Polyvinyl Alcohol Nanofibers Research Articles

Electrospinning preparation and spectral characterizations of the inclusion complex of ferulic acid and γ-cyclodextrin with encapsulation into polyvinyl alcohol electrospun nanofibers

In the present work, the inclusion complex of γ-Cyclodextrin (D) and Ferulic acid (FA) (D/FA) was encapsulated into Polyvinyl Alcohol (PVA) to form electrospun nanofibers by electrospinning under optimal condition. The structural and thermal characteristics of PVA, PVA/FA, PVA/D/FA andpure powder of FA were investigated by FT-IR, UV, 1H NMR. Smooth with uniform morphology and fiber diameter distributions were indicated by Scanning Electron Microscopy (SEM). Moreover,PVA, PVA/FA, PVA/D/FA nanofibers thermal behavior were investigated by TGA and DSC analysis. That result suggests that the thermal stability of PVA/D/FA nanofibers was enhanced due to inclusion complexation. Besides, the releasing rate of FA from the PVA nanofibers was measured by the calibration graph.A theoretical study of the γ-CD/FA inclusion complex was obtained by using Gaussian’s software, which gives good results with FT-IR and UV data.This study investigated the significant development of biobased polymeric nanofibers for active food packaging applications.

Antimicrobial Activity of Electrospun Polyvinyl Alcohol Nanofibers Filled with Poly[2-(tert-butylaminoethyl) Methacrylate]-Grafted Graphene Oxide Nanosheets.

A novel cationic polymer, poly[2-(tert-butylaminoethyl) methacrylate] (PTA), effectively kills various strains of bacteria with low toxicity to tissue cells. Graphene-based materials demonstrate exceptional electron transport capability, antibacterial activity, favorable nontoxicity, and versatile applicability. PTA can be grafted onto the graphene oxide (GO) surface (GO-g-PTA) to enhance the antimicrobial efficiency of the latter against Staphylococcus aureus (S. aureus). In this study, GO-g-PTA powders were successfully synthesized via free radical polymerization (GO-g-PTA-F) and atom transfer radical polymerization (GO-g-PTA-A). The antimicrobial efficiencies of graphene nanosheets (GNSs), GO-g-PTA-F, and GO-g-PTA-A were then investigated. Addition of GNS, GO-g-PTA-F, and GO-g-PTA-A to the PVA nanofibers was carried out elucidate the effects of filler amount and physical treatment on the morphology, microstructure, crystallization behaviors, antimicrobial efficiency, and cytotoxicity of the composite fibers. Finally, the potential applications of electrospun PVA/GNS, PVA/GO-g-PTA-F, and PVA/GO-g-PTA-A composite nanofiber mats to chronic wound care were evaluated. The resulting PVA/GO-g-PTA-A composite nanofiber mats showed enhanced antimicrobial ability against S. aureus compared with the PVA/GNS and PVA/GO-g-PTA-F composite nanofiber mats at the same filler volume percentage.

Fabrication of antibacterial and hemostatic electrospun PVA nanofibers for wound healing

Health care professionals have always had problems treating and healing wounds. Today, many of these problems have been resolved with the use of advanced wound dressings. The main aim of this work was to fabricate the wound dressings using the electrospinning method blending Tranexamic acid (TXA) with Polyvinyl alcohol (PVA) to investigate the blood coagulation properties. Also, the blending of Ceftriaxone (CTX) with Polyvinyl alcohol (PVA) was done to consider antibacterial properties. The effects of drug concentration changes on these properties were also considered. Morphological results demonstrated that nanofiber was produced uniformly and without beads. SEM image indicated that the average diameter of the nanofiber of PVA with 10 and 20 mg/ml of TXA was 110, 124 nm, respectively and the average diameter of PVA nanofibers was with 0.1, 1, 8 µg/ml of CTX was 258, 273 and 379 nm, respectively. The antibacterial properties of Gram-negative (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus) were studied and the results demonstrated that the antibacterial properties increased with increasing MIC. In PVA/CTX dressing with MIC: 8 μg/ml reached 100%. Both PVA-TXA (10 mg/ml) and PVA-TXA (20 mg/ml) dressings demonstrated the acceptable ability of blood coagulation. PVA-TXA (20 mg/ml) with an average absorption of 0.031 had higher blood coagulation ability.

Detection of Cardiovascular CRP Protein Biomarker Using a Novel Nanofibrous Substrate.

