Polyvinylpyrrolidone Nanofibers Research Articles

Electrospun porous polyacrylonitrile/polyvinylpyrrolidone nanofiber membrane with ultra-hydrophilic and high moisture-permeability for dust personal protection

The serious dust pollution in coal mine working environment can cause occupational lung diseases and other diseases, affecting the life and health of miners. Therefore, the prospect of developing an air filtration membrane with high filtration performance is of remarkable significance. This study prepared a porous Polyacrylonitrile (PAN) /Polyvinylpyrrolidone (PVP) nanofiber membrane based on Electrospinning and post-treatment technology used for downhole personal protection. The prepared porous nanofiber membrane increased the specific surface area by 133.63% and the porosity by 391.02% (compared with the pure PAN nanofiber membrane), and was able to achieve a high filtration efficiency of 98.76% and a low pressure drop of 165Pa at an air flow rate of 85L/min. Meanwhile, this study conducted contact angle and moisture permeability tests on the prepared composite fiber membrane. After 1second of water droplets falling on the fiber membrane, it had a 14° contact angle (strong hydrophilicity), and the moisture permeability reached 4256.677 cm3/m2·d·Pa, which could discharge the water vapor generated by respiration in time. In addition, given the complex and irregular pore distribution of electrospun nanofibers, the fractal correlation dimension of nanofiber membrane pores was studied through fractal theory, and the relationship between the fractal dimension of fiber pores and respiratory resistance was discussed. Based on this, the nanofiber membrane prepared in this study can be widely used in individual protection in mines.

Investigating the impact of thymol/ɤ-cyclodextrin concentrations on the properties of electrospun PLA/PVP nanofibers for packaging applications

This study focuses on the modification of Polylactic acid (PLA)/polyvinylpyrrolidone (PVP) nanofibers using thymol-loaded cyclodextrin (TC) to optimize their suitability for applications in food science and packaging. The researchers conducted a comprehensive investigation into the impact of TC concentration on the nanofiber morphology, chemistry, and functionality. Scanning electron microscopy (SEM) analysis revealed that the modification with TC led to a reduction in fiber diameter and an increase in bead formation compared to the unmodified nanofibers. Fourier transform infrared spectroscopy (FTIR) analysis confirmed chemical alterations resulting from TC incorporation. The mechanical properties of the nanofibers were significantly enhanced with increasing TC content, as demonstrated by increased tensile strength and reduced elongation. This indicates improved mechanical strength and resilience of the nanofibers. Furthermore, the modified nanofibers exhibited notable improvements in antioxidant and antibacterial activities. They demonstrated remarkable antibacterial efficacy against both E. coli and S. aureus. This suggests that the incorporation of TC enhanced the antimicrobial properties of the nanofibers. Thymol release from the nanofibers reached its peak at a TC concentration of 10 %. This indicates that the release of thymol can be optimized by adjusting the TC content in the nanofibers. Overall, the results of this study demonstrated improved properties such as moisture management, mechanical properties, and antimicrobial activity in the modified nanofibers. These findings highlight the suitability of TC-modified nanofibers for various applications in the food industry, particularly in food science and packaging.

Electrospun Photodynamic Antibacterial Konjac Glucomannan/Polyvinylpyrrolidone Nanofibers Incorporated with Lignin-Zinc Oxide Nanoparticles and Curcumin for Food Packaging.

Due to the growing concerns surrounding microbial contamination and food safety, there has been a surge of interest in fabricating novel food packaging with highly efficient antibacterial activity. Herein, we describe novel photodynamic antibacterial konjac glucomannan (KGM)/polyvinylpyrrolidone (PVP) nanofibers incorporated with lignin-zinc oxide composite nanoparticles (L-ZnONPs) and curcumin (Cur) via electrospinning technology. The resulting KGM/PVP/Cur/L-ZnONPs nanofibers exhibited favorable hydrophobic properties (water contact angle: 118.1°), thermal stability, and flexibility (elongation at break: 241.9%). Notably, the inclusion of L-ZnONPs and Cur endowed the nanofibers with remarkable antioxidant (ABTS radical scavenging activity: 98.1%) and photodynamic antimicrobial properties, demonstrating enhanced inhibitory effect against both Staphylococcus aureus (inhibition: 12.4 mm) and Escherichia coli (12.1 mm). As a proof-of-concept study, we evaluated the feasibility of applying nanofibers to fresh strawberries, and the findings demonstrated that our nanofibers could delay strawberry spoilage and inhibit microbial growth. This photodynamic antimicrobial approach holds promise for design of highly efficient antibacterial food packaging, thereby contributing to enhanced food safety and quality assurance.

