Spontaneous formation of nanoparticles on electrospun nanofibres

Electrospun nanofibrous membranes meet antibacterial nanomaterials: From preparation strategies to biomedical applications

Electrospun nanofibrous membranes (eNFMs) have been extensively developed for bio-applications due to their structural and compositional similarity to the natural extracellular matrix. However, the emergence of antibiotic resistance in bacterial infections significantly impedes the further development and applications of eNFMs. The development of antibacterial nanomaterials substantially nourishes the engineering design of antibacterial eNFMs for combating bacterial infections without relying on antibiotics. Herein, a comprehensive review of diverse fabrication techniques for incorporating antibacterial nanomaterials into eNFMs is presented, encompassing an exhaustive introduction to various nanomaterials and their bactericidal mechanisms. Furthermore, the latest achievements and breakthroughs in the application of these antibacterial eNFMs in tissue regenerative therapy, mainly focusing on skin, bone, periodontal and tendon tissues regeneration and repair, are systematically summarized and discussed. In particular, for the treatment of skin infection wounds, we highlight the antibiotic-free antibacterial therapy strategies of antibacterial eNFMs, including (i) single model therapies such as metal ion therapy, chemodynamic therapy, photothermal therapy, and photodynamic therapy; and (ii) multi-model therapies involving arbitrary combinations of these single models. Additionally, the limitations, challenges and future opportunities of antibacterial eNFMs in biomedical applications are also discussed. We anticipate that this comprehensive review will provide novel insights for the design and utilization of antibacterial eNFMs in future research.

On-Demand Bioactivation of Inert Materials With Plasma-Polymerized Nanoparticles

Conventional gas plasma treatments are crucial for functionalizing materials in biomedical applications, but have limitations hindering their broader use. These methods require exposure to reactive media under vacuum conditions, rendering them unsuitable for substrates that demand aqueous environments, such as proteins and hydrogels. In addition, complex geometries are difficult to treat, necessitating extensive customization for each material and shape. To address these constraints, an innovative approach employing plasma polymer nanoparticles (PPN) as a versatile functionalization tool is proposed. PPN share similarities with traditional plasma polymer coatings (PPC) but offer unique advantages: compatibility with aqueous systems, the ability to modify complex geometries, and availability as off-the-shelf products. Robust immobilization of PPN on various substrates, including synthetic polymers, proteins, and complex hydrogel structures is demonstrated in this study. This results in substantial improvements in surface hydrophilicity. Materials functionalization with arginylglycylaspartic acid (RGD)-loaded PPN significantly enhances cell attachment, spreading, and substrate coverage on inert scaffolds compared to passive RGD coatings. Improved adhesion to complex geometries and subsequent differentiation following growth factor exposure is also demonstrated. This research introduces a novel substrate functionalization approach that mimics the outcomes of plasma coating technology but vastly expands its applicability, promising advancements in biomedical materials and devices.

Colloidal Templating in Catalyst Design for Thermocatalysis

Conventional catalyst preparative methods commonly entail the impregnation, precipitation, and/or immobilization of nanoparticles on their supports. While convenient, such methods do not readily afford the ability to control collective ensemble-like nanoparticle properties, such as nanoparticle proximity, placement, and compartmentalization. In this Perspective, we illustrate how incorporating colloidal templating into catalyst design for thermocatalysis confers synthetic advantages to facilitate new catalytic investigations and augment catalytic performance, focusing on three colloid-templated catalyst structures: 3D macroporous structures, hierarchical macro-mesoporous structures, and discrete hollow nanoreactors. We outline how colloidal templating decouples the nanoparticle and support formation steps to devise modular catalyst platforms that can be flexibly tuned at different length scales. Of particular interest is the raspberry colloid templating (RCT) method which confers high thermomechanical stability by partially embedding nanoparticles within its support, while retaining high levels of reactant accessibility. We illustrate how the high modularity of the RCT approach allows one to independently control collective nanoparticle properties, such as nanoparticle proximity and localization, without concomitant changes to other catalytic descriptors that would otherwise confound analyses of their catalytic performance. We next discuss how colloidal templating can be employed to achieve spatially disparate active site functionalization while directing reactant transport within the catalyst structure to enhance selectivity in multistep catalytic cascades. Throughout this Perspective, we highlight developments in advanced characterization that interrogate transport phenomena and/or derive new insights into these catalyst structures. Finally, we offer our outlook on the future roles, applications, and challenges of colloidal templating in catalyst design for thermocatalysis.

