concentration of GNPs from 0 to 4 wt%. With increasing the GNPs concentration in the SPAN/GNPs solutions from 0 to 4 wt%, the average diameter of nanofibers decreased from 480 ± 78 nm to 174 ± 18 nm. All CNFs samples synthesized at 900 °C have acceptable morphological, structural, and electrical properties. Moreover, the microstructure of the SCNFs can be controlled with GNPs concentration in composite nanofibers. The electrical conductivity of CNFs attained from neat nanofibers is 0.25 × 10+4 S/m, which is increased to 1.37 × 10+4 S/m with 4 wt% GNPs. Therefore, the unique 2D structure of GNPs is very suitable for the development of low-cost and conductive CNFs with low temperatures of carbonization.

Flexible centrifugally spun PVP based SnO2@carbon nanofiber electrodes

Sodium-ion batteries (SIBs) have attracted significant attention because of the abundant resource and low-cost of sodium. Furthermore, flexible and wearable functional electronics have been presented as one of the most important emerging technology. Carbon nanofibers are promising candidates for flexible electrodes due to their high electronic conductivity and high surface area, while it is vital to use non-petroleum-based polymers considering environmental concerns. Developing flexible nanostructured electrodes by using environment friendly polymers with a fast and low-cost technique is critical to develop high performance flexible electronics. Electrochemical properties are influenced by the morphology and average fiber diameters of nanofibers. In this study, poly(vinylpyrrolidone) (PVP) solutions with various concentrations and two different solvent systems (ethanol/water and ethanol/dimethylformamide) were successfully spun into nanofibers by the fast, safe, low-cost, and environment friendly technique of centrifugal spinning. The effect of solvent system and solution concentration was investigated by using scanning electron microscopy images, and the average fiber diameters varied from 436 nm to 3 µm. Moreover, nine different heat treatments were studied, and the effect of time and temperature during stabilization and carbonization on the morphology of carbon nanofibers (CNFs) was investigated. Furthermore, flexible carbon nanofibers were fabricated and used as binder-free anodes in sodium-ion batteries. In order to enhance the electrochemical properties of flexible CNFs, flexible SnO2@CNFs were fabricated by combining centrifugal spinning and heat treatment. The electrochemical performance of the flexible SnO2@carbon nanofiber anodes was evaluated by conducting galvanostatic charge/discharge tests and cycling voltammetry. A high rate of performance was also presented. The high reversible capacity of 400 mA h/g was delivered when flexible centrifugally spun PVP based SnO2@carbon nanofiber electrodes were used in SIBs.

Environmentally friendly electrospun polycaprolactone bio-membrane fabrication for water distillation

Eco-friendly biodegradable polycaprolactone (PCL) membranes were fabricated at different polymer concentrations: 10, 12, and 14 wt% via the electrospinning technique. The membrane's fiber and average pore diameters of various fabricated nanofiber membranes were measured using SEM associated with ImageJ software. The polymer concentration of 10 wt% showed beaded nanofibers compared with 12, and 14 wt% showed bead-free nanofiber structures. Accordingly, the morphological structure, hydrophilicity, chemical structure, and mechanical properties of the two uniform nanofiber membranes of 12 and 14 wt% were compared. The analyses demonstrated that the prepared 12 wt% PCL membrane recorded the most uniform average nanofiber diameter and pore diameter of 328 nm and 0.45 μm, respectively. The contact angle of this fabricated nanofiber was recorded as 118.8°, suggesting its suitability as a hydrophobic membrane for membrane distillation. The PCL membrane's performance in a direct contact membrane distillation (DCMD) system was examined. The membrane showed increased flux that reached about 41.9 kg·m−2·h−1and salt rejection (>94%) at 50 °C feed inlet temperature, 10 °C permeate temperature, 6 L/h feed flow rate, and 10,000 ppm NaCl feed inlet concentration.

