Optimizing Protein Fiber Spinning to Develop Plant-Based Meat Analogs via Rheological and Physicochemical Analyses.

The substitution of meat products in the human diet with plant-based analogs is growing due to environmental, ethical, and health reasons. In this study, the potential of fiber-spinning technology was explored to spin protein fiber mimicking the structural element of meat muscle for the purpose of developing plant-based meat analogs. Overall, this approach involved extruding fine fibers and then assembling them into hierarchical fibrous structures resembling those found in whole muscle meat products. Considering the nutritional facts and to help build muscle fiber, soy protein, polysaccharide (pectin, xanthan gum, or carrageenan), plasticizer (glycerol), and water were used in the formulations to spin into fibers using an extruder with circular orifice dies. Extrudability and thermal and rheological properties were assessed to characterize the properties of the spun fiber. The extrusion trials showed that the presence of the polysaccharides increased the cohesiveness of the fibers. The properties of the fibers produced also depended on the temperature used during extrusion, varying from pasty gels to elastic strands. The extrudability of the fibers was related to the rheological properties (tan δ) of the formulations. This study demonstrated that fiber-spinning technology can be used to produce fibrous materials from plant-derived ingredients. However, the formulation and operating conditions must be optimized to obtain desirable physicochemical and functional attributes in the fibers produced.

Electrochemiluminescence in paired signal electrode (ECLipse) enables modular and scalable biosensing.

Electrochemiluminescence (ECL) has an inherently low background and enables precise chemical reactions through electrical control. Here, we report an advanced ECL system, termed ECLipse (ECL in paired signal electrode). We physically separated ECL generation from target detection: These two processes were carried out in isolated chambers and coupled through an electrode. The strategy allowed us to minimize cross-chemical reactions, design electrodes for high ECL signals, and integrate multiple sensors in a chip. As a proof of concept, we implemented an eight-plex ECLipse and applied it to detect host factors in human plasma. ECLipse achieved higher signal-to-noise ratio than conventional ECL assays and was >7000-fold more sensitive than enzyme-linked immunosorbent assay. In a pilot clinical study, we could detect septic conditions by measuring host factors [i.e., interleukin-3 (IL-3), IL-6, and procalcitonin (PCT)]. ECLipse assay further revealed distinct IL-3 and IL-6 patterns in patients with severe acute respiratory syndrome coronavirus 2 infection.

Smart E-Textiles: Overview of Components and Outlook.

Smart textiles have gained great interest from academia and industries alike, spanning interdisciplinary efforts from materials science, electrical engineering, art, design, and computer science. While recent innovation has been promising, unmet needs between the commercial and academic sectors are pronounced in this field, especially for electronic-based textiles, or e-textiles. In this review, we aim to address the gap by (i) holistically investigating e-textiles' constituents and their evolution, (ii) identifying the needs and roles of each discipline and sector, and (iii) addressing the gaps between them. The components of e-textiles-base fabrics, interconnects, sensors, actuators, computers, and power storage/generation-can be made at multiscale levels of textile, e.g., fiber, yarn, fabric, coatings, and embellishments. The applications, current state, and sustainable future directions for e-textile fields are discussed, which encompasses health monitoring, soft robotics, education, and fashion applications.

Temperature Responsive PBT Bicomponent Fibers for Dynamic Thermal Insulation.

Thermoresponsive self-crimping polybutylene terephtlate (PBT)-based bicomponent fibers were fabricated by melt-spinning to serve as primary constituents for textiles, such as nonwoven battings, for an adaptive single insulting layer. Due to the intrinsically mismatching modulus and coefficient of thermal expansion (CTE), the fibers curl or straighten with temperature, similar to the concept of Timoshenko's bimetallic strip. Maximizing the curvature is driven by an optimum of fiber diameter, overall CTE, and fiber moduli, which are all affected by drawing ratio and, consequently, fiber's microstructure. A draw ratio of 2.33 yielded the best combination of mechanical and thermal properties; it was observed that increasing the draw ratio does not necessarily increase the self-crimping behavior. Tests performed on non-woven battings of these fibers exhibited comparable thermoreponsive behaviors to polypropylene-based thermoresponsive fibers from previous studies in the -20 °C to 20 °C temperature range, which has potential for wearable insulations for both commercial and defense sectors alike.

Measurement of compensatory wrist joint rotation using three-dimensional motion analysis in patients with unilateral proximal congenital radioulnar synostosis.

