Electrospun Wrinkled Porous Polyimide Nanofiber-Based Filter via Thermally Induced Phase Separation for Efficient High-Temperature PMs Capture

Adjusting Morphology, Structure, and Mechanical Properties of Electrospun High-Molecular-Weight Poly(l-Lactic-Acid) Nanofibrous Yarns Through Hot Stretching Treatment

An integrated strategy that combines innovative electrospinning technique with traditional hot-stretching post-treatment is designed and implemented to generate high-molecular-weight poly(l-lactic-acid) (hmwPLLA, Mw = 2 80 000 Da) electrospun nanofiber-constructed yarns (ENCYs). The internal fiber diameter within the hmwPLLA ENCYs is found to increase gradually with the increase of hmwPLLA solution concentration. The hmwPLLA ENCY generated from a concentration of 10% (w v-1) is demonstrated with uniform morphology with an average fiber diameter of 737.7 ± 72.2 nm and an average yarn diameter of 454.9 ± 3.5 µm. Compared with the unstretched hmwPLLA ENCY, increasing the hot-stretching temperature can significantly enhance the fiber orientation and crystallinity. Moreover, the mechanical properties of stretched ENCYs are obviously enhanced compared with the unstretched control. The fiber orientation and crystallinity of stretched ENCYs are also found to be significantly improved with the increase of hot stretching rate, further resulting in the obvious increase of breaking strength and Young's modulus. Importantly, the braided textiles made from stretched hmwPLLA ENCYs exhibited great biocompatibility by effectively guiding the cell alignment and supporting the cell adhesion and proliferation. In summary, the high performance hmwPLLA ENCYs show great potential for the future design and development of advanced biomedical textiles.

Exceptionally High-Temperature-Resistant Kapton-Type Polyimides with Tg > 520 °C: Synthesis via Incorporation of Spirobis(indene)-bis(benzoxazole)-Containing Diamines

Polyimides (PIs), recognized for their exceptional thermal stability, are extensively employed in advanced applications, including aerospace, flexible displays, flexible solar cells, flame-retardant materials, and high-temperature filtration materials. However, with the continuous advancements in science and technology, the demand for improved thermal performance of PIs in these application areas has increased significantly. In this study, four spirobis(indene)-bis(benzoxazole) diamine monomers (5a, 5aa, 5b and 5bb) were designed and synthesized. These monomers were copolymerized with pyromellitic dianhydride (PMDA) and 4,4-diaminodiphenylmethane (ODA) to develop Kapton-type PIs. By varying the copolymerization molar ratios of the different diamines, a series of novel ultrahigh-temperature-resistant PI films were successfully prepared, and it was found that incorporating a highly rigid and twisted spirobis(indene)-bis(benzoxazole) structure into the PI matrix enhances the rigidity of the polymer chains and restricts their mobility, thereby significantly improving the thermal performance of the PI films. When 5a and ODA were copolymerized at molar ratios of 1:9 and 4:6, the glass transition temperature (Tg) of Kapton-type films significantly increased from 396 °C to 467 °C and >520 °C, respectively. These PI films also exhibit exceptional mechanical properties, with the modulus increasing from 1.6 GPa to 4.7 GPa, while demonstrating low dielectric performance, as evidenced by a decrease in the dielectric constant (Dk) from 3.51 to 3.08 under a 10 GHz high-frequency electric field. Additionally, molecular dynamics simulations were employed to further explore the relationships between polymer molecular structure, condensed states, and film properties, providing theoretical guidance for the development of polymers with ultrahigh thermal resistance and superior overall performance.

