The evolution of electronic systems towards small, flexible, portable and human-centered forms drives the demand for on-body power supplies with lightweight and high flexibility. Fiber solar cells that can be integrated into soft and lightweight textiles are considered as potential sustainable power sources for the next generation of wearable electronics. To this end, they have been extensively investigated in the past decade aiming to improve their photovoltaic performances, but there is still a big gap between the high-performance devices and real applications. Herein, the key advances of configurations, fabrications and performances of fiber solar cells are highlighted and analyzed. Based on the current progress, the latest ideas with regard to the remaining challenges and opportunities beyond the reach of the previous studies are presented.
In the recent COVID-19 pandemic, World Health Organization emphasized that early detection is an effective strategy to reduce the spread of SARS-CoV-2 viruses. Several diagnostic methods, such as reverse transcription-polymerase chain reaction (RT-PCR) and lateral flow immunoassay (LFIA), have been applied based on the mechanism of specific recognition and binding of the probes to viruses or viral antigens. Although the remarkable progress, these methods still suffer from inadequate cellular materials or errors in the detection and sampling procedure of nasopharyngeal/oropharyngeal swab collection. Therefore, developing accurate, ultrafast, and visualized detection calls for more advanced materials and technology urgently to fight against the epidemic. In this review, we first summarize the current methodologies for SARS-CoV-2 diagnosis. Then, recent representative examples are introduced based on various output signals (e.g., colorimetric, fluorometric, electronic, acoustic). Finally, we discuss the limitations of the methods and provide our perspectives on priorities for future test development.
Despite great efforts and achievement of nanomaterials in immune-associated diseases, the selection of appropriate nanomaterials and preparation technology remain some challenges and vast room for improvement. Immunotherapy has received tremendous attention throughout the medical process due to its clinical successes with the pathways of immunoactivation or immunosuppression. Recently, fibrous nanomaterials have facilitated advances in tissue repair and cancer treatments owing to the superiority of multi-channel structure, biocompatibility, tunable size and controlled surface modification. The immunoactivation-based nanofibers can potentially deliver functional agents to lesions and further actively promote immunologic intervention. On the contrary, the immunosuppression-based nanofibers prevent the immune system from overreacting through the blockage of critical pathways in vivo. This review summarizes the current application of nanofiber materials in diverse diseases, including cancer therapy, tissue regeneration (cartilage/bone, skin, tendon, nerves), myocardial infarction, psoriasis and organ defects. Some common fabrication technologies of biomedical nanofibers are also introduced. Meanwhile, the existing technical barriers and perspectives are rationally discussed, providing a constructive inspiration for the follow-up basic research and clinical transformation of nanofibers in the vibrant biomedical fields.
Schematic illustration of nanofibers applied in immunoregulation-based therapy. A variety of diseases can be treated via regulating immune microenvironment including tendon regeneration, bone/cartilage repair, nerve regeneration, skin regeneration and cancer therapy. Therefore, multifunctional nanofibers can provide opportunities for future construction of efficient immune therapy for cancer immunotherapy, tissue regeneration
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Membrane distillation (MD) utilizing low-grade thermal energy can be used to effectively desalinate hypersaline brines with a high freshwater recovery for water reuse. Membrane flux and durability are the two main indices used to evaluate MD membrane performance. In the past decade, electrospun nanofibrous distillation membranes (EFDMs) with a low mass transfer resistance have garnered increasing attention in MD research, owing to their high porosity and interconnected-pore structure. However, on the one hand, the pores of EFDMs compared to those of phase-inversion membranes are easily deformed and impacted by water flow, reducing membrane flux; on the other hand, the general hydrophobic interface is susceptible to being wetted, fouled and scaled during the desalination/concentration process, resulting in MD failure. This review will present a comprehensive discussion of the recent progress in electrospun nanofibers for the MD of hypersaline wastewaters with a focus on designing specially wettable membrane interfaces and welding-pore structured membranes to enhance MD distillation efficiency and durability simultaneously. Besides, the challenges and perspectives of MD in treating hypersaline wastewaters are also provided as a guide for future research on sustainable and clean freshwater recovery.
