Search

Among smart materials, piezoelectric polymeric materials have a relatively high electrical response to mechanical stimuli, and diacetylenes are highly sensitive to color-changing materials. In this study, by combining the polymers of polyvinylidene fluoride (PVDF) and 10,12-pentacosadinoic acid and adding 1, 2, 3, 6, 9, 12, 15 and 18% zinc oxide (ZnO) nanoparticles to their solution, three component composite nanofibers were electrospun and their piezoelectric property were investigated. The results show that the presence of zinc oxide caused the formation of beads in the structure, but it caused a decrease of about 45%-60% in the average diameter of the samples compared to the PVDF/PDA samples. In these samples, in the best case, the piezoelectric property showed a maximum increase of about 12 times compared to the PVDF/PDA sample. According to the other results of various tests, the sample containing up to 3% ZnO enhances the piezoelectric performance of the PVDF/PDA dual response nanofibrous piezoelectric-chromic sensors. [ABSTRACT FROM AUTHOR]

Noninvasive and real‐time detection of bilirubin concentration enables rapid assessment of liver health status and the diagnosis of jaundice‐related diseases. Herein, the study proposes a strategy to uniformly grow bimetallic FeCo metal–organic framework (MOF) films onto the surface of carbonized electrospun nanofibers via a stepwise growth strategy involving an induction effect of oxide nanomembrane prepared by atomic layer deposition, to realize high‐performance flexible nanofiber bilirubin sensors. Compared with monometallic MOF, the FeCo bimetallic MOF can attain a larger specific surface area, thus augmenting the exposed active sites. Furthermore, the synergistic interaction between the bimetallic active sites on the MOF film and the carbonized nanofibers enhances the electronic conduction network, thereby significantly enhancing the catalytic activity of the flexible electrode for bilirubin. The current nanofibers sensor exhibits excellent performance in bilirubin detection, in terms of high sensitivity, large linear detection range, and low detection limit. The synthesis of bimetallic MOF films on flexible fibers holds promise for the development of highly sensitive electrodes for wearable bilirubin detection devices. [ABSTRACT FROM AUTHOR]

In the field of nanotechnology, rotary jet spinning technology has garnered attention due to its unique advantages in fabricating composite nanofibers. The composite nanofibers prepared using this technology exhibit exceptional purity, uniformity, and consistency, thereby enhancing reliability and controllability in practical applications. During the process of rotary jet spinning, the spinning solution flows into the nozzle and converges at a micro‐triangle under the combined influence of centrifugal force, viscous force, surface tension, and gravity. Stepped jet refers to the flow phenomenon occurring within a channel with a gradually decreasing cross‐sectional area. In this process, an increase in the flow velocity of the composite spinning solution aids in stabilizing stretching at the micro‐triangle which is crucial for forming continuous jets. This article analyzes cone formation mechanisms for composite spinning solutions and stepped jet principles while establishing corresponding models that reflect relationships between solution velocity magnitude and parameters such as rotational speed, concentration, and nozzle diameter. Finally, polyethylene oxide (PEO)/polyvinylpyrrolidone (PVP) composite nanofibers were prepared using a rotary jet spinning device where experimental investigation focused on examining how parameters such as rotational speed, solution concentration, and nozzle diameter impact motion of spinning solution within micro‐triangle. Highlights: Preparation of PEO/PVP composite nanofibers by rotary jet spinning.Presentation of cone formation mechanisms for composite solutions.The stepped injection principle was proposed.Modeling of composite solution motion.Rotational speed, solution concentration, and nozzle diameter impact motion. [ABSTRACT FROM AUTHOR]

This study presents a novel composite nanofiber membrane combining polyacrylonitrile/polyvinylidene fluoride (PAN/PVDF) electrospun nanofibers with locally sourced zeolite from Sumatera, Indonesia, for pollutant dye filtration. The Ze-PAN/PVDF composite nanofiber membrane has 100% methylene blue dye rejection even after five filtration cycles with a permeation flux of 185 L m−2 h−1 bar−1. The membrane is highly selective, with 100% dye filtration efficiency for cationic dyes (i.e., methylene blue and crystal violet) vs. 78% and 1% for anionic dyes (i.e., Congo red and methyl orange, respectively). For the cationic dyes, the dye filtration mechanism is mainly governed by electrostatic attraction, while the size exclusion mechanism becomes more dominant for the anionic dyes. Overall, these results demonstrate the potential use of Ze-PAN/PVDF composite nanofiber membrane in wastewater treatment applications.

ZrO2-SnO2 nanocomposite was produced in nanofiber (NF) form in three different ratios by volume (%v/v) by electro-spinning technique. Microstructure and morphological characterization of NFs reveal the ternary system of ZrO2-SnO2-ZrSnO4. Also, when the composition ratio of NFs was changed, both the band gap and the electrical (flash) sintering (ES or FS) event affected the temperature and sinter time variation. FS experiments were used at 3.77mA/mm² current cutoff under thermal (844-878°C) and electric field (420V/mm). Highly dense nanocomposites were obtained in less than 80 seconds with a maximum power absorption of 1.58W/mm³. Thanks to the low sintering temperature and time, the nanostructured surface morphology of the nanocomposites was obtained. In addition to the FS process, ZrO2-SnO2-ZrSnO4 CNFs were sintered for 1 hour at 1200°C using the conventional sintering (GS) method. This study investigated the effects of the difference in sintering techniques on the sintering temperature and time, as well as on properties such as density and hardness. As the amount of Sn (%v/v) in the composition increases, the density increases, but the hardness value decreases. It has been proven that in ZrO2-SnO2-ZrSnO4 CNFs, denser and harder compositions are obtained with FS treatment compared to GS. When all these results are evaluated, it is believed that the synthesized nanocomposites can be used as a valid candidate in the health system such as dental implants due to their antimicrobial effect and non-toxicity in the model organism. [ABSTRACT FROM AUTHOR]

This work presents the development of hierarchical niobium pentoxide (Nb2O5)-based composite nanofiber membranes for integrated adsorption and photocatalytic degradation of methylene blue (MB) pollutants from aqueous solutions. The Nb2O5 nanorods were vertically grown using a hydrothermal process on a base electrospun nanofibrous membrane made of polyacrylonitrile/polyvinylidene fluoride/ammonium niobate (V) oxalate hydrate (Nb2O5@PAN/PVDF/ANO). They were characterized using field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) analysis, and Fourier transform infrared (FTIR) spectroscopy. These composite nanofibers possessed a narrow optical bandgap energy of 3.31 ​eV and demonstrated an MB degradation efficiency of 96 ​% after 480 ​min contact time. The pseudo-first-order kinetic study was also conducted, in which Nb2O5@PAN/PVDF/ANO nanofibers have kinetic constant values of 1.29 ​× ​10−2 ​min−1 and 0.30 ​× ​10−2 ​min−1 for adsorption and photocatalytic degradation of MB aqueous solutions, respectively. These values are 17.7 and 7.8 times greater than those of PAN/PVDF/ANO nanofibers without Nb2O5 nanostructures. Besides their outstanding photocatalytic performance, the developed membrane materials exhibit advantageous characteristics in recycling, which subsequently widen their practical use in environmental remediation applications.