Leveraging artificial intelligence for better translation of fibre-based pharmaceutical systems into real-world benefits

The increasing prominence of biologics in the pharmaceutical market requires more advanced delivery systems to deliver these delicate and complex drug molecules for better therapeutic outcomes. Fibre technology has emerged as a promising approach for creating controlled and targeted drug delivery systems. Fibre-based drug delivery systems offer unprecedented opportunities for improving drug administration, fine-tuning release profiles, and advancing the realm of personalized medicine. These applications range from localized delivery at specific tissue sites to systemic drug administration while safeguarding the stability and integrity of delicate therapeutic compounds. Notwithstanding the promise of fibre-based drug delivery, several challenges such as non-scalability impede cost-effectiveness in the mass production of fibre systems. Biocompatibility and toxicity concerns must also be addressed. Furthermore, issues relating to stability, in-vitro in-vivo correlations, degradation rates, and by-product safety present additional hurdles. Pharmacoinformatics shows the impact of technologies in pharmaceutical processes. Emerging technologies such as Artificial Intelligence (AI) are a transformative force, progressively being applied to enhance various facets of pharmacy, medication development, and clinical healthcare support. However, there is a dearth of studies about the integration of AI in facilitating the translation of predominantly lab-scale pharmaceutical technologies into real-world healthcare interventions. This article explores the application of AI in fibre technology, its potential, challenges, and practical applications within the pharmaceutical field. Through a comprehensive analysis, it presents how the immense capabilities of AI can be leveraged with existing fibre technologies to revolutionize drug delivery and shape the future of therapeutic interventions by enhancing scalability, material integrity, synthesis, and development.

Beyond aromatherapy: can essential oil loaded nanocarriers revolutionize cancer treatment?

Cancer, a complex global health burden, necessitates the development of innovative therapeutic strategies. While chemotherapy remains the primary treatment approach, its severe side effects and chemoresistance drive the search for novel alternatives. Essential oils (EOs), consisting of diverse bioactive phytochemicals, offer promise as anticancer agents. However, their limitations, such as instability, limited bioavailability, and non-specific targeting, hinder their therapeutic potential. These challenges were circumvented by utilizing nanoparticles and nanosystems as efficient delivery platforms for EOs. This review highlights the accumulating evidence based on loading EOs into several nanocarriers, including polymeric nanoparticles, nanoemulsions, nanofibers, lipid-based nanocapsules and nanostructures, niosomes, and liposomes, as effective anticancer regimens. It covers extraction and chemical composition of EOs, their mechanisms of action, and targeting strategies to various tumors. Additionally, it delves into the diverse landscape of nanocarriers, including their advantages and considerations for cancer targeting and EO encapsulation. The effectiveness of EO-loaded nanocarriers in cancer targeting and treatment is examined, highlighting enhanced cellular uptake, controlled drug release, and improved therapeutic efficacy. Finally, the review addresses existing challenges and future perspectives, emphasizing the potential for clinical translation and personalized medicine approaches.

Recent advances in harnessing biological macromolecules for wound management: A review

Wound dressings (WDs) are an essential component of wound management and serve as an artificial barrier to isolate the injured site from the external environment, thereby helping to prevent exogenous infections and supporting healing. However, maintaining a moist wound environment, providing protection from infection, good biocompatibility, and allowing for gas exchange, remain a challenge in device design. Functional wound dressings (FWDs) prepared from hybrid biological macromolecule-based materials can enhance efficacy of these systems for skin wound management. This review aims to provide an overview of the state-of-the-art FWDs within the field of wound management, with a specific focus on hybrid biomaterials, techniques, and applications developed over the past five years. In addition, we highlight the incorporation of biological macromolecules in WDs, the emergence of smart WDs, and discuss the existing challenges and future prospects for the development of advanced WDs.

