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(1) Background: Spinal cord injuries and diseases necessitate sophisticated tools for accurate diagnosis and treatment planning. However, the lack of reliable phantoms mimicking the complex structure of the spinal cord hinders the development and validation of advanced imaging techniques. This study aims to address this critical unmet need by exploring the application of electrospinning to create polymeric fibers resembling the human spinal cord; (2) Methods: Direct jet coaxial electrospinning (DJ-co-ES) is a specialized electrospinning process characterized by the presence of solely the straight segment of a fluid jet. The research firstly investigates the effects of various solution properties and process parameters on the formation and characteristics of core/shell fibers with polycaprolactone (PCL) as the shell and polyethylene oxide (PEO) as the core. Furthermore, the study explores the potential of these DJ-co-ES fibers as phantoms by measuring various diffusion MRI parameters; (3) Results: Scanning electron microscopy (SEM) revealed the successful production of hollow PCL microfibers (2–12 μm diameter) with smooth, cylindrical morphology and high orientation. The DJ-co-ES process demonstrated optimal stability when utilizing 10 w/v% PCL in DCM/DMF for the shell and 4 w/v% PEO in deionized water for the core. Additionally, the high miscibility between core and shell solvents in other core and shell solutions cases facilitated the production of fibers with smaller diameters. The findings demonstrate that the measured values fall within the range observed in both healthy and diseased spinal cord tissues; (4) Conclusions: This research paves the way for utilizing DJ-co-ES technology to develop reliable phantoms for spinal cord applications, ultimately fostering advancements in diagnosis, treatment, and research related to spinal cord conditions. [ABSTRACT FROM AUTHOR]

To avoid harm to humans and devices, developing electromagnetic interference (EMI) shielding materials possessing high shielding efficiency and enhanced electromagnetic (EM) wave absorption properties is of fundamental importance. Preventing threats caused by EMI and reducing the secondary pollution of EM waves are critical requirements for materials. In the research described here, composites of Ag nanoparticles coated with poly p-phenylene terephthalamide (PPTA) nonwoven and Fe3O4 decorated MXene nanosheets were prepared by electroless silver plating and Fe3O4-MXene deposition. The top and bottom layers of the composites were Fe3O4 nanoparticle-decorated MXene nanosheets and silicone rubber, while the middle layer consisted of a Ag nanoparticle-coated PPTA nonwoven fabric. The formation of the sandwich structure, the electromagnetic compounding, and the porous structure of the PPTA nonwoven fabric coated with Ag nanoparticles endowed the composites with excellent EMI shielding properties. An EMI shielding effectiveness of 89.92 dB was achieved in the frequency range of 8.2–12.4 GHz. The absorption coefficient A of the composites reached 0.203, which was noticeably enhanced compared with 0.013 of Ag nanoparticle-coated PPTA nonwoven fabric. [ABSTRACT FROM AUTHOR]

To meet the requirement of high stretchability, high sensitivity, and multifunction for flexible sensors, core–sheath structured polystyrene‐ethylene‐butene‐styrene (SEBS)/carbon nanotubes (CNTs)/carbonyl iron particle (CIP) fiber with SEBS/CNTs as the sheath and SEBS/CIP as the core was prepared through wet spinning. The contents of CNTs and CIP in the composite fiber were adjusted by changing the extrusion speed of the SEBS/CNTs and SEBS/CIP spinning solutions. The morphology, electromechanical sensing, and magnetic precepting performances of the fiber were studied. The SEBS/CNTs/CIP fiber sensor showed high stretchability with a maximum strain sensing range of 0%–216.9%, high sensitivity with a gauge factor (GF) of up to 1068.28, as well as excellent durability. In addition, the SEBS/CNTs/CIP fiber sensor exhibited excellent magnetic sensing performance by changing the relative resistance of 35.2% with a magnetic flux density variation of 1.2 T. The applications of SEBS/CNTs/CIP fiber in stretchable circuits, human body motion monitoring, and magnetic field perception were demonstrated. Highlights: SEBS/CNTs/CIP fiber for strain and magnetic field sensing was fabricated.The SEBS/CNTs/CIP fiber sensor could sense 216.9% strain with GF up to 1068.28.Relative resistance of SEBS/CNTs/CIP fiber sensor changed by 35.2% under 1.2 T.SEBS/CNTs/CIP fiber was used in human motion monitoring and magnetic perception. [ABSTRACT FROM AUTHOR]

Electrospun nanofibers are most often produced by needle electrospinning process, which has inherent disadvantages like clogging and low efficiency. In this study, an alternative needleless electrospinning process is reported for the fabrication of nanofibers based on a novel spinneret. Firstly, a spinneret with a 0.5-mm diameter hole in the middle of a flat plastic cap was custom-made that may be readily scaled up for mass production. Then, polyethylene oxide (PEO) aqueous solution with 6.0 wt% concentration was used to demonstrate the needleless electrospinning process. The processing window for the jet formation in the flat spinneret electrospinning process was determined. The relationships between various processing parameters (applied voltage, working distance, and flow rate) and the resultant PEO nanofibers were also investigated. It was found that stable fluid jet launched from the tip of the coned droplet anchored at the rim of the hole and formed fibers. The morphology and diameter of electrospun fibers were examined using scanning electron microscopy. The results show that PEO nanofibers produced by this needleless electrospinning have similar structure and morphology to those from the single needle source. Finally, the hole number of spinneret was increased to four holes, which was still able to produce smooth nanofibers with a higher production rate. POLYM. ENG. SCI., 49:2475-2481, 2009. ©2009 Society of Plastics Engineers, INTRODUCTION Currently, electrospinning is the only technique capable of fabricating various nanofiber assemblies such as nonwoven webs, aligned bundles, and twisted yarns (1), (2). Nanofiber assemblies by electrospinning can find [...]

