Ethyl Cellulose Nanofibers Research Articles

High-Speed Electrospinning of Ethyl Cellulose Nanofibers via Taylor Cone Optimization.

Ethyl cellulose (EC) is one of the most widely used cellulose derivatives. Nevertheless, challenges such as the formation of beaded fibers, low yield, and nonporous internal structure persist in electrospinning, limiting functional improvements and industrial applications. This study invented a groundbreaking high-speed electrospinning technique through sheath liquid assistance to optimize the Taylor cone, dramatically enhancing the yield, morphology, and formation of porous structures of EC nanofibers beyond what has been seen in the literature to date. Our study emphasizes the crucial role of the sheath liquid's physical and chemical properties in controlling the morphology and diameter of EC nanofibers. It was discovered that highly polar and viscous sheath liquids led to the formation of beaded structures. Most importantly, the sheath liquid-assisted method substantially increased the ejection rate of the EC solution tens and hundreds of times compared to the current low-speed electrospinning method (0.1-1 mL/h) by refining the shape of the Taylor cone and resolving low productivity challenges in conventional nanofiber production. Meanwhile, increasing the flow rate of the EC or the sheath liquid accelerated the phase separation of EC solutions, thereby promoting the formation of porous structures in EC nanofibers. A pronounced porous structure was observed when the core EC flow rate reached 25 mL/h or the sheath chloroform flow rate reached 20 mL/h. Furthermore, our sheath liquid-assisted high-speed electrospinning technique demonstrated universal applicability to ECs with varying molecular weights. This study comprehensively addressed challenges in controlling the yield, morphology, and internal structure of EC nanofibers through sheath-solution-assisted high-speed electrospinning technology. These findings provide an innovative approach to developing next-generation electrospinning technologies to enhance the yield and properties of natural polymers for sustainability.

Effect of pore structure regulation on the properties of 3D cellulose nanofiber electret filtration materials

The properties, electret property and purification performance, of electret filter materials are closely associated with its pore structure, but the effect mechanism of pore structure on its electret property has not been clarified. Herein, the pore structure of 3D electret fiber materials which were prepared by freeze-drying technology and corona polarization technology based on dialdehyde cellulose nanofibers (DAMCC) and ethyl cellulose nanofibers (EC) was regulated by changing the DAMCC/EC mass ratio, solvent system, pre-freezing temperature and fiber concentration to explore the influence of pore structure on its electret properties and purification performance. The results show that the charge trapping and storage properties can be altered by the regulation of pore structure, and the 3D fiber material, prepared under the conditions of DAMCC/EC nanofiber mass ratio of 1/2, TBA content of 10 %, pre-freezing temperature of −40 °C and fiber concentration of 1.5 w/v%, presents a cellular porous structure with a complete fiber mesh wall. This structure is not only beneficial to the migration of space charge to the interior of the fiber material, but also can effectively prevent the escape behavior of space charge inside the material by extending the tortuous pore channel length, thereby improving the initial and stable surface potentials from 0.72 kV and 0.02 kV to 1.19 kV and 0.47 kV respectively. Moreover, the purification time of 3D electret fiber materials can be reduced from 51 min to 13 min owe to the improvement of electret property and pore structure. These will provide guidance for the investigation of pore structure regulation to alter the properties of electret fiber material for air purification.

In vitro evaluation of ethyl cellulose and polyvinyl pyrrolidone composite nanofibers for transdermal delivery of diclofenac diethylamine