One-step fabrication of polylactic acid (PLA) nanofibrous membranes with spider-web-like structure for high-efficiency PM0.3 capture

High-efficiency air filters are in high demand to protect human health from the threat of ultrafine particulate matters (PM). However, most commercial air filters are less effective for PM0.3 capture and/or still suffer from undesirable pressure drops. They are also typically petroleum-based. Herein, a double-jet synchronous electrospinning technology was demonstrated to fabricate spider-web-like polylactic acid (PLA) nanofibrous membranes (SPNM) in one step. The properties of spinning solutions were regulated to construct favorable multi-scale nanofiber and bead structures that mimicked the structural units in spider-webs. The as-prepared SPNM exhibited excellent filtration efficiency (99.87 %) and high quality factor (0.321 Pa-1) against the PM0.3, while presenting an attractively low pressure drop (19 Pa). Additionally, the filtration performance of SPNM was almost completely preserved during 10-cycle tests and the 6-month long-term tests, showing excellent function stability and durability. Benefiting from its good hydrophobicity (WCA = 143.2°), SPNM also presented a satisfactory filtration efficiency (>99.37 %) with low pressure drop (18 Pa) at an environment with humidity at 90 % against PM0.3. Furthermore, the unique structure increased the mechanical strength of SPNM, facilitating the processability for practical applications. Overall, this work may shed light on a promising approach for developing biomass-based, highly efficient filtration materials with hierarchical structures.

Synergistic anticancer effect of Pistacia lentiscus essential oils and 5-Fluorouracil co-loaded onto biodegradable nanofibers against melanoma and breast cancer

Chemoresistance and severe toxicities represent major drawbacks of chemotherapy. Natural extracts, including the essential oils of Pistacia lentiscus (PLEO), exhibit substantial anticancer and anti-inflammatory activities where different cancers are reported to dramatically recess following targeting with PLEO. PLEO has promising antimicrobial, anticancer, and anti-inflammatory properties. However, the therapeutic properties of PLEO are restricted by limited stability, bioavailability, and targeting ability. PLEO nanoformulation can maximize their physicochemical and therapeutic properties, overcoming their shortcomings. Hence, PLEO was extracted and its chemical composition was determined by GC-MS. PLEO and 5-Fluorouracil (5FU) were electrospun into poly-ε-caprolactone nanofibers (PCL-NFs), of 290.71 nm to 680.95 nm diameter, to investigate their anticancer and potential synergistic activities against triple-negative breast cancer cells (MDA-MB-231), human adenocarcinoma breast cancer cells (MCF-7), and human skin melanoma cell line (A375). The prepared nanofibers (NFs) showed enhanced thermal stability and remarkable physical integrity and tensile strength. Biodegradability studies showed prolonged stability over 42 days, supporting the NFs use as a localized therapy of breast tissues (postmastectomy) or melanoma. Release studies revealed sustainable release behaviors over 168 h, with higher released amounts of 5FU and PLEO at pH 5.4, indicating higher targeting abilities towards cancer tissues. NFs loaded with PLEO showed strong antioxidant properties. Finally, NFs loaded with either PLEO or 5FU depicted greater anticancer activities compared to free compounds. The highest anticancer activities were observed with NFs co-loaded with PLEO and 5FU. The developed 5FU-PLEO-PCL-NFs hold potential as a local treatment of breast cancer tissues (post-mastectomy) and melanoma to minimize their  possible recurrence.

Multiphasic bone-ligament-bone integrated scaffold enhances ligamentization and graft-bone integration after anterior cruciate ligament reconstruction

The escalating prevalence of anterior cruciate ligament (ACL) injuries in sports necessitates innovative strategies for ACL reconstruction. In this study, we propose a multiphasic bone-ligament-bone (BLB) integrated scaffold as a potential solution. The BLB scaffold comprised two polylactic acid (PLA)/deferoxamine (DFO)@mesoporous hydroxyapatite (MHA) thermally induced phase separation (TIPS) scaffolds bridged by silk fibroin (SF)/connective tissue growth factor (CTGF)@Poly(l-lactide-co-ε-caprolactone) (PLCL) nanofiber yarn braided scaffold. This combination mimics the native architecture of the ACL tissue. The mechanical properties of the BLB scaffolds were determined to be compatible with the human ACL. In vitro experiments demonstrated that CTGF induced the expression of ligament-related genes, while TIPS scaffolds loaded with MHA and DFO enhanced the osteogenic-related gene expression of bone marrow stem cells (BMSCs) and promoted the migration and tubular formation of human umbilical vein endothelial cells (HUVECs). In rabbit models, the BLB scaffold efficiently facilitated ligamentization and graft-bone integration processes by providing bioactive substances. The double delivery of DFO and calcium ions by the BLB scaffold synergistically promoted bone regeneration, while CTGF improved collagen formation and ligament healing. Collectively, the findings indicate that the BLB scaffold exhibits substantial promise for ACL reconstruction. Additional investigation and advancement of this scaffold may yield enhanced results in the management of ACL injuries.