Electrospun Nanofibers with Pomegranate Peel Extract as a New Concept for Treating Oral Infections.

Pomegranate peel extract is known for its potent antibacterial, antiviral, antioxidant, anti-inflammatory, wound healing, and probiotic properties, leading to its use in treating oral infections. In the first stage of this work, for the first time, using the Design of Experiment (DoE) approach, pomegranate peel extract (70% methanol, temperature 70 °C, and three cycles per 90 min) was optimized and obtained, which showed optimal antioxidant and anti-inflammatory properties. The optimized extract showed antibacterial activity against oral pathogenic bacteria. The second part of this study focused on optimizing an electrospinning process for a combination of polycaprolactone (PCL) and polyvinylpyrrolidone (PVP) nanofibers loaded with the optimized pomegranate peel extract. The characterization of the nanofibers was confirmed by using SEM pictures, XRPD diffractograms, and IR-ATR spectra. The composition of the nanofibers can control the release; in the case of PVP-based nanofibers, immediate release was achieved within 30 min, while in the case of PCL/PVP, controlled release was completed within 24 h. Analysis of the effect of different scaffold compositions of the obtained electrofibers showed that those based on PCL/PVP had better wound healing potential. The proposed strategy to produce electrospun nanofibers with pomegranate peel extract is the first and innovative approach to better use the synergy of biological action of active compounds present in extracts in a patient-friendly pharmaceutical form, beneficial for treating oral infections.

Visible-light optical limiting of vanadia–polyvinylpyrrolidone nanofibers

In this work, vanadium pentoxide (V2O5) nanoparticles-filled electrospun polyvinylpyrrolidone (PVP) nanofibers were investigated systematically at various nanofiller weight percentages (8 and 10 wt%) and input intensities to reveal the effective optical limiting feature in the visible spectrum. XRD analysis demonstrated the purity of the produced V2O5 nanoparticles. According to SEM findings, V2O5 nanoparticles were effectively integrated into the PVP nanofibers. Two distinct absorption bands were observed at around 400 and 217 nm. These bands were related to PVP and V2O5 nanoparticles in linear absorption measurements, respectively. Moreover, an increased Urbach energy value was obtained with an increase in V2O5 nanofiller content within PVP. Open-aperture Z-scan measurements were taken at 532 nm considering the band gap energy of the V2O5 nanofillers in PVP composite nanofibers. In 8 wt% V2O5 nanofilled PVP nanofibers, one-photon absorption (OPA) was the main nonlinear absorption (NA) mechanism, and the defect states of the V2O5 nanoparticles had no contribution to NA. On the other hand, sequential two-photon absorption was the main NA mechanism, and the defect states of the nanoparticles caused more efficient NA behavior in 10 wt% V2O5 nanofilled PVP nanofibers. The effective optical limiting behavior was obtained for this composite nanofiber with lower limiting threshold as 1.49 × 10–5 J/cm2. The V2O5 nanofilled PVP nanofibers presented strong potential optical limiters in the visible wavelength region. This was attributed to their high linear transmittance at low input intensities and their robust NA behavior at higher input intensities.

Preparation and evaluation of fast-dissolving albendazole sulfoxide and praziquantel-loaded polyvinylpyrrolidone nanofiber films by electrospinning

