Electrospun nanofibers-based thin film microextraction for enrichment of phthalate esters in biodegradable plastics.

In this work, a novel electrospun nanofiber (PAN/TpBD; 2,4,6-triformylphloroglucinol [Tp] and benzidine [BD]; polyacrylonitrile [PAN]) was fabricated via a facile electrospinning method and utilized as adsorbent in thin film microextraction (TFME) of phthalate esters (PAEs) (dimethyl phthalate, diethyl phthalate, diallyl phthalate, dibutyl phthalate, and dioctyl phthalate) in biodegradable plastics. The prepared PAN/TpBD combines the strong stability of nanofibers with increased exposure sites for covalent organic frameworks and enhanced interactions with the target, thus improving the enrichment effect on the target. The extraction efficiency of PAN/TpBD reached above 80%. Based on PAN/TpBD, a TFME-high-performance liquid chromatography method was established, and the experimental parameters were optimized. Under the optimal extraction conditions, the PAEs of this method varied linearly in the range of 10-10 000 µg/L with low detection limits (0.69-2.72 µg/L). The intra-day and inter-day relative standard deviation values of the PAEs were less than 8.04% and 8.73%, respectively. The adsorbent can achieve more than 80% recovery of the five targets after six times reuse. The developed method was successfully applied for the determination of trace PAEs in biodegradable plastics with recoveries ranging from 80.1% to 113.4% and relative standard deviations were less than 9.45%. The as-synthesized PAN/TpBD adsorbent exhibited great potential in PAE analysis.

Stretchable Nanofiber-Based Felt as a String Electrode for Potential Use in Wearable Glucose Biosensors.

Nanofiber technology is leading the revolution of wearable technology and provides a unique capability to fabricate smart textiles. With the novel fabrication technique of electrospinning, nanofibers can be fabricated and then manufactured into a durable conductive string for the application of smart textiles. This paper presents an electrospun nanofiber mesh-based (NF-Felt) string electrode with a conducting polymer coating for an electrochemical enzymatic glucose sensor. The surface area of a nanofiber matrix is a key physical property for enhanced glucose oxidase (GOx) enzyme binding for the development of an electrochemical biosensor. A morphological characterization of the NF-Felt string electrode was performed using scanning electron microscopy (SEM) and compared with a commercially available cotton-polyester (Cot-Pol) string coated with the same conducting polymer. The results from stress-strain testing demonstrated high stretchability of the NF-Felt string. Also, the electrochemical characterization results showed that the NF-Felt string electrode was able to detect a glucose concentration in the range between 0.0 mM and 30.0 mM with a sensitivity of 37.4 µA/mM·g and a detection limit of 3.31 mM. Overall, with better electrochemical performance and incredible flexibility, the NF-Felt-based string electrode is potentially more suitable for designing wearable biosensors for the detection of glucose in sweat.

Shape-Persistent Conductive Nerve Guidance Conduits for Peripheral Nerve Regeneration.

To solve the problems of slow regeneration and mismatch of axon regeneration after peripheral nerve injury, nerve guidance conduits (NGCs) have been widely used to promote nerve regeneration. Multichannel NGCs have been widely studied to mimic the structure of natural nerve bundles. However, multichannel conduits are prone to structural instability. Thermo-responsive shape memory polymers (SMPs) can maintain a persistent initial structure over the body temperature range. Electrical stimulation (ES), utilized within nerve NGCs, serves as a biological signal to expedite damaged nerve regeneration. Here, an electrospun shape-persistent conductive NGC is designed to maintain the persistent tubular structure in the physiological temperature range and improve the conductivity. The physicochemical and biocompatibility of these P, P/G, P/G-GO, and P/G-RGO NGCs are conducted in vitro. Meanwhile, to evaluate biocompatibility and peripheral nerve regeneration, NGCs are implanted in subcutaneous parts of the back of rats and sciatic nerves assessed by histology and immunofluorescence analyses. The conductive NGC displays a stable structure, good biocompatibility, and promoted nerve regeneration. Collectively, the shape-persistent conductive NGC (P/G-RGO) is expected to promote peripheral nerve recovery, especially for long-gap and large-diameter nerves.