Advancing Nanofiber Research: Assessing Nonsolvent Contributions to Structure Using Coaxial Electrospinning

In this study, we explored the influence of molecular interactions and solvent evaporation kinetics on the formation of porous structures in electrospun nanofibers, utilizing polyacrylonitrile (PAN) and polystyrene (PS) as model polymers. The coaxial electrospinning technique was employed to control the injection of water and ethylene glycol (EG) as nonsolvents into polymer jets, demonstrating its potential as a powerful tool for manipulating phase separation processes and fabricating nanofibers with tailored properties. Our findings highlighted the critical role of intermolecular interactions between nonsolvents and polymers in governing phase separation and porous structure formation. Additionally, we observed that the size and polarity of nonsolvent molecules affected the phase separation process. Furthermore, solvent evaporation kinetics were found to significantly impact phase separation, as evidenced by less distinct porous structures when using a rapidly evaporating solvent like tetrahydrofuran (THF) instead of dimethylformamide (DMF). This work offers valuable insights into the intricate relationship between molecular interactions and solvent evaporation kinetics during electrospinning, providing guidance for researchers developing porous nanofibers with specific characteristics for various applications, including filtration, drug delivery, and tissue engineering.

Hydrophobic/oleophobic nanofibrous filter media with bead-on-string structure for efficient personal protection of dust in mines

Pneumoconiosis in mines occupied more than 90% of the total number of occupational diseases, poses tremendous pressure and challenges on the development of personal protection materials with high dust filtration efficiency and long-lasting comfortable wearing. In this study, a kind of polyethylene terephthalate (PET) based filter media with the bead-on-string structure and hydrophobic/oleophobic property was designed and fabricated by electrospinning technology. Nanoscale silicon dioxide (SiO₂NPs) and fluorinated polyurethane (PU) used in this work were benefited for the microstructure, surface energy and hydrophobic/oleophobic property, respectively. The morphology and composition of the membranes were conducted by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and fourier transform infrared spectroscopy (FTIR). Furthermore, the filtration performance, pressure drop, moisture permeability and breathing comfortable performance were measured for the study of personal protection of dust. The results showed that at the air flow of 85 L min^-1, PET/SiO₂/FPU double-layer nanofibrous membrane showed high filtration efficiency and low pressure drop with the filtration efficiency of 99.96%, pressure drop of 142.5 Pa and quality factor of 0.055 Pa^-1, respectively. A long term of 24 h water vapor test had proved that this membrane held an outstanding moisture permeability ability of 5296.325 g (m² 24 h)^-1. Compared with the commercial 3701CN filter media, the advantages of the regular breathing frequency and strong heart rate control ability indicated that this PET/SiO₂/FPU double-layer membrane had the better wearing comfortable performance with broad application prospects in the personal protection of dust in mines.