Albendazole sulfoxide (ALBSOX) and Praziquantel (PRZ) are broad-spectrum anthelmintic medications used in the treatment of both humans and animals that are challenging to manufacture for geriatric and pediatric populations and have poor oral bioavailability due to their low water solubility and high lipophilicity. To increase the solubility and bioavailability of the drugs, ALBSOX and PRZ-loaded nanofiber films were prepared using polyvinylpyrrolidone K90 (PVP), a non-toxic, inert polymer with high hydrophilic characteristics. SEM analysis of the produced ALBSOX and PRZ-loaded PVP nanofiber films revealed them to be uniform and smooth, with good uniformity and mechanical properties. The PVP nanofiber films of ALBSOX and PRZ disintegrated in phosphate buffer (pH 6.8) in less than 1 s and increased the solubility of ALBSOX and PRZ about five times compared to pure active ingredients. Furthermore, the prepared ALBSOX and PRZ-loaded PVP nanofiber films were found to have no cytotoxic effect in cell viability studies using L929 cells, and increased the protoscolicidal effect of the ALBSOX and PRZ combination approximately 2-fold in studies of Echinococcus granulosus protoscoleces. The findings of the present study reveal that the developed PVP nanofiber films have the potential to improve the dissolution profile and pharmacological efficacy of the ALBSOX and PRZ.

Generation of PVP Membranes Using Extracts/Phenolic Fraction of Dysphania ambrosioides, Opuntia ficus-indica, and Tradescantia pallida.

In the present work, electrospun membranes of polyvinylpyrrolidone (PVP) nanofibers were manufactured using extracts and phenolic fractions of Dysphania ambrosioides (epazote), Opuntia ficus-indica (nopal), and Tradescantia pallida (chicken grass). The characterization of the membranes was carried out by scanning electron microscopy and Fourier transform infrared spectroscopy. The membranes synthesized through the use of the extracts generally showed a slight decrease in the diameter of the fibers but an increase in the size of the pores due to the presence of nanoparticles (rosaries) on the surface of the fibers, while the membranes synthesized using the phenolic fraction demonstrated an inversely proportional relationship between the compounds of this family with the diameter of the fibers and the size of the pore, allowing to elucidate part of the polymerization mechanisms of PVP nanofibers, in addition to proposing a reaction mechanism in the interaction between PVP and phenolic compounds for surface functionalization. Likewise, we demonstrate that the generation of reaction seeds through functionalization allows the addition of other compounds to the fibers in the membranes synthesized using the complete extract.

Enhancing gas sensing performance of tungsten trioxide (WO3) nanofibers through diameter and crystallinity control

Tungsten trioxide (WO3) is one of most widely investigated metal oxide semiconductors as gas sensing material because of tunable sensing performance toward different analytes through composition modulation (e.g., dopants) and various morphology and crystallinity. In this work, we synthesized WO3 nanofibers with different diameter and crystallinity through electrospinning of ammonium metatungstate hydrate (AMH)/polyvinyl pyrrolidone (PVP) nanofibers via design of experiments (DOE) followed by thermal heat treatment with the smaller average diameter being 23.0 nm. Through varying the calcination process, WO3 nanofibers with different crystallinity were also synthesized, with the smaller average grain size being 23.0 nm. These nanofibers were then exposed to many analytes (i.e., H2S, acetone, toluene, ethanol, ethyl benzene, NO2, NO, and methane) under different operating temperatures (i.e., 250 to 450 °C) to investigate their effect toward sensing response. These systematic studies indicated that nanocrystalline WO3 nanofibers with the smaller diameter (i.e., 20 nm) and/or smaller average grain sizes (i.e.,18.7 nm) exhibited best sensing performance independent of target analytes. The barrier energy was also correlated with the gas sensing performance experimentally.

Self-templating fabrication of Ti-doped SnO2 @carbon nanotubes via electrospinning for high-performance lithium-ion batteries

Tin dioxide (SnO2) has attracted extensive attention as an anode for lithium-ion batteries (LIBs) due to its high theoretical specific capacity, however, it suffers from the severe volume changes upon lithiation/delithiation cycling, thus leading to fast capacity fading. To overcome the drawbacks, we herein report a facile one-pot self-templating fabrication of Ti-doped SnO2 @carbon nanotubes (Ti-SnO2 @CNTs), via annealing the electrospun precursor nanofibers of tetrabutyl titanate (TBT), tetraethyl orthosilicate (TEOS), polyvinylidene difluoride (PVDF), polyvinylpyrrolidone (PVP), and stannous chloride (SnCl2). Interestingly, the introduction of TBT or not can lead to the controlled fabrication of the tubular or solid fibrous structure. During the annealing process, the chemical reaction between PVDF, TEOS, and TBT in-situ leads to the formation of tubular structure, while the SnCl2 converts into ultrafine SnO2 nanoparticles, embedding into the PVP-derived N-doped carbon nanotubes. When employed as anode materials for LIBs, the Ti-SnO2 @CNTs deliver high reversible capacities of 868.6/495.9 mAh g−1 at 0.2/1.0 A g−1 after 200/500 cycles, higher than those for the fibrous SnO2 @CNFs counterpart (654.9/391.08 mAh g−1). The better lithium storage performance is related to the unique carbon nanotube structure and the Ti-doping, which bring improved electrical conductivity, enhanced structural stability, and shortened ion diffusion path. More importantly, we demonstrate the facile electrospinning fabrication of tubular nanostructured hybrid electrodes for high-performance energy storage applications.

