Glass Nanofibers Research Articles

Cotton wool-like ion-doped bioactive glass nanofibers: investigation of Zn and Cu combined effect

Electrospinning is a versatile and straightforward technique to produce nanofibrous mats with different morphologies. In addition, by optimizing the solution, processing, and environmental parameters, three-dimensional (3D) nanofibrous scaffolds can also be created using this method. In this work, the preparation and characterization of bioactive glass (BG) scaffolds based on the SiO2-CaO sol-gel system, a biomaterial with a highly reactive surface, is reported. The electrospinning technique was combined with sol-gel methods to obtain nanofibrous 3D cotton wool-like scaffolds. The addition of zinc and copper ions to the silica-calcia system was examined, and the influence of these ions on the material properties and characteristics was investigated by various characterization techniques, from morphological and chemical properties to antibacterial and wound closure capability, cell viability and ion release. Our findings show that the cotton wool-like ion-doped nanofibers are promising for wound healing applications.

Delignification of wood toward photoluminescent smart window infiltrated with glass nanofibers-reinforced polystyrene for multifunctional applications

Multifunctional photochromic and fluorescent woods that can change their color in the presence of ultraviolet light were developed. A formulation of electrospun glass nanofibers-reinforced styrene as a hosting agent and rare-earth strontium aluminate (RSA) as a photoluminescent was infiltrated into a lignin-modified wooden substrate, resulting in translucent wood with fluorescence and photochromic properties. The RSA pigment is known for its good photostability and thermal stability. An ideal method for producing transparent photoluminescent wood involves dispersing the RSA phosphor in pre-polymerized glass nanofibers-reinforced styrene without aggregation. According to the colorimetric data from the CIE (Commission Internationale de l´Eclairage) Lab color space coordinates, this photoluminescent wood substrate became green when exposed to ultraviolet light, but remained colorless when exposed to visible light. Electron microscopic images were used to investigate the morphologies of the synthesized pigment nanoparticles (NPs) and electrospun glass nanofibers, displaying diameters of 5–15 nm and 50–100 nm, respectively. The photoluminescent woods were inspected with different microscopic and spectroscopic techniques, including energy-dispersive X-ray spectroscopy (EDX), X-ray fluorescent spectroscopy (XRF), and scanning electron microscopy (SEM). Upon excitation at 365 nm, the photoluminescence transparent timbers demonstrated an emission intensity at 519 nm. When increase the phosphor content, the produced luminous wood was monitored to be more water-resistant and had better protection from ultraviolet rays. The reaction of the transparent luminous wood to ultraviolet light was rapid and reversible without fatigue.

Enhancing tendon-bone integration and healing with advanced multi-layer nanofiber-reinforced 3D scaffolds for acellular tendon complexes

Advancements in tissue engineering are crucial for successfully healing tendon-bone connections, especially in situations like anterior cruciate ligament (ACL) restoration. This study presents a new and innovative three-dimensional scaffold, reinforced with nanofibers, that is specifically intended for acellular tendon complexes. The scaffold consists of a distinct layered arrangement comprising an acellular tendon core, a middle layer of polyurethane/type I collagen (PU/Col I) yarn, and an outside layer of poly (L-lactic acid)/bioactive glass (PLLA/BG) nanofiber membrane. Every layer is designed to fulfill specific yet harmonious purposes. The acellular tendon core is a solid structural base and a favorable environment for tendon cell functions, resulting in considerable tensile strength. The central PU/Col I yarn layer is vital in promoting the tendinogenic differentiation of stem cells derived from tendons and increasing the expression of critical tendinogenic factors. The external PLLA/BG nanofiber membrane fosters the process of bone marrow mesenchymal stem cells differentiating into bone cells and enhances the expression of markers associated with bone formation. Our scaffold's biocompatibility and multi-functional design were confirmed through extensive in vivo evaluations, such as histological staining and biomechanical analyses. These assessments combined showed notable enhancements in ACL repair and healing. This study emphasizes the promise of multi-layered nanofiber scaffolds in orthopedic tissue engineering and also introduces new possibilities for the creation of improved materials for regenerating the tendon-bone interface.