Advanced functional nanofibers: strategies to improve performance and expand functions

Nanofibers have a wide range of applications in many fields such as energy generation and storage, environmental sensing and treatment, biomedical and health, thanks to their large specific surface area, excellent flexibility, and superior mechanical properties. With the expansion of application fields and the upgrade of application requirements, there is an inevitable trend of improving the performance and functions of nanofibers. Over the past few decades, numerous studies have demonstrated how nanofibers can be adapted to more complex needs through modifications of their structures, materials, and assembly. Thus, it is necessary to systematically review the field of nanofibers in which new ideas and technologies are emerging. Here we summarize the recent advanced strategies to improve the performances and expand the functions of nanofibers. We first introduce the common methods of preparing nanofibers, then summarize the advances in the field of nanofibers, especially up-to-date strategies for further enhancing their functionalities. We classify these strategies into three categories: design of nanofiber structures, tuning of nanofiber materials, and improvement of nanofibers assemblies. Finally, the optimization methods, materials, application areas, and fabrication methods are summarized, and existing challenges and future research directions are discussed. We hope this review can provide useful guidance for subsequent related work.

Graphical abstract

High-performance multifunctional electrospun fibrous air filter for personal protection: A review

With the increasingly serious air pollution and the rampant coronavirus disease 2019 (COVID–19), preparing high–performance air filter to achieve the effective personal protection has become a research hotspot. Electrospun nanofibrous membrane has become the first choice of air filter because of its small diameter, high specific surface area and porosity. However, improving the filtration performance of the filter only cannot meet the personal needs: it should be given more functions based on high filtration performance to maximize the personal benefits, called, multifunctional, which can also be easily realized by electrospinning technology, and has attracted much attention. In this review, the filtration mechanism of high–performance electrospun air filter is innovatively summarized from the perspective of membrane. On this basis, the specific preparation process, advantages and disadvantages are analyzed in detail. Furthermore, other functions required for achieving maximum personal protection benefits are introduced specifically, and the existing high–performance electrospun air filter with multiple functions are summarized. Finally, the challenges, limitations, and development trends of manufacturing high–performance air filter with multiple functions for personal protection are presented.

Binary Polyamide-Imide Fibrous Superelastic Aerogels for Fire-Retardant and High-Temperature Air Filtration

Fibrous air filtration materials are highly desirable for particle removal from high-temperature emission sources. However, the existing commercial filter materials suffer from either low filtration efficiency or high pressure drop, due to the difficulty in achieving small fiber diameter and high porosity simultaneously. Herein, we report a facile strategy to fabricate mechanical robust fibrous aerogels by using dual-scale sized PAI/BMI filaments and fibers, which are derived from wet spinning and electrospinning technologies, respectively. The creativity of this design is that PAI/BMI filaments can serve as the enhancing skeleton and PAI/BMI fibers can assemble into high-porosity interconnected networks, enabling the improvement of both mechanical property and air filtration performance. The resultant dual-scale sized PAI/PBMI fibrous aerogels show a compressive stress of 8.36 MPa, a high filtration efficiency of 90.78% (particle diameter of 2.5 μm); for particle diameter over 5 μm, they have 99.99% ultra-high filtration efficiency, a low pressure drop of 20 Pa, and high QF of 0.12 Pa^-1, as well as thermostable and fire-retardant properties (thermal decomposition temperature up to 342.7 °C). The successive fabrication of this material is of great significance for the govern of industrial dust.

HEPA filters for airliner cabins: State of the art and future development

The airliner cabin environment is very important to the health of passengers and crew members, and the use of high-efficiency particulate air (HEPA) filters for recirculated air in the environmental control systems (ECS) is essential for the removal of airborne particles such as SARS CoV-2 aerosols. A HEPA filter should be high efficiency, low-pressure drop, high dust-holding capacity (DHC), lightweight, and strong for use in aircraft. We conducted an experimental study on 23 HEPA filters with glass fiber media that are used in different commercial airliner models. The tested filters had a median filtration efficiency of >99.97% for particles with a diameter of 0.3-0.5 μm, a pressure drop of 134-412 Pa at rated airflow rate, and a DHC of 32.2-37.0 g/m² . The use of nanofiber media instead of glass fiber media can reduce the pressure drop by 66.4%-94.3% and significantly increase the quality factor by analysis of literature data. The disadvantages of poor fire resistance and small DHC can be overcome by the use of flame-retardant polymers and fiber structural design. As a new lightweight and environmentally friendly filter material, nanofiber media could be used as air filters in ECS in the future.