High‐Performance Triboelectric Nanogenerator Based on Electrospun Polyvinylidene Fluoride‐Graphene Oxide Nanosheet Composite Nanofibers

Herein, a vertical contact‐separated triboelectric nanogenerator (TENG) composed of polyvinylidene fluoride (PVDF) and graphene oxide nanosheets (GO) is prepared. The effect of GO on PVDF nanofibers is analyzed to find the optimal mass fraction of GO. The morphology, structure, and output performance of PVDF nanofibers are characterized by field emission scanning electron microscopy, X‐ray diffractometer, Fourier transform infrared spectrometer, and digital oscilloscope. The results show that PVDF/GO nanofiber films produce output voltage of about 450 V and short‐circuit current of about 35 μA. The maximum peak power density of TENG consisting of PVDF/GO with cotton fibers is about 5.1 W m−2 under impedance‐matching conditions. Addition with GO suppresses the formation of α‐phase PVDF, thus facilitating the formation of β‐phase PVDF in the crystal structure. Furthermore, doping with GO reduces the average diameter of PVDF nanofibers. The PVDF nanofibers prepared in combination with the electrospinning process yield larger effective contact areas for TENG, which can significantly improve the output performance of the TENG.

Optimization of electrospun chitosan/polyethylene oxide hybrid nanofibril composite via response surface methodology

The present study is an attempt to optimize the electrospinning parameters to fabricate chitosan/polyethylene oxide hybrid nanofiber composite with minimum diameter and coefficient of variation (homogeneity) by using response surface methodology (RSM). Based on central composite design (CCD), four factors (the chitosan/PEO ratio, the applied voltage, the needle-to-collector distance, and the spinning angle) was applied to evaluate the individual and combined effects of the parameters on the average diameter of nanofibers. Chitosan (CH) was blended with Polyethylene oxide (PEO) at weight ratios of 1:1, 2:1, 3:1, 4:1, and 5:1. As the composition ratio of chitosan was reduced, the viscosity of the chitosan/PEO blend solution also dropped. The RSM model identified the following conditions as necessary to produce the desired and most uniform CS/PEO fiber diameter: a CS/PEO blend ratio of 2:1 (w/w), a voltage of 25 kV, a distance of 20 cm, and a spinning angle of 45°. The average nanofiber diameter and homogeneity under these conditions were calculated to be 73 nm and 20.5%, respectively, compared to the predicted values of 71 nm and 15.58%, respectively.

Production and characterization of polyamide-6 (PA6) and cellulose acetate (CA) based nanofiber membranes by electrospinning method

Recently, one of the most important nanotechnology products developed is nanostructured membranes. This study aims to produce nanofiber membranes to be used as filter material by electrospinning method from Polyamide-6 (PA6)/Cellulose Acetate (CA) polymer mixtures prepared in different mixing ratios (100/0, 90/10, 80/20, 70/30, 60/40, 50/50). In the study, firstly, preliminary experiments were carried out to determine the optimum electrospinning process parameters for the production of nanofiber membranes from these PA6/CA polymer mixtures. Then, solutions were prepared from these polymer mixtures and nanofiber membranes were produced from these prepared solutions by electrospinning method. Finally; density, electrical conductivity and viscosity measurements of PA6/CA solutions and FTIR, SEM, thickness and strength tests of nanofiber membranes were performed. In addition, the average nanofiber diameters of membranes were calculated. It has been determined that the average diameter of the nanofibers in the structure of membranes produced by electrospinning method is between 150 – 300 nm. From the characteristic peak bands obtained as a result of the FTIR analysis, it was determined that the PA6/CA structure was intact in the nanofiber material. In addition, it was determined that smooth and very fine nanofibers were formed in the materials produced from SEM images. It was observed that the conductivity of the solution decreased with the increase of the CA mixing ratio in the PA6/CA polymer solution and accordingly the fiber diameter became thinner

Metal matrix composite fabricated from electrospun PAN, EGNS/PAN nanofibers and AL 5049 alloy by using friction stir processing

This work is an attempt to fabricate aluminum (AA 5049) matrix composites (AMCs) reinforced with electrospun polyacrylonitrile (PAN) nanofibers and consisting of exfoliated graphite nanosheets (EGNS/PAN) by utilizing friction stir processing (FSP) to improve the mechanical characteristics of AA 5049. The electrospinning method was used for fabricating PAN and EGNS/PAN nanofibers. The average diameter of the electrospun PAN nanofibers is 195 ± 57 nm, and after EGNS incorporation is 180 ± 68 nm. Dynamic recrystallization was the main process in the microstructure evolution of the stir zone during the FSP with PAN and EGNS/PAN nanofibers. According to PAN and EGNS/PAN nanofibers were used in the FSP procedure, the grain size reduced as a result of the pinning effects. PAN and EGNS/PAN nanofiber reinforcement enhanced the hardness to 89 and 98 Hv, respectively. Also, the ultimate tensile strength was raised to 291 MPa and 344 MPa, respectively. Tensile strength and hardness of the stir zone increased during the FSP with PAN and EGNS/PAN nanofibers due to the higher density of the strengthening mechanisms of grain boundaries and dislocations. The mechanical characteristics of AA5049 can be enhanced by the procedure of incorporating nanofibers, making them an ideal choice for applications in the automotive and aerospace industries.

