A Review of the Fundamental Principles and Applications of Solution Blow Spinning

Flexible iontronic sensing

The emerging flexible iontronic sensing (FITS) technology has introduced a novel modality for tactile perception, mimicking the topological structure of human skin while providing a viable strategy for seamless integration with biological systems. With research progress, FITS has evolved from focusing on performance optimization and structural enhancement to a new phase of integration and intelligence, positioning it as a promising candidate for next-generation wearable devices. Therefore, a review from the perspective of technological development trends is essential to fully understand the current state and future potential of FITS devices. In this review, we examine the latest advancements in FITS. We begin by examining the sensing mechanisms of FITS, summarizing research progress in material selection, structural design, and the fabrication of active and electrode layers, while also analysing the challenges and bottlenecks faced by different segments in this field. Next, integrated systems based on FITS devices are reviewed, highlighting their applications in human-machine interaction, healthcare, and environmental monitoring. Additionally, the integration of artificial intelligence into FITS is explored, focusing on optimizing front-end device design and improving the processing and utilization of back-end data. Finally, building on existing research, future challenges for FITS devices are identified and potential solutions are proposed.

Biopolymer based Fibrous Aggregate Materials for Diagnosis and Treatment: Design, Manufacturing, and Applications

Biopolymer-based fibrous aggregate materials (BFAMs) have gained increasing attention in biomedicine due to their excellent biocompatibility, processability, biodegradability, and multifunctionality. Especially, the medical applications of BFAMs demand advanced structure, performance, and function, which conventional trial-and-error methods struggle to provide. This necessitates the rational selection of materials and manufacturing methods to design BFAMs with various intended functions and structures. This review summarizes the current progress in raw material selection, structural and functional design, processing technology, and application of BFAMs. Additionally, the challenges encountered during the development of BFAMs are discussed, along with perspectives for future research offered.

Performance of Nanotechnology in Cementitious Materials: Synthesis and Application

Cementitious materials are indispensable in the construction industry and in urban development worldwide because cement pastes, mortars, and concrete provide mechanical strength, high durability, and excellent stability to various structures that are used in a lot of civil works. Owing to the impact and relevance of these materials, it is indispensable to frequently seek ways to improve their properties and characteristics. In recent years, the development of nanomaterials such as nanoparticles (NPs) and nanofibers (NFs) has allowed cementitious materials to improve their mechanical, thermal, chemical, and durability properties, among others. This can be associated with the fact that nanomaterials allow for improved cement hydration by retaining water in the mix, helping to define a more uniform microstructure and, therefore, significantly reducing porosity, which prevents contamination such as from the entry of external agents into the structure. In addition to providing an overview of the effects of using nanomaterials on enhancing the properties of cementitious materials, this review includes the most widely used nanomaterial synthesis methods in recent years and the contribution of these nanomaterials to sustainable and environmentally friendly construction.

Carbon Fibers from PAN/PVP Blends by Solution Blow Spinning to Suppress Hydrogen Evolution in Lead-Acid Batteries

In this work, carbon fibers were produced using the solution blow spinning (SBS) technique from polyacrylonitrile (PAN) blended with 0, 2.5, 5, and 10% of poly(vinylpyrrolidone) (PVP). Spun fibers were carbonized in a tubular oven and subsequently characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, carbon-nitrogen elemental analysis, and scanning electron microscopy (SEM) to observe their microstructural properties. Additionally, electrochemical tests, including potentiodynamic, potentiometric, and cyclic voltammetry, were conducted to evaluate the hydrogen evolution reaction (HER). Spectroscopic characterizations indicated that carbon fibers were produced by SBS. Moreover, it was possible to control the HER to suppress hydrogen evolution in lead-acid batteries.

Revolutionizing Inorganic Nanofibers: Bridging Functional Elements to a Future System

The advancement of intelligent ecosystems depends upon not only technological innovation but also a multidimensional understanding of material-world interactions. This theoretical transformation prompts increasing demands for multifunctional materials exhibiting hierarchical organization across multiple length scales. Inorganic nanofibers demonstrate potential in bridging the gap between microscale and macroscale through their three-dimensional architectures. However, their inherent brittleness, primarily resulting from inferior structural integrity poses, significantly limits their current applications. This critical limitation highlights the urgent necessity for developing fabrication strategies that simultaneously enhance the mechanical flexibility and robustness, ensuring reliable performance under extreme operational conditions. This comprehensive review systematically examines brittle mechanism fracture through multiscale analysis including molecular, nanoscale, and microscale dimensions. It presents innovative methodologies integrating simulation-guided structural design with advanced in situ characterization techniques capable of real-time monitoring under a practical stress-strain process. Furthermore, the discussion progresses to address contemporary challenges and emergent solutions in oxide nanofiber engineering, providing strategic insights for developing mechanically robust flexible systems with stable functional properties. Ultimately, this review examines the potential of inorganic nanofibers to overcome the limitations of nano powder materials and achieve their promising real-world applications.

Polyvinyl Alcohol-Based Membranes: A Review of Research Progress on Design and Predictive Modeling of Properties for Targeted Application

This review provides a comprehensive evaluation of the current state of polyvinyl alcohol (PVA)-based membranes, emphasizing their significance in membrane technology for various applications. The analysis encompasses both experimental and theoretical research articles, with a focus on recent decades, aiming to elucidate the potential and limitations of different fabrication approaches, structure-property relationships, and their applicability in the real world. The review begins by examining the advanced polymeric materials and strategies employed in the design and processing of membranes with tailored properties. Fundamental principles of membrane processes are introduced, with a focus on general modeling approaches for describing the fluid transport through membranes. A key aspect of discussion is the distinction between the membrane performance and process performance. Additionally, an in-depth analysis of PVA membranes in various applications is presented, particularly in environmental fields (e.g., fuel cell, water treatment, air purification, and food packaging) and biomedical domains (e.g., drug delivery systems, wound healing, tissue engineering and regenerative medicine, hemodialysis and artificial organs, and ophthalmic and periodontal treatment). Special attention is given to the relationship between membranes' characteristics, such as material composition, structure, and processing parameters, and their overall performance, in terms of permeability, selectivity, and stability. Despite their promising properties, enhanced through innovative fabrication methods that expand their applicability, challenges remain in optimizing long-term stability, improving fouling resistance, and increasing process scalability. Therefore, further research is needed to develop novel modifications and composite structures that overcome these limitations and enhance the practical implementation of PVA-based membranes. By offering a systematic overview, this review aims to advance the understanding of PVA membrane fabrication, properties, and functionality, providing valuable insights for continued development and optimization in membrane technology.

Solution blow spun polymeric nanofibres embedding cyclodextrin complexes of miltefosine: An approach to the production of sprayable dressings for the treatment of cutaneous leishmaniasis

Leishmaniasis is a neglected tropical disease caused by Leishmania genus protozoa. Treating this disease effectively and safely remains a significant challenge. Herein, hydroxypropyl-beta-cyclodextrin (HPβCD) and miltefosine (MF), an alkylphospholipid currently used for the treatment of leishmaniasis, were incorporated into nonwoven mats made of nanofibres of polyvinylpyrrolidone and the amphiphilic block copolymer Tetronic® 1307. The mats were produced in straightforward manner by solution blow spinning (SBS), after the optimisation of the experimental setup for the in-situ production. Scanning electron microscopy, FTIR spectroscopy, X-ray diffraction and differential scanning calorimetry were used to fully characterize the fibres morphology and structure. Both MF and HPβCD were embedded into the fibres at proportions adequate for the therapeutic action of MF, without affecting their global morphology. The release kinetics was controlled by the fast dissolution of the hygroscopic polymeric matrix. HPβCD-MF-loaded fibres demonstrated active against Leishmania promastigotes, displaying higher activity than MF, in addition to a reduced cytotoxicity in macrophages. The functionalised fibres affected the expression levels of parasite genes related to proliferation, differentiation, and drug response. This work demonstrates the potential of SBS for the in-situ delivery of drugs in the form of sprayable dressings, highlighting the use of CD complexes of antileishmanial agents.