Degradable, antibacterial and ultrathin filtrating electrospinning membranes of Ag-MOFs/poly(l-lactide) for air pollution control and medical protection

The widely used melt-blown polypropylene (PP) non-woven fabrics had no antibacterial functions and its large-scale use also increased the burden on the environment owing to its non-degradable property. Herein, silver (I) metal organic frameworks (Ag-2MI) were prepared with AgNO3 and 2-methylimidazole and embedded into degradable poly(l-lactide) (PLLA) to make an ultrathin filtration and antibacterial membrane by electrospinning technology with low loading of Ag-2MI. The morphology, mechanical properties, adsorption performance and antibacterial activities of the prepared films were tested and the results indicated that the addition of Ag-2MI could reduce the diameter of PLLA fibers from 910 nm to 520 nm (1.8 wt% of Ag-2MI), while the tensile strength, elongation at break of the membrane and the contact angle of the films were enhanced. Although the thickness of the prepared membranes was only about one-third of that of commercially available melt-blown cloth, they exhibited better filtering performances than the melt-blown cloth. The fiber membrane with low loading of 1.8 wt% Ag-2MI showed 99.99% inhibition rate against Escherichia coli and Staphylococcus aureus.

Experimental Research on Dynamic Filtering Characteristics of Filter Materials for Electrostatic-Fabric Integrated Precipitator

In recent years, the electrostatic-fabric integrated precipitator has been widely used, and the dust filtration performance of the core component filter bag is the most important factor affecting its dust removal efficiency. In this work, the dynamic dust removal performance of different types of filter media and different experimental conditions were studied on the filter media filtration performance test platform. The experimental study of the filtration performance of different types of filter media showed that the filtration performance stability of polyphenylene sulfide (PPS) filter media was better than that of polyimide (PI) and polytetrafluoroethylene (PTFE) filter media. Increasing the mass per unit area of the filter media had obvious advantages in the short term, and the impregnation process was beneficial to the filter performance of the filter media. Membrane-coated filter media had the best filtration performance, gradient filter media filtration performance was the second, followed by conventional filter media, ordinary blended, and ultrafine blended filter media. Studies with different experimental conditions found that the filtration efficiency increased with increasing resistance, was not significantly affected by changes in inlet dust concentration, but decreased with the increasing filtering velocity. This experimental results provided an important basis for the selection of filter bags for the electrostatic-fabric integrated precipitator project.

Multilevel structured PASS nanofiber filter with outstanding thermal stability and excellent mechanical property for high-efficiency particulate matter removal

Particulate matter (PM) pollution from industrialization poses a great threat to people's health. Although fiber-based filters are used effectively to capture PM, the traditional filters with large diameter suffer from low filtration efficiency, high pressure drop and low temperature resistance. In this study, multilayer poly arylene sulfide sulfone (M-PASS) composite filter was designed and fabricated via electrospinning technology. The M-PASS composite filter is sandwich-structure. Due to the unique structure and composition, the M-PASS filter exhibited outstanding removal efficiency of 99.97 ± 0.0050%, extremely low air resistance of 44.3 ± 0.7 Pa, excellent quality factor (QF) of 0.19 ± 0.0019 Pa^-1, and desirable mechanical strength of 7.0 ± 0.2 MPa. Furthermore, the as-prepared M-PASS filter can remain outstanding filtration performance at 200.0 ℃ due to the high thermal stability of PASS and the removal efficiency was still above 95.2 ± 0.4% after long-term filtration test. These results demonstrate that the structure of filter is the important one for air filtration and the M-PASS nanofiber filters have great potential in PM removal, especially under high temperature conditions.