It is known that different diseases have characteristic biomarkers that are secreted very early on, even before the symptoms have developed. Before any kind of therapeutic approach can be used, it is necessary that such biomarkers be detected at a minimum concentration in the bodily fluids. Here, we report the fabrication of an interdigitated sensing device integrated with polyvinyl alcohol (PVA) nanofibers and carbon nanotubes (CNT) for the detection of an inflammatory biomarker, C-reactive protein (CRP). The limit of detection (LOD) was achieved in a range of 100 ng mL−1 and 1 fg mL−1 in both phosphate buffered saline (PBS) and human serum (hs). Furthermore, a significant change in the electrochemical impedance from 45% to 70% (hs) and 38% to 60% (PBS) over the loading range of CRP was achieved. The finite element analysis indicates that a non-redox charge transduction at the solid/liquid interface on the electrode surface is responsible for the enhanced sensitivity. Furthermore, the fabricated biosensor consists of a large electro-active surface area, along with better charge transfer characteristics that enabled improved specific binding with CRP. This was determined both experimentally and from the simulated electrochemical impedance of the PVA nanofiber patterned gold electrode.

Hierarchically Porous Carbon Nanofibers with Controllable Porosity Derived from Iodinated Polyvinyl Alcohol for Supercapacitors

AbstractPorous carbon nanoframeworks have attracted considerable interest for promising applications such as water purification, catalyst supports, gas adsorption, and energy storage owing to their high surface area and electrical conductivity. Traditional synthetic methods applied for porous carbon commonly involve a number of toxic organic solvents and post‐treatments, which are time‐consuming and energy inefficient. Herein, the authors report a facile synthetic method for generating atomically small pores in carbon nanofibers, with sizes varying from ≈0.55 nm to a few nanometers, using water‐soluble and cost‐effective polyvinyl alcohol (PVA) nanofibers as a precursor through the introduction of an iodine treatment. In particular, the generation mechanism of ultrafine pores during the carbonization of iodinated PVA are deeply analyzed and elucidated through meticulous investigations into their chemical/structural properties. By the suggested mechanism, the specific surface area of the generated pores is found to be extensively controlled from 100–650 m2 g−1. This phenomenon is advanced to produce well‐controlled hierarchically porous carbon nanofibers, and analyzes the corresponding electrochemical characteristics to explore the potential usage of such fibers as a supercapacitor.

Electrospun chia seed mucilage/PVA encapsulated with green cardamonmum essential oils: Antioxidant and antibacterial property

In this work, the potential of chia seed mucilage (CSM) as a new source of carbohydrate for encapsulation of green cardamonmum Essential oils (GCEOs) was evaluated. 1H NMR spectrum, FTIR spectrum and, SEM image has confirmed the existence of the GCEOs in the nanofibers. The nanofibers of CSM and polyvinyl alcohol have not antibacterial property, while nanofibers containing GCEOs show antibacterial activity against E. coli and S. aureus. Incorporating GCEOs in CSM nanofibers improved the antioxidant of the generated nanofibers. The amount of radical scavenging for the nanofibers containing 16 (mg/ml) of GCEOs was 18% and increasing the GCEOs concentration up to 64 (mg/ml) leads to grow the activity up to 41%. Thus, our studies indicate that nanofiber can be used as a novel antioxidant and antibacterial agent in the food and pharmaceutical industry.

The use of doped conductive bionic muscle nanofibers in a tennis racket–shaped optical fiber humidity sensor

This study introduces a unique method for the production of a highly sensitive tennis racket-shaped optical fiber humidity sensor consisting of a U-shaped probe and electrospun functional nanofibers. Functional nanofibers of the racket consist of conjugated polymers prepared through a mixture of two kinds of polymer molecules electrospun in an electric field of about 1.7 kV/cm. Interpenetrating polymer networks were fabricated through electrospinning, for which a polymer solution of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) doped in polyvinyl alcohol (PVA) was used. The hydrogen-bonding interaction of the interpenetrating polymer networks/H2O plays a major role in increasing the sensitivity of the humidity sensor. The sensitivity of the sensor was found to be −0.990 nm/%RH, which was 16.02 % greater than that of undoped PEDOT:PSS PVA nanofibers.

Water-stable and finasteride-loaded polyvinyl alcohol nanofibrous particles with sustained drug release for improved prostatic artery embolization - In vitro and in vivo evaluation.