Immobilization of Saccharomyces cerevisiae on polyhydroxyalkanoate/konjac glucan nanofiber membranes: Characterization, immobilization efficiency and cellular activity

Yeast immobilization systems can recoup yeast losses in continuous batch fermentation and relieve substrate or product inhibition. We report the use of solution blow spinning process to efficiently prepare polyhydroxyalkanoate (PHB) /konjac glucomannan (KGM) nanofiber membranes as immobilization carriers for Saccharomyces cerevisiae. The prepared PHB/KGM nanofiber membranes had fiber diameters similar to the scale of yeast cells. Incorporating KGM significantly enhanced the porosity (from 87.21 % to 91.74 %), crystallinity, and hydrophilicity (reducing water contact angle from 135.8° to 110.1°), while increasing the specific surface area (from 10.24 to 17.79 m2/g) of pure PHB nanofiber membranes. Thermal stability was maintained (degradation temperatures above 250 °C). These changes enhanced the force between the nanofiber membranes and the cells and facilitated their autoimmobilization on the nanofiber membranes. The highest yeast immobilization efficiency of 87.93 % could be achieved at a KGM addition ratio of 400:2. Yeast showed no loss of cellular activity on the immobilized carriers of natural materials and maintained or even improved fermentation kinetics during at least three consecutive alcoholic fermentations These findings indicate that PHB/KGM nanofiber membranes can serve as effective carriers for yeast immobilization, promoting the sustainable production of fermented foods.

Electrospinning: A New Frontier in Peptide Therapeutics

The nanofiber technology has recently undergone an unprecedented transformation, finding widespread utilities across diverse scientific disciplines. It is noteworthy that electrospinning approaches have emerged as an adaptable and successful approach to generate fibers ranging in rapidly as a class of therapeutic agents with a high level of target specificity. Peptides encounter several challenges as drugs, including swift breakdown by the body, rapid elimination from the bloodstream, inadequate stability, and restricted ability to cross cell membranes. This renders it challenging to employ them as drugs. However, electrospun nanofibers might address these problems. This review explores the promising potential of electrospinning nanofibers for peptide delivery. We delve into recent advancements in this technique, highlighting its effectiveness in overcoming challenges associated with peptide drug delivery. It provides an analysis of the trends identified in the use of the electrospinning technique and its role in peptide drug delivery systems, based on a review of data collected over a period of five to seven years.

Micro-Nanofiber Three-Dimensional Antibacterial Sponge with Wetting/Pore Dual Gradient for Rapid Liquid Infiltration and Uniform Retention in Diapers

The core layer of disposable diapers typically contains a blend of superabsorbent polymer (SAP) and pulp, resulting in slow liquid absorption, layer separation, reverse osmosis, and potential skin issues owing to the addition of antibacterial agents to the surface layer. Therefore, a core layer with rapid liquid absorption, uniform retention, and antibacterial properties must be developed to improve wearer comfort. In this study, a three-dimensional network porous structure for the core layer of a disposable diaper was prepared by solution blow spinning (SBS). This structure comprised a superabsorbent fiber (SAF) and hydrolyzed polyacrylonitrile (HPAN) micro/nanofibers with a dual gradient in wetting/pore size. Progressively increasing the SAF content in each layer to incrementally increase wettability and controlling fiber diameter, a gradient pore structure with sizes of approximately 30 μm-16 μm-7 μm was formed. This design exhibited rapid infiltration capability, reducing the third liquid infiltration time by 13 s compared to those of commercial core layers while reducing reverse osmosis by 1.4 g, and the liquid absorption and retention rates are 47.7 times and 46.1 times, respectively, which is 1.6 times higher than those of commercial diapers. In addition, incorporating a natural antibacterial agent, ε-poly-l-lysine hydrochloride (ε-PLH), into the core layer resulted in an antibacterial rate exceeding 99.99% without direct contact with the skin; water transport capacity tests confirmed faster liquid infiltration speed, uniform absorption, and no fault formation.

Solution Blow Spinning: An Emerging Nanomaterials-Based Wound-Care Technology

Application of one-dimensional nanofibers have witnessed exponential growth over the past few decades and are still emerging with their excellent physicochemical and electrical properties. The driving force behind this intriguing transition lies in their unique high surface-to-volume ratio, ubiquitous nanodomains, improved tensile strength, and flexibility to incorporate deliberate functionalities required for specific and advanced applications. Besides numerous benefits, nanomaterials may adversely interact with biological tissues and potentially be cytotoxic and carcinogenic. However, precisely engineered design can outperform the risk with myriad benefits. Wound care technologies are evolving, and products involved in wound care management have a yearly market value of $15-22 billion. Solution blow spinning (SBS) is a facile technique to synthesize biocompatible nanofibers with scalable processing variables for multidirectional biomedical applications. SBS is feasible for a wide range of thermoplastic polymers and nanomaterials to fabricate nanocomposites. This review will focus on the relevance of SBS technology for wound care, including dressings, drug delivery, tissue engineering scaffolds, and sensors.

A Layer-by-Layer Polycaprolactone/Chitosan-Based Biomimetic Hybrid Nanofibroporous Scaffold for Enhanced Skin Tissue Regeneration: Integrating Solution Blow Spinning and Freeze Casting Techniques

Nanofibers, with their high surface area-to-volume ratio, elasticity, and mechanical strength, significantly enhance scaffold structures for skin tissue engineering. The present study introduces a unique method of combining solution blow spinning (SBS) and freeze casting to fabricate biomimetic hybrid nanofibroporous scaffolds (BHNS) using polycaprolactone (PCL) and chitosan (CH). The developed scaffolds mimic the fibrous porous natural extracellular matrix (ECM) architecture, promoting cell adhesion, proliferation, and matrix deposition. The combined SBS and freeze-casting processes resulted in scaffolds with high porosity and optimal mechanical strength, crucial for effective skin regeneration. Scanning electron microscopy (SEM) confirmed the uniform, nonwoven, and beadless architecture of the PCL fibers and the fibroporous nature of the PCL/CH scaffolds. The scaffolds exhibited excellent swelling behavior, controlled degradation rates, and enhanced mechanical properties. In vitro cell studies demonstrated scaffold cell-supportive properties in terms of cell attachment, proliferation, and migration. This innovative layer-by-layer fabrication technique, integrating nanofibers with freeze-cast scaffolds, represents a significant advancement in skin tissue engineering, promising improved outcomes in wound healing and regenerative medicine.

Fiber Technology in Drug Delivery and Pharmaceuticals

The field of fiber technology is a dynamic and innovative domain that offers novel solutions for controlled and targeted therapeutic interventions. This abstract provides an overview of key aspects within this field, encompassing a range of techniques, applications, commercial developments, intellectual property, and regulatory considerations. The foundational introduction establishes the significance of fiber-based drug delivery systems. Electrospinning, a pivotal technique, has been explored in this paper, along with its various methods and applications. Monoaxial, coaxial, triaxial, and side-by-side electrospinning techniques each offer distinct advantages and applications. Centrifugal spinning, solution and melt blowing spinning, and pressurized gyration further contribute to the field's diversity. The review also delves into commercial advancements, highlighting marketed products that have successfully harnessed fiber technology. The role of intellectual property is acknowledged, with patents reflecting the innovative strides in fiber-based drug delivery. The regulatory perspective, essential for ensuring safety and efficacy, is discussed in the context of global regulatory agencies' evaluations. This review encapsulates the multidimensional nature of fiber technology in drug delivery and pharmaceuticals, showcasing its potential to revolutionize medical treatments and underscores the importance of continued collaboration between researchers, industry, and regulators for its advancement.