Bilayer Scaffolds of PLLA/PCL/CAB Ternary Blend Films and Curcumin-Incorporated PLGA Electrospun Nanofibers: The Effects of Polymer Compositions and Solvents on Morphology and Molecular Interactions.

Tissue engineering scaffolds have been dedicated to regenerating damaged tissue by serving as host biomaterials for cell adhesion, growth, differentiation, and proliferation to develop new tissue. In this work, the design and fabrication of a biodegradable bilayer scaffold consisting of a ternary PLLA/PCL/CAB blend film layer and a PLGA/curcumin (CC) electrospun fiber layer were studied and discussed in terms of surface morphology, tensile mechanical properties, and molecular interactions. Three different compositions of PLLA/PCL/CAB-60/15/25 (TBF1), 75/10/15 (TBF2), and 85/5/10 (TBF3)-were fabricated using the solvent casting method. The electrospun fibers of PLGA/CC were fabricated using chloroform (CF) and dimethylformamide (DMF) co-solvents in 50:50 and 60:40 volume ratios. Spherical patterns of varying sizes were observed on the surfaces of all blend films-TBF1 (17-21 µm) > TBF2 (5-9 µm) > TBF3 (1-5 µm)-caused by heterogeneous surfaces inducing bubble nucleation. The TBF1, TBF2, and TBF3 films showed tensile elongation at break values of approximately 170%, 94%, and 43%, respectively. The PLGA/CC electrospun fibers fabricated using 50:50 CF:DMF had diameters ranging from 100 to 400 nm, which were larger than those of the PLGA fibers (50-200 nm). In contrast, the PLGA/CC electrospun fibers fabricated using 60:40 CF:DMF had diameters mostly ranging from 200 to 700 nm, which were larger than those of PLGA fibers (200-500 nm). Molecular interactions via hydrogen bonding were observed between PLGA and CC. The surface morphology of the bilayer scaffold demonstrated adhesion between these two solid surfaces resembling "thread stitches" promoted by hydrophobic interactions, hydrogen bonding, and surface roughness.

A noval transparent triboelectric nanogenerator as electronic skin for real-time breath monitoring.

Against the backdrop of advancements in modern multifunctional wearable electronics, there is a growing demand for simple, sustainable, and portable electronic skin (e-skin), posing significant challenges. This study aims to delineate the development of a straightforward, transparent, highly sensitive, and high power-density electronic skin based on a triboelectric nanogenerator(S-TENG), designed for harvesting human body energy and real-time monitoring of the physiological motion status. Our e-skin incorporates thermally treated polyvinylidene fluoride (PVDF) fiber membranes as the contact layer and a film of silver nanowires as the conductive electrodes. The resulting contact-separation type e-skin exhibits an impressive transparency of 80 %, along with a nice sensitivity value, capable of detecting a light touch from a 0.13 g sponge and demonstrating good working stability and breathability. Leveraging the triboelectric effect, our e-skin generates an open-circuit voltage of 301 V and a short-circuit current of 2.7 µA under an extrinsic force of 8 N over an interaction area of 4 × 4 cm2, achieving a power density up to 306 mW/m2. With its signal processing circuitry, the integrated S-TENG showcases nice energy harvesting and signal transmission capabilities. Accordingly, we contend that S-TENG has potential applications in energy capture and real-time human motion state monitoring. This research is anticipated to blaze a novel and practical trail for self-powered wearable devices and personalized health rehabilitation training regimens.

A Periosteum-Bioinspired Electrospun Janus Membrane with Antibacterial and Osteogenic Dual Function.