Prostatic artery embolization (PAE) has been a well-established treatment for benign prostatic hyperplasia (BPH). To enhance the therapeutic efficacy, a strategy is to use embolic agent preloaded with 5α-reductase inhibitors for localized drug delivery. In this study, finasteride (FNS) was encapsulated into the polyvinyl alcohol (PVA) nanofibers via co-electrospinning technique, followed by heat treatment and cryogenic grinding to convert them into nanofibrous particles as a drug-loaded embolic agent. The FNS was found to be distributed uniformly in PVA nanofibers, and the processed FNS/PVA nanofibrous particles were 272μm in mean particle size. Besides, the studies on the composition, thermal properties, swelling ratio, and water stability of the nanofibers and drug showed that the FNS remained its crystalline state in PVA nanofibers. The heat treatment increased the crystallinity of nanofibers and rendered them water stability. Both FNS and PVA possessed excellent thermal stability at high temperature (150°C). In addition, in vitro drug release studies suggested the FNS followed a favorable sustained release up to 744h. Furthermore, the cell viability and hemocompatibility assays indicated the nanofibers possessed excellent cytocompatibility and with no evidence of hemolysis. More importantly, the in vivo PAE procedures on beagles demonstrated the crosslinked FNS/PVA nanofibrous particles exhibited higher embolization efficacy with more obvious prostate volume (PV) reduction compared to crosslinked PVA nanofibrous particles after embolization for 1, 3, and 6months (P<0.05). Therefore, such drug-loaded PVA nanofibrous particles combined physical embolization and localized medical therapy together, which offer great potential to be used as an effective embolic agent for BPH therapy.

Enhancement Technology for Electrospray Polyvinyl Alcohol (PVA) Nanofiber from Zuheros Nano: A Preliminary Study

Polyvinyl alcohol PVA nanofiber is a biocompatible material that has numerous potential in health application include as bone and tissue implant, anti-fungal, anti-microbial, air filter and waste water treatment. In this study, the electrospin fiber has successfully fabricated byusing Zuheros Nano-electrospin machine. This is a new generation of electrospin machine which offer a faster, safer, controlled spinning conditions and highly reproducible. The 6 and 8 wt % of PVA was prepare and operated at different electric field of 15 and 20 kV at different distance between tip to collector (TDC) of 15 and 17cm.The physical characteristics of electrospin fiber were observed under optical microscope. Result shows that at higher voltage 20 kV, TDC 17 cm of 8 wt % PVA has produce a smooth, fine and well arrange of fibers formation compared to other electrospin parameter. The PVA electrospin membrane was successfully formed as spray durations increased to 90 minutes. The different polymer concentration (wt%), TDC (cm) and electrospray voltage (kV) effects the PVA nano-fiber formation.

Low and High-Frequency Electro-Hydrodynamic Patterns in Nematic Liquid Crystal Aligned Using Dual Layer Alignment Produced by Nanofiber

The optical properties and electro-hydrodynamics (EHD) patterns of 4-methoxybenzylidene-4-butylaniline (MBBA) which is parallel oriented by nanofibers has been observed. The alignment of the liquid crystals was made using polyvinyl alcohol (PVA) nanofiber by used modified electrospinning. Electrospinning method was modified using two commercial copper (Cu) printed circuit board (PCB) as a gap collector. These planar samples area is 20 mm x 25 mm. The optical characteristic of these samples was studied by using an optical polarizing microscope. The optical intensity changes by a rotation of crossed polarizers are observed. When an electric field was applied to these samples, the electrohydrodynamic (EHD) pattern was observed. At the low till high frequency, by increasing the voltage, the patterns were formed such as Williams domain (WD), fluctuating Williams domain (FWD), grid patterns (GP) and dynamic scattering Mode (DSM).

New Patent on Electrospinning for Increasing Rutin Loading in Nanofibers.

The electrospinning and the bubble electrospinning provide facile ways for the fabrication of functional nanofibers by incorporating rutin/hydroxypropyl-β-cyclodextrin inclusion complex (RT/HP-β-CD-IC) in Polyvinyl Alcohol (PVA). Few patents on incorporation of rutin and cyclodextrin in nanofibers has been reported. The study aimed at increasing the loading amount of rutin in the electrospun nanofibers to obtain ultraviolet resistant property. Rutin was encapsulated in the cavity of RT/HP-β-CD and formed an inclusion complex. Fourier Transform Infrared Spectroscopy (FTIR) and Differential Scanning Calorimeter (DSC) was used to verify the formation of inclusion complexes. The results showed that the inclusion between rutin and HP-β-CD had been successfully formed. The surface morphologies of nanofibrous membranes were characterized by Scanning Electron Microscope (SEM), which indicated that adding RT/HP-β-CD inclusion complexes had little influence on the morphologies and diameters of the fibers. Ultraviolet resistant results also confirmed the inclusion complex had increased the loading amount in the final nanofibrous mats, and thus had good ultraviolet resistant properties. The formed inclusion complexes had obviously enhanced the loading amount of rutin in electrospun PVA nanofibers, indicating that encapsulation of rutin in the cavity of HP-β-CD is a good way to increase the loading amount.