Surface-silanized glass nanofibers and aluminate nanoparticles as reinforcing agents for acrylic emulsion toward multifunctional stimuli-responsive composite coatings

Smart waterborne coatings have shown various functions, such as afterglow photoluminescence, antimicrobial activity, water resistance, ultraviolet blocking, and anti-counterfeiting properties. However, photoluminescent organic agents have shown poor photostability and high cost. Additionally, waterborne acrylic coatings have shown poor mechanical properties. Herein, nanoparticles of rare-earth strontium aluminate (NRESA) and electrospun glass nanofibers (EGN) were used to strengthen the bulk of acrylic (ACR) coatings to develop smart products with mechanical reliability, hydrophobicity, ultraviolet blocking, and persistent photoluminescence. By physically integrating nano-scaled particles of RESA, colorless smart coatings of EGN@ACR were produced. Photoluminescence spectra showed that the transparent EGN@ACR changed its appearance to greenish when exposed to ultraviolet rays. Hybrids of EGN@ACR with trace amounts of NRESA showed fluorescence emission with instant reversibility. As the phosphor concentration in the EGN@ACR hybrids increased, afterglow photoluminescence with delayed reversibility was detected. When excited at 370 nm, the hybrid coatings displayed an emission band at 519 nm. The morphological analysis of NRESA by transmission electron microscopy (TEM) displayed diameters of 9–21 nm. After being prepared using electrospinning technology, glass nanofibers were introduced into acrylic emulsion coatings as a reinforcement agent. Scanning electron microscopic (SEM) analysis of EGN showed diameters of 70–120 nm. The smart coatings had better resistance to scratches as compared to the control sample of NRESA-free acrylic paint. A higher concentration of NRESA resulted in enhanced hydrophobicity and ultraviolet blocking.

Designing of a Multifunctional 3D-Printed Biomimetic Theragenerative Aerogel Scaffold via Mussel-Inspired Chemistry: Bioactive Glass Nanofiber-Incorporated Self-Assembled Silk Fibroin with Antibacterial, Antiosteosarcoma, and Osteoinductive Properties.

Biomaterial-mediated bone tissue engineering (BTE) offers an alternative, interesting approach for the restoration of damaged bone tissues in postsurgery osteosarcoma treatment. This study focused on synthesizing innovative composite inks, integrating self-assembled silk fibroin (SF), tannic acids (TA), and electrospun bioactive glass nanofibers 70SiO2-25CaO-5P2O5 (BGNF). By synergistically combining the unique characteristics of these three components through self-assembly and microextrusion-based three-dimensional (3D) printing, our goal was to produce durable and versatile aerogel-based 3D composite scaffolds. These scaffolds were designed to exhibit hierarchical porosity along with antibacterial, antiosteosarcoma, and bone regeneration properties. Taking inspiration from mussel foot protein attachment chemistry involving the coordination of dihydroxyphenylalanine (DOPA) amino acids with ferric ions (Fe3+), we synthesized a tris-complex catecholate-iron self-assembled composite gel. This gel formation occurred through the coordination of oxidized SF (SFO) with TA and polydopamine-modified BGNF (BGNF-PDA). The dynamic nature of the coordination ligand-metal bonds within the self-assembled SFO matrix provided excellent shear-thinning properties, allowing the SFO-TA-BGNF complex gel to be extruded through a nozzle, facilitating 3D printing into scaffolds with outstanding shape fidelity. Moreover, the developed composite aerogels exhibited multifaceted features, including NIR-triggered photothermal antibacterial and in vitro photothermal antiosteosarcoma properties. In vitro studies showcased their excellent biocompatibility and osteogenic features as seeded cells successfully differentiated into osteoblasts, promoting bone regeneration in 21 days. Through comprehensive characterizations and biological validations, our antibacterial scaffold demonstrated promise as an exceptional platform for concurrent bone regeneration and bone cancer therapy, setting the stage for their potential clinical application.

Manufacturing of bioinspired Bouligand structures using ultrasound assisted 3D printing

Materials with bioinspired Bouligand structures provide a new approach to explore isotropic fiber-reinforced composites. However, it is challenging to manufacture composites with various fibers along with a three-dimensional helical structure. In this work, to accomplish the alignment of a three-dimensional (3D) helical structure of fibers in a composite material, an acoustically aligned fiber technology was incorporated with a rotating mechanism in a stereolithography 3D printer. Firstly, the formation process of acoustic standing wave was simulated and the relationship between standing wave parameters and planar line arrays was then established. Secondly, Bouligand composites with various parameters were fabricated using an acoustic-assisted 3D printing technology and the effect of the angle between the interlayer fiber arrays on the mechanical properties was experimentally measured. Finally, heat sink and meniscus structures with Bouligand structure were fabricated using carbon nanofiber and glass nanofiber, respectively. The 3D printing processing method integrating acoustic alignment technology and rotating mechanism provides a new method for fabrication of composite materials with complex fiber structures.

