Side Of Membrane Research Articles

Development of an In Vitro Model to Study Mechanisms of Ultrasound-Targeted Microbubble Cavitation–Mediated Blood–Brain Barrier Opening

Ultrasound-targeted microbubble cavitation (UTMC)-mediated blood-brain barrier (BBB) opening is being explored as a method to increase drug delivery to the brain. This strategy has progressed to clinical trials for various neurological disorders, but the underlying cellular mechanisms are incompletely understood. In the study described here, a contact co-culture transwell model of the BBB was developed that can be used to determine the signaling cascade leading to increased BBB permeability. This BBB model consists of bEnd.3 cells and C8-D1A astrocytes seeded on opposite sides of a transwell membrane. Pulsed ultrasound (US) is applied to lipid microbubbles (MBs), and the change in barrier permeability is measured via transendothelial electrical resistance and dextran flux. Live cell calcium imaging (Fluo-4 AM) is performed during UTMC treatment. This model exhibits important features of the BBB, including endothelial tight junctions, and is more restrictive than the endothelial cell (EC) monolayer alone. When US is applied to MBs in contact with the ECs, BBB permeability increases in this model by two mechanisms: UTMC induces pore formation in the EC membrane (sonoporation), leading to increased transcellular permeability, and UTMC causes formation of reversible inter-endothelial gaps, which increases paracellular permeability. Additionally, this study determines that calcium influx into ECs mediates the increase in BBB permeability after UTMC in this model. Both transcellular and paracellular permeability can be used to increase drug delivery to the brain. Future studies can use this model to determine how UTMC-induced calcium-mediated signaling increases BBB permeability.

Comparative histomorphologic study of basement membrane side staining and additional epithelial side staining of the anterior lens capsule with Trypan Blue.

To compare the histomorphologic changes on the anterior lens capsule by both epithelial and basement membrane side staining to those of only basement membrane side staining of the anterior lens capsule with Trypan Blue (TB). A cross-sectional study was done on 72 samples from patients who underwent cataract surgery between April 2021 and September 2022. After capsulorhexis of the TB-stained capsule, it was made into two halves externally and one half labeled as controls (sample A). The other half was immediately stained further with TB on the epithelial side and was taken as cases (sample B). Samples were analyzed for lens epithelial cells and basement membrane changes. The loss of intactness of lens epithelial cells, partial or complete detachment of lens epithelial cells, degeneration of lens epithelial cells, and basement edema were significantly higher in cases compared to controls, whereas intactness of the basement membrane did not show any statistical significance between the two groups. There was a statistically significant decrease in cell density in cases compared to controls. Staining the epithelial side of the capsular bag with TB is more detrimental to lens epithelial cells and paves the way for a further study of staining the capsular bag before intra-ocular lens implantation to reduce the incidence of posterior capsule opacification.

A Two-Dimensional Transport Model of Bipolar Membrane Electrodialysis for the Electro-Regeneration of Carbon Capture Solvents