Copper‐PCL/PVP virucidal nanofibers against coronavirus produced by electrospinning technology

AbstractThis work investigated the virucidal property of copper‐loaded poly(ε‐caprolactone) (PCL)/polyvinylpyrrolidone (PVP) blended nanofibers against coronavirus. Electrospinning solutions were prepared with 0.25, 0.75, and 1.50% [w/v] of copper salt and their properties of electrical conductivity, surface tension, and viscosity were measured. The copper‐PCL/PVP nanofibers produced electrospun composite membranes of 30.5–38 g m−2. IR spectra confirmed the blended PCL/PVP, and SEM/EDS images revealed the morphology of the randomly oriented nanofibers with homogeneously incorporated copper in the electrospun nanofibers. The copper quantification indicated the final incorporation of 5.50 ± 0.31, 14.00 ± 1.03, and 27.10 ± 3.00 mg g−1 of copper, as measured by atomic absorption spectrometry, into electrospun composite membranes for 0.25, 0.75, and 1.50% [w/v] copper solution formulations, respectively, and these compositions also affected the nanofibers mechanical properties. Copper release assays showed that copper‐PCL/PVP nanofibers readily release ions into aqueous media. The 0.75% copper‐PCL/PVP composite membrane was virucidal against coronavirus, reaching 99.99% inactivation in 1 hour and 99.999% inactivation in 24 h, and non‐cytotoxic to L929 cells in 24 h of exposure. This work presents a virucidal composite membrane with potential use in personal protective equipment against viral outbreaks or pandemics.

Methanol extract of Iraqi Kurdistan Region Daphne mucronata as a potent source of antioxidant, antimicrobial, and anticancer agents for the synthesis of novel and bioactive polyvinylpyrrolidone nanofibers

In this study, aqueous, ethanol, methanol, and hexane extracts from Iraqi Kurdistan Region Daphne mucronata were prepared due to the numerous applications and development of nanofibers in biological and medical fields, including food packaging, enzyme stabilization, and wound dressing. In the initial evaluation of the extracts, the antioxidant properties against DPPH, antimicrobial properties against 3-gram-positive bacterial species, 3-gram negative bacterial species, 3-common bacterial species between aquatic and human, and 3-fungal species, and anticancer properties against breast cancer cells were performed. The results proved that the methanol extract has the highest antimicrobial, antifungal, antioxidant, and anticancer properties. After identifying the compounds of prepared methanol extract using GC/MS, polyvinylpyrrolidone nanofibers containing methanol extract of Daphne mucronata were prepared. The structure and characteristics of prepared nanofibers were confirmed and determined using FTIR, TGA, BET, SEM, flexural strength, compressive strength, and hydrophilicity. Synthesized polyvinylpyrrolidone nanofibers containing methanol extract of D. mucronata were subjected to antimicrobial properties on the strains studied in methanol extract of D. mucronata. The antimicrobial properties of synthesized polyvinylpyrrolidone nanofibers containing methanol extract of D. mucronata were compared. The results showed that synthesized polyvinylpyrrolidone nanofibers containing methanol extract of D. mucronata have the potential to introduction bioactive natural synthesis nanoparticles.