With a view to improving applicability as a sorbent while overcoming the challenges associated with its powdery nature, cobalt-doped zeolitic imidazolate framework (ZIF 67)–derived nanoporous carbon (Co-NPC) was employed as an additive in nanofiber through the process of electrospinning. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Brunauer–Emmett–Teller (BET) surface area analysis were used to characterize the resulting nanocomposite. A microfluidic chip device with four layers, including two layers entailing spiral channels, was designed and employed to assess the analytical performance of the fabricated Co-NPC-reinforced electrospun composite. To do so, a folded piece of electrospun composite was sandwiched between two layers with spiral channels. Therefore, both sides of the folded composite acted as a sorptive phase to extract antifungal drugs as target analytes. The significant factors affecting the efficiency of the extraction process were investigated and optimized. Subsequently, the technique was verified through the utilization of liquid chromatography-tandem mass spectrometry (LC–MS/MS) by employing optimal parameters. The optimal conditions were applied to evaluate the figures of merit. A linear range was obtained for antifungal drugs within the range 0.25–200.0 ng ml−1 with an R2 value of ≥ 0.9914. The method demonstrated detection limits ranging between 0.08 and 0.40 ng ml−1. The intra-day and inter-day precisions were less than 6.9%. Relative recoveries exhibited variations between 91.4–106.8%, 95.9–103.6%, and 96.4–109.3% for ketoconazole, clotrimazole, and miconazole, respectively. The proposed approach yielded satisfactory results, demonstrating its efficiency. [ABSTRACT FROM AUTHOR]

Well distributed and uniform nanofibers (NFs) of Zinc Oxide (ZnO) decorated with Cadmium sulfide (CdS) nanoparticles (NPs) were successfully fabricated using the Electrospinning method (ES). A ZnO-CdS junction electrode was created by loading the CdS NPs onto the ZnO NFs using the deposition process. X-ray diffraction of both ZnO NFs and CdS NPs revealed a mixed phase with a hexagonal wurtzite structure. SEM images confirm that the surface of the 33–71 nm diameter and several microns long pure ZnO nanofibers was smooth and became granular when CdS nanoparticles were added. The photo-response to visible light at the ZnO-CdS CNFs junction electrode was very strong, which increased the photoelectrochemical activity. Considering this, it was determined that ZnO-CdS CNFs had an incident photon-to-current conversion efficiency (IPCE) of about 60% as opposed to pure ZnO NFs, which had an IPCE of 33%. In conclusion, ZnO-CdS CNFs generated by a simple, inexpensive, and applicable cell are a promising clean renewable source for usage such as water splitting. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Bone disease and disorder treatment might be difficult because of its complicated nature. Millions of patients each year need bone substitutes that may help them recover quickly from a variety of illnesses. Synthetic bone replacements that mirror the structural, chemical, and biological features of bone matrix structure will be very helpful and in high demand. In this research, the inorganic bioactive glass nanoparticles matrixed with organic collagen and silk fibroin structure (COL/SF/CaO-SiO2) were used to create multifunctional bone-like fibers in this study, which we describe here. The fiber structure is organized in a layered fashion comparable to the sequence in which apatite and neo tissue are formed. The amino groups in COL and SF combined with CaO-SiO2 to stabilize the resulting composite nanofiber. Morphological and functional studies confirmed that crystalline CaO-SiO2 nanoparticles with average sizes of 20 ± 5 nm are anchored on a 115 ± 10 nm COL/SF nanofiber matrix. X-ray photoelectron spectroscopic (XPS) results confirmed the presence of C, N, O, Ca, and Si in the composite fiber with an atomic percentage of 59.46, 3.30, 20.25, 3.38 and 13.61%. respectively. The biocompatibility examination with osteoblast cells (Saos-2) revealed that the CAL/SF/CaO-SiO2 composite nanofiber had enhanced osteogenic activity. Finally, when the CAL/SF/CaO-SiO2 composite nanofiber scaffolds were used to treat an osteoporotic bone defect in a rat model, the composite nanofiber scaffolds significantly promoted bone regeneration and vascularization. This novel fibrous scaffold class represents a potential breakthrough in the design of advanced materials for complicated bone regeneration.

Although electrospun nanofibers have great potential for various tissue engineering applications, owing to their large surface area and extracellular matrix-mimicking properties, their lack of appropriate mechanical strength and biological cues for cell adhesion and proliferation limits their widespread use in tissue engineering. Nanofiber composite possessing two or more desired properties and functions has garnered considerable attention regarding its utility in diverse biomedical applications. In the present study, we aimed to develop a mechanically reinforced electrospun composite nanofiber by blending cellulose acetate and levan. Crosslinking the composite nanofiber with citric acid could significantly enhance its mechanical properties and thermal stability. In fact, the composite nanofibers had an adhesive strength of up to 1.27 MPa, which is similar to that of commercial tissue adhesive fibrin glue. The bioadhesive trait of composite nanofiber and the unique properties of levan not only enabled remarkable biocompatibility but also improved the levels of cell attachment and proliferation. Overall, the developed electrospun composite nanofibers can be used as promising cell scaffolds in tissue regenerative cell therapy. [ABSTRACT FROM AUTHOR]

Membranes and filters made of nanofibers can have many medicines and water treatment applications. The use of silver nanoparticles (AgNPs) with antibacterial activity in these structures improve their efficiency. However, due to the toxicity of the compounds used in the chemical synthesis of AgNPs, in this study, AgNPs were obtained through a biological process using Fusarium sporotrichioides. AgNPs preparation conditions were optimized, including F. sporotrichioides medium and AgNO3 concentration. Next, a PVA nanofiber membrane with bentonite and AgNPs (Bio-AgNPs or Chem-AgNPs) was prepared using electrospinning. The optimal conditions for the production of Bio-AgNPs were the culture of F. sporotrichioides in the MGYP culture medium and 12 M of AgNO3. The Bio-AgNPs particle size and zeta potential were 58 nm and − 16.8 mV, respectively, with antibacterial activity. The PVA/NB/AgNPs nanofibers operation conditions included 7.5% w/w PVA, 3% w/w bentonite, and AgNPs 5% w/w at a voltage of 11 kV, feed rate of 0.5 mL/h, and 15 cm distance between the needle and the collector. The average diameter of the PVA/NB/Bio-AgNPs nanofibers was 230 nm. Also, the presence of silver in the nanofibers was confirmed through EDX and XRD methods. The antibacterial assay of the nanofibers showed that the inhibition zone of PVA/NB/Bio-AgNPs against E. coli and S. aureus was 0.62 and 0.36 mm, which is better than PVA/NB/Chem-AgNPs and comparable with chloramphenicol. The produced membrane is suitable for water treatment, food packaging, and wound dressing because of its good thermal, mechanical, and antibacterial properties. [ABSTRACT FROM AUTHOR]