Quantum Dots on a String: In Situ Observation of Branching and Reinforcement Mechanism of Electrospun Fibers

Immobilization of quantum dots (QDs) on fiber surfaces has emerged as a robust approach for preserving their functional characteristics while mitigating aggregation and instability issues. Despite the advancement, understanding the impacts of QDs on jet-fiber evolution during electrospinning, QDs-fiber interface, and composites functional behavior remains a knowledge gap. The study adopts a high-speed imaging methodology to capture the immobilization effects on the QDs-fiber matrix. In situ observations reveal irregular triangular branches within the QDs-fiber matrix, exhibiting distinctive rotations within a rapid timeframe of 0.00667 ms. The influence of FeQDs on Taylor cone dynamics and subsequent fiber branching velocities is elucidated. Synthesis phenomena are correlated with QD-fiber's morphology, crystallinity, and functional properties. PAN-FeQDs composite fibers substantially reduced (50-70%) nano-fibrillar length and width while their diameter expanded by 17%. A 30% enhancement in elastic modulus and reduction in adhesion force for PAN-FeQDs fibers is observed. These changes are attributed to chemical and physical intertwining between the FeQDs and the polymer matrix, bolstered by the shifts in the position of C≡N and C═C bonds. This study provides valuable insights into the quantum dot-fiber composites by comprehensively integrating and bridging jet-fiber transformation, fiber structure, nanomechanics, and surface chemistry.

"Nano in Nano"-Incorporation of ZnO Nanoparticles into Cellulose Acetate-Poly(Ethylene Oxide) Composite Nanofibers Using Solution Blow Spinning

In this work, the preparation and characterization of composites from cellulose acetate (CA)-poly(ethylene oxide) (PEO) nanofibers (NFs) with incorporated zinc oxide nanoparticles (ZnO-NPs) using solution blow spinning (SBS) is reported. CA-PEO nanofibers were produced by spinning solution that contained a higher CA-to-PEO ratio and lower (equal) CA-to-PEO ratio. Nanoparticles were added to comprise 2.5% and 5% of the solution, calculated on the weight of the polymers. To have better control of the SBS processing conditions, characterization of the spinning suspensions is carried out, which reveals a decrease in viscosity (two- to eightfold) upon the addition of NPs. It is observed that this variation of viscosity does not significantly affect the mean diameters of nanofibers, but does affect the mode of the nanofibers' size distribution, whereby lower viscosity provides thinner fibers. FESEM-EDS confirms ZnO NP encapsulation into nanofibers, specifically into the CA component based on UV-vis studies, since the release of ZnO is not detected for up to 5 days in deionized water, despite the significant swelling of the material and accompanied dissolution of water-soluble PEO. Upon the dissolution of CA nanofibers into acetone, immediate release of ZnO is detected, both visually and by spectrometer. ATR-FTIR studies reveal interaction of ZnO with the CA component of composite nanofibers. As ZnO nanoparticles are known for their bioactivity, it can be concluded that these CA-PEO-ZnO composites are good candidates to be used in filtration membranes, with no loss of incorporated ZnO NPs or their release into an environment.

Antimicrobial Clothing Based on Electrospun Fibers with ZnO Nanoparticles

There has been a surge in interest in developing protective textiles and clothes to protect wearers from risks such as chemical, biological, heat, UV, pollution, and other environmental factors. Traditional protective textiles have strong water resistance but lack breathability and have a limited capacity to remove water vapor and moisture. Electrospun fibers and membranes have shown enormous promise in developing protective materials and garments. Textiles made up of electrospun fibers and membranes can provide thermal comfort and protection against a wide range of environmental threats. Because of their multifunctional properties, such as semi-conductivity, ultraviolet absorption, optical transparency, and photoluminescence, their low toxicity, biodegradability, low cost, and versatility in achieving diverse shapes, ZnO-based nanomaterials are a subject of increasing interest in the current review. The growing uses of electrospinning in the development of breathable and protective textiles are highlighted in this review.