Glass nanofibers and lanthanide aluminate nanoparticles as reinforcement nanofillers for polyurethane composite toward smart applications

Mechanically reliable photoluminescent bricks were prepared from polyurethane (PUR) by reinforcement with electrospun glass nanofibers (EGNF). To enhance the mechanical qualities of the PUR sheets, EGNF were electrospun and applied to the PUR sheets as a reinforcement agent. We physically incorporated nanoparticles of rare-earth doped strontium aluminate (NRSA) into EGNF@PUR bricks to create photoluminescent and photochromic properties. In order to confirm the transparency of EGNF@PUR with the ability to change color to greenish beneath ultraviolet irradiation, both photoluminescence spectra and CIE (Commission Internationale de l'Eclairage) Lab coordinates were examined. When irradiated at 365 nm, an emission peak was monitored at 519 nm. With low concentrations of NRSA, the emission characteristic of the EGNF@PUR hybrid bricks was immediately reversible, revealing fluorescence emission. Persistent emission with delayed reversibility was observed in EGNF@PUR when using high concentrations of NRSA. Examining the morphological properties of NRSA and EGNF using transmission electron microscopy (TEM) revealed diameters of 4-9 nm and 75-125 nm, respectively. Both EGNF and EGNF@PUR bricks were subjected to morphological analysis using different analytical methodologies. As the concentration of NRSA rose, the material became more hydrophobic and more ultraviolet-protective. When compared to NRSA-free EGNF@PUR bricks, those containing NRSA had superior scratch resistance.

Reinforcement of styrene‐acrylonitrile polymer bulk with glass nanofibers to introduce photoluminescent bricks

AbstractTransparent and mechanically reliable plastic was developed by reinforcing styrene‐acrylonitrile polymer (SAP) with electrospun glass nanofibers (EGN). The physical inclusion of strontium aluminate nanoparticles (SAN) produced long‐persistent photoluminescent and photochromic EGN@SAP bricks or smart windows. EGN were fabricated by electrospinning technique and incorporated as a toughening mediator into styrene‐acrylonitrile plastic to boost its mechanical properties. Transparency of EGN@SAP with the capacity to shift to green under ultraviolet (UV) illumination was verified using photoluminescence analysis and CIE Lab parameters. EGN@SAP with low content of SAN exhibited immediate reversibility of the photochromic feature, proving fluorescence emission. Afterglow emission from EGN@SAP embedded with high concentration of SAN persisted for longer time and was less easily reversed. After excitation at 365 nm, the emission peaked at 519 nm. Increasing the SAN content resulted in improved hydrophobicity and UV protection. Diameter measurements of SAN (6–14 nm) and EGN (75–300 nm) were taken utilizing transmission electron microscopy and scanning electron microscopy, respectively. EGN and EGN@SAP bricks were analyzed for their morphological characteristics using a variety of analytical techniques. The scratch resistance of EGN@SAP bricks containing SAN was enhanced in comparison to SAN‐free EGN@SAP bricks.

Preparation of luminescent polyethylene plastic composite nano‐reinforced with glass fibers

AbstractElectrospun glass nanofibers (EGNFs) were prepared to reinforce polyethylene (PE) plastic waste towards the development of photochromic anti‐counterfeiting patterns and long‐persistent photoluminescent materials, such as smart windows and concrete. By physical integration of lanthanide‐doped aluminate (LdA) nanoparticles (NPs) into polyethylene plastic reinforced with EGNFs, a transparent lanthanide‐doped aluminate nanoparticles (LdANPs)/EGNFs@PE sheet was produced. The colorless EGNFs@PE hybrids became green under ultraviolet (UV) rays and greenish‐yellow in a darkened room as proved by CIE Lab and photoluminescence analysis. In the luminescent LdANPs/EGNFs@PE hybrids, the identified photochromism was promptly reversed at low concentrations of LdANPs to designate fluorescence emission. Photoluminescence was maintained with slow reversibility for the high phosphor concentrations to designate afterglow emission. LdANPs exhibit diameters of 5–12 nm, whereas glass nanofibers have diameters of 70–120 nm. The morphologies of LdANPs/EGNFs@PE substrates were studied by energy‐dispersive x‐ray spectroscopy (EDX), scanning electron microscopy (SEM), and x‐ray fluorescence (XRF). The mechanical properties of the prepared polyethylene plastic were enhanced by reinforcement with glass nanofibers as a roughening agent. The photoluminescent substrates showed markedly improved scratch resistance in comparison to LdANPs‐free EGNFs@PE substrate. The obtained luminescence spectra displayed an emission band at 519 nm upon excitation at 365 nm. The results demonstrated that the luminous plastic has improved hydrophobicity and UV shielding upon increasing the LdANPs content.