For a guided bone regeneration membrane, it is critical to possess osteogenic capability while inhibiting infection caused by bacteria. Inspired by the bilayer structure of the native periosteum, an electrospun Janus membrane with osteogenic and antibacterial dual-function is fabricated for guided bone regeneration. Hydrophilic moxifloxacin (MXF) and hydrophobic icariin (ICA) are loaded in the nanofibers made of a mixture of polycaprolactone and gelatin at the top and bottom layers, respectively, leading to the opposing hydrophilic/hydrophobic properties of the bilayer Janus membranes. The as-obtained Janus membrane exhibits excellent physical properties (tensile strength > 6.0 MPa) and robust biocompatibility, indicating the immense potential as a suitable replacement for the native periosteum. The membrane has a superior surface morphology and outstanding degradation performance in vitro. Besides, the rapid release of MXF and the slow release of ICA can meet the different needs of drug release rates. Only ≈30% ICA is released from the as-obtained Janus membrane after 21 d while almost 80% MXF is released. Mimicking the bilayer structure of the native periosteum, the electrospun Janus membrane containing ICA and MXF exhibits excellent comprehensive properties, which provides a promising strategy for preparing multifunctional scaffolds for tissue engineering.

Nanofiber-microwell cell culture system for spatially patterned differentiation of pluripotent stem cells in 3D.

The intricate interplay between biochemical and physical cues dictates pluripotent stem cell (PSC) differentiation to form various tissues. While biochemical modulation has been extensively studied, the role of biophysical microenvironments in early lineage commitment remains elusive. Here, we introduce a novel 3D cell culture system combining electrospun nanofibers with microfabricated polydimethylsiloxane (PDMS) patterns. This system enables the controlled formation of semispherical human induced pluripotent stem cell (hiPSC) colonies, facilitating the investigation of local mechanical stem cell niches on mechano-responsive signaling and lineage specification. Our system unveiled spatially organized RhoA activity coupled with actin-myosin cable formation, suggesting mechano-dependent hiPSC behaviors. Nodal network analysis of RNA-seq data revealed RhoA downstream regulation of YAP signaling, DNA histone modifications, and patterned germ layer specification. Notably, altering colony morphology through controlled PDMS microwell shaping effectively modulated the spatial distribution of mechano-sensitive mediators and subsequent differentiation. This study provides a cell culture platform to decipher the role of biophysical cues in early embryogenesis, offering valuable insights for material design in tissue engineering and regenerative medicine applications.

Unveiling the Dual-Enhancing Mechanisms of Kinetically Controlled Silver Nanoparticles on Piezoelectric PVDF Nanofibers for Optimized SERS Performance.

Noble metal nanoparticle (NMP)-based composite substrates have garnered significant attention as a highly promising technique for surface-enhanced Raman scattering (SERS) in diverse scientific disciplines because their remarkable ability to amplify and functionalize Raman signals has positioned them as valuable tools for molecular detection. However, optimizing the size and distribution of NMPs has not received sufficient emphasis because of challenges associated with the precise control of deposition and the modulation of reducing rates during growth. In this research, we achieved the optimized size and spatial patterns of AgNWs on electrospun poly(vinylidene fluoride) (PVDF) nanofibers by utilizing a polydopamine (PDA) layer as a mild and controllable reduction mediator, by which the size and density of the AgNWs could be relatively precisely manipulated, achieving a dense distribution of effective "hot spots". On the other hand, harnessing the inherent piezoelectric properties of the electrospun PVDF nanofibers further boosted the LSPR effect during the SERS test, forming a flexible dual-enhancing composite SERS substrate with excellent sensitivity. In addition to addressing structural aspects, exploiting synergistic systems capable of transferring external energy or forces to enhance the SERS performances presents a compelling avenue to broaden the practical applications of SERS. The dual-enhanced substrate achieved an exceptional enhancement factor (EF) of 1.05 × 108 and a low detection limit (LOD) of 10-10 M during the SERS test. This study focuses on integrating NMPs with electrospun piezoelectric polymer nanofibers to develop a dual-enhancing SERS substrate with excellent sensitivity and practicality. The findings provide valuable insights into controllably depositing NMPs on electrospun polymer fibers and hold significant implications for the development of highly sensitive and practical SERS substrates across various applications.

Amine response smartphone-based portable and intelligent polyvinyl alcohol films for real-time detection of shrimp freshness.