Electrospinning of smart nanofibers based on PVP/PDA for wound dressing applications

In the present study, electrospinning of polyvinylpyrrolidone (PVP) and polydiacetylene (PDA) with pomegranate peel (PG) extract was investigated for the preparation of smart and antibacterial nanofibers. Briefly, PDA-PVP solutions were firstly prepared at two different ratios and electrospun under different conditions. Based on the SEM results, the 1:3 ratio of PDA:PVP nanofibers, with an average fiber diameter of 130 ± 40 nm, electrospun at a voltage of 15 kV, feeding rate of 0.5 ml/h and collector distance of 15 cm was selected as the optimal conditions. The addition of PG resulted in an increase in the diameter of the fibers. The color of the electrospun fibers was altered from blue to red due to changes in either temperature or pH or exposure to different solvents. The antibacterial test showed high antimicrobial activity of the fibers loaded with PG extract against both S. aureus and E. coli. MTT assay and cell attachment also validated the biocompatibility of the fabricated nanofibers. Thus, the prepared smart PG-loaded nanofibers had a high potential to be used in wound dressing applications.

Effects of Reduced Graphene Oxide on Structural, Morphological, and Contact Angle Measurements of Poly (Vinyl Alcohol)/Polyvinyl Pyrrolidone Nanofibers

Polymer blend nanofibers are attracting considerable attention due to their wide applications in energy storage, water purification, drug delivery, and wettability studies. To date, research on poly (vinyl alcohol)/polyvinyl pyrrolidone (PVA/PVP) embedded with graphene-related materials like graphene oxide or reduced graphene oxide(rGO) are synthesized from solution mixing and casting into film, with limited efforts on developing polymer blend nanofibrous films. The present study focuses on developing the PVA/PVP blend nanofibrous film embedded with rGO using the electrospinning technique. The X-ray Diffraction (XRD), Field Emission scanning electron microscopy (FESEM), and contact angle measurements are used to investigate the structural, morphological, and wettability of the synthesized nanofibrous film. The rGO is synthesized by the improved Hummer’s method. The study provides insights into the tuning of the contact angles by modifying the morphology of nanofibers. The as-synthesized nanofibers have a diameter of about 150-250 nm and with the increase in rGO weight percentage show a drastic change in contact angle from 64° to 35.2°. These results highlight the modification of the wettability properties of blend nanofiber films by embedding rGO.

Carbon dot and FITC conjugated dual-emission nanoprobe and its electrospun film for the sensing of ammonia

Nanomaterials are at the forefront of next-generation sensing technologies because of their unique and tunable properties. For monitoring trace ammonia (NH3) in human metabolism, we synthesized a dual-emission nanoprobe with an average diameter of 4 nm by conjugating the NH3-sensitivity fluorescein derivative, the fluorescein isothiocyanate isomer (FITC, green emitter), onto the surface of carbon dots (CDs, blue emitter). A significant Förster resonance energy transfer (FRET) effect was observed, where the CDs acted as energy donors and FITC moieties acted as energy acceptors. The fluorescent color changed obviously from blue to green once ammonia was introduced into the test chamber. Subsequently, the dual-emission nanoprobe was immobilized in polyvinyl pyrrolidone nanofibers with an average diameter of 400 nm via electrospinning, thus obtaining a ratiometric NH3 sensor. Results showed that the fabricated sensor with a high surface area exhibited high sensitivity (theoretical detection limit was 0.53 ppm), short response time (∼4.3 s), excellent selectivity, and good reversibility in tracing 0–300 ppm NH3. Further prototyped application studies reveal that the sensor is expected to serve as an indicator for monitoring breath/blood ammonia concentration. Thus, the newly developed fluorescent sensor was able to be a feasible solution for the application of nanomaterials in health and medicine.

Polyvinylpyrrolidone Nanofibers Incorporating Mesoporous Bioactive Glass for Bone Tissue Engineering.