A flexible strain sensor with excellent mechanical and electrical properties was fabricated by depositing carboxylated multiwalled carbon nanotubes (CNTs) and graphene (Gr) onto thermoplastic polyurethane (TPU) nanofibrous membranes. The deposition efficiency and fastness of CNTs and Gr particles on TPU nanofibrous membranes were improved by vacuum assisted deposition and ultrasonication. Furthermore, a flexible strain sensor with excellent sensing performance was obtained by optimizing the optimal hybrid ratio between CNTs and Gr. Electromechanical experiments showed that the strain sensor had a wide working range of 172% with a high‐gauge factor of approximately 217 for TPU/5CNTs5Gr composite. Moreover, the TPU/5CNTs5Gr composite also exhibited good durability in 10,000 tensile loading‐unloading cycles, and had superior sensing performance when monitoring the bending motions of human finger, elbow and knee. [ABSTRACT FROM AUTHOR]

Recent advances in bioimaging, biochemistry, and bioinformatics have facilitated the development of personalized and precision medicine. Theranostics, combining imaging modalities and therapeutic agents, have garnered a lot of attention in this context, owing to their potential to monitor and control treatment for individual patients. A promising strategy to achieve this goal involves the development of therapy guided by magnetic resonance imaging (MRI). MRI has a high degree of soft tissue contrast, low invasiveness, high depth of penetration and good spatial resolution. MRI‐guided therapy could thus allow precise and time‐resolved assessment of disease conditions and therapeutic progression. This article will give a brief introduction to the principles of MRI, and describe recently developed strategies to produce MRI‐guided therapies. A number of theranostics based on T1, T2, or chemical exchange saturation transfer (CEST) MRI have been explored to track the route of drug carriers in vivo and image diseased tissue so as to enhance bioavailability, overcome complex delivery barriers, and assess therapeutic responses. In addition, the integration of thermal therapy and MRI imaging offers a strategy to noninvasively identify target areas, plan treatment, and provide real‐time assessment of the efficacy of tumor ablation. We also discuss advances in intelligent nanoparticles combining small molecule drugs, thermal treatment and multimodal imaging, arguing that these multifunctional agents can further improve therapeutic outcomes. [ABSTRACT FROM AUTHOR]

Fiber‐based strain sensors are considered to be an important part of smart wearables due to their flexible performance, lightness, and easily processing into various structures. However, the low sensitivity of fiber‐based strain sensors has limited their real‐life applications for detecting human movements. In this work, a poly(styrene‐butadiene‐styrene) (SBS)/multi‐walled carbon nanotube (MWCNTs) core–sheath fiber (SSCCSF) strain sensor is fabricated via a simple and facile coaxial wet‐spinning method. The cross‐sectional morphology, the mechanical properties, and the electromechanical performance of the SSCCSFs are investigated. Scanning electron microcopy results show that SSCCSFs have a bean‐like cross‐section with SBS as the core and SBS/MWCNTs as the sheath. Electromechanical performance evaluation confirms that the SSCCSF show a high sensitivity in a broad working range (gauge factor = 25832.77 at 41.5% strain) and excellent durability (5000 cycles at 10% strain). Furthermore, the SSCCSF displays outstanding sensing performance for detecting large motions in human movements including hand joint bending (such as knuckles and wrists) and subtle motions in physiological activities, involved in swallowing behavior, breathing, and pulse beat. This study demonstrates the potential application of SSCCSFs for wearable electronics with activity monitoring sensors. [ABSTRACT FROM AUTHOR]

Purpose: To develop a biomimetic tumor tissue phantom which more closely reflects water diffusion in biological tissue than previously used phantoms, and to evaluate the stability of the phantom and its potential as a tool for validating diffusion‐weighted (DW) MRI measurements. Methods: Coaxial‐electrospraying was used to generate micron‐sized hollow polymer spheres, which mimic cells. The bulk structure was immersed in water, providing a DW‐MRI phantom whose apparent diffusion coefficient (ADC) and microstructural properties were evaluated over a period of 10 months. Independent characterization of the phantom's microstructure was performed using scanning electron microscopy (SEM). The repeatability of the construction process was investigated by generating a second phantom, which underwent high resolution synchrotron‐CT as well as SEM and MR scans. Results: ADC values were stable (coefficients of variation (CoVs) < 5%), and varied with diffusion time, with average values of 1.44 ± 0.03 µm2/ms (Δ = 12 ms) and 1.20 ± 0.05 µm2/ms (Δ = 45 ms). Microstructural parameters showed greater variability (CoVs up to 13%), with evidence of bias in sphere size estimates. Similar trends were observed in the second phantom. Conclusion: A novel biomimetic phantom has been developed and shown to be stable over 10 months. It is envisaged that such phantoms will be used for further investigation of microstructural models relevant to characterizing tumor tissue, and may also find application in evaluating acquisition protocols and comparing DW‐MRI‐derived biomarkers obtained from different scanners at different sites. Magn Reson Med 80:147–158, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. [ABSTRACT FROM AUTHOR]