Stable and large-scale organic-inorganic halide perovskite nanocrystal/polymer nanofiber films prepared via a green in situ fiber spinning chemistry method

Organic-inorganic halide perovskite nanocrystals (PNCs) have shown great advantages in recent years due to their tunable emission wavelengths, narrow full-width at half-maximum (FWHM) and high photoluminescence quantum yield (PLQY). However, PNCs still face the challenges of poor stability, difficulty in processing and generation of heavy metal wastes; therefore, it is necessary to develop a green synthetic method to prepare PNCs. Here, we present for the first time a facile fiber spinning chemistry (FSC) method for the rapid preparation of organic-inorganic halide PAN/MAPbX₃ (MA = CH₃NH₃, X = Cl, Br and I) nanofiber films at room temperature. The FSC process utilizes spinning fibers as the reactor, and polymer solidification and the in situ generation of PNCs occur simultaneously with solvent evaporation during the spinning process. This method not only achieves a continuous large-scale preparation of PNC/polymer nanofiber films but also avoids the generation of heavy metal waste. The organic-inorganic halide PAN/MAPbX₃ nanofiber films fabricated by FSC demonstrated tunable emission in the range of 464-612 nm and PLQY of up to 58%, and the fluorescence intensity remained essentially unchanged after 90 days of storage in the atmospheric environment. Interestingly, we successfully prepared high-efficiency white light-emitting diodes (WLEDs) and wide color gamut liquid crystal displays (LCDs) with a color gamut of 116.1% using PAN/MAPbBr₃ nanofiber films as fluorescence conversion materials. This study provides a novel way to construct high-performance PNC/polymer fiber composites on a large scale.

Comparison of Nozzle-Based and Nozzle-Free Electrospinning for Preparation of Fast-Dissolving Nanofibers Loaded with Ciprofloxacin

The study aimed to prepare ciprofloxacin-loaded polyvinylpyrrolidone electrospun nanofibers for oral drug delivery, using a conventional nozzle-based and a lab-built nozzle-free electrospinning equipment. To produce nanofibers, electrospinning is the process most often used. However, from the industry’s point of view, conventional electrospinning does not have sufficiently high productivity. By omitting the nozzle, productivity can be increased, and so the development of nozzle-free processes is worthwhile. In this study, a solution of ciprofloxacin and polyvinylpyrrolidone was electrospun under similar conditions, using both single-nozzle and nozzle-free methods. The two electrospinning methods were compared by investigating the morphological and physicochemical properties, homogeneity, in vitro drug release, and cytotoxicity. The stability of the nanofibers was monitored from different aspects in a 26 month stability study. The results showed that the use of the nozzle-free electrospinning was preferable due to a higher throughput, improved homogeneity, and the enhanced stability of nanofiber mats, compared to the nozzle-based method. Nevertheless, fast dissolving nanofibers loaded with poorly water-soluble ciprofloxacin were produced by both electrospinning methods. The beneficial properties of these nanofibers can be exploited in innovative drug development; e.g., nanofibers can be formulated into orodispersible films or per os tablets.

Selective Separation Catalysis Membrane for Highly Efficient Water and Soil Decontamination via a Persulfate-Based Advanced Oxidation Process

The application of sulfate radical advanced oxidation for organic pollutant removal has been hindered by some shortages such as the recycling difficulty of a powered catalyst, the low utilization efficiency of oxidants, and the secondary pollution (including soil acidification) after reaction. Herein, we fabricate a selective separation catalysis membrane (SSCM) for a highly efficient and environment-friendly persulfate-based advanced oxidation process. The SSCM comprises a top polydimethylsiloxane layer which is selectively penetrable to hydrophobic organic pollutants, followed by a catalyst layer with a magnetic nitrogen-doped porous carbon material, targeting the advanced oxidation of the selected pollutants. Compared with the catalyst in powder form, such SSCM devices significantly reduced the dosage of peroxymonosulfate by more than 40% and the catalyst dosage by 97.8% to achieve 80% removal of phenol with the coexistence of 20 mg L^-1 humic acid (HA). The SSCM can extract target pollutants while rejecting HA more than 91.43% for 100 h. The pH value in the receiving solution demonstrated a significant reduction from 7.01 to 3.00. In comparison, the pH value in the feed solution varied from 6.05 to a steady 4.59. The results can be ascribed to the specific functionality for the catalyst anchored, natural organic matter isolation, and reaction compartmentation provided by SSCMs. The developed SSCM technology is beneficial for catalysts reused in remediation practices, saving oxidant dosage, and avoiding acidification of soil and water, thus having tremendous application potential.