Composite biomaterials that combine osteoconductive and osteoinductive properties are a promising approach for bone tissue engineering (BTE) since they stimulate osteogenesis while mimicking extracellular matrix (ECM) morphology. In this context, the aim of the present research was to produce polyvinylpyrrolidone (PVP) nanofibers containing mesoporous bioactive glass (MBG) 80S15 nanoparticles. These composite materials were produced by the electrospinning technique. Design of experiments (DOE) was used to estimate the optimal electrospinning parameters to reduce average fiber diameter. The polymeric matrices were thermally crosslinked under different conditions, and the fibers' morphology was studied using scanning electron microscopy (SEM). Evaluation of the mechanical properties of nanofibrous mats revealed a dependence on thermal crosslinking parameters and on the presence of MBG 80S15 particles inside the polymeric fibers. Degradation tests indicated that the presence of MBG led to a faster degradation of nanofibrous mats and to a higher swelling capacity. The assessment of in vitro bioactivity in simulated body fluid (SBF) was performed using MBG pellets and PVP/MBG (1:1) composites to assess if the bioactive properties of MBG 80S15 were kept when it was incorporated into PVP nanofibers. FTIR and XRD analysis along with SEM-EDS results indicated that a hydroxy-carbonate apatite (HCA) layer formed on the surface of MBG pellets and nanofibrous webs after soaking in SBF over different time periods. In general, the materials revealed no cytotoxic effects on the Saos-2 cell line. The overall results for the materials produced show the potential of the composites to be used in BTE.

Improving Solubility and Permeability of Hesperidin through Electrospun Orange-Peel-Extract-Loaded Nanofibers.

Orange peel, which is a rich source of polyphenolic compounds, including hesperidin, is produced as waste in production. Therefore, optimization of the extraction of hesperidin was performed to obtain its highest content. The influence of process parameters such as the kind of extraction mixture, its temperature and the number of repetitions of the cycles on hesperidin content, the total content of phenolic compounds and antioxidant (DPPH scavenging assay) as well as anti-inflammation activities (inhibition of hyaluronidase activity) was checked. Methanol and temperature were key parameters determining the efficiency of extraction in terms of the possibility of extracting compounds with the highest biological activity. The optimal parameters of the orange peel extraction process were 70% of methanol in the extraction mixture, a temperature of 70 °C and 4 cycles per 20 min. The second part of the work focuses on developing electrospinning technology to synthesize nanofibers of polyvinylpyrrolidone (PVP) and hydroxypropyl-β-cyclodextrin (HPβCD) loaded with hesperidin-rich orange peel extract. This is a response to the circumvention of restrictions in the use of hesperidin due to its poor bioavailability resulting from low solubility and permeability. Dissolution studies showed improved hesperidin solubility (over eight-fold), while the PAMPA-GIT assay confirmed significantly better transmucosal penetration (over nine-fold). A DPPH scavenging assay of antioxidant activity as well as inhibition of hyaluronidase to express anti-inflammation activity was established for hesperidin in prepared electrospun nanofibers, especially those based on HPβCD and PVP. Thus, hesperidin-rich orange peel nanofibers may have potential buccal applications to induce improved systemic effects with pro-health biological activity.

Effect of molecular weight and content of polyvinylpyrrolidone on cell proliferation, loading capacity and properties of electrospun green tea essential oil-incorporated polyamide-6/polyvinylpyrrolidone nanofibers

Electrospun nanofibers demonstrate a novel category of materials that display great potential in numerous biomedical applications including tissue engineering, drug delivery, regenerative medicine, and wound healing. Here, composite nanofibrous scaffolds of polyamide-6 (PA-6), polyvinylpyrrolidone (PVP), and tea tree oil (TTO) was fabricated by electrospinning method and the effect of various molecular weight of PVP on properties of produced fiber scaffolds was studied. The investigations showed that the increase in the molecular weight of PVP, as well as the decrease in its content provides the thinner fibers (220.90 ± 59.0 nm) with higher porosity (∼90%), high water vapor transmission rate (WVTR) (3945. g/m2.24 h), and low surface wettability (∼85°). The morphological investigation accomplished with scanning electron microscope (SEM) showed the uniform bead-free electrospun fibers scaffold. The structural characteristics of the produced scaffolds were investigated with Fourier Transform Infrared Spectroscopy (FTIR). The results of the mechanical test of the produced fibers confirmed their ability to protect the wound area against external forces during the healing process. Antibacterial and antioxidant tests of samples containing TTO showed excellent and strong activities. Besides, the in vitro cytotoxicity, and cell adhesion was evaluated, that the obtained results illustrated that the electrospun fibers were biocompatible and supported cell adhesion. Based on the findings, this new electrospun matrix is expected to be effective as a potential wound dressing for skin regeneration.