Food freshness monitoring is an important component in ensuring food safety for consumers and the food industry. Therefore, there is an urgent need for a portable, low-cost, and efficient detection method to determine the freshness. In this study, polyvinyl alcohol (PVA) was used as polymer carrier to prepare electrospinning film containing curcumin (Cur) and gardenia blue (GB) as intelligent indicator label on food packaging for real-time nondestructive detection of freshness of shrimp. The detection limit of ammonia response is less than or equal to 20 ppm, and the detection time is about 1 min, indicating that it has a sensitive response effect. At the same time, a smartphone application that can identify amines in response to color changes has been developed, and consumers can understand freshness by scanning the label. This study demonstrates the huge potential of smart indicator labels for food freshness monitoring.

α-Lactalbumin based scaffolds for infected wound healing and tissue regeneration.

Interruption of wound healing by multi-drug resistant-bacterial infection is a harmful issue for the worldwide health care system, and conventional treatment approaches may not resolve this issue due to antimicrobial resistance. So, there is an unmet need to develop scaffolds with intrinsic wound healing properties to combat bacterial-infected wounds. Inspired by the α-lactalbumin's (Lalb's) ability to promote collagen synthesis, we herein electrospun Lalb with cephalexin (CPL) and epigallocatechin (EP) to produce nanofibers (CE-Lalb NFs) to solve this issue. The CE-Lalb NFs were prepared using the electrospinning technique and subjected to physicochemical characterizations, in vitro, and in vivo assessments. The CE-Lalb NFs promoted fibroblast migration, proliferation, and collagen synthesis, while CPL/EP annihilated MRSA and E. coli infections. Physicochemical characterizations proved the successful fabrication and doping of CE-Lalb NFs. Antimicrobial assays and fractional inhibitory concentration index (FICI) declared synergistic antibacterial activity of CE-Lalb NFs against MRSA and E. coli. The in vivo and immunohistochemical data evidenced its exceptional potential for wound healing, promoting growth factor, collagen synthesis, and reduced scar formation. The presence of mature collagen, fewer inflammatory cytokines, increased expression of blood vessels, and low expression of IL-6 at the wound site support in vitro and in vivo results. In our view, the tailored scaffold is the next step for personalized wound dressings that could meet patients with infected wounds' unmet needs by the subscription of noninvasive and easily navigable therapeutic options.

Nanofiber-based delivery of evodiamine impedes malignant properties of intrahepatic cholangiocarcinoma cells by targeting HDAC4 and restoring TPM1 transcription.

The electrospun nanofiber system is correlated with high efficacy of drug delivery. This study aims to investigate the effect of nanofiber-based delivery of evodiamine, an indole alkaloid derived from Rutaceae plants Evodia rutaecarpa (Juss.) Benth, on intrahepatic cholangiocarcinoma (ICC), as well as to explore the molecular mechanisms. An electrospun nanofiber system carrying evodiamine was generated. Compared to evodiamine treatment alone, the nano-evodiamine exhibited more pronounced effects on suppressing proliferation, colony formation, invasiveness, migration, apoptosis resistance, cell cycle progression, and in vivo tumorigenesis of two ICC cell lines (HUCC-T1 and RBE). ICC cells exhibited increased expression of histone deacetylase 4 (HDAC4) while decreased tropomyosin 1 (TPM1). HDAC4 suppressed TPM1 expression by removing H3K9ac modifications from its promoter. Nano-evodiamine reduced HDAC4 protein levels in ICC cells, thus promoting transcription and expression of TPM1. Either overexpression of HDAC4 or downregulation of TPM1 negated the tumor-suppressive effects of nano-evodiamine. Collectively, this study demonstrates that the electrospun nanofiber system enhances the efficiency of evodiamine. Additionally, evodiamine suppresses the malignant properties of ICC cells. The findings may provide fresh insights into the application of electrospun nanofiber system for drug delivery and the effects of evodiamine on tumor suppression.

The Use of Photoactive Polymeric Nanoparticles and Nanofibers to Generate a Photodynamic-Mediated Antimicrobial Effect, with a Special Emphasis on Chronic Wounds.