Polymer-Based Nanofiber-Nanoparticle Hybrids and Their Medical Applications

The search for higher-quality nanomaterials for medicinal applications continues. There are similarities between electrospun fibers and natural tissues. This property has enabled electrospun fibers to make significant progress in medical applications. However, electrospun fibers are limited to tissue scaffolding applications. When nanoparticles and nanofibers are combined, the composite material can perform more functions, such as photothermal, magnetic response, biosensing, antibacterial, drug delivery and biosensing. To prepare nanofiber and nanoparticle hybrids (NNHs), there are two primary ways. The electrospinning technology was used to produce NNHs in a single step. An alternate way is to use a self-assembly technique to create nanoparticles in fibers. This paper describes the creation of NNHs from routinely used biocompatible polymer composites. Single-step procedures and self-assembly methodologies are used to discuss the preparation of NNHs. It combines recent research discoveries to focus on the application of NNHs in drug release, antibacterial, and tissue engineering in the last two years.

Drug delivery to the anterior segment of the eye: A review of current and future treatment strategies

Research in the development of ophthalmic drug formulations and innovative technologies over the past few decades has been directed at improving the penetration of medications delivered to the eye. Currently, approximately 90% of all ophthalmic drug formulations (e.g. liposomes, micelles) are applied as eye drops. The major challenge of topical eye drops is low bioavailability, need for frequent instillation due to the short half-life, poor drug solubility, and potential side effects. Recent research has been focused on improving topical drug delivery devices by increasing ocular residence time, overcoming physiological and anatomical barriers, and developing medical devices and drug formulations to increase the duration of action of the active drugs. Researchers have developed innovative technologies and formulations ranging from sub-micron to macroscopic size such as prodrugs, enhancers, mucus-penetrating particles (MPPs), therapeutic contact lenses, and collagen corneal shields. Another approach towards the development of effective topical drug delivery is embedding therapeutic formulations in microdevices designed for sustained release of the active drugs. The goal is to optimize the delivery of ophthalmic medications by achieving high drug concentration with prolonged duration of action that is convenient for patients to administer.

A Review: Optimization for Poly(glycerol sebacate) and Fabrication Techniques for Its Centered Scaffolds

Poly(glycerol sebacate) (PGS), an emerging promising thermosetting polymer synthesized from sebacic acid and glycerol, has attracted considerable attention due to its elasticity, biocompatibility, and tunable biodegradation properties. But it also has some drawbacks such as harsh synthesis conditions, rapid degradation rates, and low stiffness. To overcome these challenges and optimize PGS performance, various modification methods and fabrication techniques for PGS-based scaffolds have been developed in recent years. Outlining the current modification approaches of PGS and summarizing the fabrication techniques for PGS-based scaffolds are of great importance to accelerate the development of new materials and enable them to be appropriately used in potential applications. Thus, this review comprehensively overviews PGS derivatives, PGS composites, PGS blends, processing for PGS-based scaffolds, and their related applications. It is envisioned that this review could instruct and inspire the design of the PGS-based materials and facilitate tissue engineering advances into clinical practice.

Composite Poly(vinyl alcohol)-Based Nanofibers Embedding Differently-Shaped Gold Nanoparticles: Preparation and Characterization

Poly(vinyl alcohol) nanofibrous mats containing ad hoc synthesized gold nanostructures were prepared via a single-step electrospinning procedure and investigated as a novel composite platform with several potential applications. Specifically, the effect of differently shaped and sized gold nanostructures on the resulting mat physical-chemical properties was investigated. In detail, nearly spherical nanoparticles and nanorods were first synthesized through a chemical reduction of gold precursors in water by using (hexadecyl)trimethylammonium bromide as the stabilizing agent. These nanostructures were then dispersed in poly(vinyl alcohol) aqueous solutions to prepare nanofibrous mats, which were then stabilized via a humble thermal treatment able to enhance their thermal stability and water resistance. Remarkably, the nanostructure type was proven to influence the mesh morphology, with the small spherical nanoparticles and the large nanorods leading to thinner well defined or bigger defect-rich nanofibers, respectively. Finally, the good mechanical properties shown by the prepared composite mats suggest their ease of handleability thereby opening new perspective applications.