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most prominent painkiller and anti-inflammatory drugs with gastrointestinal (GI) adverse effects. Transdermal drug delivery systems (TDDS) could overcome GI adverse effects associated with oral ingestion of NSAIDs as well as maintaining a prolonged release of the drug. The main aim of this study was to prepare and investigate diclofenac diethylamine (DDA) loaded nanofibers made of ethyl cellulose (EC) and polyvinyl pyrrolidone K90 (PVP) using electrospinning. The impact of penetration enhancers such as nerolidol and farnesol on release profiles through cellophane membranes and other characteristics of nanofibers were also investigated. Based on release studies, some formulations were selected for release examination through rate skin using Franz diffusion cells. To gain insight about potential interactions between drug and polymers FTIR, DSC, and XRD analyses were performed. Morphology examination was also conducted using scanning electron microscopy (SEM). Morphology studies showed that nanofibers made of EC only are greater in the mean diameter than other nanofibers while other formulations were not significantly different from each other regardless of the presence of penetration enhancers. EC nanofibers had the lowest elastic modulus and tensile strength and most elongation at break which makes them the least tough and most flexible nanofibers among all the formulations. The addition of PVP increased the toughness and decreased the flexibility of nanofibers. The addition of nerolidol did not alter the mechanical properties of nanofibers significantly, while the addition of farnesol increased elastic modulus, tensile strength, and elongation at break significantly in a concentration-dependent manner. EC nanofibers had the lowest release rate and lowest total cumulative release content while the addition of PVP significantly improved both of these features. In release studies through cellophane membrane, the addition of 5 % of penetration enhancer slightly increased the release rate while did not significantly alter cumulative release while the addition of 10 % farnesol notably increased the release rate and total cumulative released content. Release studies through rat skin were in accordance with cellophane membrane studies and the formulation with 10 % farnesol had the most release rate and total cumulative release and these findings confirm the positive effect of penetration enhancers. DSC thermogram showed an amorphous state of the drug in fibres and this was supported by XRD results. The FTIR results confirmed that no chemical interaction between the drug and other formulation components has occurred and no new compounds have been formed. Based on these results, the utilization of DDA-loaded PVP and EC nanofibers in conjunction with a penetration enhancer showed significant potential for application in transdermal patches.

Exploring temperature-responsive drug delivery with biocompatible fatty acids as phase change materials in ethyl cellulose nanofibers

This study introduces a novel temperature-responsive drug delivery system using ethyl cellulose (EC) nanofibers encapsulating a eutectic mixture of lauric acid/stearic acid (LA/SA) as phase change materials (PCMs) and Rhodamine B (RhB) as a model drug. Employing blend electrospinning, the nanofibers achieved controlled drug release responsive to temperature changes. The peak shift of the carbonyl group in FTIR analysis confirmed drug-polymer compatibility, while the absence of RhB peaks in the XRD and DSC assessments revealed RhB's amorphous distribution within the fibers. Our findings demonstrate that RhB release is dependent on its loading, with a slow initial release (<2 %) for 1 % and 5 % RhB loadings and a burst release (~12 %) for 10 % loading. Notably, the release rate was tunable at 37 °C by adjusting LA/SA concentration. The optimal LA/SA loading for temperature-responsive release is identified as 10 %. Over 240 h, there is a 32 % increase in RhB release at 37 °C, and an additional 8 % increase at 40 °C, compared to 25 °C. This research illustrates the potential of PCM-integrated nanofibers in smart drug delivery, particularly for chemotherapy, antibiotics, and anti-inflammatory drugs, showcasing an innovative approach to improving therapeutic efficiency while reducing side effects.

Modulating digestibility and stability of Pickering emulsions based on cellulose nanofibers

Cellulose nanofibers (CNF) have been widely studied for their biodegradability and for their unique advantages as a stabilizer in Pickering-type emulsions. However, it is challenging to produce cellulose nanofibers from agroindustry waste with good techno-functional properties, without the use of harsh process conditions. Green alternatives (eco-friendly) have been studied to obtain nanofibers, such as enzymatic hydrolysis and/or application of mechanical processes. In this work, we used acid hydrolysis (as a control and example of an efficient method), enzymatic hydrolysis and a mechanical process (ultrasound) to obtain cellulose nanofibers. We also evaluated the effect of the presence of ethyl groups in the cellulosic matrix (ethylcellulose) on the stabilizing mechanism of emulsions. All cellulose nanofibers were able to produce Pickering emulsions at concentrations of 0.01–0.05% (w/w), although showing differences in emulsion stability and digestibility. Morphology of the different cellulose nanofibers affected the viscosity of the aqueous suspensions used as continuous phase. Emulsions with nanofibers obtained from cassava peel (without the presence of ethyl groups) were stabilized only by the Pickering-type mechanism, while ethylcellulose nanofibers also showed surface activity that contributed to the stability of the emulsion. Furthermore, these latter emulsions showed greater release of free fatty acids in in vitro digestion compared to emulsions stabilized by cellulose nanofibers. Despite these differences, in vitro digestion showed the potential of applying cellulose-stabilized emulsions to control the rate of lipid digestion, due to the low amount of free fatty acids released (<20%).