Shore hardness of bulk polyurethane affects the properties of nanofibrous materials differently

The present study shows the effect of the hardness of bulk polyurethane on the properties of nanofibrous materials produced in the solution blow spinning process. This study focuses on nanofibrous materials made from medical-grade polyurethanes with different hardness values on the Shore scale, from 75A to 75D. We aimed to determine the effect of the intrinsic properties of polyurethane used to produce nanofibers on the tensile properties of the resulting nanofibrous materials and in vitro platelet adhesiveness. This study used a solution blow spinning process to produce nanofibrous materials from polyurethane solutions. It evaluates their properties using scanning electron microscopy, followed by porosity determination, tensile testing, and platelet adhesion assays. Generally, the bulk polymer's Shore hardness affects nanofibrous products' porosity and tensile properties. In the tested Shore hardness range, the most visible differences in material properties were observed for the fibers produced from the hardest (75D) and softest (75A) polyurethanes. The nanofibrous material produced using 75D polyurethane exhibited the highest porosity, up to approximately 0.87, owing to the low packing density of the stiff nanofibers. It also remained the stiffest, with the highest Young's modulus. On the other hand, the softest 75A polyurethane produced a less porous nanofibrous mat with the highest tensile strength among the tested polyurethanes. All tested nanofibrous materials retained their platelet adhesion resistance upon processing into nanofibers, with a mean platelet coverage below 1 % of the nanofibrous mat surface. The study results provide insights into the relationship between the hardness of bulk polyurethane and the properties of nanofibrous materials, which can be useful in various biomedical applications, particularly in producing tissue-engineered vascular grafts.

Protein and Polysaccharide Fibers via Air Jet Spinning: Emerging Techniques for Biomedical and Sustainable Applications

Polymers play a critical role in the biomedical and sustainable materials fields, serving as key resources for both research and product development. While synthetic and natural polymers are both widely used, synthetic polymers have traditionally dominated due to their ability to meet the specific material requirements of most fiber fabrication methods. However, synthetic polymers are derived from non-renewable resources, and their production raises environmental and health concerns. Natural polymers, on the other hand, are derived from renewable biological sources and include a subset known as biopolymers, such as proteins and polysaccharides, which are produced by living organisms. These biopolymers are naturally abundant and offer benefits such as biodegradability and non-toxicity, making them especially suitable for biomedical and green applications. Recently, air jet spinning has emerged as a promising method for fabricating biopolymer fibers, valued for its simplicity, cost-effectiveness, and safety-advantages that stand out compared to the more conventional electrospinning process. This review examines the methods and mechanisms of air jet spinning, drawing on empirical studies and practical insights to highlight its advantages over traditional fiber production techniques. By assembling natural biopolymers into micro- and nanofibers, this novel fabrication method demonstrates strong potential for targeted applications, including tissue engineering, drug delivery, air filtration, food packaging, and biosensing, utilizing various protein and polysaccharide sources.

Comparing solution blow spinning and electrospinning methods to produce collagen and gelatin ultrathin fibers: A review

Ultrathin fibers have been used to design functional nanostructured materials for technological and biomedical applications. Combining the use of renewable and compatible sources with the emerging alternative SBS (solution blow spinning) technique opens new opportunities for material applications. In this review, we introduce the benefits of SBS over the classical electrospinning technique by following studies that use collagen or gelatin. SBS offers distinct advantages over electrospinning in the preparation of ultrathin fibers based on natural proteins, including the absence of high-voltage sources and the possibility of using fewer toxic solvents. Notably, there is also the prospect of using SBS directly in injured tissues, opening new strategies for in situ structure assembly SBS is a suitable approach to produce fibers at the nanoscale that can be tailored to distinct diameters by blending or simply adjusting experimental conditions. The focus on producing collagen or gelatin fibers contributes to designing highly biocompatible mats with potential for promoting cellular growth and implantation, even though their applications can be found also in food packaging, energy, and the environment. Therefore, a comprehensive analysis of the topic is essential to evaluate the current strategies regarding these materials and allow for their expanded production and advanced applications.

Biointerface Fiber Technology from Electrospinning to Inflight Printing

Building two-dimensional (2D) and three-dimensional (3D) micro- and nanofibril structures with designable patterns and functionalities will offer exciting prospects for numerous applications spanning from permeable bioelectronics to tissue engineering scaffolds. This Spotlight on Applications highlights recent technological advances in fiber printing and patterning with functional materials for biointerfacing applications. We first introduce the current state of development of micro- and nanofibers with applications in biology and medical wearables. We then describe our contributions in developing a series of fiber printing techniques that enable the patterning of functional fiber architectures in three dimensions. These fiber printing techniques expand the material library and device designs, which underpin technological capabilities from enabling fundamental studies in cell migration to customizable and ecofriendly fabrication of sensors. Finally, we provide an outlook on the strategic pathways for developing the next-generation bioelectronics and "Fiber-of-Things" (FoT) using nano/micro-fibers as architectural building blocks.

Pulsed Airstream-Driven Hierarchical Micro-Nano Pore Structured Triboelectric Nanogenerator for Wireless Self-Powered Formaldehyde Sensing

Formaldehyde (HCHO), as a common volatile organic compound, has a serious impact on human health in the daily lives and industrial production scenarios. Given the security issue of HCHO detection and danger warning, a ZIF-8/copper foam based pulsed airstream-driven triboelectric nanogenerator (ZCP-TENG) is designed to develop the self-powered HCHO sensors. By combining contact electrification and electrostatic induction, the ZCP-TENG can be utilized for airflow energy harvesting and HCHO concentration detection. The short-circuit current and output power of the ZCP-TENG can reach 2.0 µA and 81 µW (20 ppm). With the high surface area, abundant micro-nano pores, and excellent permeation flux, the ZCP-TENGs exhibit excellent HCHO sensing response (61.3% at 100 ppm), low detection limit (≈2 ppm), and rapid response/recovery time (14/15 s), which can be served as a highly sensitive and selective HCHO sensor. By connecting an intelligent wireless alarm, the ZCP-TENGs are designed to construct a self-powered warning system to monitor and remind the HCHO of exceedance situations. Moreover, by combining a support vector machine model, the difference concentrations can be quickly identified with an average prediction accuracy of 100%. This study illustrates that ZCP-TENGs have broad application prospects and provide guidance for HCHO monitoring and danger warnings.

Hybrid Passive Cooling for Power Equipment Enabled by Metal-Organic Framework

While providing electrical energy for human society, power equipment also consumes electricity and generate heat. Cooling equipment consumes a significant amount of electricity, further increasing energy consumption and load on the power grid. Therefore, there is an urgent need to develop low-energy and sustainable cooling technologies for power equipment. In this study, a hybrid passive cooling composite designed to enhance heat dissipation for heavy-load power equipment is introduced. Specifically, the composite material achieves outstanding radiative cooling performance with an average solar reflectance of up to 0.98, while its excellent atmospheric water harvesting performance ensures high evaporation cooling power without the need for manual water replenishment. As a result, the composite effectively lowers the temperature of outdoor heavy-load power equipment (e.g., transformers) by 25.3 °C. The excellent heat dissipation properties of the composite make it a powerful tool in safeguarding electrical systems.