Design and development of a nozzle-free electrospinning device for the high-throughput production of biomaterial nanofibers

This technical note provides a step-by-step guide for the design and construction of a temperature-controlled nozzle-free electrospinning device. The equipment uses a rotating mandrel partially immersed within a polymer solution to produce fibers in an upward motion by inducing the formation of multiple Taylor cones and subsequently multi-jetting out of an electrified open surface. Free-surface electrospinning can overcome limitations and drawbacks associated with single and multi-nozzle spinneret configurations, such as low yield, limited production capacity, nonuniform electric field distribution, and clogging. Most importantly, this lab-scaled high-throughput device can provide an alternative economical route for needleless electrospinning research, in contrast to the high costs associated with industrially available upscaling equipment. Among the device's technical specifications, a key feature is a cryo-collector mandrel, capable of collecting fibers in sub-zero temperatures, which can induce ultra-porous nanostructures, wider pores, and subsequent in-depth penetration of cells. A multi-channel gas chamber allows the conditioning of the atmosphere, temperature, and airflow, while the chamber's design averts user exposure to the high-voltage components. All the Computer-Aided Design (CAD) files and point-by-point assembly instructions, along with a list of the materials used, are provided.

In Vitro Drug Release, Permeability, and Structural Test of Ciprofloxacin-Loaded Nanofibers

Nanofibers of the poorly water-soluble antibiotic ciprofloxacin (CIP) were fabricated in the form of an amorphous solid dispersion by using poly(vinyl pyrrolidone) as a polymer matrix, by the low-cost electrospinning method. The solubility of the nanofibers as well as their in vitro diffusion were remarkably higher than those of the CIP powder or the physical mixture of the two components. The fiber size and morphology were optimized, and it was found that the addition of the CIP to the electrospinning solution decreased the nanofiber diameter, leading to an increased specific surface area. Structural characterization confirmed the interactions between the drug and the polymer and the amorphous state of CIP inside the nanofibers. Since the solubility of CIP is pH-dependent, the in vitro solubility and dissolution studies were executed at different pH levels. The nanofiber sample with the finest morphology demonstrated a significant increase in solubility both in water and pH 7.4 buffer. Single medium and two-stage biorelevant dissolution studies were performed, and the release mechanism was described by mathematical models. Besides, in vitro diffusion from pH 6.8 to pH 7.4 notably increased when compared with the pure drug and physical mixture. Ciprofloxacin-loaded poly(vinyl pyrrolidone) (PVP) nanofibers can be considered as fast-dissolving formulations with improved physicochemical properties.

The Drug-Loaded Electrospun Poly(ε-Caprolactone) Mats for Therapeutic Application

Diclofenac sodium salt (DSS)-loaded electrospun nanofiber mats on the base of poly(ε-caprolactone) (PCL) were investigated as biocompatible nanofibrous mats for medical applications with the ability to inhibit bacterial infections. The paper presents the characteristics of fibrous mats made by electrospinning and determines the effect of medicament on the fiber morphology, chemical, mechanical and thermal properties, as well as wettability. PCL and DSS-loaded PCL nanofibrous mats were characterized using scanning electron microscopy, transmission electron microscopy, attenuated total reflectance-Fourier transform infrared spectrometry, dynamic mechanical analysis, and contact angle measurements. Electron paramagnetic resonance measurements confirmed the lifetime of DSS before and after application of high voltage during the electrospinning process. In vitro biocompatibility was studied, and it was proved to be of good viability with ~92% of the diploid human cells culture line composed of lung fibroblast (MRC 5) after 48 h of incubation. Moreover, the significant activity of DSS-loaded nanofibers against cancer cells, Ca Ski and HeLa, was established as well. It was shown that 12.5% (m/V) is the minimal concentration for antibacterial activity when more than 99% of Escherichia coli (Gram-negative) and 99% of Staphylococcus aureus (Gram-positive) have been exterminated.

Proton transport mechanism and pathways in the superprotonic phase of M3H(AO4)2 solid acids from ab initio molecular dynamics simulations

The proton transport mechanism in superprotonic phases of solid acids has been a subject of experimental and theoretical studies for a number of years. Despite this, details of the mechanism still need further clarification. In particular in the M3H(AO4)2 family of crystals, where M = NH4, K, Rb, Cs, and A = S, Se, the proton diffusion is mostly considered in the (001) plane, whereas it is relatively high in the [001] direction as well. In this paper, we report the results of our ab initio molecular dynamics simulations of the Cs3H(SeO4)2 superprotonic phase and propose an atomic-level mechanism of proton transport and pathways both in the (001) plane and along the [001] direction. It turned out that structural configurations formed by hydrogen-bonded tetrahedral anions during the proton diffusion are more complicated and diverse than those considered so far in the literature. Our predicted values of the proton conductivity and activation energy agree well with available experimental data. This validates the reliability of the computational results obtained.