Customizing the Protoscolicidal Activity by a Drug Delivery System: Application of Guar Gum in Electrospun Nanofibers.

Background:The present study aimed to control mebendazole drug release from ethyl cellulose nanofibers containing guar gum produced by Electrospinning Method (ESM) on mortality of hydatid cyst protoscoleces under laboratory conditions.Methods:The study was conducted in Arak Islamic Azad University, 2019. After preparation of ethyl cellulose nanofibers containing guar gum with concentrations 10, 250, 50 and 500 ppm with ESM, the uniformity and fineness of nanofibers were investigated by electron microscope. By determining the absorption of nanofibers during 312 h via spectrophotometry method, the amount of drug release was obtained. Then, the mortality of live protoscoleces in-vitro with nanofibers made with different concentrations was studied during 13 days.Results:Guar gum nanofiber with four concentrations of 10, 50, 250 and 500 ppm had 0.78512, 0.83729, 1.0098 and 1.0633 absorption respectively and showed drug release 42.09%, 39.95%, 33.05% and 30.96% after 312 hours. Therefore, the survival of protoscoleces in the presence of guar gum with four concentrations was zero after 3, 6, 11 and 13 days (P<0.05).Conclusion:To produce nanofibers carrying the drug for research related to the treatment of hydatid cysts, the electrospinning technique can be considered as a reliable method.

Sequential electrospinning of multilayer ethylcellulose/gelatin/ethylcellulose nanofibrous film for sustained release of curcumin

In this work, sequential electrospinning was utilized to fabricate a multilayer film with ethylcellulose nanofibers as the outer layer and curcumin-loaded gelatin nanofibers as the inner layer. Field-emission scanning electronic microscopy observations showed that the outer and inner layers had a smooth surface and clear boundary. The hydrophobic outer layers decreased the water vapor permeability and improved the water contact resistance of the hydrophilic inner layer, and the intimate interactions of hydrogen bonds between two adjacent layers enhanced the thermal stability. The multilayer film exhibited a sustained release manner of the encapsulated curcumin for 96 h, compared to the burst release within 30 min from the gelatin film. In addition, the antioxidant activities of the released curcumin from the multilayer film were well retained within 96 h. These results suggested that the multilayer nanofibrous film fabricated by sequential electrospinning has potential applications in bioactive encapsulation and controlled release.

The effect of collection substrate on electrospun ciprofloxacin-loaded poly(vinylpyrrolidone) and ethyl cellulose nanofibers as potential wound dressing materials.

In this work, nanofibers based on hydrophilic poly(vinylpyrrolidone) (PVP) and hydrophobic ethyl cellulose (EC) were generated via electrospinning. A model antibiotic, ciprofloxacin (CIF), was also incorporated into the fibers. Fibers were collected on both a foil substrate and a commercial gauze, the latter in the interests of developing a smart fabric. Electron microscopy images revealed that the fibers collected on both foil and fabric were homogeneous and cylindrical. Infrared spectroscopy, X-ray diffraction and differential scanning calorimetry demonstrated that CIF was successfully loaded into the fibers and present in the amorphous physical form. In vitro drug release tests were conducted to simulate drug release from the formulations into a wound site, and as expected the hydrophilic fibers showed much faster release than their hydrophobic analogues. CIF was released through a combined mechanism of polymer erosion and drug diffusion, and the EC nanofibers displayed close to zero-order release over three days. Fibroblast cells are able to grow and proliferate on the fibers. Finally, inhibition zone assays revealed that the growth of both Gram positive and Gram negative bacteria could be effectively inhibited as a result of the presence of CIF in the fibers. There were no marked differences between the fibers collected on foil and on gauze, and electrospinning can be performed directly onto a gauze substrate to prepare a smart fabric.