Electrospinning of glass nanofibers to roughen a waterborne polyurethane coating toward smart applications

Polyurethane (PU) coating bulk was reinforced with electrospun glass nanofibers (GNF) and nanoparticles of lanthanide-doped strontium aluminate (NLSA) to produce mechanically reliable long-lasting photoluminescent and photochromic smart products. Transparent smart coatings of GNF@PU were prepared by the physical integration of lanthanide-doped strontium aluminate nanoparticles. The transparent appearance of GNF@PU was found to shift to green when exposed to ultraviolet light as proved by spectral examinations using photoluminescence and CIE Lab parameters. Fluorescence emission with instantaneous reversibility was monitored for GNF@PU hybrids with trace amounts of NLSA. Afterglow photoluminescence with slow reversibility was observed at higher phosphor concentrations in the GNF@PU hybrids. The coating hybrids revealed an emission band at 517 nm when excited at 365 nm. Transmission electron microscopic (TEM) analysis of the morphological properties of NLSA and GNF showed diameters of 8–12 nm and 75–250 nm, respectively. After being fabricated by electrospinning technique, GNF were incorporated into polyurethane coatings as a roughening agent. X-ray fluorescence (XRF), energy-dispersive X-ray (EDX), and scanning electron microscope (SEM) were used to investigate the morphological features of GNF and smart coatings of GNF@PU. Scratch resistance of smart coatings was found to be higher than that of NLSA-free polyurethane control sample. Both of hydrophobicity and UV resistance improved with an increase in NLSA content.

Nanosensor detection of reactive oxygen and nitrogen species leakage in frustrated phagocytosis of nanofibres.

Exposure to widely used inert fibrous nanomaterials (for example, glass fibres or carbon nanotubes) may result in asbestos-like lung pathologies, becoming an important environmental and health concern. However, the origin of the pathogenesis of such fibres has not yet been clearly established. Here we report an electrochemical nanosensor that is used to monitor and quantitatively characterize the flux and dynamics of reactive species release during the frustrated phagocytosis of glass nanofibres by single macrophages. We show the existence of an intense prolonged release of reactive oxygen and nitrogen species by single macrophages near their phagocytic cups. This continued massive leakage of reactive oxygen and nitrogen species damages peripheral cells and eventually translates into chronic inflammation and lung injury, as seen during in vitro co-culture and in vivo experiments.

Multifunctional 3D matrixes based on flexible bioglass nanofibers for potential application in postoperative therapy of osteosarcoma.

Postoperative treatment of osteosarcoma is one of the major challenging clinical issues since both elimination of residual tumors and acceleration of bone regeneration should be considered. Photothermal therapy has been widely studied due to its advantages of small side-effect, low-toxicity, high local selectivity and noninversion, and bone tissue engineering is an inevitable trend in postoperative treatment of osteosarcoma. In this study, we combined the tissue engineering and photothermal therapy together, and developed a kind of multifunctional nanofibrous 3D matrixes for postoperative treatment of osteosarcoma. The flexible bioactive glass nanofibers (BGNFs) prepared by sol-gel electrospinning and calcination acted as the basic blocks, and the genipin-crosslinked gelatin (GNP-Gel) acted as the cement to bond the BGNFs forming a stable 3D structure. The stable porous 3D scaffolds were obtained through ice crystal templating method and freeze-drying technology. The obtained GNP-Gel/BGNF 3D matrixes showed a nanofibrous structure that highly biomimetics the extracellular matrix. The excellent compression recovery performance in water of these matrixes made them suitable for minimally invasive surgery. In addition, these 3D matrixes were not only biocompatible in vitro, but also benefit for the formation of mineralized bone in vivo. Furthermore, the dark blue GNP-Gel also acted as the photothermal agent, which endowed the GNP-Gel/BGNF 3D matrixes with efficient photothermal antitumor and photothermal antibacterial performance without addition of other toxic photothermal agents. Therefore, this study provides an ingenious avenue to prepare multifunctional nanofibrous 3D matrixes with photothermal therapy for postoperative treatment of osteosarcoma.