This review is concerned with chronic wounds, with an emphasis on biofilm and its complicated management process. The basics of antimicrobial photodynamic therapy (PDT) and its underlying mechanisms for microbial eradication are presented. Intrinsically active nanocarriers (polydopamine NPs, chitosan NPs, and polymeric micelles) that can further potentiate the antimicrobial photodynamic effect are discussed. This review also delves into the role of photoactive electrospun nanofibers, either in their eluting or non-eluting mode of action, in microbial eradication and accelerating the healing of wounds. Synergic strategies to augment the PDT-mediated effect of photoactive nanofibers are reviewed.

Experimental and theoretical study of improved mesoporous titanium dioxide perovskite solar cell: The impact of modification with graphene oxide.

The present study serves experimental and theoretical analyses in developing a hybrid advanced structure as a photolysis, which is based on electrospun Graphene Oxide-titanium dioxide (GO-TiO2) nanofibers as an electron transfer material (ETMs) functionalized for perovskite solar cell (PVSCs) with GO. The prepared ETMs were utilized for the synthesis of mixed-cation (FAPbI3)0.8(MAPbBr3)0.2. The effect of GO on TiO2 and their chemical structure, electronic and morphological characteristic were investigated and discussed. The elaborated device, namely ITO/Bl-TiO2/3 wt% GO-TiO2/(FAPbI3)0.8(MAPbBr3)0.2/spiro-MeTAD/Pt, displayed 20.14% disposition and conversion solar energy with fill factor (FF) of 1.176%, short circuit current density (Jsc) of 20.56 mA/cm2 and open circuit voltage (VOC) 0.912 V. The obtained efficiency is higher than titanium oxide (18.42%) and other prepared GO-TiO2 composite nanofibers based ETMs. The developed materials and device would facilitate elaboration of advanced functional materials and devices for energy storage applications.

Fucoidan loaded PVA/Dextran blend electrospun nanofibers for the effective wound healing.

Chronic wounds have become a serious global health issue. In this study, we investigated the effect of increasing fucoidan (FD) concentration on the characteristics of nanofibers and their wound healing potential at in vitro as well as in vivo level. The results showed that increasing FD content (0.25 to 1 %) led to an significant increase in nanofiber diameter (487.7 ± 125.39 to 627.9 ± 149.78 nm), entrapment efficiency (64.26 ± 2.6 to 94.9 ± 3.1 %), and water uptake abilities (436.5 ± 1.2 to 679.7 ± 11.3 %). However, the in vitro biodegradation profile decreased with an increase in FD concentration. Water vapor transmission rate analysis showed that it was within the standard range for all FD concentrations. Nanofibers with 1 % PVA/DX/FD exhibited slow-release behavior, suggesting prolonged FD availability at the wound site. In vivo studies in rats with full-thickness wounds demonstrated that applying 1 % FD-enriched PVA/DEX nanofibers significantly (p < 0.0001) improved mean wound area closure. These findings suggest that FD-enriched nanofibers have immense potential as a wound dressing material in future if explored further.

Development and characterization of a non-enzymatic electrochemical biosensor for rapid determination of sorbent-based extracted trazodone and doxepin in complicated samples.