Tunable drug release from blend poly(vinyl pyrrolidone)-ethyl cellulose nanofibers

The management of pain and inflammation arising from wounds is essential in obtaining effective healing rates. The application of a wound dressing loaded with an anti-inflammatory drug would enable both issues to be ameliorated, and the aim of this work was to fabricate such a dressing by electrospinning. Fibers comprising ethyl cellulose (EC) and poly(vinyl pyrrolidone) (PVP) loaded with naproxen (Nap) were developed to be used in the early stages of wound care. A family of PVP/EC/Nap systems was prepared by varying the PVP: EC ratio. In all cases, the products of electrospinning comprise non-woven mats of fibers which generally have smooth and cylindrical morphologies. The formulations exist as amorphous solid dispersions, and there appear to be intermolecular interactions between the three components. Adjusting the polymer ratios results in tunable drug release, and formulations have been produced which give zero-order drug release over 20 and 80 h. The fiber mats generated in this work thus have great potential to be used as dressings for the treatment of wound pain and inflammation.

Electrospun Poly(N-isopropylacrylamide)/Ethyl Cellulose Nanofibers as Thermoresponsive Drug Delivery Systems

Fibers of poly(N-isopropylacrylamide) (PNIPAAm), ethyl cellulose (EC), and a blend of both were successfully fabricated by electrospinning. Analogous drug-loaded fibers were prepared loaded with ketoprofen (KET). Scanning and transmission electron microscopy showed that the fibers were largely smooth and cylindrical, with no phase separation observed. The addition of KET to the spinning solutions did not affect the morphology of resultant fibers, and no drug particles could be observed to separate from the polymer matrix. X-ray diffraction demonstrated that the drug was present in the amorphous physical form in the fiber matrix. There are significant intermolecular interactions between KET and polymers, as evidenced by IR spectroscopy and molecular modeling. Water contact angle measurements proved that the PNIPAAm and PNIPAAm/EC fibers switched from being hydrophilic to hydrophobic when the temperature was increased through the lower critical solution temperature of 32°C. In vitro drug release studies found that the PNIPAAm/EC blend nanofibers were able to synergistically combine the properties of the 2 polymers, giving temperature-sensitive systems with sustained release properties. In addition, they were established to be nontoxic and suitable for cell growth. This study demonstrates that electrospun-blend PNIPAAm/EC fibers comprise effective and biocompatible materials for drug delivery systems and tissue engineering.

Fabrication and Characterization of Antimicrobial Ethyl Cellulose Nanofibers Using Electrospinning Techniques.

Ethyl cellulose nanofibers were fabricated by electrospinning techniques using ethyl cellulose solution having concentrations of 150 g/l, using different volume ratios of a binary THF (tetrahydrofuran): DMAc (N,N dimethylacetamide) solvent system. The influence of the composition of the binary solvent system on the surface morphology of ethyl cellulose nanofibers with or without adhered antibiotics was investigated using field emission scanning electron microscope (FE-SEM). To assess the effectiveness of drug release from the nanofibers and their antibacterial activities toward S. aureus, streptomycin was selected as the antibiotic. Disc diffusion and optical density tests were used for the assessment. The antibiotic release from ethyl cellulose fibers was best when the THF to DMAc volume ratio was 3 to 2 (v/v). The optical density test showed the antibacterial effective time of the streptomycin antibiotics loaded in nanofibers was longer than that of the bulk antibiotics against S. aureus bacteria.

Tunable biphasic drug release from ethyl cellulose nanofibers fabricated using a modified coaxial electrospinning process.

This manuscript reports a new type of drug-loaded core-shell nanofibers that provide tunable biphasic release of quercetin. The nanofibers were fabricated using a modified coaxial electrospinning process, in which a polyvinyl chloride (PVC)-coated concentric spinneret was employed. Poly (vinyl pyrrolidone) (PVP) and ethyl cellulose (EC) were used as the polymer matrices to form the shell and core parts of the nanofibers, respectively. Scanning and transmission electron microscopy demonstrated that the nanofibers had linear morphologies and core-shell structures. The quercetin was found to be present in the nanofibers in the amorphous physical status, on the basis of X-ray diffraction results. In vitro release profiles showed that the PVP shell very rapidly freed its drug cargo into the solution, while the EC core provided the succedent sustained release. Variation of the drug loading permitted the release profiles to be tuned.