H‐Bonded Amorphous Polymer Glass Nanofibers with Simultaneously Large Enhancement in Strength, Toughness, Ductility, and Thermal Stability

AbstractUnderstanding the direct effects of hydrogen bonding (H‐bonding) on the mechanical response of glassy state polymers remains a challenge, largely owing to the use of semicrystalline polymers in such studies, wherein, separating the contributions due to the changes in degree of crystallinity and direct H‐bonding effects on the observed mechanical properties is extremely difficult. This limitation is overcome by studying the mechanical behavior of amorphous, glassy polyvinylpyrrolidone (PVP), H‐bonded with tannic acid (TA). Uniaxial tension experiments on individual submicron scale PVP fibers (0.6–1.0 µm diameters) with different TA concentrations are conducted to capture their elasto‐plastic deformation characteristics. Amorphous PVP‐TA complexes exhibited some distinctive trends in elasto‐plastic properties with increasing H‐bond density, which are not observed earlier. These distinctive trends are discussed in terms of the competing effects of H‐bond driven crosslinking and TA‐induced reduction in entanglement density, and their differing roles during elastic and plastic deformation. The improvements in elasto‐plastic properties (particularly ductility and toughness) are simultaneously accompanied by uniquely significant thermal stability (i.e., glass transition temperature, Tg) improvements, that can help improve the practical applicability, operational life, and performance of these materials.

Glass nanofibers as a reinforcement agent to polylactic acid smart plastic window

Polylactic acid (PLA) was roughened with electrospun glass nanofibers (EGNF; 50–250 nm) as a reinforcement agent to create afterglow and photochromic smart windows, and anti-counterfeiting patterns. Luminescent transparent film was prepared by physical immobilization of lanthanide aluminate nanoparticles (LAN) into EGNF@PLA composites. Transmission electron microscopy (TEM) was utilized to inspect the morphology of LAN (5–15 nm). After experimenting with CIE Lab and luminescence spectrum measurements, we found that the EGNF@PLA samples changed color from colorless to green upon exspoure to ultraviolet (UV) lightening. Using various analytical methods, the morphology and chemical compositions of luminous EGNF@PLA hybrids were explored. When raising the LAN content in EGNF@PLA, the resistance to scratches was observed to considerably improve. When stimulated at 365 nm, the emission spectra displayed two emission bands at 436 nm and 517 nm. Photochromism was rapidly reversed in EGNF@PLA with low LAN contents to designate fluorescence emission, whereas EGNF@PLA with higher LAN concentrations exhibited sustained luminosity to designate afterglow emission. Light-emitting colorless EGNF@PLA hybrids were found to exhibit improved superhydrophobic and UV-blocking properties.

Surface-Modified Electrospun Glass Nanofibers from Silane Treatment and Their Use for High-Performance Epoxy-Based Nanocomposite Materials.

As a new and promising reinforcing filler, electrospun glass nanofibers (EGNFs) have attracted attention in the field of polymer composite materials. However, the reinforcing effectiveness of surface-modified EGNFs using different silane coupling agents in epoxy resin is still not quite clear. In this research, a series of silane coupling agents with increasing chain lengths in the order of methyl trimethoxysilane (MTMS), (3-aminopropyl) triethoxysilane (APTES), (3-glycidyloxypropyl) trimethoxysilane (GPTMS), and dual silane coupling agent APTES-GPTMS were employed to carry out surface treatment on the EGNFs. The pristine and silane functionalized EGNFs were then incorporated into epoxy resin as reinforcing fillers at low loading levels, i.e., 0.25 wt.%, 0.5 wt.%, and 1 wt.%, and the mechanical properties of the resultant epoxy nanocomposites, including strength, stiffness, ductility, and toughness, were evaluated. A commercial product of glass nanoparticles (GNPs) was used as a control to compare the reinforcing effectiveness of the EGNFs and the GNPs. This study revealed that the EGNFs could provide significant reinforcing and toughening effects at ultra-low loading (0.25 wt.%) in epoxy nanocomposite materials. Furthermore, surface modification of the EGNFs with silane coupling agents with long chain lengths, e.g., by using dual silane coupling agents, APTES-GPTMS, could enhance the interfacial bonding between the EGNFs and the epoxy matrix and further increase the mechanical performance of the EGNF-reinforced epoxy nanocomposite materials. Through this research, we realized epoxy nanocomposite materials with much-improved mechanical properties, i.e., 37%, 24%, 18%, 57% improvement in strength, stiffness, ductility, and toughness, respectively, with respect to those of the cured neat epoxy material with an ultra-low loading (0.25 wt.%) of APTES-GPTMS-EGNFs. Our research paves the road for developing lighter and stronger epoxy nanocomposite materials with EGNFs.