A Highly Sensitive Flexible Pressure Sensor Based on Inter-Comb Structured Graphene Electrodes

Susceptible and flexible pressure sensors have broad application prospects and market demands in bionic skin, human–machine interface, and intelligent wearable electronic devices. However, optimizing the sensor’s sensitivity through a simple, low-cost process is still a considerable challenge. In this work, the sensitivity of a capacitive pressure sensor was effectively improved by optimizing the geometry of the laser-scribed graphene (LSG) electrodes. The pressure sensor, based on the inter-comb structured LSG electrodes and polyvinyl pyrrolidone nanofiber membrane (PVP NM) dielectric layer, has a high sensitivity (4.352 kPa <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-\text{1}}$</tex-math> </inline-formula> at 0–2 kPa), a fast response/recovery time (40/37 ms), an ultralow detection limit ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim$</tex-math> </inline-formula> 12 Pa), and excellent mechanical stability (6000 cycles). The sensor developed in this research can be used in health monitoring such as carotid artery pulsation and respiratory disease. In addition, the 6 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times$</tex-math> </inline-formula> 6 sensor array can precisely characterize the regional pressure distribution. This study demonstrates the significant potential of the inter-comb structured LSG electrodes in highly sensitive flexible pressure sensors.

An investigation of the influence of nanofibers morphology on the performance of QCM-based ethanol vapor sensor utilizing polyvinylpyrrolidone nanofibers active layer

Quartz crystal microbalances (QCMs) coated by polyvinylpyrrolidone (PVP) nanofibers with controlled morphology have been made for ethanol vapor detection. We used electrospinning to deposit PVP nanofibers of different morphologies (spherical-beaded, spindle-beaded, and pure nanofiber) on a QCM surface to study the effect on sensor performance. BET characterization revealed that the spherical-beaded nanofiber had the highest BET-specific surface area than the other morphologies, which improves the QCM sensor sensitivity, limit of quantification (LOQ), limit of detection (LOD), and sensor response. QCM coated with spherical-beaded nanofiber showed improved sensitivity of 2.632 Hz/ppm, lower LOD and LOQ of 0.018 ppm and 0.061 ppm, and better response compared to those coated with spindle-beaded and pure nanofiber. Based on adsorption isotherm models, Freundlich adsorption isotherm was found to be the most suitable for describing ethanol vapor adsorption on the sensor. The high sensitivity of the sensor to ethanol vapor was attributed to hydrogen bonding interactions between the sensor and the ethanol molecules. This study shows that the QCM-based sensor performance can be improved by modifying the morphology of nanofibrous coating layer.

Super disintegrating oromucosal nanofiber patch of zolmitriptan for rapid delivery and efficient brain targeting

Oromucosal administration of zolmitriptan using electrospun nanofiber can potentially result in blood plasma concentrations analogous to intravenous kinetics and targeting the brain due to anatomical features of the delivery site. Herein, we report the optimization of zolmitriptan and polyvinylpyrrolidone nanofibers using a Quality by Design approach. Fourier transform infrared spectroscopy, and Thermogravimetric analysis ruled out any physical and/or chemical interaction between the drug and excipient. Diffraction studies revealed a sharp decrease in the crystalline index of pure zolmitriptan from 85.75% to 8.35%. Likely, calorimetry studies show a sharp decline in the enthalpy of fusion from 126.4 J/g before electrospinning to 67.24 J/g post electrospinning, demonstrating amorphization of the drug. The disintegration of nanofiber occurs within less than a second, and about 82% of the medicament was released in 60 s in an in vitro test, compared to 67% from the Zomig Rapimelt® tablet. Rapid drug flux of 22.07 and 22.62 μg/cm2/h occurred when nanofiber patches were applied to buccal and soft palate mucosa in an ex vivo permeability test. Biocompatibility studies established that the nanofiber patches were neither toxic nor irritating to the oral epithelium. Groups of rabbits received the zolmitriptan solution intravenously and orally, or optimized nanofibers were applied to the buccal and soft palate mucosa. Pharmacokinetic analysis in blood plasma indicated similar kinetics of oromucosal patches and intravenous administration. More importantly, concentrations achieved in the hindbrain after administration of the patch over the soft palatal mucosa produce significantly higher concentrations than buccal or IV administration (>2-folds). The drug targeting these brain regions likely resulted from rapid dissolution, enhanced permeation, amorphization, and specialized drug transport via a trigeminal nose base-pons-medullary axis.