Electrospun PAN-HNTs composite nanofiber membranes for efficient electrostatic capture of particulate matters

The fine particulate matter (PM) pollution has become a serious concern to public health. As the core part of PM air filters, high-performance electrostatic nanofiber membranes are urgently needed. However, the existing air filters remain challenging to further decrease the pressure drop to improve the wearer comfort. On the other hand, the rapidly disappearing static electricity of the existing electrostatic nanofiber inevitably gives rise to a relatively short service life. Here, we demonstrate a novel and enhanced electrostatic nanofiber membrane by introducing the halloysite nanotubes (HNTs) to the traditional electrospun PAN nanofiber membrane. The optimal PAN-HNTs nanofiber membrane shows a high removal efficiency of 99.54%, a low pressure drop of 39 Pa, and a high quality factor of 0.89 Pa^-1. This greatly improved filtration performance can be attributed to the increased surface area and diameter of nanofiber after introducing the HNTs as additives with suitable doping concentrations. More importantly, compared with the pure PAN nanofiber membrane, the electrostatic capacity of the PAN-HNTs nanofiber membrane is significantly enhanced, which is confirmed by the leaf electroscope. After introducing the HNTs as additives, the surface of the PAN-HNTs nanofiber membrane becomes hydrophilic, which benefits for preventing foulants from attaching to the surface. We anticipate that the PAN-HNTs nanofibers as high-performance membrane air filters will bring great benefits to public health.

Advances in particulate matter filtration: Materials, performance, and application

Air-borne pollutants in particulate matter (PM) form, produced either physically during industrial processes or certain biological routes, have posed a great threat to human health. Particularly during the current COVID-19 pandemic, effective filtration of the virus is an urgent matter worldwide. In this review, we first introduce some fundamentals about PM, including its source and classification, filtration mechanisms, and evaluation parameters. Advanced filtration materials and their functions are then summarized, among which polymers and MOFs are discussed in detail together with their antibacterial performance. The discussion on the application is divided into end-of-pipe treatment and source control. Finally, we conclude this review with our prospective view on future research in this area.

A Review on Electrospun Nanofibers Based Advanced Applications: From Health Care to Energy Devices

Electrospun nanofibers have been exploited in multidisciplinary fields with numerous applications for decades. Owing to their interconnected ultrafine fibrous structure, high surface-to-volume ratio, tortuosity, permeability, and miniaturization ability along with the benefits of their lightweight, porous nanofibrous structure, they have been extensively utilized in various research fields for decades. Electrospun nanofiber technologies have paved unprecedented advancements with new innovations and discoveries in several fields of application including energy devices and biomedical and environmental appliances. This review article focused on providing a comprehensive overview related to the recent advancements in health care and energy devices while emphasizing on the importance and uniqueness of utilizing nanofibers. A brief description regarding the effect of electrospinning techniques, setup modifications, and parameters optimization on the nanofiber morphology was also provided. The article is concluded with a short discussion on current research challenges and future perspectives.

Breaking the barriers for the delivery of amikacin: Challenges, strategies, and opportunities

Hypodermic delivery of amikacin is a widely adopted treatment modality for severe infections, including bacterial septicemia, meningitis, intra-abdominal infections, burns, postoperative complications, and urinary tract infections in both paediatric and adult populations. In most instances, the course of treatment requires repeated bolus doses of amikacin, prolonged hospitalization, and the presence of a skilled healthcare worker for administration and continuous therapeutic monitoring to manage the severe adverse effects. Amikacin is hydrophilic and exhibits a short half-life, which further challenges the delivery of sufficient systemic concentrations when administered by the oral or transdermal route. In this purview, the exploitation of novel controlled and sustained release drug delivery platforms is warranted. Furthermore, it has been shown that novel delivery systems are capable of increasing the antibacterial activity of amikacin at lower doses when compared to the conventional formulations and also aid in overcoming the development of drug-resistance, which currently is a significant threat to the healthcare system worldwide. The current review presents a comprehensive overview of the developmental history of amikacin, the mechanism of action in virulent strains as well as the occurrence of resistance, and various emerging drug delivery solutions developed both by the academia and the industry. The examples outlined within the review provides significant pieces of evidence on novel amikacin formulations in the field of antimicrobial research paving the path for future therapeutic interventions that will result in improved clinical outcome.