The feasibility of preparing cellulose acetate/carbon black (CA/CB) composite nanofiber in one step through electrospinning process and investigating its potential oil absorbability and application for machine oil removal from aquatic environment was reported. Different CA/CB composite nanofibers were fabricated by electrospinning of cellulose acetate (CA) solution containing different loads of 0.7, 1.5, and 2.2% CB relative to the weight of CA and labeled as CA/CB0.7, CA/CB1.5, and CA/CB2.2. The scanning electron microscope (SEM) images showed continuous and smooth fiber with submicron diameter ranging from 400–900 nm with good adhering of CB into CA nanofiber. Furthermore, the CA/CB composite nanofibers exhibited high surface area compared with CA nanofiber, which reached 3.057, 2.8718 and 8.244 m2/g for CA/CB0.7, CA/CB1.5 and CA/CB2.2, respectively. Oil adsorption tests were performed with heavy and light machine oils. The CA/CB composite nanofibers showed higher affinity for oil removal from an aqueous solution than pure CA nanofiber. The CA/CB1.5 composite nanofiber has an exceptional performance for the adsorption of both oils, and the maximum oil adsorbed reached 10.6 and 18.3 g/g for light and heavy machine oils, respectively. The kinetic of machine oils adsorption was fitted well by the pseudo-second-order model. Besides, CA/CB composite nanofiber exposed good adsorption properties and respectable reusability after regeneration for four consecutive cycles. The results advocate the excellent potential of as-fabricated CA/CB composite nanofiber as a promising reusable oil adsorbent for oil spill cleanup applications. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid materials are promising candidates for biomedical applications. In this study, chitosan, gelatin, and stearic acid coated nano-CaCO3 were electrospun to fabricate non-woven fibrous mats. The prepared chitosan/gelatin/nano-CaCO3 fibers with different CaCO3 contents (0%, 1%, 3%, and 5% w/v to polymer solution) were examined in terms of morphology, structure, thermal behavior, and antibacterial activity. Fourier-transform infrared spectroscopy results confirmed the formation of electrostatic interactions between chitosan, gelatin, and CaCO3. Chitosan/gelatin/nano-CaCO3 could be successfully electrospun into nanofibers with average fiber diameters between 184 ± 45 and 237 ± 55 nm and enhanced thermal stability. Electrospinning biopolymer blend with added calcium carbonate at higher concentration (3–5%) resulted in the formation of antibacterial fibers against B. subtilis, C. albicans, K. pneumonia, and S. aureus. According to all these favorable features, electrospun chitosan, gelatin, and nano-CaCO3 fibers seem to be attractive materials for biomedical applications.

To investigate the influence of nanorod ceramic powders MTiO 3 (M: Mg, Co, Ni) as fillers on the electrical performance, piezoelectric nanogenerators (PENG) device, were constructed using the electrospinning method with polyvinylidene fluoride (PVDF), reduced graphene oxide (RGO), and ceramic powders. The composite nanofibers were characterized using SEM, EDX, ATR-FTIR, EDS-mapping analysis, and XRD. Sensing capacity of the PVDF-RGO-MTiO 3 nanofiber-based PENG were compared. Utilizing CoTiO 3 (CT) in the PENG resulted in a voltage output of 17.03, which exhibited the best piezoelectric response. Observations revealed that mechanical stimulation could charge different capacitors, suggesting a viable platform for removing the requirement of an external power source for operating portable devices. With varying resistances in the circuit, the resistance of 104 Ω produced the maximum power density of 1.40 mW/cm2. When comparing the P-RGO-CT composite to pure PVDF, the differential scanning calorimetric analysis revealed that the thermal stability and crystallinity percentage increased. Tensile testing was used to evaluate the mechanical characteristics of P-RGO-CT PENG. The maximum stress and breaking strain that the nanofiber film can tolerate are 50 kPa and 33.9 %, respectively. EIS investigations obtained that the real intrinsic internal resistance of the P-RGO-CT PENG electrode is lower than PVDF, demonstrating the good conductivity of the synthesized PENG electrode. The impedance spectrum of the PENG electrode is almost parallel to the Z im axis, demonstrating good capacitance performance. [Display omitted] • Piezoelectric nanogenerators were constructed using lead-free perovskite materials. • Energy harvesting and sensing capability were evaluated. • The impedance spectrum demonstrates good capacitance performance. • The incorporation of MTiO 3 enhances the mechanical stability of the polymer matrix. • PENGs are more resilient of withstanding the forces and stresses of human motions. [ABSTRACT FROM AUTHOR]

ZrO 2 –SnO 2 –ZrSnO 4 composite nanofibers (CNFs) were fabricated by an electrospinning technique in three different ratios by volume (%v/v). Changing the composition ratio of CNFs affected the temperature and sinter time variation of both the band gap and the flash sintering (FS) phenomenon. FS experiments were used at a current cut-off of 3.77 mA/mm2 under thermal (844–878 °C) and electric field (420 V/mm). Highly dense CNFs were obtained in less than 80 s with a maximum power absorption of 1.58 W/mm3. In addition to the FS process, CNFs were sintered with the conventional sintering (CS) method at 1200 °C for 1 h. As the amount of Sn in the composition (%v/v) increases, the density increases, but the hardness value decreases. The FS process was proven to produce faster, denser, and harder material than CS. Long-term and permanent results are obtained by designing biocompatible nanocomposite materials in health. However, determining the long-term effects of CNFs, which are considered non-toxic, is necessary. Drosophila melanogaster female food was covered with these different v/v% ratios CNFs (ZrSn, Zr2Sn; 2ZrSn) and contact by life span: The effects were evaluated on movement, weight, egg production, longevity, and antioxidant system (Superoxide dismutase-SOD, catalase-CAT, glutathione-GSH, and 2,2-diphenyl-1-picrylhydrazil-DPPH). It can be said that Zr2S CNFs were not toxic by not changing the life span, egg production, climbing, and biochemical parameters of the fly. However, it was determined that CNFs used in ZrSn and 2ZrSn ratios slightly reduced the behavioral (movement and longevity) and antioxidant activities (SOD and CAT) of the individual. [Display omitted] • CS, density, and hardness tests of ZrO 2 -SnO 2 -ZrSnO 4 CNFs (ternary system) were investigated. • The FS, yielded a short-time process, denser and harder compositions compared to CS. • The long-term toxicity of FS ZrO 2 -SnO 2 -ZrSnO 4 CNFs did not produce short-term toxicity using Drosophila melanogaster. • In aging flies, ZrSn and 2ZrSn CNFs decreased SOD and CAT activity and resulting in weight gain and reduced locomotion. • Flies in groups 2 and 4 had a reduced lifespan because of continuous contact with CNFs. [ABSTRACT FROM AUTHOR]

[Display omitted] • YSZ@SnS 2 /Ag 2 S composite nanofibers was well tailored. • Ag 2 S quantum dots attached to vertical SnS 2 nanosheets supported by YSZ nanofibers. • High response and swift response/recovery times exhibited at room temperature. • The permeable hierarchical structure and heterojunction enhanced gas transmission/diffusion and reaction kinetics. • Heterojunction based composite nanofibers suitable for real-time room-temperature gas sensor. Air pollution has emerged as a critical global issue, necessitating the development of effective real-time gas monitoring technologies. However, conventional gas sensors face limitations such as high energy consumption and sluggish response/recovery kinetics. In this study, we report a novel SnS 2 /Ag 2 S heterojunction supported by yttria-stabilized zirconia nanofibers (YSZ@SnS 2 /Ag 2 S) through a facile electrospinning, hydrothermal and subsequent cation-exchange method. This hierarchical composite nanofiber consists of well-distributed Ag 2 S quantum dots (QDs) attached to vertical anchored SnS 2 nanosheets, forming an interconnected network supported by YSZ nanofibers. The integrated sensor exhibited high response of 3.27 and swift response/recovery times of 12/27 s to 1 ppm NO 2 at room temperature, respectively. Benefited from highly permeable three-dimensional continuous conductive nanofibers, along with the hierarchical nanosheets/QDs structure, the gas transmission/diffusion and number of reactive sites were ensured. Additionally, the interfacial built-in electric field of SnS 2 /Ag 2 S heterojunction further enhanced the electron transfer, carrier migration and gas-sensitive reaction kinetics. This study provides insights into the development of functional composite nanofibers and paves the way for the exploitation of real-time room-temperature gas sensing applications. [ABSTRACT FROM AUTHOR]