Fabrication and Characterization of PVC-Based Nanofiber Membranes for Water Filtration Application

Polyvinyl chloride (PVC) dissolved in N-dimethylacetamide (DMAC) and filled with polyvinyl pyrrolidone (PVP) has been studied for water treatment applications due to the material being hydrophobic, rigid, and biodegradable. However, it does not have antibacterial properties. The chitosan nanoparticles (CSNPs) as a natural antibacterial polymer are added into PEO/PVC blend to fabricate nanofiber membranes for well water filtration. We investigate the effects of adding PEO and CSNPs to PVC on the morphology, tensile properties, water contact angle, and water filtration efficiency of the nanofiber membranes. The PEO-PVC polymer solutions are dissolved in DMAC by varying concentrations of 0, 1, 2, 3, and 4% PEO (w/w), then fabricated to be the nanofiber membranes by the electrospinning technique. The PEO/PVC membrane’s contact angle decreases with the PEO concentration and by adding 1% CSNPs. This trend aligns with the average nanofiber diameter but is opposite to the tensile strength. The 1% CSNPs/4% PEO/PVC membrane has shown 78% and 92% efficiency in filtering Coliform and Colitinja bacteria in the well water, respectively.

Impact of Ag Nanoparticles on the Spectral and Optical Properties of Electrospun Nanofibrous Poly(vinyl alcohol)–Poly(acrylamide)

Nanofibers based on the polymer mixture that was associated with poly(vinyl alcohol) (PVA) and poly(acrylamide) (PAAm) (50/50 wt.%) doped with different ratios of silver nanoparticles (Ag NPs) were successfully synthesized using electrospun method, which was performed at room temperature (RT) and high voltage (12 kV). The products were studied using techniques including scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR), X-ray diffraction (XRD) and ultraviolet–visible absorption spectroscopy. SEM results show uniform structures and a smooth surface without particles visible on the surface of the nanofibers. Also, SEM images show that the average diameter of polymer blend nanofibers is 157.40 nm and decreases with the increasing concentration of Ag NPs. The small capacity of the carbonyl group to operate as a powerful electron donor for interacting with [Formula: see text] cation is shown by the fact that the FTIR signal strength decreases with increasing dopant concentration, indicating an increase in the basicity of the major functional groups. The X-ray diffraction pattern results confirm the amorphous nature (nano-crystalline) of the PVA–PAAm. The XRD results show that the crystallite size increases with the increase of the concentration of Ag and the peaks of weak intensity at a concentration of 6% agree with Ag in the cubic structure. Indirect allowed and forbidden transition optical energy gap values decreased with increasing Ag NPs content. The effect of doping on the other parameters (absorption coefficients, refraction index and extinction coefficient) of different blend behavior was investigated in detail which qualifies them for solar cell applications.

PHB/PEG Nanofiber Mat Obtained by Electrospinning and Their Performances

In this work, a nanofiber mat based on PHB/PEG with various PEG contents was obtained by electrospinning process. The thermal and mechanical properties of the PHB/PEG nanofiber mat were investigated. In addition, PHB/PEG nanofiber mats were characterized by Fourier transforms infrared spectroscopy (FTIR), differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, and water contact angle measurement. It was shown that, by increasing the PEG contents from 1 to 4%, the average diameter of PHB nanofibers decreased from 1177 nm to 1101 nm, corresponding to 2% PEG, then the diameter of the fiber increased again from 1101 nm to 1136 nm, corresponding to 4% PEG. Tensile strength increased from 3.6 MPa to 4.4 MPa, then decreased from 4.4 MPa to 2.9 MPa. Thermogravimetric analysis showed a difference in the process of thermal degradation of nanofiber mats. The degree of crystallinity measured by XRD and DSC methods gives different values at some points. The results demonstrated that adding PEG improved the mechanical properties, hydrophobicity, porosity, and thermal stability of the PHB fiber mat, which showed that the PHB/PEG nanofiber mat has great potential for air filtration or water filtration.