Preparation of glass nanofibers to reinforce polymethyl methacrylate toward persistent photoluminescent bricks

Polymethyl methacrylate (PMMA) was subjected to a reinforcement process by using electrospun glass nanofibers (GNF) to produce durable and transparent bricks. Photoluminescent and photochromic GNF@PMMA bricks were prepared by physical incorporation of lanthanide-activated aluminum strontium oxide (LASO) nanoparticles (NPs). Both CIE (Commission internationale de l'éclairage) Lab parameters and photoluminescence analysis were investigated to verify transparency of GNF@PMMA with the capability to change to green under UV lighting. The photochromic property was instantaneously reversible for GNF@PMMA hybrid bricks with low concentrations of LASO NPs, demonstrating fluorescence emission. GNF@PMMA with high concentrations of LASO NPs exhibited persistent photoluminescence afterglow emission with slower reversibility. An emission peak was detected at 517 nm upon excitation at 365 nm. Both hydrophobicity and ultraviolet shielding improved as LASO NPs content increased. Both of X-ray diffraction (XRD) and transmission electron microscopic analysis (TEM) were applied to examine the morphological features of LASO NPs and GNF to show diameters of 10–19 nm and 100–250 nm, respectively. Electrospinning technology was applied to prepare GNF, which were used to reinforce PMMA bricks as a roughening agent to improve their mechanical properties. Different analytical methods were utilized to analyze GNF and GNF@PMMA bricks for their morphological features. The scratching resistance of LASO NPs-containing GNF@PMMA bricks improved as compared to LASO NPs-free GNF@PMMA.

Photoluminescent polymer-based smart window reinforced with electrospun glass nanofibres.

Poly(vinyl chloride) (PVC) was reinforced with electrospun glass nanofibres (EGN) to develop photochromic and afterglow materials such as smart windows and anti-counterfeiting prints. A colourless electrospun glass nanofibres@poly(vinyl chloride) (EGN@PVC) sheet was prepared by physical integration of lanthanide-doped aluminate nanoparticles (LANP). The low concentrations of LANP in the photochromic and photoluminescent EGN@PVC hybrids displayed fluorescence emission with instant reversibility. EGN@PVC with the highest phosphor concentrations showed persistent phosphorescence emission with slow reversibility. Based on the results of the Commission Internationale de l'éclairage Laboratory and luminescence spectroscopy, the translucent EGN@PVC samples became green in the presence of ultraviolet illumination and greenish-yellow in the absence of light. According to scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, the morphological study of EGN and LANP showed diameters of 75-95 and 11-19 nm, respectively. The morphology of the EGN@PVC substrates was studied using SEM, X-ray fluorescence, and energy-dispersive X-ray spectroscopy. The mechanical characteristics of PVC were enhanced by reinforcement with EGN as a roughening agent. When comparing the scratching resistance of LANP-free substrate to photoluminescent EGN@PVC substrates, it was observed that the latter was much superior. The photoluminescence spectra were reported to have an emission peak at 519 nm when excited at 365 nm. These findings demonstrated that the luminous transparent EGN@PVC composites had improved superhydrophobic and UV-blocking characteristics.