Bipolar membrane electrodialysis (BPMED) is a promising technology that uses an electric field to split water into H+ and OH- ions. A repeating stack of cation selective, anion selective, and bipolar membranes are placed between two electrodes, creating a repeating pattern of acid, base, and diluting flow chambers. A major application of BPMED is the electrochemical solvent regeneration of capture solutions used in CO2 point source (PS) or direct air capture (DAC). Protons generated using BPMED can be used to shift the acid-base equilibria back to CO2, providing a more sustainable alternative to traditional thermal regeneration methods when integrated with renewable electricity sources. This method combines electrosynthesis and separation, producing a pure stream of CO2 for sequestration and a concentrated base stream.Despite its potential, current limitations to BPMED implementation for this application stem from a large power consumption and high membrane costs. In addition, gas bubbles in solution can cause high electrical resistances, and experimental studies of this phenomenon are challenging due to the small scale on which it occurs. To address these challenges, we present a two-dimensional model of BPMED for CO2 capture solvent recovery. This model depicts a single repeating cell triplet and was constructed using COMSOL Multiphysics version 6.1. The Navier-Stokes equations were implemented to compute a convection field, and the ionic species concentration was found by solving the Nernst-Planck equation. A source term in the concentration partial differential equations was implemented to account for ionic speciation and water splitting reactions, captured through kinetic rate expressions.Experimental validation was conducted on a PC Cell BED 1-4 recirculating batch system with a stack of seven cell pairs of PC acid 60 (anion selective), PC SK (cation selective), and PC Bip (bipolar) membranes. Good agreement between the model and experimental results across a range of conditions and variables demonstrates accuracy and robustness. The calculated pH and concentration profiles revealed that the majority of the speciation reaction takes place inside, or directly adjacent to, the bipolar membrane, including bubble nucleation. Bubbles form inside membrane pores and displace the electrolyte, greatly increasing the electrical resistance of the membrane, particularly when membrane porosity is low. However, the reaction plane location where bubbles are generated can be manipulated by increasing the channel width or reducing the applied voltage.Future research will focus on expanding to multiphase CFD simulations to investigate the effect on flow. Our two-dimensional model provides valuable insights into the complex and multifaceted nature of BPMED, offering a powerful tool for investigating small-scale processes and advancing the use of BPMED for CO2 capture solvent recovery. Figure 1

Solubility-permeability interplay of a supersaturated lutein delivery system constructed by glycosylated stevioside and hydroxypropyl-methylcellulose

This study investigated the solubilizing capacity of glycosylated stevioside/hydroxypropyl-methylcellulose (stevia-G-HPMC) complexes with varying mass ratios on lutein. The impact on the steady-state flux and permeability coefficient of intracellular lutein was also explored through the construction of a Caco-2 cellular transport model. The results indicated that the equilibrium solubility of lutein linearly increased with an increase in stevia-G amount. The stability constants of the ternary system surpassed those of the binary system. Molecular dynamics simulation revealed a tight and stable structure in lutein supersaturated complexes. Meanwhile, lutein-stevia-G-HPMC complexes demonstrated superior cumulative penetrations, with the peak Papp (AP → BL) value being (3.24 ± 0.89) × 10−5 cm·s−1. There was a slight decrease in Papp (BL → AP), which improved the forward transport of lutein. Highly soluble lutein in aqueous environments saturated the extracellular transport proteins on the AP side of cell membranes, thereby maintaining the high permeability transport. Notably, the permeability trend of lutein in Caco-2 cells negatively correlated with the equilibrium solubility and matched the single exponential growth model. When the mass ratio of lutein, stevia-G and HPMC was 1:21:5, the solubility-permeability trade-off of lutein was effectively maintained.

Screening Therapeutic Effects of MSC-EVs to Acute Lung Injury Model on A Chip.

Acute lung injury (ALI) is a lethal disease with high mortality rate, and its physiologically relevant models that could mimic human disease processes are urgently needed to study pathophysiology and predict drug efficacy. Here, this work presents a novel lipopolysaccharide(LPS) based ALI model on a microfluidic chip that reconstitutes an air-liquid interface lined by human alveolar epithelium and microvascular endothelium for screening the therapeutic effects of mesenchymal stem cells (MSC) derived extracellular vesicles (MSC-EVs) to the biomimetic ALI. The air-liquid interface is established by coculture of alveolar epithelium and microvascular endothelium on the opposite sides of the porous membrane. The functionalized architecture is characterized by integrate cell layers and suitable permeability. Using this biomimetic microsystem, LPS based ALI model is established, which exhibits the disrupted alveolar-capillary barrier, reduced transepithelial/transendothelial electrical resistance (TEER), and impaired expression of junction proteins. As a reliable disease model, this work examines the effects of MSC-EVs, and the data indicate the therapeutic potential of EVs for severe ALI. MSC-EVs can alleviate barrier disruption by restoring both the epithelial and endothelial barrier integrity. They hope this study can become a unique approach to study human pathophysiology of ALI and advance drug development.