Versatile strategies have been developed to construct electrospun fiber-based drug delivery systems for tissue regeneration and cancer therapy. We first introduce the construction of electrospun fiber scaffolds and their various structures, as well as various commonly used types of drugs. Then, we discuss some representative strategies for controlling drug delivery by electrospun fibers, with specific emphasis on the design of endogenous and external stimuli-responsive drug delivery systems. Afterwards, we summarize the recent progress on controlling drug delivery with electrospun fiber scaffolds for tissue engineering, including soft tissue engineering (such as skin, nerve, and cardiac repair) and hard tissue engineering (such as bone, cartilage, and musculoskeletal systems), as well as for cancer therapy. Furthermore, we provide future development directions and challenges facing the use of electrospun fibers for controlled drug delivery, aiming to provide insights and perspectives for the development of smart drug delivery platforms and improve clinical therapeutic effects in tissue regeneration and cancer therapy.
Basalt fibers (BFs) have emerged as a promising thermal insulation material for various applications, such as fireproof clothes/walls and protective equipment in military and civil engineering. BFs have many desirable characteristics, such as low thermal conductivity, excellent flame resistance, exceptional mechanical strength, facile manipulability, environmental friendliness, and cost-effectiveness. Nevertheless, the low intrinsic interfacial properties of BFs due to their chemical inertness and macro-scaled sizes have been a challenge for high performance of BFs-reinforced polymeric composites (BFRPs). Since the mechanical properties of BFRPs significantly depend on the interfacial interaction between the fibers and the matrix, it is critical to understand how incorporating BFs influences the properties of the composites. To this end, the aim of this review is to report on recent research progress with emphasis on the interfacial behavior in BFRPs. The relationships between the fiber–matrix interfacial adhesion and the mechanical properties of the BFRPs are briefly described with systematic and up-to-date surface modification techniques summarized into two categories: surface modifications (“wet” and “dry”) and multi-scaled structures. Finally, several strategies for increasing the interfacial adhesion of BFs within the polymeric matrix to provide new ideas and insight for future research on the BFRPs are discussed.
Electrospun nanofiber materials, with the advantages of large specific surface area, small pore size, high porosity, good channel connectivity, and ease of functional modification, have been widely used in various fields including environmental governance, safety protection, and tissue engineering. With the development of functional fiber materials, the construction of three-dimensional (3D) fiber materials with stable structures has become a critical challenge to expanding application and improving the performance of electrospun fibers. In recent years, researchers have carried out a lot of studies on the 3D reconstruction of electrospun fiber membranes and direct electrospinning of fiber sponges. Specifically, a variety of 3D fibrous sponges were constructed by the 3D reconstruction of electrospun fiber membranes, including embedded hydrogels, 3D printing, gas-foaming, and freeze-drying methods. Meanwhile, the direct electrospinning methods of 3D fibrous sponges have also been successfully developed, which are mainly divided into layer-by-layer stacking, liquid-assisted collection, 3D template collection, particle leaching, and humidity field regulation. Moreover, the applications of these fibrous sponges in many fields have been explored, such as sound absorption, warmth retention, thermal insulation, air filtration, adsorption/separation, and tissue engineering. These research works provide new ideas and methods for the fabrication of 3D fiber materials. Herein, the electrospinning technology and principle were briefly introduced, the representative progress of 3D fiber sponges in recent years was summarized, and their future development prospected.
Metal–organic frameworks (MOFs) are attractive in many fields due to their unique advantages. However, the practical applications of single MOF materials are limited. In recent years, a large number of MOF-based composites have been investigated to overcome the defects of single MOF materials to broaden the avenues for the practical applications of MOFs. Among them, MOF-based hybrid nanofiber membranes fabricated by electrospinning combine the advantages of polymer nanofibers and inorganic porous materials, receiving extensive attention and development in energy storage and environmental protection. This review systematically summarizes the recent progress of MOF-based hybrid nanofiber membranes prepared by electrospinning from the perspectives of preparation and application. Firstly, two main methods for preparing MOF/polymer nanofibrous membranes are discussed. Next, the applications of MOF/polymer nanofibrous membranes in energy storage and environmental protection are summarized at length. Finally, to fully tap the potential of MOF-based nanofiber membranes in more fields, the current challenges are proposed, and future research directions are discussed.