Formulation of Orally Disintegrating Films as an Amorphous Solid Solution of a Poorly Water-Soluble Drug

The objective of the present study was to develop an orally disintegrating film (ODF) for a poorly water-soluble drug, phenytoin (PHT), using the cosolvent solubilization technique to achieve the amorphization of the drug, followed by the preparation of ODFs. Eleven formulations were prepared with different polymers, such as polyvinyl alcohol (PVA) and high methoxyl pectin (HMP) by the solvent casting method. The prepared films were subjected to characterization for weight variations, thickness, surface pH, disintegration time and mechanical strength properties. Then, differential scanning calorimetry, X-ray diffraction analysis and the drug release patterns of the selected films were evaluated. Among the prepared formulations, the formulation composed of 1% w/w of PVA, 0.04% w/w of sodium starch glycolate with polyethylene glycol 400, glycerin and water as cosolvents (PVA-S4) showed promising results. The physical appearance and mechanical strength properties were found to be good. The PVA-S4 film was clear and colorless with a smooth surface. The surface pH was found to be around 7.47 and the in vitro disintegration time was around 1.44 min. The drug content of the PVA-S4 film was 100.27%. X-ray diffractometry and thermal analysis confirmed the transition of phenytoin in the PVA-S4 film into a partially amorphous state during film preparation using the cosolvent solubilization approach. The resulting PVA-S4 film showed a higher dissolution rate in comparison to the film without a cosolvent. Overall, this study indicated the influence of cosolvents on enhancing the solubility of a poorly water-soluble drug and its film dissolution.

Three-dimensional surface printing method for interconnecting electrodes on opposite sides of substrates

As the application of the direct printing method becomes diversified, printing on substrates with non-flat surfaces is increasingly required. However, printing on three-dimensional surfaces suffers from a number of difficulties, which include ink flow due to gravity, and the connection of print lines over sharp edges. This study presents an effective way to print a fine pattern (~ 30 μm) on three different faces with sharp edge boundaries. The method uses a deflectable and stretchable jet stream of conductive ink, which is produced by near-field electrospinning (NFES) technique. Due to added polymer in the ink, the jet stream from the nozzle is less likely to be disconnected, even when it is deposited over sharp edges of objects. As a practical industrial application, we demonstrate that the method can be effectively used for recent display applications, which require the connection of electrical signal and power on both sides of the glass. When the total length of printed lines along the ‘Π’ shaped glass surfaces was 1.2 mm, we could achieve the average resistance of 0.84 Ω.

Recent Advances in Electrospun Sustainable Composites for Biomedical, Environmental, Energy, and Packaging Applications

Electrospinning has gained constant enthusiasm and wide interest as a novel sustainable material processing technique due to its ease of operation and wide adaptability for fabricating eco-friendly fibers on a nanoscale. In addition, the device working parameters, spinning solution properties, and the environmental factors can have a significant effect on the fibers' morphology during electrospinning. This review summarizes the newly developed principles and influence factors for electrospinning technology in the past five years, including these factors' interactions with the electrospinning mechanism as well as its most recent applications of electrospun natural or sustainable composite materials in biology, environmental protection, energy, and food packaging materials.

Localized delivery of active targeting micelles from nanofibers patch for effective breast cancer therapy

Nanofibers based transdermal drug delivery is a promising platform, and it effectively delivers the drug to tumor sites. The objective of the study was to fabricate stimuli-responsive polymeric nanofibers encapsulated with an active targeting micellar system for in situ drug delivery. Stimuli-responsive core-shell nanofibers release thedrug at target sites with minimum side effects to the other organs, decrease the drug administration concentration. Initially, we prepared CA conjugated PCPP polymeric micelles loaded with PTX. Then, core-shell nanofibers were prepared using PHM with coaxial electrospinning and distinct core-shell nanofibers formation confirm by SEM and TEM. Nanofibers showed a homogenous distribution of micelles inside the fiber mesh, diffusion, and erosion processes lead to a controlled release of PTX.In vitro drug release and swelling, revealed the pH based sustained release of the drug for 180 h from the nanofibers mat. Functional and stimuli-responsive nanofibers highly absorb H⁺ ions and repulsion of cations promoting maximum swelling to release more drugs in acidic pH. An increased transportation rate of 70% drug release through epidermis for 120 h. Nanofibers effectively internalize to the skin, and it confirmed by confocal microscopy. MCF-7 cells grown and spread over the nanofibers, which show the biocompatibility of nanofibers. Compared to PTX, drug-loaded nanofibers exhibited higher cytotoxicity for 8 days which was confirmed by the flow cytometry. These promising results confirm, the novel stimuli-responsive core-shell nanofibers actively target breast cancer cells and lead the way to safe cancer therapy.