Influence of sheath solvents on the quality of ethyl cellulose nanofibers in a coaxial electrospinning process

The influence of different types of solvents as sheath fluids on the quality of electrospun ethyl cellulose (EC) nanofibers is investigated in this paper by a modified coaxial process. With 24 w/v % EC in ethanol as electrospinning core fluid and pure solvents including methanol, ethanol and N,N-dimethyl formamide (DMF) as sheath fluids, EC nanofibers were generated by the modified processes. Field emission scanning electron microscope observations demonstrate that the modified process is effective in improving the nanofibers' quality in terms of nanofibers' diameters, distributions and structural uniformity. The key of the modified coaxial process is the reasonable selection of the sheath solvents that is suitable for the drawing process of core EC fluid during the electrpospinning. The EC nanofibers' diameters (D, nm) could be manipulated through the reasonable selection of the type of the sheath solvents based on their boiling point (T, °C) D = 841-3.71T (R=0.9753). This paper provides useful methods for the implementation of the modified coaxial process controllably to obtain polymer nanofibers with high quality.

Higher quality quercetin sustained release ethyl cellulose nanofibers fabricated using a spinneret with a Teflon nozzle

This study investigates the usage of a spinneret with a Teflon nozzle for fabrication of higher quality drug sustained-release electrospun nanofibers. Ethyl cellulose (EC) and quercetin were used as a filament-forming polymer matrix and an active pharmaceutical ingredient, respectively. The electrospinning was conducted using both a traditional stainless steel spinneret and a spinneret with a Teflon nozzle. Experimental results demonstrated that a Teflon-fluid interface at the spinneret's nozzle provided a better performance for implementing electrospinning than a traditional metal-fluid interface in the following aspects: (1) keeping more electrical energy on the working fluids for an efficacious process; (2) exerting less negative effect on the fluid to draw it back to the tube; and (3) making less possibility of clogging. The resulted nanofibers from the spinneret with a Teflon nozzle exhibited higher quality than those from the traditional spinneret in those: (1) smaller diameter and narrower distribution, 520±70nm for the former and 750±280nm for the later, as indicated by the field emission scanning electron microscopic images; and (2) better sustained-release profiles of quercetin from the former than the latter, as demonstrated by the in vitro dissolution tests. The new protocols about usage of Teflon as a spinneret's nozzle and the related knowledge disclosed here should promote the preparation and application of electrospun functional nanofibers.

Sub-nanomolar sensing of ionic mercury with polymeric electrospun nanofibers

Ethyl cellulose (EC) based electrospun nanofibers were exploited for sub-nanomolar level optical chemical sensing of ionic mercury. An azomethine ionophore was used as Hg (I) and Hg (II) sensing material. Ethyl cellulose nanofibers with varying amounts of the ionic liquid; 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) were prepared and characterized. The nanofibers were fabricated by electrospinning technique. The offered chemosensor allow determination of mercury ions in a large linear working range between 1.0×10−10 and 1.0×10−4molL−1. Limit of detection was found to be 0.07nM which makes this technique alternative to cold-vapor atomic absorption spectrometry (CV-AAS), flame emission methods and to inductively coupled plasma-mass spectrometry (ICP-MS).The electrospun nanofibers exhibited excellent sensitivity for Hg (II) with respect to the continuous thin films prepared with same composition. The observed high sensitivity can be attributed to the high surface area of the nanofibrous materials and enhanced diffusibility of the mercury ions to the ionophore.

Preparation of Ethyl-Cellulose Nanofibers via An Electrospinning

Ethyl-cellulose (EC) nanofibers were fabricated by an electrospinning of an EC solution with a 6-12 wt% concentration. Fiber morphology was observed under a scanning electron microscope and the effects of instrument parameters including the solution concentration, flow rate and electric voltage were investigated.