Fibers and textiles that harvest mechanical energy via the triboelectric effect are promising candidates as power supplies for wearable electronics. However, triboelectric fibers and textiles are often hindered by problems such as complex fabrication processes, limited length, performances below the state-of-the-art of 2D planar configurations, etc. Here, we demonstrated a scalable fabrication of core-sheath-structured elastomer triboelectric fibers that combine silicone hollow tubes with gel-electrodes. Gel-electrodes were fabricated via a facile freeze–thawing process of blending polyvinyl alcohol (PVA), gelatin, glycerin, poly (3,4-ethylene dioxythiophene): poly (styrene sulfonate) (PEDOT: PSS), and sodium chloride (NaCl). Such fibers can also be knitted into deformable triboelectric nanogenerator textiles with high electrical outputs up to 106 V and 0.8 μA, which could work as reliable power supplies for small electronics. Moreover, we demonstrated fabric materials recognition, Morse code communication, and human-motion-recognition capabilities, making such triboelectric fiber platform an exciting avenue for multifunctional wearable systems and human–machine interaction.
Carbon cloth (CC)-based electrodes have attracted extensive attention for next-generation wearable energy-storage devices due to their excellent electrical conductivity and mechanical flexibility. However, the application of conventional CC-based electrodes for zinc (Zn) storage severely hinders Zn ion transport and induces deleterious Zn dendrite growth, resulting in poor electrochemical reliability. Herein, a novel oxygen plasma-treated carbon cloth (OPCC) is rationally designed as a current collector for flexible hybrid Zn ion supercapacitors (ZISs). The modified interface of OPCC with abundant oxygenated groups enables enhanced electrolyte wettability and uniform superficial electric field distribution. A prolonged working lifespan for Zn electrodeposition is achieved by the OPCC due to the improved interfacial kinetics and homogenized ion gradient. The as-prepared hybrid ZIS also delivers excellent cycling endurance (98.5% capacity retention for 1500 cycles) with outstanding operation stability under various extreme conditions. This facile surface modification strategy provides a new way for developing future flexible electrodes for wearable electronic products.
Herein, a flexible ZIF-67/PAN hybrid membrane was successfully prepared by the incorporation of ZIF-67 nanoparticles and PAN nanofibers through electrospinning method. The hybrid membrane presented tomatoes on sticks structures with one single PAN fiber stringing series of ZIF-67 nanoparticles. The morphology, electrolyte wettability, heat resistance, flexibility, and electrochemical properties of the electrospun ZIF-67/PAN membranes were discussed. Among the membranes prepared with different percentage of ZIF-67, the 30% ZIF-67/PAN membrane exhibited outstanding heat shrinkage resistance (remained intact at 200 ℃ for 1 h), excellent electrolyte uptake (556.39%), wide electrochemical window (~ 5.25 V) and high ionic conductivity (2.98 mS cm−1). When used as lithium-ion batteries (LIBs) separators, the cells assembled by 30% ZIF-67/PAN membrane presented excellent rate capacity and high capacity retention of 86.9% after 300 cycles at 1C. More importantly, the cells assembled with ZIF-67/PAN membranes repeated bent for 1000 times also exhibited high rate performance and maintained capacity retention of 92% after 100 cycles at 1 C. The characterization and the electrochemical testing suggest the electrospinning prepared ZIF-67/PAN flexible membranes can be expected to be used as potential separator for advanced batteries with high safety and high performance.
Flexible ionotronic devices have great potential to revolutionize epidermal electronics. However, the lack of breathability in most ionotronic devices is a significance barrier to practical application. Herein, a breathable kirigami-shaped ionotronic e-textile with two functions of sensing (touch and strain) is designed, by integrating silk fabric and kirigami-shaped ionic hydrogel. The kirigami-shaped ionic hydrogel, combined with fluffy silk fabric, allows the ionotronic e-textile to achieve excellent breathability and comfortability. Furthermore, the fabricated ionotronic e-textile can precisely perform the function of touch sensing and strain perception. For touch-sensing, the ionotronic e-textile can detect the position of finger touching point with a fast response time (3 ms) based on the interruption of the ion field. For strain sensing, large workable strain range (> 100%), inconspicuous drift (< 0.78%) and long-term stability (> 10,000 cycles) is demonstrated. On the proof of concept, a fabric keyboard and game controlling sleeve have been designed to display touch and strain sensing functions. The ionotronic e-textile break through the bottlenecks of traditional wearable ionotronic devices, suggesting a great promising application in future wearable epidermal electronics.