Fast and sustainable production of smart nanofiber mats by solution blow spinning for food quality monitoring: Potential of polycaprolactone and agri-food residue-derived anthocyanins

The shelf life of perishable foods is estimated through expensive and imprecise analyses that do not account for improper storage. Smart packaging, obtained by agile manufacturing of nanofibers functionalized with natural pigments from agri-food residues, presents promising potential for real-time food quality monitoring. This study employed the solution blow spinning (SBS) technique for the rapid production of smart nanofiber mats based on polycaprolactone (PCL), incorporating extracts of agricultural residues rich in anthocyanins from eggplant (EE) or purple cabbage (CE) for monitoring food quality. The addition of EE or CE to the PCL matrix increased the viscosity of the solution and the diameter of the nanofibers from 156 nm to 261-370 nm. The addition of extracts also improved the mechanical and water-related properties of the nanofibers, although it reduced the thermal stability. Attenuated total reflectance Fourier-transform infrared spectroscopy confirmed the incorporation of anthocyanins into PCL nanofibers. Nanofiber mats incorporated with EE or CE exhibited visible color changes (ΔE ≥ 3) in response to buffer solutions (pH between 3 and 10), and ammonia vapor. Smart nanofibers have demonstrated the ability to monitor fish fillet spoilage through visible color changes (ΔE ≥ 3) during storage. Consequently, smart nanofibers produced by the SBS technique, using PCL and anthocyanins from agro-industrial waste, reveal potential as smart packaging materials for food.

Key Advances in Solution Blow Spinning of Polylactic-Acid-Based Materials: A Prospective Study on Uses and Future Applications

Solution blow spinning (SBS) is a versatile and cost-effective technique for producing nanofibrous materials. It is based on the principles of other spinning methods as electrospinning (ES), which creates very thin and fine fibers with controlled morphologies. Polylactic acid (PLA), a biodegradable and biocompatible polymer derived from renewable resources, is widely used in biomedical fields, environmental protection, and packaging. This review provides a theoretical background for PLA, focusing on its properties that are associated with structural characteristics, such as crystallinity and thermal behavior. It also discusses various methods for producing fibrous materials, with particular emphasis on ES and SBS and on describing in more detail the main properties of the SBS method, along with its processing conditions and potential applications. Additionally, this review examines the properties of nanofibrous materials, particularly PLA-based nanofibers, and the new applications for which it is thought that they may be more useful, such as drug delivery systems, wound healing, tissue engineering, and food packaging. Ultimately, this review highlights the potential of the SBS method and PLA-based nanofibers in various new applications and suggests future research directions to address existing challenges and further enhance the SBS method and the quality of fibrous materials.

Highly fluorescent hybrid nanofibers as potential nanofibrous scaffolds for studying cell-fiber interactions

In this study, we report on the fabrication of hybrid nanofibers for labeling and bioimaging applications. Our approach is involved for developing highly fluorescent nanofibers using a blend of polylactic acid, polyethyleneglycol, and perylenediimide dyes, through the solution blow spinning technique. The nanofibers are exhibited diameters ranging from 330 nm to 420 nm. Nanofibers showed excellent red and near-infrared fluorescence emissive properties in fluorescent spectroscopy. Moreover, the strong two-photon absorption phenomenon was observed for nanofibers under confocal microscopy. To assess the applicability of these fluorescent nanofibers in bioimaging settings, we employ two types of mammalian cells B16F1 melanoma cells and J774.A1 macrophages. Both cell types exhibit negligible cytotoxicity after 24 h incubation with the nanofibers, indicating the suitability of nanofibers for cell-based experiments. We also observe strong interactions between the nanofibers and cells, as evidenced by two major events: a) the acquisition of an elongated cellular morphology with the major cellular axis parallel to the nanofibers and b) the accumulation of actin filaments along the points of contact of the cells with the fibers. Our findings demonstrate the suitability of these newly developed fluorescent nanofibers in cell-based applications for guiding cellular behavior. We expect that these fluorescent nanofibers have the potential to serve as scaffold materials for long-time tracking of cell-fiber interactions in fluorescence microscopy.

Efficient Solution Blow Spinning of PAN-CNTs Nanofiber-Based Pressure Sensors with Sandwich Structures

High-performance sensors play a crucial role in smart wearable technology and human-machine interaction. However, traditional metal- and silicon-based sensors face drawbacks, including limited flexibility, high cost, degradation issues, and insufficient sensitivity. Conductive composite fibers were produced using the spinning solution of PAN and PVB mixed with CNTs and spun at a flow rate of 20 mL·h-1. PAN-CNTs fiber felt formed a sandwich structure by impregnating CNTs aqueous solution, mechanical pressing, and coating graphene. A cost-effective PAN-CNTs nanofiber-based pressure sensor (PCPS) was developed, demonstrating excellent flexibility, conductivity, sensitivity, mechanical properties, and biocompatibility. Nanofiber-based pressure sensors exhibited high sensitivity, with an approximately 75% relative resistance change under a 1 N pressure load. They can withstand 360° bending and have a rapid response time of about 160 ms. PCPS holds significant potential for flexible electronics, smart wearables, and micropressure detection.

Gas-Blows-Liquid Spinning Strategy Toward Mechanically Strong, Thermally Protective, Efficiently Hemostatic Aerogel Fibers/Fabrics

Nanoporous aerogel fibers enjoy the luxury of being one of the most attractive nanomaterials. However, the representative fabrication pathways have faced up with low production rates due to significant speed mismatch between slow sol-gel transition and as fast as possible spinning in the same period. Herein, a novel gas-blows-liquid spinning (GS) strategy with a spinning speed of 300-700 m s-1 is developed to get the high-speed and high-efficiency production of aerogel fibers/fabrics. The spinning speed of the GS strategy is 900 times higher than various techniques reported for aerogel fibers. The resulting aerogel fibers exhibit a high specific surface area (180 m2 g-1). In comparison, the aerogel fiber possesses the highest tensile strength (58.7±3.9 MPa) among its counterparts and aerogel fabric with surprising water-absorption and microparticle-blocking performances exhibits the application prospect for better hemostasis than that of commercial gauze and cotton ball. Besides, the GS aerogel fabrics with hierarchical aligned structures show better thermal insulation (≈0.035 Wm-1K-1) than wet spinning aerogel fabric and commercial insulation felts. This work has provided inspiration for fast fabricating more aerogel fibers/fabrics with this GS strategy, and the resulting aerogel fibers/fabrics may find significant application in the fields of 5G smart phones, wound hemostasis, etc.

Overexpressed Artificial Spidroin Based Microneedle Spinneret for 3D Air Spinning of Hybrid Spider Silk

Efforts have been devoted to developing strategies for converting spider silk proteins (spidroins) into functional silk materials. However, studies mimicking the exact natural spinning process of spiders encounter arduous challenges. In this paper, consistent with the natural spinning process of spiders, we report a high-efficient spinning strategy that enables the mass preparation of multifunctional artificial spider silk at different scales. By simulating the structural stability mechanism of the cross-β-spine of the amyloid polypeptide by computer dynamics, we designed and obtained an artificial amyloid spidroin with a significantly increased yield (13.5 g/L). Using the obtained artificial amyloid spidroin, we fabricated artificial spiders with artificial spinning glands (hollow MNs). Notably, by combining artificial spiders with 3D printing, we perform patterned air spinning at the macro- and microscales, and the resulting patterned artificial spider silk has excellent pump-free liquid flow and conductive and frictional electrical properties. Based on these findings, we used macroscale artificial spider silk to treat rheumatoid arthritis in mice and micro artificial spider silk to prepare wound dressings for diabetic mice. We believe that artificial spider silk based on an exact spinning strategy will provide a high-efficient way to construct and modulate the next generation of smart materials.