Mimic the electric activity in a heat-sensitive membrane in circuit

The membrane potential of an isolated biological neuron results from the concentration difference between intracellular and extracellular ions. Any external disturbance and synaptic current from adjacent neurons will break the balance of electromagnetic field induced by gradient distribution of ions. Neurons develop different biophysical functions and then more neurons are clustered with controllable synapses to form different functional regions in the brain. In this Letter, two linear circuits (LCs) are coupled via a nonlinear resistor for mimicking the electric characteristic of cell membrane. Thermistors are included to approach a thermal-sensitive membrane. The neuron model developed from the coupled circuits with thermistors has two capacitive variables, which represent the external and inner electric field, and energy balance between inner and outer membranes are controlled by the coupling channel via a nonlinear resistor. The neuron excitability is relative to the temperature, two kinds of thermistors are used in the coupled LCs to investigate the consensus and difference between inner and outer media. Energy propagation is blocked when the thermal properties have distinct difference between two sides of the cell membrane, and potential diversity supports continuous firing patterns. The results provide possible clues to design artificial cell membrane which is sensitive to temperature.

Dual Mg-Reinforced PCL Membrane with a Janus Structure for Vascularized Bone Regeneration and Bacterial Elimination.

Commercially available guided bone regeneration (GBR) membranes often exhibit limited mechanical properties or bioactivity, leading to poor performance in repairing bone defects. To surmount this limitation, we developed a Janus structural composite membrane (Mg-MgO/PCL) reinforced by dual Mg (Mg sheets and MgO NPs) by using a combined processing technique involving casting and electrospinning. Results showed that the addition of Mg sheets and MgO NPs enhanced the mechanical properties of the composite membrane for osteogenic space maintenance, specifically tensile strength (from 10.2 ± 1.2 to 50.3 ± 4.5 MPa) and compression force (from 0 to 0.94 ± 0.09 N mm-1), through Mg sheet reinforcement and improved crystallization. The dense cast side of the Janus structure membrane displayed better fibroblast barrier capacity than a single fiber structure; meanwhile, the PCL matrix protected the Mg sheet from severe corrosion due to predeformation. The porous microfibers side supported preosteoblast cell adhesion, enhanced osteogenesis, and angiogenesis in vitro, through the biomimetic extracellular matrix and sustainable Mg2+ release. Furthermore, the Mg-MgO/PCL membrane incorporating 2 wt % MgO NPs exhibited remarkable antimicrobial properties, inducing over 88.75% apoptosis in Staphylococcus aureus. An in vivo experiment using the rat skull defect model (Φ = 5 mm) confirmed that the Mg-MgO/PCL membrane significantly improved new bone formation postsurgery. Collectively, our investigation provides valuable insights into the design of multifunctional membranes for clinical oral GBR application.

Examination of Bovine Red Blood Cell Death in Vitro in Response to Pathophysiologic Proapoptotic Stimuli.

Interspecies variations in mammalian red blood cells (RBCs) are observed in circulating RBC lifespan, cell size, fluidity, aggregation, water permeability, metabolism, lipid composition, and the overall proteome. Bovine RBC cell membrane is deficient in phosphatidylcholine and exhibits anomalies in the arrangement of phosphatidylethanolamine within the lipid bilayer. However, like human RBCs, virtually all the aminophospholipid phosphatidylserine (PS) is found within the cytoplasmic side of the cell membrane of intact circulating bovine RBCs. During apoptotic cell death of human and murine RBCs, PS translocates to the outer leaflet of the cell membrane via Ca2+-dependent and -independent signaling mechanisms. However, little is known about this process in bovine RBCs. Using cytofluorometry analyses, we characterized and compared the cell death responses in bovine and human RBCs in vitro exposed to various pathophysiologic cell stressors. Ionic stress, by ionophore treatment, and oxidative stress enhanced cytoplasmic Ca2+ levels and cell membrane PS expression in both bovine and human RBCs. Fever-grade hyperthermia and energy starvation promoted Ca2+ influx and elevated reactive oxygen species levels in both human and bovine RBCs. However, bovine RBCs displayed minimal increases in PS expression elicited by hyperthermia, energy starvation, and extracellular hypertonicity as compared to human RBCs. In response to decreased extracellular osmolality, bovine RBCs exhibited significantly enhanced fragility as compared to human RBCs. Bovine RBCs display differential cell death patterns as compared to human RBCs, only partly explained by increased Ca2+ influx and oxidative stress. Premature removal of circulating RBCs could potentially contribute to the pathogenesis of anemia in cattle caused by a wide range of factors such as systemic diseases, parasitic infections, and nutritional deficiencies.