Wearable fiber-based electronics have found diverse applications including energy storage, healthcare or thermal management, etc. In particular, additive-free aqueous inks play significant roles in fabrication of wearable fiber-based devices, owning to their nontoxic nature and ease of manufacturing. Herein, wearable carbon fiber-based asymmetric supercapacitors (WASSC) are developed based on additive-free aqueous MXene inks, for self-powering healthcare sensors. The sediments of MXene without further modification are used as inks. Furthermore, combined with additive-free aqueous MXene/polyaniline (MP) inks, WASSC, with a wide voltage window and high capacitance is developed for practical energy supply. Impressively, WASSC has been successfully utilized to power wearable pressure sensors that could monitor motions and pulse signals. This wearable self-powered monitoring system on can accurately monitor the human motions, pronunciation, swallow or wrist pulse, without using the rigid batteries. This advantage realizes a great potential in simple and cost effective monitoring of human health and activities. Besides, self-powered system enables waste recycling of MXene and provides an effective approach for designing wearable and fiber-based self-powered sensors.
Outdoor passive heating to maintain a constant human body temperature is critical for human activities. However, most traditional energy-exhausted heating systems and inefficient passive heating technologies are incapable of dealing with the cold outdoor environment. Developing fabrics with low thermal radiation and conduction to passively heat the human body is a viable way to overcome the constraints of existing passive heating strategies. Herein, a multimaterial aerogel fabric was developed to realize passive personal heating without any energy input. The multimaterial aerogel fabric was fabricated by coating an Ag layer on an aerogel composite fabric. The lightweight aerogel composite fabric, woven from aerogel composite fibers with multi-scale porous structure, exhibits excellent thermal insulation, self-cleaning, mechanical and thermal stability. Furthermore, by coating with an Ag layer, the multimaterial aerogel fabric exhibits both low thermal conductivity and low infrared emissivity at 7–14 μm, demonstrating superior thermal insulating performance. As a result, the proposed multimaterial aerogel fabric with a thickness of only 1.29 mm is capable of improving the human body temperarure of 5.7 °C in a cold environment without energy input. This strategy offers a potential energy-saving alternative for future outdoor passive heating.
The harsh microenvironment in wound (HMW) remains a major obstacle to chronic wound healing. Although a series of bioactive materials have been developed, few of them are multi-functional and able to accelerate wound healing via precisely remodeling the HMW. Herein, a series of dihydromyricetin (DHM)-incorporated multilayer nanofibers (termed DQHP-n, n = 0, 2, 6 and 10) are fabricated using a layer-by-layer (LBL) self-assembly technique. The average diameters of DQHP-n significantly increase from 0.30 ± 0.16 μm to 0.84 ± 0.28 μm (P < 0.05) along with the n value increased from 0 to 10, the tensile strength of that is also significantly improved from 1.12 ± 0.15 MPa to 2.16 ± 0.30 MPa (P < 0.05), and the water contact angle of that significantly decreases from 129.1 ± 1.5° to 76.6 ± 3.9° (P < 0.05). The DQHP-n are found to be biocompatible, in which DQHP-6 promoted cell migration through activation of the epithelial–mesenchymal transformation (EMT) pathway and reconstruction of the HMW by stopping bleeding, killing bacteria, eliminating inflammation, and scavenging reactive oxygen species (ROS). The in vivo evaluation is carried out via an E. coli-infected rat skin regeneration model. The DQHP-6 group demonstrates the best effect, as it healed up to 98.5 ± 1.0% of the wound area at day 15. DQHP-6 differentially regulates the mRNA expressions of several cytokines (FGF2, PDGF, IL-1α, IL-6, IL10, and TGF-β), which ends to reductions of total inflammatory cells (CD45+ cells) and M1 macrophages (CD80+ and CD86+ cells), proliferation of host cell (Ki67+ cells), and enhancement of collagen synthesis. In conclusion, DQHP-6 exhibits multifunctional properties for HMW, and can serve as a promising wound dressing for clinical transformation.