Fibres-threads of intelligence-enable a new generation of wearable systems

Fabrics represent a unique platform for seamlessly integrating electronics into everyday experiences. The advancements in functionalizing fabrics at both the single fibre level and within constructed fabrics have fundamentally altered their utility. The revolution in materials, structures, and functionality at the fibre level enables intimate and imperceptible integration, rapidly transforming fibres and fabrics into next-generation wearable devices and systems. In this review, we explore recent scientific and technological breakthroughs in smart fibre-enabled fabrics. We examine common challenges and bottlenecks in fibre materials, physics, chemistry, fabrication strategies, and applications that shape the future of wearable electronics. We propose a closed-loop smart fibre-enabled fabric ecosystem encompassing proactive sensing, interactive communication, data storage and processing, real-time feedback, and energy storage and harvesting, intended to tackle significant challenges in wearable technology. Finally, we envision computing fabrics as sophisticated wearable platforms with system-level attributes for data management, machine learning, artificial intelligence, and closed-loop intelligent networks.

Advances in Light-Responsive Smart Multifunctional Nanofibers: Implications for Targeted Drug Delivery and Cancer Therapy

Over the last decade, scientists have shifted their focus to the development of smart carriers for the delivery of chemotherapeutics in order to overcome the problems associated with traditional chemotherapy, such as poor aqueous solubility and bioavailability, low selectivity and targeting specificity, off-target drug side effects, and damage to surrounding healthy tissues. Nanofiber-based drug delivery systems have recently emerged as a promising drug delivery system in cancer therapy owing to their unique structural and functional properties, including tunable interconnected porosity, a high surface-to-volume ratio associated with high entrapment efficiency and drug loading capacity, and high mass transport properties, which allow for controlled and targeted drug delivery. In addition, they are biocompatible, biodegradable, and capable of surface functionalization, allowing for target-specific delivery and drug release. One of the most common fiber production methods is electrospinning, even though the relatively two-dimensional (2D) tightly packed fiber structures and low production rates have limited its performance. Forcespinning is an alternative spinning technology that generates high-throughput, continuous polymeric nanofibers with 3D structures. Unlike electrospinning, forcespinning generates fibers by centrifugal forces rather than electrostatic forces, resulting in significantly higher fiber production. The functionalization of nanocarriers on nanofibers can result in smart nanofibers with anticancer capabilities that can be activated by external stimuli, such as light. This review addresses current trends and potential applications of light-responsive and dual-stimuli-responsive electro- and forcespun smart nanofibers in cancer therapy, with a particular emphasis on functionalizing nanofiber surfaces and developing nano-in-nanofiber emerging delivery systems for dual-controlled drug release and high-precision tumor targeting. In addition, the progress and prospective diagnostic and therapeutic applications of light-responsive and dual-stimuli-responsive smart nanofibers are discussed in the context of combination cancer therapy.

Characterization of Blow-Spun Polyurethane Scaffolds-Influence of Fiber Alignment and Fiber Diameter on Pericyte Growth

In this study, fibrous polyurethane (PU) materials with average fiber diameter of 200, 500, and 1000 nm were produced using a solution blow spinning (SBS) process. The effects of the rotation speed of the collector (in the range of 200-25 000 rpm) on the fiber alignment and diameter were investigated. The results showed that fiber alignment was influenced by the rotation speed of the collector, and such alignment was possible when the fiber diameter was within a specific range. Homogeneously oriented fibers were obtained only for a fiber diameter ≥500 nm. Moreover, the changes in fiber orientation and fiber diameter (resulting from changes in the rotation speed of the collector) were more noticeable for materials with an average fiber diameter of 1000 nm in comparison to 500 nm, which suggests that the larger the fiber diameter, the better the controlled architectures that can be obtained. The porosity of the produced scaffolds was about 65-70%, except for materials with a fiber diameter of 1000 nm and aligned fibers, which had a higher porosity (76%). Thus, the scaffold pore size increased with increasing fiber diameter but decreased with increasing fiber alignment. The mechanical properties of fibrous materials strongly depend on the direction of stretching, whereby the fiber orientation influences the mechanical strength only for materials with a fiber diameter of 1000 nm. Furthermore, the fiber diameter and alignment affected the pericyte growth. Significant differences in cell growth were observed after 7 days of cell culture between materials with a fiber diameter of 1000 nm (cell coverage 96-99%) and those with a fiber diameter of 500 nm (cell coverage 70-90%). By appropriately setting the SBS process parameters, scaffolds can be easily adapted to the cell requirements, which is of great importance in producing complex 3D structures for guided tissue regeneration.

Nonwoven fiber meshes for oxygen sensing

Accurate oxygen sensing and cost-effective fabrication are crucial for the adoption of wearable devices inside and outside the clinical setting. Here we introduce a simple strategy to create nonwoven polymeric fibrous mats for a notable contribution towards addressing this need. Although morphological manipulation of polymers for cell culture proliferation is commonplace, especially in the field of regenerative medicine, non-woven structures have not been used for oxygen sensing. We used an airbrush spraying, i.e. solution blowing, to obtain nonwoven fiber meshes embedded with a phosphorescent dye. The fibers serve as a polymer host for the phosphorescent dye and are shown to be non-cytotoxic. Different composite fibrous meshes were prepared and favorable mechanical and oxygen-sensing properties were demonstrated. A Young's modulus of 9.8 MPa was achieved and the maximum oxygen sensitivity improved by a factor of ∼2.9 compared to simple drop cast film. The fibers were also coated with silicone rubbers to produce mechanically robust sensing films. This reduced the sensing performance but improved flexibility and mechanical properties. Lastly, we are able to capture oxygen concentration maps via colorimetry using a smartphone camera, which should offer unique advantages in wider usage. Overall, the introduced composite fiber meshes show a potential to significantly improve cell cultures and healthcare monitoring via absolute oxygen sensing.

Numerical Analysis of the Airflow Field and Experiments of Fiber Motion for Solution Blowing

Solution blowing is a rapidly developing technology for the rapid and large-scale preparation of nanofibers, driven by its advantages, such as wide adaptability to raw materials, simple and safe operation, and ease of scalable production. Most of the research related to solution blowing mainly focuses on the fiber spinning and forming principle, fiber structure and properties, and the development of new materials. Limited studies have focused on the airflow field and fiber motion in solution blowing. In this paper, nine nozzles for solution blowing with varying geometrical parameters were designed by adjusting the outer nozzle diameter, inner nozzle outstretched distance, and inner nozzle diameter. The centerline airflow velocity, turbulence intensity, and velocity distribution of the solution blowing were analyzed using the numerical simulation method. The results showed that the outer nozzle diameter had the greatest influence on the air velocity and turbulence intensity. The airflow velocity increased and the turbulence intensity decreased with the increase of the outer nozzle diameter. The inner nozzle outstretched distance only affected the airflow convergence point and had less effect on the airflow velocity and turbulence intensity. The captured trajectory of the polymer jet initially shows a straight or slightly curved development that eventually diverges from the airflow field. With an increasing distance, dispersed fibers exhibit instability, including loop formation, bonding, and separation. The experimental observation of fiber morphology in the solution-blowing web further verified the instability during the fiber movement.

Spinning the Future: The Convergence of Nanofiber Technologies and Yarn Fabrication

The rapid advancement in nanofiber technologies has revolutionized the domain of yarn materials, marking a significant leap in textile technology. This review dissects the nexus between cutting-edge nanofiber technologies and yarn manufacturing, aiming to illuminate the pathway toward engineering advanced textiles with unparalleled functionality. It first discusses the fundamentals of nanofiber assemblies and spinning techniques, primarily focusing on electrospinning, centrifugal spinning, and blow spinning. Additionally, the study delves into integrating nanofiber spinning technologies with traditional and modern yarn fabrication principles, elucidating the design principles that underlie the creation of yarns incorporating nanofibers. Twisting technologies are explored to examine how they can be optimized and adapted for incorporating nanofibers, thus enabling the production of innovative nanofiber-based yarns. Special attention is given to scalable strategies like centrifugal and blow spinning, which are spotlighted for their efficiency and scalability in fabricating nanofiber yarns. This review further analyses recently developed nanofiber yarn applications, including wearable sensors, biomedical devices, moisture management textiles, and energy harvesting and storage devices. We finally present a forward-looking perspective to address unresolved issues in nanofiber-based yarn technologies.