A Josephson junction-coupled neuron with double capacitive membranes

The channel currents have distinct magnetic field effect and any changes of the electromagnetic field or electirc stimulus will change the membrane potential effectively. A feasible neuron model considers the distinct physical characteristic is more suitable to mimic the neural activities accompanying with shift in energy level. A Josephson junction (JJ) is connected to a neural circuit for estimating the effect of external magnetic field and two capacitors are connected via a linear resistor for mimicing the capacitive field beside two sides of the cell membrane. Its equivalent Hamilton energy is calculated to show the relation between firing mode and energy level. Noisy disturbance is imposed to predict the occurrence of coherence resonance, and the biophysical neuron is excited to present higher energy level. This new neuron model can address the field effect and the biophysical property of cell membrane considered as combination of capacitive fields in double capacitors. It can mimic the physical property of outer and inner membranes, and energy exchange across the double membranes explains the energy mechanism in neural activities. Time-varying energy diveristy between capacitive field is crucial for supporting continuous firing activities. The JJ channel discerns slight changes in external magnetic field and regularity is stabilized under coherence resonance in presence of noisy excitation on the membrane or ion channels.

Transmembrane coupling of liquid-like protein condensates

Liquid-liquid phase separation of proteins occurs on both surfaces of cellular membranes during diverse physiological processes. In vitro reconstitution could provide insight into the mechanisms underlying these events. However, most existing reconstitution techniques provide access to only one membrane surface, making it difficult to probe transmembrane phenomena. To study protein phase separation simultaneously on both membrane surfaces, we developed an array of freestanding planar lipid membranes. Interestingly, we observed that liquid-like protein condensates on one side of the membrane colocalized with those on the other side, resulting in transmembrane coupling. Our results, based on lipid probe partitioning and mobility of lipids, suggest that protein condensates locally reorganize membrane lipids, a process which could be explained by multiple effects. These findings suggest a mechanism by which signals originating on one side of a biological membrane, triggered by protein phase separation, can be transferred to the opposite side.

Osmotic and Gibbs–Donnan equilibrium for ions and neutral solutes

The general set of equations for the equilibrium of two solutions with a mixture of non-permeating and permeating ions and neutral solutes at each side of a permselective membrane is formulated using the principles of electroneutrality and mass conservation law for each solution, and equilibrium conditions: equality of electrochemical potentials at both sides of the membrane for each permeating solution component. There is at least one permeating neutral chemical species (solvent) in the system. The theory is in general valid for non-ideal solutions. The generalized Gibbs–Donnan (G–D) equilibrium coefficients depend on activities/fractions of all species at one side of the membrane, and charges of ions and partial molar volumes of all species. The equilibrium osmotic pressure across the membrane is also provided by the theory and can be calculated using the ratio of activities (or equivalently the G–D factor) of any permeating neutral solute (including solvent) or the ratios of activities (or equivalently the G–D factors) of any two permeating ions.

Pharmacokinetics of Novel Dopamine Transporter Inhibitor CE-123 and Modafinil with a Focus on Central Nervous System Distribution.