Smart textiles are able to self-adapt to an irregular surface. So, they found new applications in intelligent clothes and equipments, where the properties and functionality of traditional polymeric fibers are insufficient, and hard to be realized. Inspired by the supercontraction behavior of the spider silk, we prepared a spinnable hydrogel to form a sheath-core-like composite yarn, after being coated on cotton yarn. The strong hydrogen bonding between the cotton yarn and the polar groups of the hydrogel provides an outstanding mechanical stability, and the twists insertion forms a spiral-like architecture, which exhibited moisture-responsive super contraction behavior. By structural tailoring the chirality of the fiber twists and coiling extends into homo-chiral and heterochiral architectures, as displays contraction and expansion when is exposed to the moisture. Once the relative humidity is increased from 60 to 90%, a homochiral yarn exhibits 90% contraction, while a heterochiral yarn shows 450% expansion, and the maximum work capacity reached up to 6.1 J/Kg. The super contracted yarn can be re-stretched to its original length manifesting cyclability, which can be exploited to build a smart textile, self-adaptive to irregular surfaces. Such a strategy may be further extended to a wide variety of materials to achieve intelligent textiles from common fiber or yarns.
Currently, the gradual depletion of fossil resources and the large amount of plastic waste are causing serious harm to the land and marine ecology. The rapid development of wearable smart fibers is accompanied by rapid growth in the material demand for fibers, and the development of green and high-performance biomass-based fibers has become an important research topic to reduce the dependence on synthetic fiber materials and the harm to the environment. Here, chitosan is first prepared from the waste material by chemical methods. Then the chitosan-based self-powered induction fibers are prepared by electrospinning core wire technique. Chitosan-based self-powered sensing fiber is ultra-light and flexible, which can achieve about 2500 collisions without damaging the surface. Chitosan-based self-powered sensing fiber can also be used in smart home sensing applications to control home appliance switches with a light touch, which has a great application prospect in smart home and wearable fields.
The rapid expansion of the fast fashion industry brings about environmental concerns such as dyestuffs-related water pollutions and waste textiles. Conventional wastewater-disposal strategies emphasize the optimization of photocatalytic activity to improve pollutant degradation efficiency, while the absorptivity, recyclability and sustainability of photocatalysts are always ignored. The overproduced textiles are still in urgent of being recycled and reutilized in eco-friendly approaches. In this work, a scalable dyeing technology is employed to achieve green and sustainable reutilization of waste textiles. The functionalized TiO2/reduced graphene oxide wool fabrics show excellent sustainability, remarkable adsorbing capacity and enhanced photocatalytic performance. By taking advantage of these properties, we develop an integrated strategy of night-time adsorption and day-time photodegradation which could significantly optimize the dyestuffs degradation efficiency. The concept of waste textiles reutilization and wastewater treatment in this work provides practical potential for efficient and sustainable environmental remediation.
Concept of waste textiles reutilization and wastewater treatment.
In this paper, both steady-state and transient thermal simulations were performed on functional fibers having an embedded electronic chip acting as a heat source. Simulations were conducted for a range of different fiber materials and arbitrary fiber cross-sectional shapes. We show that under steady-state heating conditions, the thermal response for any arbitrary fiber shape and fiber material system was convection dominated regardless of the effective thermal conductivity of the fiber, and that the corresponding temperature rise within the fiber can be predicted analytically allowing for the maximum temperature to be estimated for any known heat load and fiber geometry. In the case of transient heating, we show that for pulsed power operation of the embedded electronic device, the maximum temperature reached in the fiber is always greater than the maximum temperature of the equivalent steady-state average power. However, high peak powers can be safely achieved if the power-on pulse time and duty cycle are selected to limit the maximum temperature reached in the fiber. Based on the results from the transient simulations, a set of criteria was developed to determine whether the operating conditions would be: (1) allowable for the fiber system, thus requiring no transient simulations, (2) requiring a transient simulation to verify that the maximum temperature is acceptable, and (3) the operating conditions are too severe and device operation at these conditions are not practical.