A new strain of bacterial cellulose (BC)-producing Gluconobacter cerinus HDX-1 was isolated and identified, and a simple, low-cost complexation method was used to biosynthesis Lactobacillus paracasei 1∙7 bacteriocin BC (BC-B) nanofiber. The structure and antibacterial properties of the nanofibers were evaluated. Solid-state nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FT-IR) and x-ray diffraction (XRD) analysis showed that BC and BC-B nanofibers had typical crystalline form of the cellulose I. X-ray photoelectron spectrometer (XPS), scanning electron microscope (SEM) and atomic force microscopy (AFM) revealed that the bacteriocin and BC were successfully compounded, and the structure of BC-B nanofiber was tighter than BC nanofiber, with lower porosity, swelling ratio and water vapor transmission rate (WVTR). The tensile strength and Young's modulus of BC-B nanofibers were 13.28 ± 1.26 MPa and 132.10 ± 4.92 MPa, respectively, higher than that of BC nanofiber (6.12 ± 0.87 MPa and 101.59 ± 5.87 MPa), indicating that bacteriocin enhance the mechanical properties of BC nanofiber. Furthermore, the BC-B nanofibers exhibited significant thermal stability, antioxidant capacity and antibacterial activity than BC nanofiber. Therefore, bacteriocin-loaded BC nanofiber may be used as antimicrobial agents in active food packaging and medical material. [Display omitted] [ABSTRACT FROM AUTHOR]

Vitamin D 3 , vitamin K 2 , and Mg (10%, 1.25%, and 5%, w/w , respectively)-loaded PLA (12%, w/v) (TCP (5%, w/v))/PCL (12%, w/v) 1:1 (v/v) composite nanofibers (DKMF) were produced by electrospinning method (ES) and their osteoinductive effects were investigated in cell culture test. Neither pure nanofibers nor DKMF caused a significant cytotoxic effect in fibroblasts. The induction of the stem cell differentiation into osteogenic cells was observed in the cell culture with both DKMF and pure nanofibers, separately. Vitamin D 3, vitamin K 2 , and magnesium demonstrated to support the osteogenic differentiation of mesenchymal stem cells by expressing Runx2, BMP2, and osteopontin and suppressing PPAR-γ and Sox9. Therefore, the Wnt/β-catenin signaling pathway was activated by DKMF. DKMF promoted large axonal sprouting and needle-like elongation of osteoblast cells and enhanced cellular functions such as migration, infiltration, proliferation, and differentiation after seven days of incubation using confocal laser scanning microscopy. The results showed that DKMF demonstrated sustained drug release for 144 h, tougher and stronger structure, higher tensile strength, increased water up-take capacity, decreased degradation ratio, and slightly lower Tm and Tg values compared to pure nanofibers. Consequently, DKMF is a promising treatment approach in bone tissue engineering due to its osteoinductive effects. [Display omitted] • Vitamin D 3 , vitamin K 2 , and Mg were loaded in PLA(TCP)/PCL nanofibers (DKMF). • DKMF supported the osteogenic differentiation of mesenchymal stem cells. • DKMF expressed Runx2, BMP2, and osteopontin and suppressed PPAR-γ and Sox9. • The Wnt/β-Catenin signaling pathway was activated by DKMF. • DKMF promoted large axonal sprouting and needle-like elongation of osteoblast cells. [ABSTRACT FROM AUTHOR]

Organic–inorganic hybrid materials are promising candidates for biomedical applications. In this study, chitosan, gelatin, and stearic acid coated nano-CaCO3 were electrospun to fabricate non-woven fibrous mats. The prepared chitosan/gelatin/nano-CaCO3 fibers with different CaCO3 contents (0%, 1%, 3%, and 5% w/v to polymer solution) were examined in terms of morphology, structure, thermal behavior, and antibacterial activity. Fourier-transform infrared spectroscopy results confirmed the formation of electrostatic interactions between chitosan, gelatin, and CaCO3. Chitosan/gelatin/nano-CaCO3 could be successfully electrospun into nanofibers with average fiber diameters between 184 ± 45 and 237 ± 55 nm and enhanced thermal stability. Electrospinning biopolymer blend with added calcium carbonate at higher concentration (3–5%) resulted in the formation of antibacterial fibers against B. subtilis, C. albicans, K. pneumonia, and S. aureus. According to all these favorable features, electrospun chitosan, gelatin, and nano-CaCO3 fibers seem to be attractive materials for biomedical applications. [ABSTRACT FROM AUTHOR]

Black seed and its extracts have been used in alternative medicine since ancient times. The aim of this study is to produce and characterize composite nanofibrous surfaces by electrospinning with the addition of black seed oil with different concentrations into the thermoplastic polyurethane polymer for wound dressings. During electrospinning the flow rate, and the distance between the needle and the collector were changed. The morphologies of the surfaces were analyzed by scanning electron microscopy (SEM). The nanofiber diameters, pore size and porosity of the nanofibrous mats were determined. The presence of black seed oil was investigated by FTIR analysis and the wettability of the surfaces was examined by contact angle measurements. As a result, optimum electrospinning process parameters and the most appropriate black seed oil concentration were determined to produce continuous, uniform and bead-free nanofibers.

Wearable energy harvesters and sensors have recently attracted significant attention with the rapid development of artificial intelligence and the Internet of Things (IoT). Compared to high-output bulk materials, these wearable devices are mainly fabricated by thin-film-based materials that limit their application. Therefore, the enhancement of output voltage and power for these devices has recently become an urgent topic. In this paper, the lead-free bismuth titanate-barium titanate (0.93(Na0.5Bi0.5)TiO3-0.07BaTiO3(BNBT)) nanoparticles and nanofibers were embedded into the PVDF nanofibers. They produced high inorganic electrical voltage coefficients, high electromechanical coupling coefficients, and environmentally friendly properties that enhance the electromechanical performance of pure PVDF nanofibers, and they are all the critical requirements for modern flexible pressure sensors. In detail, PVDF and PVDF-based composites nanofibers were prepared by electrospinning, and different flexible sandwich composite devices were fabricated by the PDMS encapsulation method. As a result, the six-time enhancement maximum output voltage was obtained in a PVDF-BNBT (fiber)-based composite sensor compared to the pure PVDF one. Our results indicate that the output voltage of the pressure sensors has been significantly enhanced, and the development gate is enabled by analyzing the related physical process and influence mechanism.

Three dimensional (3D) bioprinting, which involves depositing bioinks (mixed biomaterials) layer by layer to form computer-aided designs, is an ideal method for fabricating complex 3D biological structures. However, it remains challenging to prepare biomaterials with micro-nanostructures that accurately mimic the nanostructural features of natural tissues. A novel nanotechnological tool, electrospinning, permits the processing and modification of proper nanoscale biomaterials to enhance neural cell adhesion, migration, proliferation, differentiation, and subsequent nerve regeneration. The composite scaffold was prepared by combining 3D bioprinting with subsequent electrochemical deposition of polypyrrole and electrospinning of silk fibroin to form a composite polypyrrole/silk fibroin scaffold. Fourier transform infrared spectroscopy was used to analyze scaffold composition. The surface morphology of the scaffold was observed by light microscopy and scanning electron microscopy. A digital multimeter was used to measure the resistivity of prepared scaffolds. Light microscopy was applied to observe the surface morphology of scaffolds immersed in water or Dulbecco's Modified Eagle's Medium at 37°C for 30 days to assess stability. Results showed characteristic peaks of polypyrrole and silk fibroin in the synthesized conductive polypyrrole/silk fibroin scaffold, as well as the structure of the electrospun nanofiber layer on the surface. The electrical conductivity was 1 × 10−5–1 × 10−3 S/cm, while stability was 66.67%. A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was employed to measure scaffold cytotoxicity in vitro. Fluorescence microscopy was used to observe EdU-labeled Schwann cells to quantify cell proliferation. Immunohistochemistry was utilized to detect S100β immunoreactivity, while scanning electron microscopy was applied to observe the morphology of adherent Schwann cells. Results demonstrated that the polypyrrole/silk fibroin scaffold was not cytotoxic and did not affect Schwann cell proliferation. Moreover, filopodia formed on the scaffold and Schwann cells were regularly arranged. Our findings verified that the composite polypyrrole/silk fibroin scaffold has good biocompatibility and may be a suitable material for neural tissue engineering.