Low-cost FDM 3D-printed modular electrospray/electrospinning setup for biomedical applications

Here, we report on the inexpensive fabrication of an electrospray/electrospinning setup by fused deposition modelling (FDM) 3D printing and provide the files and parameters needed to print this versatile device. Both electrospray and electrospinning technologies are widely used for pharmaceutical, healthcare and bioengineering applications. The setup was designed to be modular, thus its parts can be exchanged easily. The design provides a safe setup, ensuring that the users are not exposed to the high voltage parts of the setup. PLA, PVA, and a thermoplastic elastomer filament were used for the 3D printing. The filament cost was $100 USD and the rig was printed in 6 days. An Ultimaker 3 FDM 3D printer was used with dual print heads, and the PVA was used as a water-soluble support structure. The end part of the setup had several gas channels, allowing a uniform gas flowing against the direction of the nanoparticles/nanofibers, enhancing the drying process by enhancing the evaporation rate. The setup was tested in both electrospray and electrospinning modes successfully. Both the .sldprt and .stl files are provided for free download.

High-throughput production of silk fibroin-based electrospun fibers as biomaterial for skin tissue engineering applications

In this work, a nozzle-free electrospinning device was built to obtain high-throughput production of silk fibroin-based biocompatible composite fibers with tunable wettability. Synthetic biomaterials tend to present suboptimal cell growth and proliferation, with many studies linking this phenomenon to the hydrophobicity of such surfaces. In this study, electrospun mats consisting of Poly(caprolactone) blended with variant forms of Poly(glycerol sebacate) (PGS) and regenerated silk fibroin were fabricated. The main aim of this work was the development of fiber mats with tunable hydrophobicity/hydrophilicity properties depending on the esterification degree and concentration of PGS. A variation of the conventional protocol used for the extraction of silk fibroin from Bombyx mori cocoons was employed, achieving significantly increased yields of the protein, in a third of the time required via the conventional extraction protocol. By altering the surface properties of the electrospun membranes, the trinary composite biomaterial presented good in vitro fibroblast attachment behavior and optimal growth, indicating the potential of such constructs towards the development of an artificial skin-like platform that can aid wound healing and skin regeneration.

Anti-oil-fouling hydrophobic-superoleophobic composite membranes for robust membrane distillation performance

As a promising thermally driven separation process, membrane distillation (MD) is capable of treating challenging wastewaters. However, the traditional hydrophobic membranes are vulnerable to fouling by non-polar contaminants owing to the strong hydrophobic-hydrophobic interactions. To address this problem, we developed novel anti-oil-fouling MD membranes in this study. The composite membranes with asymmetric wettability were fabricated through electrospinning polyacrylonitrile (PAN) fibrous coating on a hydrophobic polytetrafluoroethylene (PTFE) membrane, followed by hydrolyzing the PAN coating with ethylenediamine (EDA) and NaOH, respectively. These two composite membranes exhibited excellent underwater superoleophobicity, with the underwater oil contact angle >150°, which can be attributed to the fibrous and re-entrant surface structure and the optimized surface hydrophilicity of the electrospun coating. During MD process using saline and oily emulsion as feed, the composite membranes presented robust anti-oil-fouling performance, indicating by stable permeate flux and salt rejection. A novel oil-droplet adhesion force probe was introduced to quasi-quantitatively elucidate oil-membrane interaction and evaluate membrane fouling propensity, the force spectroscopy indicated that the fabricated composite membranes had fairly less attractive to crude oil compared with the PTFE membrane. Our research results suggest that the novel composite membranes with asymmetric wettability were competent to serve as an anti-oil-fouling MD membrane for desalinating challenging saline and oily wastewaters.

Electrospun Nanofibers for Drug Delivery and Biosensing

Early diagnosis and efficient treatment are of paramount importance to fighting cancers. Monitoring the foreign body response of a patient to treatment therapies also plays an important role in improving the care that cancer patients receive by their medical practitioners. As such, there is extensive research being conducted into ultrasensitive point-of-care detection systems and "smart" personalized anticancer drug delivery systems. Electrospun nanofibers have emerged as promising materials for the construction of nanoscale biosensors and therapeutic platforms because of their large surface areas, controllable surface conformation, good surface modification, complex pore structure, and high biocompatibility. Electrospun nanofibers are produced by electrospinning, which is a very powerful and economically viable method of synthesizing versatile and scalable assemblies from a wide array of raw materials. This review describes the theory of electrospinning, achievements, and problems currently faced in producing effective biosensors/drug delivery systems, in particular, for cancer diagnosis and treatment. Finally, insights into future prospects are discussed.