Immunomodulatory poly(L-lactic acid) nanofibrous membranes promote diabetic wound healing by inhibiting inflammation, oxidation and bacterial infection

Background

Given the significant impact on human health, it is imperative to develop novel treatment approaches for diabetic wounds, which are prevalent and serious complications of diabetes. The diabetic wound microenvironment has a high level of reactive oxygen species (ROS) and an imbalance between proinflammatory and anti-inflammatory cells/factors, which hamper the healing of chronic wounds. This study aimed to develop poly(L-lactic acid) (PLLA) nanofibrous membranes incorporating curcumin and silver nanoparticles (AgNPs), defined as PLLA/C/Ag, for diabetic wound healing.

Methods

PLLA/C/Ag were fabricated via an air-jet spinning approach. The membranes underwent preparation and characterization through various techniques including Fourier-transform infrared spectroscopy, measurement of water contact angle, X-ray photoelectron spectroscopy, X-ray diffraction, scanning electron microscopy, assessment of in vitro release of curcumin and Ag+, testing of mechanical strength, flexibility, water absorption and biodegradability. In addition, the antioxidant, antibacterial and anti-inflammatory properties of the membranes were evaluated in vitro, and the ability of the membranes to heal wounds was tested in vivo using diabetic mice.

Results

Loose hydrophilic nanofibrous membranes with uniform fibre sizes were prepared through air-jet spinning. The membranes enabled the efficient and sustained release of curcumin. More importantly, antibacterial AgNPs were successfully reduced in situ from AgNO3. The incorporation of AgNPs endowed the membrane with superior antibacterial activity, and the bioactivities of curcumin and the AgNPs gave the membrane efficient ROS scavenging and immunomodulatory effects, which protected cells from oxidative damage and reduced inflammation. Further results from animal studies indicated that the PLLA/C/Ag membranes had the most efficient wound healing properties, which were achieved by stimulating angiogenesis and collagen deposition and inhibiting inflammation.

Conclusions

In this research, we successfully fabricated PLLA/C/Ag membranes that possess properties of antioxidants, antibacterial agents and anti-inflammatory agents, which can aid in the process of wound healing. Modulating wound inflammation, these new PLLA/C/Ag membranes serve as a novel dressing to enhance the healing of diabetic wounds.

Fabrication of antimicrobial PCL/EC nanofibrous films containing natamycin and trans-cinnamic acid by microfluidic blow spinning for fruit preservation

Fruit is susceptible to various postharvest pathogens; thus, the development of multifunctional preservation materials that can achieve the broad-spectrum inhibition of different pathogens is a current research hotspot. Here, microfluidic blow spinning was used to create a biodegradable polycaprolactone/ethyl cellulose (PCL/EC) nanofibrous film that incorporated two naturally-sourced compounds, natamycin and trans-cinnamic acid, resulting in multi-microbial inhibition. The PCL/EC-based film had a smooth and even morphology, indicating the favorable integration of PCL and EC. After the incorporation of ingredients, the film exhibited good inhibitory activity against Escherichia coli, Staphylococcus aureus, and Botrytis cinerea, and it had finer fiber diameters, higher permeability, and antioxidant properties. We further demonstrated that strawberries that were padded with the film had good resistance to Botrytis cinerea. Also, the film did not interference with the qualities of the strawberries during storage. The study demonstrates a promising application for multi-antimicrobial and bio-friendly packaging materials in postharvest fruit preservation.

Properties and environmental sustainability of fungal chitin nanofibril reinforced cellulose acetate films and nanofiber mats by solution blow spinning

Materials from biological origin composed by renewable carbon facilitate the transition from linear carbon-intensive economy to a sustainable circular economy. Accordingly, we use solution blow spinning to develop fully biobased cellulose acetate films and nanofiber mats reinforced with fungal chitin nanofibrils (ChNFs), an emerging bio-colloid with lower carbon footprint compared to crustacean-derived nanochitin. This study incorporates fungal ChNFs into spinning processes for the first time. ChNF addition reduces film surface roughness, modifies film water affinity, and tailors the nanofiber diameter of the mats. The covalently bonded β-D-glucans of ChNFs act as a binder to improve the interfacial properties and consequently load transference to enhance the mechanical properties. Accordingly, the Young's modulus of the films increases from 200 ± 18 MPa to 359 ± 99 MPa with 1.5 wt% ChNFs, while the elongation at break increases by ~45 %. Life cycle assessment (LCA) is applied to quantify the environmental impacts of solution blow spinning for the first time, providing global warming potential values of 69.7-347.4 kg·CO2-equiv.·kg-1. Additionally, this work highlights the suitability of ChNFs as reinforcing fillers during spinning and proves the reinforcing effect of mushroom-derived chitin in bio-based films, opening alternatives for sustainable materials development beyond nanocelluloses in the near future.

Selective Enhancement of Viewing Angle Characteristics and Light Extraction Efficiency of Blue Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes through an Easily Tailorable Si3N4 Nanofiber Structure

We selectively improved the viewing angle characteristics and light extraction efficiency of blue thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) by tailoring a nanofiber-shaped Si3N4 layer, which was used as an internal scattering layer. The diameter of the polymer nanofibers changed according to the mass ratio of polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) in the polymer solution for electrospinning. The Si3N4 nanofiber (SNF) structure was fabricated by etching an Si3N4 film using the PAN/PMMA nanofiber as a mask, making it easier to adjust parameters, such as the diameter, open ratio, and height, even though the SNF structure was randomly shaped. The SNF structures exhibited lower transmittance and higher haze with increasing diameter, showing little correlation with their height. However, all the structures demonstrated a total transmittance of over 80%. Finally, by applying the SNF structures to the blue TADF OLEDs, the external quantum efficiency was increased by 15.6%. In addition, the current and power efficiencies were enhanced by 23.0% and 25.6%, respectively. The internal light-extracting SNF structure also exhibited a synergistic effect with the external light-extracting structure. Furthermore, when the viewing angle changed from 0° to 60°, the peak wavelength and CIE coordinate shift decreased from 20 to 6 nm and from 0.0561 to 0.0243, respectively. These trends were explained by the application of Snell's law to the light path and were ultimately validated through finite-difference time-domain simulations.

Precise Fabrication and Manipulation of Individual Polymer Nanofibers

Polymer nanofibers hold promise in a wide range of applications owing to their diverse properties, flexibility, and cost effectiveness. In this study, we introduce a polymer nanofiber drawing process in a scanning electron microscope and focused ion beam (SEM/FIB) instrument with in situ observation. We employed a nanometer-sharp tungsten needle and prepolymer microcapsules to enable nanofiber drawing in a vacuum environment. This method produces individual polymer nanofibers with diameters as small as ∼500 nm and lengths extending to millimeters, yielding nanofibers with an aspect ratio of 2000:1. The attachment to the tungsten manipulator ensures accurate transfer of the polymer nanofiber to diverse substrate types as well as fabrication of assembled structures. Our findings provide valuable insights into ultrafine polymer fiber drawing, paving the way for high-precision manipulation and assembly of polymer nanofibers.