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An efficient approach was presented to prepare polyaniline/polypyrrole (PANi/PPy) composite nanofibers by growing PPy layers on the surface of PANi nanofibrous seeds as electrode materials for supercapacitors in neutral electrolyte. Core layer of PANi nanofiber was firstly synthesized by the chemical oxidative polymerization of aniline monomers under free melting condition of reaction solutions in fully aqueous system without the assistance of any templates or organic solvents. Then the shell layer of PPy was fabricated by in-situ chemical oxidative polymerization of pyrrole monomers with the above-mentioned PANi nanofiber as a seed, and the PPy shell layer thicknesses were tuned by changing the molar ratio of aniline to pyrrole. The resulting PANi/PPy composites were investigated by field-emission scanning electron microscopy, ultraviolet-visible spectroscopy, Fourier transform infrared and Raman spectrometry. Furthermore, electrochemical behaviors in Na2SO4 electrolyte were tested by cyclic voltammetry, galvanostatic charge-discharge techniques and electrochemical impedance spectroscopy. It turned out that low molar ratio of aniline to pyrrole is helpful to increase the PPy shell layer thicknesses, yield and conductivity of PANi/PPy composite nanofibers. A great improvement on the capacitive properties could be achieved by choosing appropriate PPy shell layer thickness. The results showed that benefiting from strong synergy effect and π-π interaction between PANi core and PPy shell layer as well as low electrochemical impedance, PANi/PPy composite nanofibers prepared with the molar ratio of 1:1 (PPy shell layer thickness of about 12.5 nm) displayed the highest specific capacitance of 1550.2 F g−1 at scan rate of 5 mV s−1 and 758.8 F g−1 at the current density of 1 A g−1 with the best cycling stability of 70.3 % after 500 cycles in 0.5 M Na2SO4 electrolyte, which exhibited a great potential in the development of high-performance electrode materials operated in environmentally friendly electrolyte. [ABSTRACT FROM AUTHOR]

In this research, we successfully fabricated a novel closed pore polyacrylonitrile (PAN)/polyvinyl pyrrolidone (PVP) composite nanofibrous membrane (PCNM) on the substrate of a commercial polypropylene window mesh. First, smooth and uniform PAN/PVP composite nanofibers (PCNs) were manufactured by blending PAN and PVP with a mass ratio of 5:5 during electrospinning. Subsequently, the prepared PCNs were hot pressed in a vacuum drying oven at a given temperature of 90°C. The morphology and filter efficiency of PCN and PCNM were investigated. It was found that hot-pressing treatment significantly affected the pore structure and orientation of PCNM, which contributed to its closed pore structure and good alignment. The filter efficiency results indicated that the hot-pressed PCNMs have excellent removal efficiency of up to 96.8% of fine particulate matter. This research demonstrates that PCNMs have potential as filters for indoor dust removal and will provide a new idea for the development of air filters. [ABSTRACT FROM AUTHOR]

To improve the interaction between cells and scaffolds, the appropriate surface chemical property is very important for tissue engineering scaffolds. In this study, the thermoplastic polyurethane (TPU) nanofibers was firstly fabricated by electrospinning technique, and then its surface was modified with cellulose nanofibrils (CNF) particles by ultrasonic-assisted to obtain TPU/CNF nanofibers. Subsequently, the TPU/CNF-polydopamine (PDA) composite nanofibers with core/shell structure were fabricated by PDA coating method. In comparison with TPU nanofibers, the uniformization of PDA coating layer on the surface of TPU/CNF composite nanofibers significantly increased due to the addition of CNF, which used as the active sites to guide the PDA particles accumulated along with the fiber direction. The water absorption and hydrophilicity of TPU/CNF-PDA composite nanofibers were significantly increased in comparison with those of TPU and TPU/CNF nanofibers. The mechanical properties of the TPU/CNF-PDA composite nanofibers were higher than those of the TPU and TPU/CNF nanofibers due to the formation of strong hydrogen bonds between PDA and TPU/CNF, making TPU, CNF and PDA strongly adhere to each other. The attachment and viability of mouse embryonic osteoblasts cells (MC3T3-E1) cultured on TPU/CNF-PDA composite nanofibers were obviously enhanced compared with TPU and TPU/CNF nanofibers. Those results suggested that the modified TPU/CNF-PDA composite nanofibers have excellent mechanical and biological properties, which promoting them potentially useful for tissue engineering scaffolds. The presented strategy represents a general route to modify the surface of scaffolds, which are promising for tissue engineering applications. [ABSTRACT FROM AUTHOR]

Composite nanofibers of polyacrylonitrile/fluorescent core–shell silica particles were fabricated. Two different sizes of fluorescent core–shell silica particles were synthesized. The first one consisted of particles with the diameter of about 310 nm (Bigger size fluorescent core-shell silica particles [BFSPs]) and the other one had the diameter of about 166 nm (smaller size fluorescent core-shell silica particles [SFSPs]). The images obtained by scanning and transmission electron microscopy confirmed the synthesis of spherical and nearly uniform particles. However, some clusters of smaller unformed silica particles were observed, especially in SFSPs. The results of Fourier transform infrared spectra spectroscopy confirmed the linkage between silica and fluorescein isothiocyanate. Scanning electron microscopy images of the composite nanofibers showed that the shell had a uniform morphology; however, there were some points having a higher diameter, where the core–shell particles were located. The fluorescence microscopy images of the composite nanofibers also showed the fluorescence property of the composite nanofibers with bright spots on them, where the particles were located. The fluorescence intensity of the composite nanofibers was significantly increased with the enhancement of the pH value in the range of 4.00–8.00. The observed pattern of composite nanofibers under ultraviolet radiation suggested that these composite nanofibers could be applied as anticounterfeiting markers for special clothes as well as pH-sensitive parts in smart clothing. [ABSTRACT FROM AUTHOR]