Collagen type I cross-linked to gelatin/chitosan electrospun mats: Application for skin tissue engineering

Skin tissue engineering can provide advanced/medicated dressings by using a wide range of biodegradable polymers. Electrospun nanofibrous mats have been exposed as a great potential for skin tissue regeneration by resembling extracellular matrix. In the present study, electrospun mats were prepared using 90:10 vol ratio of gelatin/chitosan (CS) blend. Then collagen type I cross-linked to CS to improve its biological properties. FTIR results confirmed the expected chemical composition and intermolecular cross-links. SEM images represented a homogeneous structure with minimum structural defects. The average nanofiber diameters of unmodified and collagen type I-modified gelatin/CS (90:10 v/v) mats were also found around 193 ± 80 nm and 302 ± 150 nm, respectively. Collagen presence increased young modules of the mats up to 3.72 kPa, which caused better-supported cell attachment and proliferation. MTT assay displayed that the presence of collagen type I significantly increased cell viability and migration up to 89% after three days. It is to be concluded that the proposed modified mats exhibited convenient structural and functional characteristics and also provided a promising solution for skin tissue engineering applications.

Encapsulation of caffeine in sandwich structured Alyssum homolocarpum seed gum/PVA/gelatin nanofibers using electrospinning technique

In this study, multilayer sandwich nanofibers from Alyssum homolocarpum seed gum (AHSG), polyvinyl alcohol (PVA) and gelatin were created by electrospinning technique and used to encapsulate caffeine. The middle layer was prepared by electrospinning of AHSG and PVA with different mixing ratios. The average diameter of electrospun nanofibers decreased with increasing AHSG to PVA ratios. Due to their ideal morphology (smooth, uniform, and bead-free) and thinner fiber diameter, nanofibers with the volume ratio of 30:70 AHSG to PVA were chosen as the best sample for caffeine encapsulation. The second step involved spinning gelatin onto the AHSG/PVA nanofibers containing caffeine, as the outer layers. These nanofibers effectively trapped caffeine and had high thermal stability and amorphous structures. The multilayer nanofiber containing 1% caffeine had the highest encapsulation efficiency (88.2%). More than 50% of the caffeine in single-layer nanofiber was released into the saliva simulator environment in less than 60 s, but after that point the caffeine release slowed down gradually. Sandwich structured nanofibers were more resistant to caffeine release and had slower release rate. The Korsmeyer-Peppas model was chosen as the model that best describes the mechanism of caffeine release from single-layer and multi-layer nanofiber, and the release followed non-Fickian diffusion.

Nanofiber PVA/ZnO Sebagai Material Antimikroba Pada Wound Dressings

Nanofibers are ideal for forming multifunctional medical products, one of which is wound dressings. Nanofibers wound dressings made from polyvynyl alcohol (PVA) and zinc oxide (ZnO) using the electrospinning method with varying voltages of 15 kv, 16 kv, 18 kv, and 20 kv, to determine the effect of stress on morphology, absorption and antibacterial activity. The resulting nanofibers have a smooth surface and an almost uniform fiber diameter. SEM analysis showed that the diameter of PVA 10% with a magnification of 50000X was 252 nm and PVA/ZnO 20 kv with a magnification of 30000X was obtained 231 nm, the EDX spectrum contained elements of C, O, and Zn respectively 37.40%, 62.14%, and 0.46%. The results of the FTIR analysis showed that the functional groups seen in the PVA/ZnO samples were O-H, CH2, C-H, C-O, and Zn-O. UV-Vis transmission showed that PVA had a high UV transmission of 12% but all PVA/ZnO nanofibers showed a UV transmission of almost 0%. Antimicrobial activity showed that the number of bacterial colonies in PVA/ZnO samples was less than the control. The average nanofibers diameter increases when ZnO nanoparticles are added, but when tension is increased, the average diameter of the nanofibers decreases. The morphology of the nanofibers is very uniform and there are no ZnO nanoparticle crystals, so PVA/ZnO nanofibers can be chosen as an ideal biomaterial for wound dressings.

Collagen Nanoyarns: Hierarchical Three-Dimensional Biomaterial Constructs.