S-CE-123, a novel dopamine transporter inhibitor, has emerged as a potential candidate for cognitive enhancement. The objective of this study was to compare the tissue distribution profiles, with a specific focus on central nervous system distribution and metabolism, of S-CE-123 and R-modafinil. To address this objective, a precise liquid chromatography-high resolution mass spectrometry method was developed and partially validated. Neuropharmacokinetic parameters were assessed using the Combinatory Mapping Approach. Our findings reveal distinct differences between the two compounds. Notably, S-CE-123 demonstrates a significantly superior extent of transport across the blood-brain barrier (BBB), with an unbound brain-to-plasma concentration ratio (Kp,uu,brain) of 0.5, compared to R-modafinil's Kp,uu,brain of 0.1. A similar pattern was observed for the transport across the blood-spinal cord barrier. Concerning the drug transport across cellular membranes, we observed that S-CE-123 primarily localizes in the brain interstitial space, whereas R-modafinil distributes more evenly across both sides of the plasma membrane of the brain's parenchymal cells (Kp,uu,cell). Furthermore, our study highlights the substantial differences in hepatic metabolic stability, with S-CE-123 having a 9.3-fold faster metabolism compared to R-modafinil. In summary, the combination of improved BBB transport and higher affinity of S-CE-123 to dopamine transporters in comparison to R-modafinil makes S-CE-123 a promising candidate for further testing for the treatment of cognitive decline.

Probing the Hydrophobic Region of a Lipid Bilayer at Specific Depths Using Vibrational Spectroscopy.

A novel spectroscopic approach for studying the flexibility and mobility in the hydrophobic interior of lipid bilayers at specific depths is proposed. A set of test compounds featuring an azido moiety and a cyano or carboxylic acid moiety, connected by an alkyl chain of different lengths, was synthesized. FTIR data and molecular dynamics calculations indicated that the test compounds in a bilayer are oriented so that the cyano or carboxylic acid moiety is located in the lipid head-group region, while the azido group stays inside the bilayer at the depth determined by its alkyl chain length. We found that the asymmetric stretching mode of the azido group (νN3) can serve as a reporter of the membrane interior dynamics. FTIR and two-dimensional infrared (2DIR) studies were performed at different temperatures, ranging from 22 to 45 °C, covering the Lβ-Lα phase transition temperature of dipalmitoylphosphatidylcholine (∼41 °C). The width of the νN3 peak was found to be very sensitive to the phase transition and to the temperature in general. We introduced an order parameter, SN3, which characterizes restrictions to motion inside the bilayer. 2DIR spectra of νN3 showed different extents of inhomogeneity at different depths in the bilayer, with the smallest inhomogeneity in the middle of the leaflet. The spectral diffusion dynamics of the N3 peak was found to be dependent on the depth of the N3 group location in the bilayer. The obtained results enhance our understanding of the bilayer dynamics and can be extended to investigate membranes with more complex compositions.

Combinatorial Atoh1, Gfi1, Pou4f3, and Six1 gene transfer induces hair cell regeneration in the flat epithelium of mature guinea pigs

Flat epithelium (FE) is a condition characterized by the loss of both hair cells (HCs) and supporting cells and the transformation of the organ of Corti into a simple flat or cuboidal epithelium, which can occur after severe cochlear insults. The transcription factors Gfi1, Atoh1, Pou4f3, and Six1 (GAPS) play key roles in HC differentiation and survival in normal ears. Previous work using a single transcription factor, Atoh1, to induce HC regeneration in mature ears in vivo usually produced very few cells and failed to produce HCs in severely damaged organs of Corti, especially those with FE. Studies in vitro suggested combinations of transcription factors may be more effective than any single factor, thus the current study aims to examine the effect of co-overexpressing GAPS genes in deafened mature guinea pig cochleae with FE. Deafening was achieved through the infusion of neomycin into the perilymph, leading to the formation of FE and substantial degeneration of nerve fibers. Seven days post neomycin treatment, adenovirus vectors carrying GAPS were injected into the scala media and successfully expressed in the FE. One or two months following GAPS inoculation, cells expressing Myosin VIIa were observed in regions under the FE (located at the scala tympani side of the basilar membrane), rather than within the FE. The number of cells, which we define as induced HCs (iHCs), was not significantly different between one and two months, but the larger N at two months made it more apparent that there were significantly more iHCs in GAPS treated animals than in controls. Additionally, qualitative observations indicated that ears with GAPS gene expression in the FE had more nerve fibers than FE without the treatment. In summary, our results showed that co-overexpression of GAPS enhances the potential for HC regeneration in a severe lesion model of FE.