BiOBr-based nanocomposite photocatalysts are used for removing the organic pollutants, but their poor adsorption/photocatalytic performances and the low potential for recycling limit their application. To solve the issue, herein we report a large-area recyclable CFC/BiOBr/ZIF-67 filter-membrane-shaped photocatalyst prepared by in situ growth of BiOBr/ZIF-67 nanocomposites on carbon fiber cloth (CFC). Fabrication process is based on hydrothermal synthesis of BiOBr nanosheets (diameter 0.5–1 μm) on carbon fiber cloth (as substrate material) and then a chemical bath route is used to grow ZIF-67 nanoparticles (diameter 300–600 nm) in situ on the surface of CFC/BiOBr. Resulted composite, CFC/BiOBr/ZIF-67, exhibits a high specific surface area (545.82 m2 g−1) and a wide photoabsorption, accompanied by an absorption edge (~ 620 nm). In dark condition, CFC/BiOBr/ZIF-67 adsorbs bisphenol A (BPA) and orange 7 (AO7) within 60 min, respectively with 20.0% and 40.1% efficiency. This level of efficiencies are correspondingly 2.6 and 3.2 times more that of the bare CFC/BiOBr (7.6% for BPA and 12.4% for AO7). Under visible light irradiation, CFC/BiOBr/ZIF-67 can degrade 69.7% of BPA and 96.0% of AO7, in 120 min, which are, respectively, 1.3 and 1.8 times higher than the absorption efficiency of bare CFC/BiOBr (53.2% for BPA, 52.0% for AO7). When CFC/BiOBr/ZIF-67 is used as a filter membrane for photocatalytic removal of pollutants in flowing wastewater (AO7, rate: ~ 1.5 L h−1), 92.2% of AO7 can be decomposed after 10 filtering cycles. This study suggests CFC/BiOBr/ZIF-67 as a novel highly functional, recyclable and environmental friendly photo-driven membrane filter for purification and recovery of flowing surface waste waters.
Circularly polarized luminescence (CPL)-active nanomaterials have attracted tremendous attention. However, it is still a big challenge to conveniently fabricate multi-color and white CPL-active nanomaterials on a large scale. Herein, a simple and scalable approach to achieve the above goals is presented. Multicolor CPL-active nanofibers are fabricated from chiral helical substituted polyacetylene, achiral fluorescent dyes and polyacrylonitrile via uniaxial electrospinning; the highest luminescence dissymmetry factor (g lum) of the resulting nanofibers can reach 10− 2. Furthermore, white CPL-active nanofibers are obtained by coaxial electrospinning, in which the resulting core-shell structure has excellent adjustability and can be utilized to physically isolate different fluorescent dyes to reduce energy transfer efficiency; therefore, stable white CPL emissions can be achieved with high g lum values up to 10− 3. Notably, the prepared white-emission CPL nanofibrous films show bright white circularly polarized light when coated on UV chips, demonstrating their future application in constructing low-cost and flexible light-emitting devices such as circularly polarized light-emitting diodes.
Multi-color tunable and white circularly polarized luminescence (CPL)-active nanofibers are prepared from chiral helical polymers and commercial fluorescence dyes via electrospinning process. The obtained composite nanofibers exhibit considerable luminescence dissymmetry factor (g lum), with the highest g lum up to 10−2. White circularly polarized light-emitting diodes are further fabricated by packaging the white CPL nanofiber film on UV chip.
Catheterization is indispensable in the field of modern medicine. However, catheter-related thrombosis and infections almost inevitably occur during the process, and as drugs can only be administered at the end of catheter, auxiliary strategies are required for successful implantation. Considering these intractable limitations, a type of self-adaptive, anti-coagulate liquid-based fibrous catheter has been developed. More importantly, it has positional drug release property that traditional catheters desperately need but couldn’t attain. Although enlightening, the feasibility and performance of the positional drug release have only been demonstrated by fluorescents, the specific drug release kinetics remains unknown for adaptation to application scenarios. Therefore, we systematically investigate the structural and interfacial effects of drug molecules and fibrous matrixes on drug release kinetics in a liquid-based fibrous catheter. Theoretical calculations and experiments demonstrate that oleophilic and hydrophilic molecules release slowly due to a dissolution-diffusion mechanism. Amphipathic molecules, however, will significantly affect the gating performance by affecting the interfacial stability, hence they release quickly with emulsifying the gating liquid. Besides the significant impact of molecular properties and interfacial effects, matrix pore size also has a slight influence that molecules release faster in bigger pores. Through this study, the liquid-based fibrous catheter may step further toward practical applications including chemotherapy, haemodialysis, angiography, etc. to overcome the existing catheter-related limitations.