Carboxymethyl chitosan-based hydrogel-Janus nanofiber scaffolds with unidirectional storage-drainage of biofluid for accelerating full-thickness wound healing

Self-pumping wound scaffolds designed for directional biofluid transport are extensively investigated. They efficiently extract excessive biofluids from wounds, while maintaining an optimally humid wound environment, thus facilitating rapid wound healing. However, the existing designed scaffolds are insufficiently focused on stimulating the hydrophobic layer at the wound site, thereby exacerbating inflammation and impeding the wound healing process. Herein, we engineered and fabricated a hydrophilic-hydrophobic-hydrophilic sandwich-structured hydrogel-Janus nanofiber scaffold (NFS) employing a Layer-by-Layer (LbL) method. This scaffold comprises a hydrophilic carboxymethyl chitosan/silver (CMCS-Ag) hydrogel component in conjunction with a poly(caprolactone)/poly(caprolactone)-poly(citric acid)-co-ε-polylysine (PCL/PCL-PCE) Janus NFS. It is noteworthy that the hydrogel-Janus nanofiber scaffold not only demonstrates outstanding water absorption (202.2 %) and unidirectional biofluid transport capability but also possesses high breathability (308.663 m3/m2 h kPa), appropriate pore size (6.7-7.5 μm), excellent tensile performance (270 ± 10 %), and superior mechanical strength (26.36 ± 1.77 MPa). Moreover, in vitro experimentation has convincingly demonstrated the impeccable biocompatibility of hydrogel-Janus NFS. The inherent dual-antibacterial properties in CMCS-Ag and PCE significantly augment fibroblast proliferation and migration. In vivo studies further underscore its capability to expedite wound healing by absorption and expulsion of wound exudates, thereby fostering collagen deposition and vascularization. As such, this work potentially provides fresh insights into the design and fabrication of multifunctional biomimetic scaffolds, holding immense potential in the medical field for efficient wound healing.

Anti-adhesive and antibacterial chitosan/PEO nanofiber dressings with high breathability for promoting wound healing

Wound dressings are crucial for wound healing. Ideal wound dressings should possess many functions such as wettability, antibacterial activity and anti-adherent property to promote wound healing. In the present study solution blown spinning (SBS) technology was applied to prepare chitosan/polyethylene oxide (CS/PEO) nanofiber dressings in high efficiency. The obtained nanofiber dressings were treated with anhydrous ethanol to improve the fiber structure and enhance the functionality of the fiber dressings. The results show that the treated nanofibers had higher crystallinities and higher CS contents. The CS/PEO nanofiber dressings fabricated by using no additives and crosslinking had excellent wettability, water stability and antibacterial activity against Escherichia coli and Staphylococcus aureus reached to over 99.99 %. In addition, the CS/PEO nanofiber dressings exhibited high breathability, antioxidant activity and anti-adhesion function. The in vivo animal experiment confirmed that the nanofiber dressings enhanced cell proliferation and significantly accelerated the wound healing within 10 days. The developed CS/PEO nanofiber dressings have great potential in the clinical field of wound healing.

Solution blow spun bilayer chitosan/polylactic acid nanofibrous patch with antibacterial and anti-inflammatory properties for accelerating acne healing

The quercetin (QC) loaded chitosan (CS) nanofibrous patch (CSQC) was designed and fabricated successfully by solution blow spinning (SBS). And it was employed to explore a functional double-layer nanofibrous patch (CSQC/PLA) with polylactic acid (PLA) for overcoming the resistance of acne-causing bacteria to antibiotics and local cutaneous irritation. The nanofibrous patch possessed a fluffy bilayer structure with good air permeability, which may be befitted from the SBS method. The 10 % QC loaded CSQC0.10/PLA had sustained release ability of QC for 24 h. A high free radical clearance rate (91.18 ± 2.26 %) and robust antibacterial activity against P. acnes (94.4 %) were achieved for CSQC0.10/PLA with excellent biocompatibility. Meanwhile, E. coli and S. aureus were also suppressed with 99.4 % and 99.2 %, respectively. Moreover, the expression of pro-inflammatory cytokines (IL-6 and TNF-α) was significantly reduced, conducive to acne healing. Therefore, the CSQC0.10/PLA bilayer nanofibrous patch designed here may shed some light on developing multifunctional materials for treating acne infectious wounds.

Influence of Fast Drying on the Morphology of α-Fe2O3 and FeMnO3/α-Fe2O3 Fibers Produced by Solution Blow Spinning

α-Fe2O3 and FeMnO3/α-Fe2O3 fibers were successfully prepared via Solution Blow Spinning (SBS). The effect of drying during the SBS process on fiber morphology was evaluated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption-desorption isotherms. A slow drying promoted continuous fibers with rough surfaces and lower average diameters. However, fast drying enabled the production of fibers with low densification and many surface pores with higher BET-specific surface areas. The porous fibers produced have potential applications in energy generation and storage.

Multi-needle blow-spinning technique for fabricating collagen nanofibrous nerve guidance conduit with scalable productivity and high performance

Nerve guidance conduits (NGCs) have been widely accepted as a promising strategy for peripheral nerve regeneration. Fabricating ideal NGCs with good biocompatibility, biodegradability, permeability, appropriate mechanical properties (space maintenance, suturing performance, etc.), and oriented topographic cues is still current research focus. From the perspective of translation, the technique stability and scalability are also an important consideration for industrial production. Recently, blow-spinning technique shows great potentials in nanofibrous scaffolds fabrication, possessing high quality, high fiber production rates, low cost, ease of maintenance, and high reliability. In this study, we proposed for the first time the preparation of a novel NGC via blow-spinning technique to obtain optimized performances and high productivity. A new collagen nanofibrous neuro-tube with the bilayered design was developed, incorporating inner oriented and outer random topographical cues. The bilayer structure enhances the mechanical properties of the conduit in dry and wet, displaying good radial support and suturing performance. The porous nature of the blow-spun collagen membrane enables good nutrient delivery and metabolism. The in vitro and in vivo evaluations indicated the bilayer-structure conduit could promoted Schwann cells growth, neurotrophic factors secretion, and axonal regeneration and motor functional recovery in rat.

Fibrous Structures Produced Using the Solution Blow-Spinning Technique for Advanced Air Filtration Process

This study proposes utilising the solution blow-spinning process (SBS) for manufacturing a biodegradable filtration structure that ensures high efficiency of particle filtration with an acceptable pressure drop. The concept of multi-layer filters was applied during the design of filters. Polylactic acid (PLA) was used to produce various layers, which may be mixed in different sequences, building structures with varying filtration properties. Changing the process parameters, one can create layers with diverse average fibre diameters and thicknesses. It enables the design and creation of optimal filtration materials prepared for aerosol particle filtration. The structures were numerically modelled using the lattice Boltzmann approach to obtain detailed production guidelines using the blow-spinning technique. The advantage of this method is the ability to blow fibres with diameters in the nanoscale, applying relatively simple and cost-effective equipment. For tested PLA solutions, i.e., 6% and 10%, the mean fibre diameter decreases as the concentration decreases. Therefore, the overall filtering efficiency decreases as the concentration of the used solution increases. The produced multi-layer filters have 96% overall filtration efficiency for particles ranging from 0.26 to 16.60 micrometres with a pressure drop of less than 160 Pa. Obtained results are auspicious and are a step in producing efficient, biodegradable air filters.