Industrial-scale water splitting processes will require economical and efficient electrocatalyst materials. Many oxygen evolution electrocatalysts prepared with non-precious metals have been reported. However, transition metal-based nanomaterials experience unavoidable aggregation and low stability in corrosion environments, which substantially reduces their catalytic performance. Herein, we successfully used a simple electrospinning technique followed by carbonation to synthesize a porous B-doped carbon fiber electrocatalyst with embedded B-doped FeNi alloy nanoparticles. To prepare the optimal catalyst sample, 1.05 g PAN, 5.0 mmol H 3 BO 3 , 2.5 mmol Fe(NO 3) 3 , and 2.5 mmol Ni(NO 3) 2 were used as precursors. The electrospun pristine fibers were annealed for 1 h at 800 °C in argon. Its overpotential for oxygen evolution at a current density of 10 mA cm−2 was only 231 mV, and a 60.99 mV·dec−1 Tafel slope was achieved. At this current density, this catalyst exhibits good performance for over 24 h or for more than 1000 CV cycles. This is due to the doping of non-metallic B atoms into the alloy nanoparticles, as well as the support and protection on them by carbon nanofibers. Insight This research provides a more thorough understanding of the preparation and practical application of low-cost and high-efficiency transitional metal alloy based water splitting catalysts. [Display omitted] • Novel B-doped FeNi/C alloy nanofibers. • Facile and highly efficient synthesis method based on electrospinning. • High efficient electrocatalyst for oxygen evolution in water splitting. • Mechanism for improved electrocatalytic activity. [ABSTRACT FROM AUTHOR]

An efficient, environmentally compatible and highly porous, silver surface-modified photocatalytic zinc oxide/cellulose acetate/ polypyrrole ZnO/CA/Ppy hybrid nanofibers matrix was fabricated using an electrospinning technique. Electrospinning parameters such as solution flow rate, applied voltage and the distance between needles to collector were optimized. The optimum homogenous and uniform ZnO/CA/Ppy polymeric composite nanofiber was fabricated through the dispersion of 0.05% wt ZnO into the dissolved hybrid polymeric solution with an average nanofiber diameter ranged between 125 and 170 nm. The fabricated ZnO-polymeric nanofiber was further surface-immobilized with silver nanoparticles to enhance its photocatalytic activity through the reduction of the nanofiber bandgap. A comparative study between ZnO polymeric nanofiber before and after silver immobilization was investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) and thermal gravimetric analysis (TGA). The photocatalytic degradation efficiency of the two different prepared nanofibers before and after nanosilver immobilization for malachite green (MG) dye was compared against various experimental parameters. The optimum degradation efficiency of nanosilver surface-modified ZnO-polymeric nanofibers was recorded as 93.5% for malachite green dye after 1 h compared with 63% for ZnO-polymeric nanofibers.

The article describes modern methods for producing one-, two-, and three-dimensional composite matrices for tissue engineering based on resorbable and non-resorbable polymers. Coagulation method for producing composite fibers based on chitosan and chitin nanofibrils, electrospinning method for composite nanofibers, lyophilization of chitosan solutions and their mixtures with nanoparticles to obtain three-dimensional porous matrices with increased stability of mechanical characteristics in aqueous media. The results of the study of the adhesion and kinetics of proliferation of stem and somatic cells of humans and animals on the developed matrices are presented. In vivo experiments have shown that materials in the form of fibers, films, tubular samples, and sponges can be used as implants for blood vessels, effective wound dressings. The article contains the results of the study of the kinetics of resorption of the studied materials in a living organism.

With a view to improving applicability as a sorbent while overcoming the challenges associated with its powdery nature, cobalt-doped zeolitic imidazolate framework (ZIF 67)-derived nanoporous carbon (Co-NPC) was employed as an additive in nanofiber through the process of electrospinning. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and Brunauer-Emmett-Teller (BET) surface area analysis were used to characterize the resulting nanocomposite. A microfluidic chip device with four layers, including two layers entailing spiral channels, was designed and employed to assess the analytical performance of the fabricated Co-NPC-reinforced electrospun composite. To do so, a folded piece of electrospun composite was sandwiched between two layers with spiral channels. Therefore, both sides of the folded composite acted as a sorptive phase to extract antifungal drugs as target analytes. The significant factors affecting the efficiency of the extraction process were investigated and optimized. Subsequently, the technique was verified through the utilization of liquid chromatography-tandem mass spectrometry (LC-MS/MS) by employing optimal parameters. The optimal conditions were applied to evaluate the figures of merit. A linear range was obtained for antifungal drugs within the range 0.25-200.0 ng ml -1 with an R 2 value of ≥ 0.9914. The method demonstrated detection limits ranging between 0.08 and 0.40 ng ml -1 . The intra-day and inter-day precisions were less than 6.9%. Relative recoveries exhibited variations between 91.4-106.8%, 95.9-103.6%, and 96.4-109.3% for ketoconazole, clotrimazole, and miconazole, respectively. The proposed approach yielded satisfactory results, demonstrating its efficiency., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Electrospun nanofibrous mats represent a new generation of medical textiles with promising applications in heart valve tissue reconstruction. It is important for biomaterials to mimic the biological and mechanical microenvironment of native extracellular matrix (ECM). However, the major challenges are still remaining for current biomedical materials, including appropriate mechanical properties, biocompatibility, and hemocompatibility. In the present work, the novel composite nanofibrous mats of poly(p-dioxanone) (PDO) and poly(ester-urethane)ureas (PEUU) are fabricated by electrospinning system. The optimal combination ratio of PDO to PEUU may balance the mechanical properties and cellular compatibility to match the newly formed tissue. In PDO/PEUU composite nanofibrous mats, PEUU can provide the biomimetic elastomeric behavior, and PDO could endow the excellent biocompatibility. In comparison to nanofibrous mat of neat PDO, the composite showed significantly improved mechanical properties, with 5-fold higher initial elongation at break. Furthermore, human umbilical vein endothelial cells (HUVECs) were cultured on the composite to evaluate its ability to rapidly endothelialize as heart valve tissue engineering. The results revealed that PDO/PEUU composite nanofibrous mats could promote cell adhesion and proliferation, especially for the ratio of 60/40. Overall, PDO/PEUU composite nanofibrous mats (60/40) show the excellent mechanical properties, appropriate biocompatibility and hemocompatibility which meet the necessary norm for tissue engineering and may be suitable for potential heart valve tissue reconstruction. [ABSTRACT FROM AUTHOR]

Superabsorbent polymers (SAPs) have been widely studied and used in various industries. In this study, SAPs based on sodium polyacrylate (NaPAA) and poly(vinyl alcohol) were successfully prepared in the form of nanofibers using the electrospinning technique. The heat‐treated superabsorbent nanofibers (SANs) with 7 wt% of NaPAA and containing both crystal structures and crosslinks presented the best absorption performance, with up to 3.9 times and 134% increase in the absorption area and swelling ratio, respectively. Furthermore, the crystal structure and crosslinking of the SANs enabled them to maintain their fiber network during water absorption and recovery. The absorption rate of SANs having both crystal structures and crosslinks was slightly lower than that of nanofibers with only crystal structures, but it was still higher than that of SAPs because of the highly porous nature of the nanowebs. The easy processing and structural stability of SANs are expected to be useful in a wide range of applications. © 2019 Society of Chemical Industry Complete superabsorbent nanofibers were successfully prepared by electrospinning. The produced nanofibers that showed fast and high absorbency were able to maintain their fiber shapes with crystal structure and crosslinks. [ABSTRACT FROM AUTHOR]