Nozzle-free electrospinning of Polyvinylpyrrolidone/Poly(glycerol sebacate) fibrous scaffolds for skin tissue engineering applications

A novel composite for skin tissue engineering applications by use of blends of Poly(vinylpyrrolidone) (PVP) and Poly (glycerol sebacate) (PGS) was fabricated via the scalable nozzle-free electrospinning technique. The formed PVP:PGS blends were morphologically, thermochemically and mechanically characterized. The morphology of the developed fibers correlated to the blend ratio. The tensile modulus appeared to be affected by the concentration of PGS within the blends, with an apparent decrease in the elastic modulus of the electrospun mats and an exponential increase of the elongation at break. Ultraviolet (UV) crosslinking of the composite fibers significantly decreased the construct's wettability and stabilized the formed fiber mats, which was indicated by contact angle measurements. In vitro examination showed good viability and proliferation of human dermal fibroblast cells. The present findings provide valuable insights for tuning the elastic properties of electrospun material by incorporating this unique elastomer as a promising future candidate for skin substitute constructs.

Porous Aromatic Framework Modified Electrospun Fiber Membrane as a Highly Efficient and Reusable Adsorbent for Pharmaceuticals and Personal Care Products Removal

Water contamination by emerging organic pollutants, such as pharmaceuticals and personal care products (PPCPs), is becoming more and more serious. Porous aromatic frameworks (PAFs) are considered as promising adsorbents to remove the PPCPs. To overcome the limitation of PAFs in their powder forms for large-scale applications, herein, we proposed a strategy to covalently anchor PAFs onto electrospun polymer fiber membranes. Polyaniline (PANI) played the role of aromatic seed layer, which was coated on the electrospun polyacrylonitrile (PAN) fiber membrane first. Then, PAF-45 modification was in situ synthesized in the presence of the PANI-coated electrospun PAN fiber membrane. This study could make the PAF-based materials be handled more easily and improve the surface area of electrospun fiber membrane. The obtained composite adsorbent (PAF-45-PP FM) was applied for the adsorption of three PPCPs: ibuprofen (IBPF), chloroxylenol (CLXN), and N, N-diethyl-meta-toluamide (DEET), which exhibited high adsorption capacity and good recycling ability. According to the Langmuir model, the maximum adsorption capacities of PAF-45-PP FM toward IBPF, CLXN and DEET were 613.50, 429.18, and 384.61 mg/g, respectively. In addition, after ten adsorption-desorption cycles, the adsorption capacities toward the three PPCPs decreased slightly. Through an adsorption comparison test, the adsorption capacity of PAF-45-PP FM almost attributed to the loading PAF-45. The adsorption mechanism analysis illustrated that there were pore capture, hydrophobic interaction and π-π interaction between PPCPs and PAF-45-PP FM. Therefore, the PAF-45-PP FM can be potential adsorbents to purify water contaminated with PPCPs.

Lightweight and flexible hybrid film based on delicate design of electrospun nanofibers for high-performance electromagnetic interference shielding

High-performance electromagnetic interference (EMI) shielding materials possess features of light weight, flexibility and excellent EMI shielding effectiveness. However, continuous efforts are still needed to satisfy the urgent demand for electromagnetic pollution shielding. In this study, a lightweight and flexible hybrid film with a multi-scale double-continuous conductive network (TiO2/SiO2@PPy) and sandwich structure (TiO2/SiO2@PPy@rGO) was prepared via a delicate structure design of electrospun TiO2/SiO2 nanofibers. The hybrid film worked as an effective dissipative medium, leading to a high EMI shielding effectiveness of approximately 30 dB in the X band (8-12 GHz) and excellent specific EMI shielding effectiveness (SE) of ∼13 829 dB cm2 g-1. The hybrid film has a tensile strength of 2.71 MPa, while its density is only 0.089 g cm-3. The hybrid films maintained good electrical and EMI shielding properties after repeated bending, indicating their favorable flexibility. The delicate structure-design strategy of the electrospun nanofibers presents a practicable way to prepare lightweight and flexible hybrid films for high-performance EMI shielding materials in flexible electronics, military and healthcare applications.