Electrospun Momordica charantia incorporated polyvinyl alcohol (PVA) nanofibers for antibacterial applications

Momordica charantia MC (bitter gourd) is a natural remedy for diabetic patients. Keeping in view valuable and fruitful properties of MC, authors have loaded bitter gourd extract in combination with polyvinyl alcohol (PVA) on electrospinning and characterized for possible testing. Antibacterial properties of PVA/MC nanofibers were examined by disk diffusion method and it was observed that PVA/MC nanofibers have potential antibacterial activity against both gram positive and gram negative bacteria stains. Morphological properties of PVA/MS nanofibers were observed by scanning electron microscopy (SEM), and it was observed that addition of MC extract caused beads formation during electrospinning of PVA/MC solution. Addition of 50 % MC in PVA solution produced few nanofibers while surface was fully covered by courser beads. However authors suggest that 40 % (w/w) MC extract will be optimum ratio considering the results of different characterizations. Possibility of chemical reactivity between active functionalities of PVA and MC was also observed by FTIR-ATR spectra, but there was no significant peak change observed. Cytotoxicity of prepared composite nanofibers was also examined by WST-1 absorption. Crystallinity and mechanical properties were also studied by X-ray diffraction (XRD) and Universal Testing Machine (UTM). It is expected that prepared composite nanofibers have potential applications as sustainable antibacterial wound dressings for smooth and speedy recovery of open wounds.

Electrospun poly(vinyl alcohol)/reduced graphene oxide nanofibrous scaffolds for skin tissue engineering

Graphene is composed of a two-dimensional (2D) layer of carbon atoms arranged in a honeycomb lattice configuration. In this paper, we adopted a green synthetic method of producing reduced graphene oxide using glucose as a reducing and stabilizing agent. We also investigated the fabrication of electrospun nanofibers of glucose-reduced graphene oxide (GRGO) (0–1.0 wt%) reinforced with polyvinyl alcohol (PVA) as (PG) scaffolds, and chemically crosslinked with acidic glutaraldehyde (GA) in acetone medium to mimic the extracellular matrix (ECM) for skin tissue engineering applications. These PG scaffolds were evaluated for morphology, mechanical strength, surface wettability, thermal properties, hemocompatibility, and biocompatibility. Field emission-scanning electron microscopy (FE-SEM) revealed an increase in the thickness of nanofibers in PG scaffolds with an increase in the concentration of GRGO. X-ray diffraction and attenuated total reflectance-infrared and Raman spectra showed the GRGO was incorporated in the PVA nanofibrous matrix. As the concentration of GRGO was increased in PG scaffolds, tensile strengths and elongations at break decreased, whereas thermal properties increased. The biological activities of PG scaffolds were evaluated using in vitro hemolysis, using CCD-986Sk (a human skin fibroblast cell line) viability and proliferation assays, and by live/dead cell imaging. Results showed GRGO inclusion in PVA nanofibers caused a slight hydrophilic to hydrophobic shift. PG scaffolds did not cause hemolysis of red blood cells even at a GRGO loading of 1.0 wt%, and PG-1.0 scaffold (with a GRGO loading of 1.0 wt%) exhibited excellent compatibility with fibroblasts and significantly increased metabolic activity after culture for 21 days as compared with PG-0 controls. DAPI staining and live/dead imaging assays showed that all PG scaffolds increased fibroblast proliferation and viability, indicating the potential for skin tissue engineering applications.