Development of a high flux Janus PVDF membrane for oily saline water desalination by membrane distillation via PDA-TEOS-APTES surface modification

Membrane distillation (MD) is a promising approach for water desalination. However, in practice, this process is hindered by poor water flux and severe membrane fouling. In this study, a series of Janus membranes were designed for the desalination of oily saline water via direct contact membrane distillation (DCMD). Janus membranes were fabricated by a simple and facile method, direct deposition of dopamine (DA), tetraethylorthosilicate (TEOS), and aminopropyltriethoxysilane (APTES) on one side of the polyvinylidene fluoride (PVDF) membrane, which was modified by hydrophobic SiO2 nanoparticles. In brief, one side of the optimum Janus membrane was strongly hydrophobic (WCA: 149.7 ± 1°) while another side exhibited in air hydrophilicity (WA: 36.3 ± 1.2°) and underwater superoleophobicity. Additionally, the optimum Janus membrane experienced a remarkable enhancement in water flux, reaching an impressive value of 52.6 kg/m2h, (69.2 % increment compared to the pristine PVDF). Notably, the optimal Janus membrane demonstrated long-term stability and significant resistance toward oil fouling during the DCMD desalination of oily saline water while preserving its rejection and high vapor flux. The applied strategies may offer a fresh perspective on membrane design with efficient performance for MD by a facile method.

EXTH-15. A NOVEL IMMUNE-BASED TREATMENT STRATEGY FOR COMBATTING PROTEIN TUMOR HETEROGENEITY

Abstract Cell-based immunotherapy has revolutionized the treatment of many hematological malignancies but has mostly fail against solid tumors, including glioblastoma (GBM). The reason for this failure is multi-fold, but one of the most significant barriers is the extensive intratumoral heterogeneity that characterizes these tumors. Unfortunately, this problem has not been eliminated by personalized medicine strategies aimed at sequencing individual tumors and targeting the uncovered neoantigens. Thinking “outside the box” led us to examine other types of tumor-specific alterations that might more ubiquitously characterize tumor cells, while still being targetable by an immune-based platform. Our investigations led us to the phospholipid phosphatidylserine (PS). PS is typically present on the cytoplasm-facing side of the plasma membrane, where it remains out of view to the immune system. Cellular stresses can lead to dysregulation of processes that keep PS facing internally and instead promote PS exposure on the cell surface. We show here that tumor cells frequently lose the capacity to regulate their plasma membrane and exhibit detectable levels of PS on their surface. Moreover, inducing cell stress through radiation and chemotherapy of tumor cells further enhanced PS exposure. In this study, we aimed to target PS with an immune-based therapy. To this end, we engineered a bi-specific T cell engager (BiTE) consisting of the natural high-affinity PS receptor TIM4 linked to an anti-CD3scFv. This TIM4 BiTE is hypothesized to redirect all T cells to PS, resulting in T cell-mediated killing of tumor cells with exposed PS. Indeed, TIM4 BiTE facilitated potent killing of multiple human tumor cell lines in vitro, including in models of protein heterogeneous tumors. When TIM4 BiTE was delivered intratumorally to a heterogeneous glioma-bearing mouse, survival was significantly extended. These data provide evidence that targeting PS with an immune-based platform represents a potential novel treatment strategy for combatting tumor heterogeneity.

A neuron model with nonlinear membranes.