Building bimodal structures by a wettability difference-driven strategy for high-performance protein air-filters

Building bimodal structures for air-filters is promising to reduce the airflow resistance without sacrificing the filtration efficiency. To do so, multi-jet electrospinning is among the most broadly used methods, yet the interplay between single fibers in electrospinning, which is significant to their morphologies, is overlooked. In this study, we report a wettability difference-driven strategy to fabricate a bimodal protein fabric with superior filtration performance. We surprisingly find that only by co-spinning of two proteins, zein and gelatin, with different wettability between them, a drastic change of fiber diameters is spontaneously achieved. The generated protein-blend fabric possesses bimodally distributed diameters of 270 nm for gelatin fibers and of 1.12 µm for zein fibers; both pure protein fabrics via single-jet electrospinning have diameters unimodally distributed in the range of 500-700 nm. The bimodal protein-blend fabric delivers exceptional removal efficiencies of 99.67% for PM_2.5 and 98.80% for PM_0.3, yielding an ultra-low airflow resistance of 38 Pa. The PM_2.5 removal efficiency retains to be 96.04% after filtering 1000 L polluted air, indicating a good long-term performance. This study brings about a new insight into fabrication of bimodal structures using multi-jet electrospinning method and promotes the development of natural products for broad applications.

High performance, environmentally friendly and sustainable nanofiber membrane filter for removal of particulate matter 1.0

Particulate matter (PM) air pollution is becoming more and more serious and dangerous to public health, especially in developing countries where industrialization is accelerating. The use of electrospun membrane-based materials for air filtration is a widespread and effective way to help individuals avoid air pollution. However, most electrospun membrane preparation processes require the use of organic solvents, resulting in secondary environmental pollution. In this study, an environmentally friendly polyvinyl alcohol (PVA) - tannic acid (TA) composite nanofiber membrane filter was prepared by the green electrospinning and the physical cross-linking method. The filtration efficiency of the membrane filter for PM_1.0 reached 99.5%, and the pressure drop was only 35 Pa. In addition, due to the existence of intermolecular hydrogen bond between PVA and TA, the mechanical properties of the nanofiber membrane were improved to meet the requirements of practical application of the filter. Therefore, the PVA-TA composite nanofiber membrane is expected to provide a solution for the development of efficient and environmentally friendly air filter.

One-Step, Large-Scale Blow Spinning to Fabricate Ultralight, Fibrous Sorbents with Ultrahigh Oil Adsorption Capacity

The cleanup of spilled oil from water has always been a severe and urgent issue, which attracted great attention and interest. In this study, we reported a highly efficient large-scale blow spinning technique to fabricate fibrous oil sorbents including the polystyrene (PS) fibrous sponge and polyvinylidene fluoride (PVDF)/polystyrene (PS) composite package with ultrahigh oil adsorption capacity. The wide diameter distributions and multilevel pore structure of PS fibers were obtained by controlling the precursor solution compositions used in blow spinning. The PS fibrous sponge formed by accumulating naturally exhibited an ultralow density, whose oil adsorption capacity ranged from 74 to 440 g/g for various oils and organic solvents. To enhance the mechanical strength of the PS fibrous sponge, the PVDF/PS composite package with the sandwich structure was fabricated by alternately blow spinning. The PVDF/PS composite package possessed 2.7 times the tensile strength of the PS fibrous sponge while the oil adsorption capacity had merely a slight decrease. Moreover, the fabrication strategy of blow spinning used to produce the fibrous sponge and composite package is highly efficient, cost-effective, and environment-friendly, which is suitable for large-scale industrial production of oil sorbents and oil spill cleanup in environment protection.