Functionalized poly(acrylic acid)/SiO2 (PAA/SiO2) composite nanofiber with mercapto groups have been prepared through an electro spinning process. The characterization of the composite nanofiber was performed using FTIR, optical microscopy, SEM, TEM and Brunauer-Emmett-Teller (BET) analysis. Finally, the prepared nanofiber was used for the adsorption of humic acid (HA) from an aqueous solution using a batch adsorption technique. The effects of pH, contact time, initial concentration, dosages and temperature on adsorption capacities were studied in a batch mode. The experimental data was well described by the Langmuir isotherm model with an adsorption capacity of 427.62 mg/g. It was found that the kinetic data follow the pseudo-second-order models. The data of thermodynamic parameters indicated that the HA adsorption process was non-spontaneous and endothermic under the experimental conditions with the values of Gibbs free energy (ΔG°) being in the range of 3.235 to 5.914 kJ mol–1; as well as the values of enthalpy (ΔH°) and entropy (ΔS°) that were found to be 22.41 kJ mol–1 and 55.59 J mol–1. K–1, respectively. The functionalized composite nanofiber exhibited as a high potential adsorbent for the adsorption of HA from an aqueous solution. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Bicomponent cellulose/PAN fiber was successfully fabricated by electrospinning method. • The bicomponent fiber mat showed high oil-in-water separation efficiency. • The as-fabricated fiber showed excellent oil/water separation for corrosive solutions. • The fiber mat exhibited good extent of reusability for oil-in-water separations. Abstract In this study, a simple electrospinning method was employed for the fabrication of a durable and renewable cellulose/polyacrylonitrile (cellulose/PAN) composite nanofiber by alternatively piled one over other as stacking. The stacking layers of cellulose/PAN composite fiber was subjected to the hot roller press at 80 °C to enhance the firm attachment of fibers. The hydrophilic composite fiber was fabricated for oil-in-water mixture separation in harsh conditions of different pH. The fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermal stability was monitored by TGA analysis. The tensile stress and the surface wetting behavior were greatly improved for cellulose/PAN composite fiber. The different oils like n-hexane, diesel oil, and toluene were used to prepare oil-in-water mixture solutions. The hydrophilic composite fiber served as a substrate to ensure the high water permeation flux and high separation efficiency with excellent stability and durability. This work projects an easy cost-effective fabrication method of composite fiber for on-demand oil-in-water separation process having good application in adverse situations with excellent recyclability and the maximum separation efficiency up to 97.31%. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Dual sustained drug release system was designed by a facile strategy. • Biocompatible and mesoporous Fe 3 O 4 −COOH nanoparticles were synthesized for designing drug carrier. • Improved mechanical performance and sustained drug release behavior were achieved. Abstract A facile strategy to incorporate dual sustained-release system in electrospun poly(lactic acid) (PLA) nanofibers is proposed for emerging applications in advanced drug delivery. Firstly, a model antimicrobial therapeutics, tetracycline hydrochloride (TCH) was blended with Fe 3 O 4 -COOH nanoparticles via electrostatic interaction to form novel composite nanoparticles. Then the influence of Fe 3 O 4 -COOH or TCH/Fe 3 O 4 -COOH nanoparticle incorporation on the morphology, porosity and hydrophilicity of electrospun PLA nanofiber membranes were elucidated. By studying drug release profiles, the newly designed TCH/Fe 3 O 4 -COOH/PLA nanofibrous membrane exhibited an obvious transition of drug release mechanisms from zero order release kinetics within the initial 6 days to modulated release beyond 6 days (until 14 days) in PBS. In contrast, TCH/Fe 3 O 4 -COOH and TCH/PLA nanofibrous membrane display single mechanism of burst like release within 3.5 days and 2.5 days, respectively. The Young's modulus, tensile strength and toughness of TCH/Fe 3 O 4 -COOH/PLA nanofibers are increased by 191%, 150% and 223%, respectively, compared with those of plain PLA electrospun nanofibers. Most importantly, TCH/Fe 3 O 4 -COOH/PLA nanofibrous membrane exhibited significantly stronger antibacterial activities against E. coli and S. aureus compared to TCH/Fe 3 O 4 -COOH and TCH/PLA nanofibrous membrane. The improved mechanical performance and sustained drug release behavior on TCH/Fe 3 O 4 -COOH/PLA pave the way for the emerging applications in drug delivery and tissue engineering. [ABSTRACT FROM AUTHOR]

Coaxial electrospinning technique was used to fabricate the core-sheath composite nanofibers of ZnO nanoparticle (Nps) (10%, 20% w/w) doped polymethyl methacrylate (PMMA) (as sheath) and polyvinyl alcohol (PVA) (as core). Fourier transform infrared (FT-IR) spectra were confirmed the weak forces arise between ZnO Nps, PMMA and PVA matrixes. The hexagonal (wurtzite) structure of ZnO Nps with ~ 30.8 nm of diameter was confirmed from the X-ray diffraction pattern. The morphology and microstructure of core-sheath composite nanofibers were confirmed from the scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It is clearly seen from the TEM images that the PMMA encapsulate the PVA core. Core-sheath composite nanofibers were assessed against Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) bacteria through quantitative, disk diffusion and viable cell count methods. It was found that ZnO Nps doped core-sheath nanofibers were effectively inhibit the growth of gram positive bacteria, B. subtilis. [ABSTRACT FROM AUTHOR]

Here, we developed a novel biliary stent coating material that is composed of tri-layer membrane with dual function of sustained release of paclitaxel (PTX) anticancer drug and antibacterial effect. The advantages of using electrospinning technique were considered for the even distribution of PTX and controlled release profile from the nanofiber mat. Furthermore, film cast method was utilized to fabricate AgNPs-immobilized PU film to direct the release towards the tumor site and suppress the biofilm formation. The in vitro antibacterial test conducted against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria species showed excellent antibacterial effect. The in vitro drug release study confirmed the sustained release of PTX from the tri-layer membrane and the release profile fitted first order with correlation coefficient of R2 = 0.98. Furthermore, the release mechanism was studied using Korsmeyer–Peppas model, revealing that the release mechanism follows Fickian diffusion. Based on the results, this novel tri-layer membrane shows curative potential in clinical development.

Herein, we report a drug eluting scaffold composed of a composite nanofibers of poly(ε-caprolactone) (PCL) and poly(glycerol sebacate) (PGS) loaded with Hydroxyapatite nanoparticles (HANPs) and simvastatin (SIM) mimicking the bone extracellular matrix (ECM) to improve bone cell proliferation and regeneration process. Indeed, the addition of PGS results in a slight increase in the average fiber diameter compared to PCL. However, the presence of HANPs in the composite nanofibers induced a greater fiber diameter distribution, without significantly changing the average fiber diameter. The in vitro drug release result revealed that the sustained release of SIM from the composite nanofiber obeying the Korsemeyer–Peppas and Kpocha models revealing a non-Fickian diffusion mechanism and the release mechanism follows diffusion rather than polymer erosion. Biomineralization assessment of the nanofibers was carried out in simulated body fluid (SBF). SEM and EDS analysis confirmed nucleation of the hydroxyapatite layer on the surface of the composite nanofibers mimicking the natural apatite layer. Moreover, in vitro studies revealed that the PCL-PGS-HA displayed better cell proliferation and adhesion compared to the control sample, hence improving the regeneration process. This suggests that the fabricated PCL-PGS-HA could be a promising future scaffold for control drug delivery and bone tissue regeneration application.

In this study, polyvinyl pyrrolidone/silica composite nanofiber adsorbents were synthesized by the electrospinning method, and their applications for adsorption of thorium ions from aqueous solution in a batch sorption process were studied. The functional groups of the composite nanofiber and its morphology were characterized by FTIR and SEM analyses. The influences of several variables such as SiO2 content, 3-aminpropyltriethoxysilane content, pH, adsorbent dosage, contact time, solution initial concentration and temperature were evaluated. The maximum adsorption capacity of thorium ions was found to be 161.3 mg/g at 45°C and pH 5. The kinetic data were analyzed by the pseudo-first-order, pseudo-second-order and double-exponential kinetic models. The Freundlich, Lanmuir and Dubinin-Radushkevich isotherm models, were applied to describe the equilibrium data. Thermodynamic parameters indicated that the thorium adsorption onto the composite nanofiber adsorbent is an endothermic and spontaneous process. The modified polyvinyl pyrrolidone/silica composite nanofiber with amine functional group is regenerated by 0.5 M HNO3/0.1 M HCl in the equal ratio solution and the adsorption capacity did not change remarkably after the five sorption-desorption cycles.