Multifunctional bilayer membranes composed of poly(lactic acid), beta-chitin whiskers and silver nanoparticles for wound dressing applications

Nanomaterial-based wound dressings have been extensively studied for the treatment of both minor and life-threatening tissue injuries. These wound dressings must possess several crucial characteristics, such as tissue compatibility, non-toxicity, appropriate biodegradability to facilitate wound healing, effective antibacterial activity to prevent infection, and adequate physical and mechanical strength to withstand repetitive dynamic forces that could potentially disrupt the healing process. Nevertheless, the development of nanostructured wound dressings that incorporate various functional micro- and nanomaterials in distinct architectures, each serving specific purposes, presents significant challenges. In this study, we successfully developed a novel multifunctional wound dressing based on poly(lactic acid) (PLA) fibrous membranes produced by solution-blow spinning (SBS) and electrospinning. The PLA-based membranes underwent surface modifications aimed at tailoring their properties for utilization as effective wound dressing platforms. Initially, beta-chitin whiskers were deposited onto the membrane surface through filtration, imparting hydrophilic character. Afterward, silver nanoparticles (AgNPs) were incorporated onto the beta-chitin layer using a spray deposition method, resulting in platforms with antimicrobial properties against both Staphylococcus aureus and Escherichia coli. Cytotoxicity studies demonstrated the biocompatibility of the membranes with the neonatal human dermal fibroblast (HDFn) cell line. Moreover, bilayer membranes exhibited a high surface area and porosity (> 80%), remarkable stability in aqueous media, and favorable mechanical properties, making them promising candidates for application as multifunctional wound dressings.

Fiber Sedimentation and Layer-By-Layer Assembly Strategy for Designing Biomimetic Quasi-Ordered Mullite Fiber Aerogels as Extreme Conditions Thermal Insulators

Ceramic fiber aerogels are attractive thermal insulating materials. In a thermomechanical coupling environment, however, they often show limited mechanical strength and considerably increased heat transfer which can lead to thermal runaway. In this paper, inspired by bird's nest and nacre, we demonstrate a sample strategy combining fiber sedimentation and layer-by-layer assembly to fabricate ultrastrong mullite fiber aerogels (MFAs) with quasi-ordered structures. The fibrous layers and fiber bridges are constructed in a fiber sedimentation self-assembly process. The fiber sedimentation technique optimizes the structure of the MFAs by regulating the fiber orientation. Owing to the quasi-ordered structure, the fabricated MFAs exhibit the integrated properties of high compression fatigue resistance, temperature-invariant compression resilience from -196 to 1300 °C, and low thermal conductivity (0.034 W·m-1·K-1). By deliberately pressing multilayer MFAs into a thin paper, we substantially enhance the load-bearing capacity of the MFAs and achieve large temperature differences (563 °C) between the cold and hot surfaces by using a thin layer of MFAs (3-5 mm) under the simulated high-temperature (685 °C) and high-pressure (0.9 MPa) environment test. The combination of compression resistance, mechanical flexibility, and excellent thermal insulation provides an appealing material for efficient thermal insulation in extreme environments.

Evaluation of polycaprolactone nanofibers' spinnability using green solvent systems by solution blow spinning (SBS)

Solution blow spinning (SBS) is a promising alternative to produce fibrous matrices for a wide range of applications, such as packaging and biomedical devices. Polycaprolactone (PCL) is a biodegradable polyester commonly used for spinning. The usual choices for producing PCL solutions include chlorinated solvents (CS), such as chloroform. However, the high toxicity of CS makes it difficult for biological and green applications. This work evaluates the influence of two less toxic solvents, acetic acid (AA) and acetone (Acet), and their mixtures (AA/Acet) on the properties of PCL fibers produced by SBS. The results showed that Acet does not cause degradation of the PCL chains, in opposition to AA. Furthermore, adding acetone to the acetic acid tended to preserve the size of PCL chains. It was not possible to produce fibers using PCL in 100% acetone. However, the AA/Acet mixture allowed the efficient production of PCL fibers. The proportion of Acet and AA in the mixture modulated the fiber morphology and orientation, making it possible to use this green solvent system according to the desired application.

Advances in Biomedical Applications of Solution Blow Spinning

In recent years, Solution Blow Spinning (SBS) has emerged as a new technology for the production of polymeric, nanocomposite, and ceramic materials in the form of nano and microfibers, with similar features to those achieved by other procedures. The advantages of SBS over other spinning methods are the fast generation of fibers and the simplicity of the experimental setup that opens up the possibility of their on-site production. While producing a large number of nanofibers in a short time is a crucial factor in large-scale manufacturing, in situ generation, for example, in the form of sprayable, multifunctional dressings, capable of releasing embedded active agents on wounded tissue, or their use in operating rooms to prevent hemostasis during surgical interventions, open a wide range of possibilities. The interest in this spinning technology is evident from the growing number of patents issued and articles published over the last few years. Our focus in this review is on the biomedicine-oriented applications of SBS for the production of nanofibers based on the collection of the most relevant scientific papers published to date. Drug delivery, 3D culturing, regenerative medicine, and fabrication of biosensors are some of the areas in which SBS has been explored, most frequently at the proof-of-concept level. The promising results obtained demonstrate the potential of this technology in the biomedical and pharmaceutical fields.

Research progress of polyphenols in nanoformulations for antibacterial application

Infectious disease is one of the top 10 causes of death worldwide, especially in low-income countries. The extensive use of antibiotics has led to an increase in antibiotic resistance, which poses a critical threat to human health globally. Natural products such as polyphenolic compounds and their derivatives have been shown the positive therapeutic effects in antibacterial therapy. However, the inherent physicochemical properties of polyphenolic compounds and their derivatives limit their pharmaceutical effects, such as short half-lives, chemical instability, low bioavailability, and poor water solubility. Nanoformulations have shown promising advantages in improving antibacterial activity by controlling the release of drugs and enhancing the bioavailability of polyphenols. In this review, we listed the classification and antibacterial mechanisms of the polyphenolic compounds. More importantly, the nanoformulations for the delivery of polyphenols as the antibacterial agent were summarized, including different types of nanoparticles (NPs) such as polymer-based NPs, metal-based NPs, lipid-based NPs, and nanoscaffolds such as nanogels, nanofibers, and nanoemulsions. At the same time, we also presented the potential biological applications of the nano-system to enhance the antibacterial ability of polyphenols, aiming to provide a new therapeutic perspective for the antibiotic-free treatment of infectious diseases.

A Review on Electrospun Nanofiber Composites for an Efficient Electrochemical Sensor Applications

The present review article discusses the elementary concepts of the sensor mechanism and various types of materials used for sensor applications. The electrospinning method is the most comfortable method to prepare the device-like structure by means of forming from the fiber structure. Though there are various materials available for sensors, the important factor is to incorporate the functional group on the surface of the materials. The post-modification sanction enhances the efficiency of the sensor materials. This article also describes the various types of materials applied to chemical and biosensor applications. The chemical sensor parts include acetone, ethanol, ammonia, and CO2, H2O2, and NO2 molecules; meanwhile, the biosensor takes on glucose, uric acid, and cholesterol molecules. The above materials have to be sensed for a healthier lifestyle for humans and other living organisms. The prescribed review articles give a detailed report on the Electrospun materials for sensor applications.

Alumina Ceramic Nanofibers: An Overview of the Spinning Gel Preparation, Manufacturing Process, and Application

As an important inorganic material, alumina ceramic nanofibers have attracted more and more attention because of their excellent thermal stability, high melting point, low thermal conductivity, and good chemical stability. In this paper, the preparation conditions for alumina spinning gel, such as the experimental raw materials, spin finish aid, aging time, and so on, are briefly introduced. Then, various methods for preparing the alumina ceramic nanofibers are described, such as electrospinning, solution blow spinning, centrifugal spinning, and some other preparation processes. In addition, the application of alumina ceramic nanofibers in thermal insulation, high-temperature filtration, catalysis, energy storage, water restoration, sound absorption, bioengineering, and other fields are described. The wide application prospect of alumina ceramic nanofibers highlights its potential as an advanced functional material with various applications. This paper aims to provide readers with valuable insights into the design of alumina ceramic nanofibers and to explore their potential applications, contributing to the advancement of various technologies in the fields of energy, environment, and materials science.