Hierarchical fibrous scaffolds (HFS) consist of nanoscale fibers arranged in larger macroscale structures, much in the same pattern as in native tissue such as tendon and bone. Creation of continuous macroscale nanofiber yarns has been made possible using modified electrospinning set-ups that combine electrospinning with techniques such as twisting, drawing, and winding. In this paper, a modified electrospinning setup was used to create continuous yarns of twisted type I collagen nanofibers, also known as collagen nanoyarns (CNY), from collagen solution prepared in acetic acid. Fabricated CNYs were cross-linked and characterized using SEM imaging and mechanical testing, while denaturation of collagen and dissolution of the scaffolds were assessed using circular dichroism (CD) and UV-vis spectroscopy, respectively. HeLa cells were then cultured on the nanoyarns for 24 h to assess cell adhesion on the scaffolds. Scanning electron micrographs revealed a twisted nanofiber morphology with an average nanofiber diameter of 213 ± 60 nm and a yarn diameter of 372 ± 23 μm that shrank by 35% after covalent cross-linking. Structural denaturation assessment of native collagen using circular dichroism (CD) spectroscopy showed that 60% of the triple-helical collagen content in CNYs was retained. Cross-linking of CNYs significantly improved their mechanical properties as well as stability in buffered saline with no sign of degradation for 14 days. In addition, CNY strength and stiffness increased significantly with cross-linking although in the wet state, significant loss in these properties, with a corresponding increase in elasticity, was observed. HeLa cells cultured on cross-linked CNYs for 24 h adhered to the yarn surface and oriented along the nanofiber alignment axis, displaying the characteristic spindle-like morphology of cells grown on surfaces with aligned topography. Collectively, the results demonstrate the promising potential of collagen nanoyarns as a new class of shapable biomaterial scaffold and building block for generating macroscale fiber-based tissues.

FABRICATION AND CHARACTERIZATION OF ALOE VERA AND TEA TREE OIL LOADED ANTIMICROBIAL NANOFIBEROUS DRESSING

Skin infections due to microbes are reported with high spread and reportedly affected one –third of the world population. Connective tissue cells produce collagen and connective tissue fibers to heal wounds of skin and white blood cells produce antibodies to fight against harmful microbes. This study presents the process of synthesis of nanofiberous dressing loaded with Aloe vera and tea tree oil. Aloe Vera and Tea tree oil contain glucomannan and terpinin-4-ol, which help in the production of collagen and kill microbes. The surface morphology of prepared dressing was studied using Scanning Electron Microscope micrographs. The average diameter of nanofibers was measured to be 137.32nm. Fourier transform infrared spectroscopy of nanofiberous dressing confirmed the loading of aloe vera and tea tree oil. Drug release profile was analyzed by UV-vis spectroscopy. It was observed that 100% drug released within 12 minutes. The antimicrobial properties of prepared fibers against Aspergillus Niger (fungi) and Escherichia coli (bacteria) were systematically evaluated. The results showed that aloe vera- tea tree oil composite fibrous dressing was found to be effective for antimicrobial activity.

Metal Oxide Electrospun Nanofibrous Membranes for Effective Dye Degradation and Sustainable Photocatalysis

The fabrication of metal oxide nanofibers using (titanium (IV) isopropoxide) and (tin (IV) tert-butoxide) of weight ratio 1:1 precursor in presence of poly (vinyl pyrrolidone) as a binder using a well-known electrospinning technique is reported. The average diameter of TiO2, SnO2, and composite TiO2-SnO2 nanofibers were found to be in the range 75–110 nm. The nanofibers were characterized using thermogravimetric analysis (TGA) to understand the polymer evaporation temperature and further analyzed using scanning electron microscopy (SEM) to study the morphology of the nanofibers. The oxidation states of titanium (Ti) and tin (Sn) ions were analyzed using X-ray photoelectron spectroscopy (XPS), indicating that the TiO2 undergoes a change even after loading SnO2. The photocatalytic efficiency of the composite TiO2-SnO2 fibers was investigated to study the degradation capabilities under ultraviolet (UV) light towards industrial polluting dyes such as Alcian Blue, Alizarin Red S, Bilirubin, Brilliant Blue, Bromophenol Blue, and Rhodamine B ITC. Rhodamine B showed a significant degradation rate of about 0.0064 min−1 in comparison to the other dyes.