Electrospun glass nanofibers to strengthen polycarbonate plastic glass toward photoluminescent smart materials

Electrospun glass nanofibers (GNFs) were used to strengthen polycarbonate (PC) to create long-persistent photoluminescent and fluorescent smart materials such as afterglow concrete and smart window. Physical integration of lanthanide-activated aluminate (LA) nanoparticles (NPs) yielded transparent GNFs@PC smart sheets. Spectral investigations utilizing photoluminescence and CIE Lab parameters were performed to confirm that the translucent appearance of GNFs@PC changed to green when exposed to UV light. This fluorescence activity was quickly reversible for the GNFs@PC hybrids with low concentrations of LANPs, which indicate fluorescence emission. Higher phosphor concentrations in GNFs@PC led to longer-lasting afterglow photoluminescence and slower reversibility. The GNFs@PC hybrids showed an emission band detected at 518 nm upon excitation at 368 nm. The morphological characteristics of LANPs and GNFs were analyzed by transmission electron microscopy (TEM), which revealed sizes of 11–26 nm and 250–300 nm, respectively. GNFs were prepared using electrospinning technology and then used as a roughening agent into PC sheets. Morphological characteristics of GNFs and GNFs@PC smart sheets were examined using energy-dispersive X-ray spectroscopy (EDXA), X-ray fluorescence (XRF) and scanning electron microscopy (SEM). The GNFs@PC smart sheets were shown to have enhanced scratch resistance in comparison to LANPs-free PC control sample. Increases in LANPs concentration enhanced both hydrophobicity and UV protection.

Preparation of dual mode encoding photochromic electrospun glass nanofibers for anticounterfeiting applications

Photochromism has shown to be a promising tool for improving the authenticity of commercially available products. Additionally, improving the engineering process of authentication patterns has been crucial to offer mechanically reliable anticounterfeiting nanofibers. Herein, the electrospinning technology was applied to develop mechanically reliable and photoluminescent silicon dioxide-based electrospun glass nanofibers (80–110 nm) embedded with lanthanide-activated aluminate (LA) nanoparticles (NPs; 1–2 nm) for anticounterfeiting purposes. The produced nanocomposite films exhibited photochromism from colorless in visible spectrum to green under ultraviolet irradiation. The nanofibrous film transparency was maintained by presenting the strontium aluminate pigment as nano-scaled particles, which improves its distribution and prevents the formation of aggregates in the electrospun glass nanofibrous bulk. After being excited at 365 nm, the nanofibers made of phosphor@glass (LANPs@GLS) displayed an emission band at 519 nm. Increases in the pigment ratio enhanced the hydrophobicity of the LANPs@GLS nanofibers without altering their intrinsic characteristics. The LANPs@GLS films exhibited fast and reversible photochromism without fatigue when activated by UV light. Transparency and flexibility were shown by the nanofibrous mats. The proposed technique is reliable for making a wide range of anticounterfeiting materials.

Nanoscale borosilicate bioactive glass for regenerative therapy of full-thickness skin defects in rabbit animal model.

Bioactive glass (BG) occupies a significant position in the field of hard and soft tissue regeneration. Different processing techniques and formulas have been introduced to expand their regenerative, angiogenic, and antibacterial properties. In the present study, a new formula of bborosilicate bioactive glass nanofibers was prepared and tested for its wound-healing efficacy in a rabbit animal model. The glass formula ((1-2) mol% of B2O3 (68-69) mol% of SiO2, and (29-30) mol% of CaO) was prepared primarily by the sol-gel technique followed by the electrospinning technique. The material was characterized for its ultrastructure using scanning electron microscopy, chemical composition using FTIR, and its dynamic in vitro biodegradability using ICP-AES. Twelve rabbits were subjected to surgical induction of full-thickness skin defects using a 1cm2 custom-made stainlessteel skin punch. The bioactive glass nanofibers were used as a grafting material in 6 experimental rabbits, while the defects in the remaining rabbits were considered as the negative control samples. All defects were assessed clinically for the decrease in wound size and clinical signs of healing and histologically for angiogenesis, collagen density, inflammatory response, cell recruitment, epithelial lining, and appendages at 1,2 and 3weeks following the intervention. Structural analysis of the glass fibers confirmed their nano-size which ranged from 150 to 700nm. Moreover, the chemical analysis confirmed the presence of SiO2 and B2O3 groups within the structure of the nanofibers. Additionally, dynamic biodegradation analysis confirmed the rapid degradation of the material starting from the first 24h and rapid leaching of calcium, silicon, and boron ions confirming its bioactivity. The wound healing study of the nanofibrous scaffold confirmed its ability to accelerate wound healing and the closure rate in healthy rabbits. Histological analysis of the defects confirmed the angiogenic, regenerative and antibacterial ability of the material throughout the study period. The results unveil the powerful therapeutic properties of the formed nanofibers and open a new gate for more experimental and clinical applications.