BACKGROUND: Given the importance of achieving optimal therapeutical concentration in patients treated with antidepressants, this study investigates a novel technique for the simultaneous determination of trazodone (TRZ) and doxepin (DOX) in human plasma and serum samples for the first time. RESULTS: To achieve simultaneous determination of two antidepressants, TRZ and DOX, a novel detection system was designed: a non-enzymatic voltammetric biosensor based on boron-reduced graphene oxide/manganese oxide nanoparticles (GCE/B-rGO/MnO NPs). The detection was accomplished after pre-concentration and extraction trace amounts of the analytes using the thin film-solid phase microextraction (TF-SPME) technique, which employed polyvinyl alcohol/polyvinyl acetate/copper oxide nanoparticles (PVA/PVAc/CuO NPs) electrospun nanofibers. The successful preparation of composite nanofibers and modified electrodes was confirmed using the evaluation of field emission-scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX). Also, the composite nanofibers were characterized with attenuated total reflectance-Fourier transform-infrared (ATR-FT-IR) and X-ray diffraction (XRD). In the solution of TRZ and DOX, under optimum experimental conditions, the linear dynamic ranges (LDRs) were 0.1-20.0 µmol L-1 and 0.5-27.0 µmol L-1, respectively. Also, the limit of detection (LOD) values of TRZ and DOX were 0.032 and 0.150 µmol L-1. SIGNIFICANCE: PVAc acts as a cross-linking agent for PVA, and their mixture is effective for sample preparation and pre-concentration of analytes in complex matrices. Also, adding CuO NPs to this polymeric mixture enhanced the adsorption efficiency. Taking advantage of the high surface area of MnO NPs and the high electrical conductivity of B-rGO, and considering the superiority of their simultaneous utilization, the constructed electrochemical biosensor is both cost-effective and rapid. It demonstrates excellent stability, repeatability, and sensitivity for the simultaneous determination of TRZ and DOX under optimal conditions. This biosensor, the first of its kind, is specifically designed for the simultaneous determination of TRZ and DOX in human plasma and serum samples, representing a significant advancement in biosensing technology.

Adhesive Antibacterial Moisturizing Nanostructured Skin Patch for Sustainable Development of Atopic Dermatitis Treatment in Humans.

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a complex etiology that lacks effective treatment. The therapeutic goals include alleviating symptoms, such as moisturizing and applying antibacterial and anti-inflammatory medications. Hence, there is an urgent need to develop a patch that effectively alleviates most of the AD symptoms. In this study, we employed a "green" cross-linking approach of poly(vinyl alcohol) (PVA) using glycerol, and we combined it with polyacrylonitrile (PAN) to fabricate core-shell (CS) nanofibers through electrospinning. Our designed structure offers multiple benefits as the core ensures controlled drug release and increases the strength of the patch, while the shell provides skin moisturization and exudate absorption. The efficient PVA cross-linking method facilitates the inclusion of sensitive molecules such as fermented oils. In vitro studies demonstrate the patches' exceptional biocompatibility and efficacy in minimizing cell ingrowth into the CS structure containing argan oil, a property highly desirable for easy removal of the patch. Histological examinations conducted on an ex vivo model showed the nonirritant properties of developed patches. Furthermore, the eradication of Staphylococcus aureus bacteria confirms the potential use of CS nanofibers loaded with argan oil or norfloxacin, separately, as an antibacterial patch for infected AD wounds. In vivo patch application studies on patients, including one with AD, demonstrated ideal patches' moisturizing effect. This innovative approach shows significant promise in enhancing life quality for AD sufferers by improving skin hydration and avoiding infections.

Functionalized electrospun nanofibers to enhance ß-Galactosidase immobilization and catalytic activity for efficient galactooligosaccharide synthesis.

This study aimed to immobilize ß-galactosidase (ß-GAL) into enhanced polystyrene (PS) electrospun nanofiber membranes (ENMs) with functionalized graphene oxide (GO). Initially, GO sheets were functionalized by salinization with 3-aminopropyl triethoxysilane (APTES). Then the ENMs (PS, PS/GO, and PS/GO-APTES) were prepared and characterized. Then, the ß-GAL was immobilized in the different ENMs to produce the ß-GAL-bound nanocomposites (PS-GAL, PS/GO-GAL, and PS/GO-APTES-GAL). Immobilization of ß-GAL into PS/GO-APTES significantly improved enzyme adsorption by up to 87 %. Also, PS/GO-APTES-GAL improved the enzyme activity, where the highest enzyme activity was obtained at enzyme concentrations of 4 mg/L, 50 °C, and pH 4.5. Likewise, the storage stability and reusability of immobilized ß-GAL were improved. Furthermore, this process led to enhanced catalytic behavior and transgalactosylation efficiency, where GOS synthesis (72 %) and lactose conversion (81 %) increased significantly compared to the free enzyme. Overall, the immobilized ß-GAL produced in this study showed potential as an effective biocatalyst in the food industry.

Electrospun Fiber Membrane with the Dual Affinity of Chelation and Covalent Interactions for the Efficient Enrichment of Glycoproteins.