STUDY ON PREPARATION AND PROPERTIES OF PVA/AgNPs COMPOSITE NANOFIBER MASK MATERIAL

In this paper, the preparation and properties of polyvinyl alcohol (PVA)/silver nanoparticles (AgNPs) composite nanofiber mask material were studied. Firstly, PVA spinning solution was prepared, and PVA nanofibers with different mass fractions (5 wt%, 7 wt%, 8 wt%, 9 wt% and 11 wt%) were prepared by electrospinning technology. The morphology of PVA nanofibers was observed under electron microscope, and the results showed that 8 wt% PVA nanofibers had the best morphology. AgNPs with different mass fractions (0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt% and 0.06 wt%) were dispersed in pure water and blended with 8 wt% PVA solution to prepare PVA/AgNPs composite nanofibers by electrospinning. The effects of different mass fractions of AgNPs on the morphology of PVA/AgNPs composite nanofibers were analyzed. Infrared spectroscopy and X-ray diffraction were used to test the PVA/AgNPs composite nanofibers. PVA/AgNPs composite nanofiber mask fabric was prepared by using activated carbon nonwoven fabric as substrate. The filterability, air permeability and moisture permeability of PVA/AgNPs composite nanofiber mask material were tested and analyzed. The result showed that PVA/AgNPs composite nanofiber mask material has good filtration, moisture permeability and air permeability, and has broad application prospects.

Low-temperature synthesis of novel polyvinylalcohol (PVA) nanofibrous membranes for catalytic dye degradation

Electrospun nanofibre membranes are employed to treat wastewater from dye pollution because of their outstanding properties. In this study, novel polyvinyl alcohol (PVA)-based hydrophilic electrospun nanofibre membranes were prepared using low-temperature synthesis (LTS) at 50 °C with a persulfate (PS) reagent and applied successfully to catalytic methylene blue (MB) dye degradation. The prepared nanofibre membranes were characterised with scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA). The LTS–based PVA nanofibre membranes had small diameters, and exhibited better mechanical stability and enhanced hydrophilicity. The catalytic degradation percentage of MB increased in the presence of the LTS PVA membrane due to the generation of sulphate radicals and the crosslinking between PVA and PS. The degradation of MB by the LTS PVA membrane was also found to be satisfactory when MB was mixed with methyl orange (MO) in a binary system. The influences of operational parameters including solution pH, initial MB concentration, and catalyst dosage on the degradation performance of MB were evaluated. The role of inorganic ions such as NaCl and NaHCO3 on MB degradation was also investigated under optimised conditions. The LTS PVA nanofibre membrane exhibited excellent stability after repeated recycling experiments (90% after five cycles), and provided an economical, sustainable process with low carbon emissions 18,75% lower than the HTS process, for good environmental impact.

Bactericidal and antifouling electrospun PVA nanofibers modified with a quaternary ammonium salt and zwitterionic sulfopropylbetaine.

Bacterial adhesion and colonization on material surfaces have attracted great attention due to their potential threat to human health. Combining bactericidal and antifouling functions has been confirmed as an optimal strategy to prevent microbial infection. In this work, biodegradable electrospun polyvinyl alcohol (PVA) nanofibers were chosen due to its high specific area and abundant reactive hydroxyl groups. A quaternary ammonium salt (IQAS) and zwitterionic sulfopropylbetaine (ISB), both containing isocyanate (NCO) groups, were chemically bonded to the PVA nanofiber surface via a coupling reaction between the OH groups of the PVA nanofibers and the NCO groups of IQAS or ISB. The results indicated that the antimicrobial rates of PVA nanofibers modified by IQAS (0.5%) reached 99.9% against both gram-positive Staphylococcus aureus (S. aureus, ATCC 6538) and gram-negative Escherichia coli (E. coli, ATCC 25922). Additionally, the live/dead staining and cytotoxicity test indicated that the dual functional IQAS/ISB/PVA nanofibers exhibited excellent bactericidal and antifouling activities with low cytotoxicity. This work may provide practical guidelines to fabricate bactericidal and antifouling materials for healthcare applications, including but not limited to wound dressings, textile, food packaging and air filtration.

Tensile testing and fracture mechanism analysis of polyvinyl alcohol nanofibrous webs

AbstractA tensile properties testing study was conducted to understand the influence of thickness, cross‐head speed (speed of testing), gauge length (GL; specimen test length), and sample shape on important tensile properties of polyvinyl alcohol (PVA) nanofiber webs. The effects of each testing parameter on load at break, extension at break, Young's modulus, and tensile stress–strain curve of PVA nanofiber webs are analyzed. The Welch two samplet‐tests show the significant difference among tested data. Using interaction plots, two‐way analysis of variance, and margin mean plots, the interaction effects among testing parameters have been analyzed. Of all the factors, cross‐head speed, the interaction among GL, and sample thickness (GL: Thickness) and the interaction among GL, testing speed and sample thickness (GL: Speed: Thickness) have significant influence on the tensile properties of PVA nanofiber webs. Moreover, the hypothesized model of mechanism of tensile strain–stress curve of PVA nanofiber webs has been proposed. Based on the model, the tensile strain–stress curve can be split into three stages: linear elastic, partial break up, and complete breakage. This study will provide a better understanding of tensile testing parameters' effects and their interaction effects on the tensile properties of nanowebs.