Investigation and multiscale modeling of PVA/SA coated poly lactic acid scaffold containing curcumin loaded layered double hydroxide nanohybrids.

Applying hydrophilic coatings on polymeric nanofibers combined with layered double hydroxide (LDH) not only enhances the efficiency of drug delivery systems but also increases cell adhesion. This work aimed to prepare poly(vinyl alcohol)/sodium alginate (PVA/SA) (2/1)-coated poly(lactic acid) (PLA) nanofibers containing curcumin-loaded layered double hydroxide (LDH) and to investigate their drug release and mechanical properties and their biocompatibility. The optimum PLA nanofibrous sample was considered to be that based on 3 wt% of curcumin-loaded LDH (PLA-3%LDH) with a drug encapsulation efficiency of ∼18% in which a minimum average nanofiber diameter of ∼476 nm along with a high tensile strength of 3.00 MPa were obtained. In the next step, a PVA/SA (2/1) layer was coated on the PLA-3%LDH; as a result, the hydrophilicity of the sample was improved and the elongation at break was decreased remarkably. In this regard the cell viability reached 80% for the coated PLA. Moreover, the formation of a layer of (PVA/SA) on the PLA nanofibers lowered the burst release and resulted in a more sustained drug release, which is a vital feature in dermal applications. A multiscale modeling method was applied for simulation of the mechanical properties of the composite scaffold and the results showed that this method can predict the data with 83% accuracy. The results of this study indicate that the formation of a layer of PVA/SA (2/1) has a significant effect on hydrophilicity and consequently improves cell adhesion and proliferation.

EMULSION ELECTROSPINNING OF PVA NANOFIBERS CONTAINING HYPERICUM PERFORATUM OIL

The aim of this study is to produce essential oil loaded nanofiber wound dressings from PVA, which is a biodegradable and biocompatible polymer, by emulsion electrospinning method. Hypericum Perforatum oil, known for its antibacterial, antioxidant and anti-inflammatory properties on skin disorders, was used and Kolliphor RH40 surfactant was added to emulsify oil in polymer solution. In order to examine the effect of surfactant amount on nanofiber morphology, surfactant was used at 2%, 4% and 6% (w/w) ratios. The effect of surfactant concentration on solution viscosity and fibre morphology were investigated by viscosity measurements and SEM analysis. To confirm the presence of Hypericum Perforatum oil in nanofibers structure FT-IR spectroscopy analysis were carried out. According to the results, the solution viscosity increased as the amount of surfactant increased. Additionally, it was observed that the average diameters of nanofibers, containing 2%, 4%, and 6% surfactant (w/w), increased compared to the pristine PVA nanofiber. In conclusion, the fiber morphology of Hypericum Perforatum oil-containing PVA nanofibers has been changed with the effect of surfactant.

Lawsonia inermis-loaded poly (L-lactide-co-D, L-lactide) nanofibers for healing acceleration of burn wounds

This study aimed to develop a new bioactive wound dressing based on electrospun poly (L-lactide-co-D, L-lactide) (PLDLLA) nanofibers containing Lawsonia inermis (LI) for burn wounds. The SEM results showed that loading LI increased the average diameter of PLDLLA nanofibers to 528 nm with smooth and beadless morphology. The analysis of LI release from PLDLLA nanofibers and film samples was measured by UV-vis spectrophotometry, and the obtained results revealed that LI molecules could diffuse from the nanofibrous sample with higher rate than film during 48 h. In this regard, the PLDLLA nanofibrous sample as a drug carrier has advantages compared to the film. Moreover, the antibacterial results confirmed the positive influence of LI related to the bacteria which in turn the growth inhibition zones were increased from 6 to 22 mm for P. aeruginosa, and from 3 to 16 mm for S. aureus while the LI concentration was set at 1.4% (w/v). Finally, animal model studies demonstrated that PLDLLA-LI nanofibers accelerated burn wound closure remarkably; thereby decreasing the wound area approximately 90% during the treatment period of 19 days. The histological observations dedicated that the appearance of the epithelial layer was increased dramatically alongside the thickness of around 40% for the wound treated with PLDLLA-LI nanofibrous sample rather than that without LI. Besides the epithelialization, it has been found that the wound covered by PLDLLA-LI wound dressing has condensed collagen fibers with no necrosis.