Multilayer nanofibrous scaffolds are gaining great attention in biomedical fields especially as tissue regeneration materials as well as drug delivery devices. Herein, we report the unique design of a tri-layered composite nanofiber scaffold mimicking the bone ECM for bone tissue regeneration. The tri-layered membrane consists of a superficial layer of PVA-PVAc loaded with simvastatin to initiate and improve osteogenesis process via sustained release of the drug as well as the excellent bioactivity of its blended polymers. The PCL-CA-β-tcp middle layer acts as a platform for stimulating the bio mineralization process mimicking the apatite like layer which mainly start after the first week of implantation. The final PCL layer performs as the fundamental layer to keep mechanical properties of the composite mat. The as prepared scaffolds were investigated in terms of morphology characterization, physiochemical properties, biomimetic mineralization, drug release and biocompatibility. The in vitro drug release study confirms the sustained release of simvastatin from the tri-layered membrane by obeying the Korsemeyer-Peppas, Higushi model and Kopcha model. The results demonstrate that the proposed biocompatible tri-layered scaffold will be a promising future material for bone tissue regeneration application by providing higher mineralization, enhanced cell attachment and proliferation. [ABSTRACT FROM AUTHOR]

A nanofiber was obtained by electrospinning of "dialdehyde cellulose" (periodate-oxidized cellulose, DAC) and polyvinyl alcohol (PVA), using only water as the solvent. Celluloses of four different origins were fully oxidized with sodium periodate to water-soluble DAC. Aqueous solution of DAC showed inadequate spinnability regardless of the polymer concentration and the electrospinning conditions used. Addition of PVA improved the solution's viscoelasticity and, consequently, the solution's spinnability. We examined the effects of DAC/PVA composition and electrospinning parameters on fiber morphology. Highly homogeneous nanofibers were prepared from 1:1 up to 2:1 (weight) DAC/PVA blends while samples of lower viscosity or higher relative DAC contents resulted in continuous, beaded fiber networks. Characterization of the electrospun fabrics revealed a highly crosslinked DAC structure reinforced with PVA, strongly interacting through hemiacetal bonds and hydrogen bonding. Fluorescence labeling confirmed the presence of reactive aldehyde functionalities in the electrospun web. The versatile properties of DAC as reactive material can now be imparted on electrospun fiber and nanofiber material - which was not possible so far -further widening the application scope of this interesting cellulose derivative. [ABSTRACT FROM AUTHOR]

The nanoscale heterojunctions in the nanofiber (NF) structure have been widely utilized in semiconductor metal oxide-based gas sensors to optimize the sensing characteristics. In this study, the CuO-Co 3 O 4 composite and CuO/Co 3 O 4 mixed-NFs were synthesized to compare the influence level of internal- and external- junctions within NF on the gas sensing characteristics. The gas-sensing properties of four kinds of sensors based on NFs (CuO-Co 3 O 4 composite, CuO/Co 3 O 4 mixed, pristine CuO, and pristine Co 3 O 4 NFs) were investigated in the concentration ranges of 0.1–1 ppm H 2 S reducing gas and 1–10 ppm NO 2 oxidizing gas at different working temperatures from 250 °C to 450 °C. In addition, the response/recovery times, and the detection limits of NF sensors toward the target gases were explored. The evidence confirmed that both the internal and external junctions influenced the gas sensing performances for the reducing and oxidizing gases in two opposite trends. The response of hetero-junction NF sensors was increased to H 2 S gas while reduced to NO 2 gas. Thermal fingerprint analysis using the machine learning algorithm was applied to strengthen the selection of the gases. The results confirmed the internal junction existing within NFs was mainly governing the gas sensing performance. • Electrospun CuO-Co 3 O 4 composite and CuO/Co 3 O 4 mixed-nanofibers were synthesized. • H 2 S and NO 2 gas sensing performance of fabricated nanofiber sensors investigated. • Gas response of hetero-junction NF sensors enhanced for H 2 S but reduced for NO 2. • Internal junction NFs showed the dominant influences on the gas sensing performance. • LDA algorithm was utilized to strengthen the selective detection of gases. [ABSTRACT FROM AUTHOR]

To provide adequate conditions for the regeneration of damaged bone, it is necessary to develop piezoelectric porous membranes with antioxidant and anti-inflammatory activities. In this study, composite nanofibers comprising poly(vinylidene fluoride) (PVDF) and a polyhedral oligomeric silsesquioxane⁻epigallocatechin gallate (POSS⁻EGCG) conjugate were fabricated by electrospinning methods. The resulting composite nanofibers showed three-dimensionally interconnected porous structures. Their average diameters, ranging from 936 ± 223 nm to 1094 ± 394 nm, were hardly affected by the addition of the POSS⁻EGCG conjugate. On the other hand, the piezoelectric β-phase increased significantly from 77.4% to 88.1% after adding the POSS⁻EGCG conjugate. The mechanical strength of the composite nanofibers was ameliorated by the addition of the POSS⁻EGCG conjugate. The results of in vitro bioactivity tests exhibited that the proliferation and differentiation of osteoblasts (MC3T3-E1) on the nanofibers increased with the content of POSS⁻EGCG conjugate because of the improved piezoelectricity and antioxidant and anti-inflammatory properties of the nanofibers. All results could suggest that the PVDF composite nanofibers were effective for guided bone regeneration.

In this study, composite nanofibers from a solution of polyacrylonitrile (PAN), functionalized multi-walled carbon nanotubes (f-MWCNTs), and silver nitrate (AgNO3) in dimethylsulfoxide were successfully produced by the electrospinning method. Aqueous solution of hydrazinium hydroxide was used for the chemical reduction of silver ions. The effects of the simultaneous use of carbon nanotubes (either pristine or amine-functionalized) and silver nitrate in different percentages and the application of chemical reduction on the properties of the nanocomposite nanowebs were investigated. FTIR, SEM, conductivity meter, tensile tester, XRD, and DSC were used for the characterization. Antibacterial activities of the nanocomposite nanowebs were determined against S. Aureus. Full factorial experimental design was utilized in order to be able to evaluate the contributions of the selected factors (f-MWCNT content, AgNO3 content, and application of reduction process) to the variations in ultimate tensile strength, elongation, and conductivity of the composite nanowebs. Analysis of variance (ANOVA) and multiple comparisons were carried out to evaluate the average nanofiber diameters and mechanical properties. PAN/f-MWCNTs/AgNPs nanowebs displayed enhanced conductivity and antimicrobial properties particularly when the chemical reduction process was applied. Besides they showed improved crystallinity compared with pure PAN nanofibers. While the reduction process made the highest contribution to the ultimate tensile strength, elongation, and conductivity of the nanowebs, f-MWCNT content had negligible effect on conductivity of the nanowebs. Considering all the results obtained in this study, composite nanofiber webs of PAN with 1 w% f-MWCNTs and 1 w%AgNO3 can be suggested for use as antistatic and antibacterial filaments. [ABSTRACT FROM AUTHOR]