The structure of sulfur host materials plays a key role in alleviating the shuttle effect, volume expansion and sluggish redox reaction of lithium–sulfur batteries (LSBs). In this work, the well-designed multichannel carbon fibers decorated by carbon nanotubes (CNTs) and CoS nanoparticles (MCF/CoS/CNT) are synthesized and serve as the flexible sulfur host. The in situ grown CNTs network and embedded CoS enhance the overall conductivity of electrode and facilitate the redox reaction of sulfur-related electrochemistry. Benefitting from these merits, the MCF/CoS/CNT-based cathode exhibits a high reversible capacity of 927 mAh g−1 after 180 cycles with a low decay of 0.034% per cycle at 1.0 C. A superb areal capacity of 5.2 mAh cm−2 could be obtained under a high sulfur loading of 6.3 mg cm−2 and an ultralow electrolyte/sulfur ratio of 6.5 μL mg−1 after 100 cycles. This work offers a promising approach to the reasonable design of flexible sulfur host for LSBs toward high energy density.
Photothermal therapy (PTT) is a treatment that increases the temperature of tumors to 42–48 °C, or even higher for tumor ablation. PTT has sparked a lot of attention due to its ability to induce apoptosis or increase sensitivity to chemotherapy. Excessive heat not only kills the tumor cells, but also damages the surrounding healthy tissue, reducing therapeutic accuracy and increasing the possible side effects. Herein, a phase change fiber (PCF) scaffold serving as a thermal trigger in mild photothermal–chemo tumor therapy is developed to regulate temperature and control drug release. These prepared PCFs, comprised of hollow carbon fibers (HCFs) loaded with lauric acid as a phase change material (PCM), can effectively store and release any excess heat generated by irradiating with a near-infrared (NIR) laser through the reversible solid–liquid transition process of the PCM. With this feature, the optimal PTT temperature of implanted PCF-based composite scaffolds was identified for tumor therapy with minimal normal tissue damage. In addition, controlled release of chemotherapeutic drugs and heat shock protein (HSP) inhibitors from the PCF-based composite scaffolds have been shown to improve the efficacy of mild PTT. The developed PCF-based scaffold sheds light on the development of a new generation of therapeutic scaffolds for thermal therapy.
In vivo, vascular endothelial growth factor (VEGF) and vascular endothelial cadherin (VE-cadherin) co-regulate the dynamic organization of endothelial cells during vascular sprouting, balancing angiogenesis and vascular stability. In this study, a novel bioactive surface integrating human VE-cadherin-Fc and VEGF-Fc fusion proteins was innovatively developed for the modification of poly(ε-caprolactone) (PCL) small-caliber electrospun fibrous grafts (VE-cad/VEGF-PCL) to promote the regeneration of functional endothelium and improve the patency of artificial vascular grafts. These fusion proteins self-assembled on the PCL fibers through the hydrophobic binding of Fc domains, improving surface hydrophilicity while reducing the adhesion of fibrinogen. In vitro results showed that the VE-cadherin/VEGF surface upregulated the expression of endogenous VE-cadherin and synergistically activated the VE-cadherin/VEGFR2/FAK/AKT/ERK signal transduction, which facilitated the functioning of human umbilical vein endothelial cells (HUVECs). Moreover, the VE-cadherin/VEGF surface significantly enhanced cellularization and capillary formation, then subsequently accelerated the regeneration of functional endothelium and smooth muscle in the VE-cad/VEGF-PCL grafts in a rat abdominal aorta replacement model. Together, these results highlight the advantages of VE-cadherin/VEGF surface in enhancing rapid endothelialization of electrospun vascular grafts and provide new insights into the design of cross-activating biomaterials.