Antimicrobial Bilayer Nanocomposites Based on the Incorporation of As-Synthetized Hollow Zinc Oxide Nanotubes.

An antimicrobial polymeric bilayer structure based on the application of an acrylic coating containing hollow zinc oxide nanotubes over a polymeric substrate was developed in this work. Firstly, zinc oxide nanotubes (ZnONT) were obtained by an atomic layer deposition (ALD) process over electrospun polyvinyl alcohol nanofibers followed by polymer removal through calcination with the purpose of obtaining antimicrobial nanostructures with a high specific area. Parameters of electrospinning, ALD, and calcination processes were set in order to obtain successfully hollow zinc oxide nanotubes. Morphological studies through scanning electron microscopy (SEM) and transmission electron microscopy (TEM) microscopies confirmed the morphological structure of ZnONT with an average diameter of 180 nm and thickness of approximately 60 nm. Thermal and X-ray diffraction (XRD) analyses provided evidence that calcination completely removed the polymer, resulting in a crystalline hexagonal wurtzite structure. Subsequently, ZnONT were incorporated into a polymeric coating over a polyethylene extruded film at two concentrations: 0.5 and 1 wt. % with respect to the polymer weight. An antimicrobial analysis of developed antimicrobial materials was performed following JIS Z2801 against Staphylococcus aureus and Escherichia coli. When compared to active materials containing commercial ZnO nanoparticles, materials containing ZnONT presented higher microbial inhibition principally against Gram-negative bacteria, whose reduction was total for films containing 1 wt. % ZnONT. Antiviral studies were also performed, but these materials did not present significant viral reduction.

Design and fabrication of electrospun SBA-15-incorporated PVA with curcumin: a biomimetic nanoscaffold for skin tissue engineering

Fabricating and designing a scaffold is a complex and highly challenging process in the current scenario. The present study deals with the design and fabrication of electrospun Santa Barbara Amorphous (SBA)-15-incorporated polyvinyl alcohol (PVA) with curcumin, which can be used as a biomimetic nanoscaffold for skin tissue engineering. Curcumin was selected due to its effective anti-microbial and anti-inflammatory properties. SBA-15 was selected for its characteristic drug-carrying potential. Fourier transform infrared spectroscopy and x-ray diffraction characterizations of the fabricated nanofiber demonstrated the interaction of PVA, SBA-15 and curcumin. The scanning electron microscopy results depicted that the nanofiber was highly interconnected with a porous structure mimicking the extracellular matrix. The nanofibrous scaffold showed a higher percentage of cell migration, proliferation, cytocompatibility and biocompatibility with absence of cytotoxicity which was evidenced from the results of MTT assay, cell adhesion and live/dead assay using HaCaT cells. The results of the anti-bacterial test depicted that the synthesized nanofiber forms a potent material for skin wound-healing therapeutics. The in vitro drug release study performed over a period of 80 h revealed a sustained release pattern of curcumin from the SBA-15-incorporated PVA nanofiber. Finally, the in vivo results confirmed that SBA-15-incorporated PVA nanofiber with curcumin showed efficient wound-healing activities.

Reversible swelling as a strategy in the development of smart membranes from electrospun polyvinyl alcohol nanofiber mats

AbstractThis work presents an electrospun nanofibrous membrane for water treatment, designed to reduce its pores through polymer swelling to retain contaminants, and after that, reopening them for easy cleaning. It consists of a polyvinyl alcohol (PVA) mat crosslinked with a natural agent to avoid water solubility but allow a high swelling of its nanofibers. Then, when the membrane is brought into contact with water, a transitory state occurs during which nanofibers increase their diameter 68%, closing the pores between them. For studying the swelling reversal effect, distilled water filtering was used observing a decrease in the permeate flow over time until a steady state is reached. This phenomenon is explained by the closure of pores, and it is described with a fouling model widely used in the literature. Thanks to this decrease in the pore size, the membrane achieves a rejection rate much higher than conventional PVA electrospun membranes, being capable to retain 20 nm nanoparticles with a rejection rate up to 99%. Swelling is reversible through a simple drying process, which allows reopening the pores and cleaning the fouling easily. Both the membrane and its use strategy extend the capacity of electrospun mats in a sustainable way.