OBJECTIVE: This study aims to investigate compensatory rotational movements of the wrist joint in patients with proximal congenital radioulnar synostosis (CRUS), using a valid and reliable three-dimensional (3D) motion analysis technique. METHODS: A total of 26 patients (6 females, 14 males; mean age=15.3 years; and age range=6-32 years) who were diagnosed with unilateral proximal CRUS but were not operated were enrolled in this study. Patients were then categorized into 2 groups: Group I included 5 patients younger than 10 years, and Group II included 15 patients older than 10 years. Eighteen light-reflective skin markers were placed on the bony landmarks of both upper limbs, and both distal forearms were fixed using a U-shaped device to minimize forearm rotation. Each patient grasped the handle of an instrument that used a goniometer to measure wrist rotation; maximal passive pronation and supination angles of the wrist were measured in this manner and also using 3D motion analysis. RESULTS: There was a significant correlation between measurements by the goniometer and 3D motion analysis (r=0.985, p<0.001). The test-retest reliability of the 3D motion analysis was acceptable for both the affected side (ICC=0.992) and the contralateral normal side (ICC=0.997) with low standard measurement errors (1.3° and 0.8°, respectively). Although no significant difference was observed in the range of the wrist rotation between the affected and contralateral sides in Group I (p=0.686), there was a significant difference in the wrist rotation between the affected and contralateral sides in Group II (p=0.001). Further, the pronation angle of the wrist joint was significantly larger in the affected side than that in the contralateral normal side in Group II (p=0.001). CONCLUSION: The 3D motion analysis technique seems to be a valid and reliable method to measure the rotation of the wrist joint. Unilateral proximal CRUS patients older than 10 years of age may develop rotational hypermobility of the wrist joint compared to the contralateral normal side as a compensatory phenomenon. LEVEL OF EVIDENCE: Level III, Diagnostic Study.

Facile Synthesis of Porous Silicon Nanofibers by Magnesium Reduction for Application in Lithium Ion Batteries.

We report a facile fabrication of porous silicon nanofibers by a simple three-stage procedure. Polymer/silicon precursor composite nanofibers are first fabricated by electrospinning, a water-based spinning dope, which undergoes subsequent heat treatment and then reduction using magnesium to be converted into porous silicon nanofibers. The porous silicon nanofibers are coated with a graphene by using a plasma-enhanced chemical vapor deposition for use as an anode material of lithium ion batteries. The porous silicon nanofibers can be mass-produced by a simple and solvent-free method, which uses an environmental-friendly polymer solution. The graphene-coated silicon nanofibers show an improved cycling performance of a capacity retention than the pure silicon nanofibers due to the suppression of the volume change and the increase of electric conductivity by the graphene.

Formation of interconnected morphologies via nanorod inclusion in the confined assembly of symmetric block copolymers.

We have investigated the effect of nanorods on the symmetry breaking of a model diblock copolymer under cylindrical confinement using coarse-grained molecular dynamics. Unlike nanoparticles, nanorods can readily be interconnected with each other and also induce connection across self-assembly domains at much lower loading than nanoparticles. Such interconnecting nanorods, when incorporated within the nanofiber confined assembled block copolymer, have great potential for providing highly conductive pathways for energy applications, such as battery electrodes and separators. Symmetric block copolymers (BCP) under cylindrical confinement with a nanorod aspect ratio (N) of 1, 5, and 10 are examined with three different types of nanorod-BCP attractions: (a) neutral nanorods, (b) A (wall-attractive phase)-attractive nanorods, and (c) B (wall-repulsive phase)-attractive nanorods. The system was studied with both selective and neutral walls, which affect the orientation of the interconnected nanorod network. Upon close examination of the BCP-nanorod self-assembly, we discovered that the ratio of the interphase distance to the nanorod aspect ratio (I/N) can be correlated to the onset of nanorod interconnectivity and formation of asymmetrical interconnected BCP morphology. By developing a phase diagram with respect to I/N, one can predict the formation of desired BCP morphology and the critical loading of nanorods for connected morphologies in cylindrical confinement.

Controlling the dispersion and orientation of nanorods in polymer melt under shear: coarse-grained molecular dynamics simulation study.

Incorporation of nanorods (NRs) into a polymer matrix can greatly enhance the material properties, but the aggregation of NRs prevents the full realization of their potential. Using coarse-grained molecular dynamics simulation with the dissipative particle dynamics thermostat, we have systematically examined how key material and processing parameters, such as aspect ratio, particle diameter, rigidity and concentration of NR, polymer chain length, and shear rate can influence the placement and orientation of the self-aggregating NRs in a model polymer melt under shear. When compared with nanoparticles (NPs), the NRs tend to aggregate more severely even under strong shear flow. To improve the dispersion of NRs within the polymer matrix under a given flow condition, we incorporated additional NPs with selective interactions into polymer/NR composites, demonstrating that the current mesoscale simulation study offers insights on how to control the dispersion and orientation of NRs in polymer under shear flow.