As important biomarkers of many diseases, glycoproteins are of great significance to biomedical science. It is essential to develop efficient glycoprotein enrichment platforms and investigate their adsorption mechanism. In this work, a conspicuous enrichment strategy for glycoproteins was developed by using an electrospun fiber membrane wrapped with polydopamine (PDA) and modified with 3-aminophenylboronic acid and nickel ions, named PAN/DA@PDA@APBA/Ni. The enrichment characteristics of PAN/DA@PDA@APBA/Ni toward glycoproteins were explored through adsorption behavior. Thanks to the existence of two sites of interaction (metal ion chelation and boronate affinity), PAN/DA@PDA@APBA/Ni exhibited significant enrichment capacity for glycoproteins, ovalbumin (604.6 mg/g), and human immunoglobulin G (331.0 mg/g). The adsorption kinetic results of glycoprotein ovalbumin on PAN/DA@PDA@APBA/Ni conform to the pseudo-first-order kinetic model in the first adsorption stage, while the second half adsorption stage is more in line with the pseudo-second-order kinetic model. Moreover, the physical characteristics of PAN/DA@PDA@APBA/Ni and subsequent adsorption experiments on electrospun fiber modified with only phenylboronic acid or nickel ions both confirmed two sites of interaction (metal ion chelation and boronate affinity, respectively). Furthermore, a stepwise elution method with dual-affinity interaction was designed and successfully applied to enrich glycoproteins in real biological samples. This work provides an idea for sample pretreatment, especially for the design of dual-affinity materials in glycoproteins enrichment.

Incorporation of Cu-TATAB metal-organic framework within polyurethane nanocomposite for enhanced thin film microextraction of some chlorinated pesticides.

In this research, electrospun nanofibers based on copper-based metal organic framework (MOF)/polyurethane (PU) were prepared in order to achieve an applicable and superior extractive phase. The incorporation of MOF, in the synthesized nanocomposite contributed to the enhanced sorption efficiency. The prepared sorbent was implemented for the thin film microextraction (TFME) of target compounds with subsequent quantification using gas chromatography-mass spectrometry (GC-MS). To obtain the maximum efficiency of the synthesized sorbent, the influential parameters on extraction and desorption steps, including the MOF percentage in nanocomposite, desorption solvent type and its volume, desorption time, solution ionic strength and extraction time were optimized. After method development, the linear dynamic range (0.02-700 µg L-1), limits of detection (LODs) (0.005-0.1 µg L-1) and limits of quantification (LOQs))0.02-0.33 µg L-1(were calculated. The relative standard deviations values for intra-day and inter-day analysis were found to be in the range of 4.3-5.3 % and 6.2-8.1 %, respectively. The developed method was validated for the TFME of model organochlorine (OC) pesticide residues in fish, soil and water samples. the recovery values for the spiked samples at two concentration levels of 5 and 100 µg l-1 were found in the range of 72-110 %.

The urchin-like gold nanoparticles/poly(ε-caprolactone)/chitosan electrospun nanofibers for antibacterial active packaging.

Inspired by the natural antimicrobial effect of the topographical features of insect wings, this study prepared urchin-like gold nanoparticles (UGNPs) and deposited them on poly(ε-caprolactone) (PCL)/chitosan (P/C) electrospun nanofiber film to strengthen antibacterial activities of this active packaging. Results showed that L-Dopa was a suitable reducing agent to prepare UGNPs, and the spine length of UGNPs increased from 21.23 to 35.83 nm as the molar ratio of L-Dopa:HAuCl4 increased from 1 to 3. As the nanofiber film was immersed in the nanoparticle solution for a longer time, the UGNP content in P/C nanofibers increased. As the spine length of UGNPs and depositing UGNP content increased, the inhibition rate against S. aureus and E. coli. of P/C nanofiber film increased. In addition, P/C nanofiber film deposited with UGNPs also exhibited good thermal stability, hydrophilicity, mechanical strength, and water vapor permeability, exhibiting its potential as an antibacterial active packaging.