Tailoring nanorod alignment in a polymer matrix by elongational flow under confinement: simulation, experiments, and surface enhanced Raman scattering application.

Mesoscale simulation, electrospinning and Raman scattering experiments have been carried out to demonstrate that examination and control of nanorod configuration in a polymer matrix under elongational flow and confinement can lead to enhanced sensing. First, coarse-grained molecular dynamics (CGMD) was employed to probe the diffusivity, orientation, and dispersion of nanorods in a model polymer melt under planar elongational flow. Compared to shear flow, elongational flow gives rise to enhanced dispersion and orientation of nanorods, which are predicted to be improved with increasing the aspect ratio of nanorods and polymer chain length. As comparative experiments, we have electrospun gold (Au) nanorods with polyvinyl alcohol (PVA), and the resulting Au nanorod configuration in PVA nanofibers is in good agreement with the predicted simulation. Furthermore, coaxial electrospinning of Au nanorod/PVA-PVA (shell-core) was applied to selectively place Au nanorods in the cylindrical sheath layer, and the alignment of Au nanorods near the fiber surface was confirmed by TEM analysis and CGMD simulation under uniaxial elongation. Finally, the Au nanorod-PVA fibers were tested for surface-enhanced Raman spectroscopy for sensing applications. The coaxially electrospun fibers have demonstrated much greater signal peak strength when compared with monoaxially electrospun fibers with the same Au nanorod loading. This comprehensive study demonstrates how extensional flow and multi-layered fluids can direct the orientation and dispersion of nanorod in a polymer matrix, leading to enhanced sensing performance.

Preparation and characterization of amphiphilic triblock terpolymer-based nanofibers as antifouling biomaterials.

Antifouling surfaces are critical for the good performance of functional materials in various applications including water filtration, medical implants, and biosensors. In this study, we synthesized amphiphilic triblock terpolymers (tri-BCPs, coded as KB) and fabricated amphiphilic nanofibers by electrospinning of solutions prepared by mixing the KB with poly(lactic acid) (PLA) polymer. The resulting fibers with amphiphilic polymer groups exhibited superior antifouling performance to the fibers without such groups. The adsorption of bovine serum albumin (BSA) on the amphiphilic fibers was about 10-fold less than that on the control surfaces from PLA and PET fibers. With the increase of the KB content in the amphiphilic fibers, the resistance to adsorption of BSA was increased. BSA was released more easily from the surface of the amphiphilic fibers than from the surface of hydrophobic PLA or PET fibers. We have also investigated the structural conformation of KB in fibers before and after annealing by contact angle measurements, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and coarse-grained molecular dynamics (CGMD) simulation to probe the effect of amphiphilic chain conformation on antifouling. The results reveal that the amphiphilic KB was evenly distributed within as-spun hybrid fibers, while migrated toward the core from the fiber surface during thermal treatment, leading to the reduction in antifouling. This suggests that the antifouling effect of the amphiphilic fibers is greatly influenced by the arrangement of amphiphilic groups in the fibers.

Confined assembly of asymmetric block-copolymer nanofibers via multiaxial jet electrospinning.

Multiaxial (triaxial/coaxial) electrospinning is utilized to fabricate block copolymer (poly(styrene-b-isoprene), PS-b-PI) nanofibers covered with a silica shell. The thermally stable silica shell allows post-fabrication annealing of the fibers to obtain equilibrium self-assembly. For the case of coaxial nanofibers, block copolymers with different isoprene volume fractions are studied to understand the effect of physical confinement and interfacial interaction on self-assembled structures. Various confined assemblies such as co-existing cylinders and concentric lamellar rings are obtained with the styrene domain next to the silica shell. This confined assembly is then utilized as a template to guide the placement of functional nanoparticles such as magnetite selectively into the PI domain in self-assembled nanofibers. To further investigate the effect of interfacial interaction and frustration due to the physically confined environment, triaxial configuration is used where the middle layer of the self-assembling material is sandwiched between the innermost and outermost silica layers. The results reveal that confined block-copolymer assembly is significantly altered by the presence and interaction with both inner and outer silica layers. When nanoparticles are incorporated into PS-b-PI and placed as the middle layer, the PI phase with magnetite nanoparticles migrates next to the silica layers. The migration of the PI phase to the silica layers is also observed for the blend of PS and PS-b-PI as the middle layer. These materials not only provide a platform to further study the effect of confinement and wall interactions on self-assembly but can also help develop an approach to fabricate multilayered, multistructured nanofibers for high-end applications such as drug delivery.