One-layer membrane separates the gradient field in and out of the cell, while some two-layer membranes filled with excitable media/material are important to regulate the energy flow when ions are propagated and diffused. The intracellular and extracellular media can be effectively separated by the membrane. It is important to clarify and describe the biophysical function and then the capacitive property can be reproduced in equivalent neural circuit. Here, we suggest the cell membrane has certain thickness and becomes flexible under external stimuli, therefore, it is considered as a kind of nonlinear media. To mimic the physical property of the two-layer cell membrane, a nonlinear resistor is used to connect two linear circuits, which is used to describe the electrical characteristic of two sides of the cell membrane, respectively. The combination of two linear circuits via a nonlinear resistor can describe the energy characteristic and firing mode in the flexible membrane of biophysical neurons. Circuit equations are defined and converted into equivalent nonlinear oscillator like a neuron. The voltage difference for the two capacitors can be consistent with the membrane potential for the neuron. The Hamilton energy function for this neuron can be mapped from the field energy in the electronic components, and it is also derived by using Helmholtz's theorem. The neuron can show similar spiking and bursting firing patterns, and uncertain diversity in membrane potentials is effective to support continuous firing patterns and mode transition under external stimulus. Furthermore, noisy disturbance is applied to induce coherence resonance. The results indicate that the lower coefficient variability and higher average energy level supports periodic firing in the neuron under coherence resonance. Therefore, this neuron model with nonlinear membranes (or two-layer form) is more suitable for identifying the biophysical property of biological neuron.

An electrospinning carbon nanofiber composite electrode with gradient porous structure for deep eutectic solvent electrolyte-based iron‑vanadium redox flow battery

This work designs and prepares a composite electrode that is made of triple-layer micropore/mesopore electrospinning carbon nanofiber (ECNF) felts with gradient pore distributions and graphite felt (GF) as backing layer. The micropore ECNF felt can provide sufficient reactive surface area as well as reduce the charge transfer resistance near the membrane side. Meanwhile, the other two mesopore ECNF felts prepared by two nozzle vertical same-side blending spinning method are sandwiched between GF backing layer and micropore ECNF felt, thus making a trade-off between the reducing charge transfer resistance and the decreasing electrolyte flow resistance. Experimental results indicate that the deep eutectic solvent electrolyte-based vanadium‑iron redox flow battery (RFB) assembled with this gradient porous composite electrodes has the energy efficiency of 82.02 % at 5 mA·cm−2, which is 42.57 % higher than that of conventional RFB with mono-layer GF electrode. Even at 10 mA·cm−2, its energy efficiency can still be above 70 %, which is 70.62 % higher than that of a conventional RFB. In addition, the peak power density is also 77.44 % higher than that of the GF electrode. It has been demonstrated that the performance of non-aqueous RFB can be greatly improved by using carbon nanofiber composite electrodes with gradient pore structure.

Silk fibroin based flexible and self-powered sensor for real-time monitoring of abdominal respiration

Personal health monitoring is very important for the health operation of special populations, like newborns and the old. But how to construct a sensor that can achieve real-time monitoring without the need for an external power supply still faces serious challenges. In this paper, a flexible, breathable and self-powered sensor based on triboelectric nanogenerators (TENG) was designed. Silk fibroin (SF) and poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) fiber membranes were prepared by electro-spinning, and a u-shaped circuit was sprayed on one side of the fiber membrane as the electrode. Separating by an elastic silicone ring of the two fiber membranes, the all-fiber and self-powered sensor with a simple structure, good stability, and high output performance was developed. The as prepared sensor can instantly light up hundreds of LEDs by hand tapping. The sensor prepared in this work may have some potential applications in wearable devices and energy systems for real-time monitoring of abdominal breathing.

Evaluation of Immunomodulatory Effects of Fusarium Mycotoxins Using Bacterial Endotoxin-Stimulated Bovine Epithelial Cells and Macrophages in Co-Culture.

Mycotoxins are secondary metabolites produced by a variety of fungi that contaminate animal food and feeds and are capable of inducing a wide range of toxicities. Predictive in vitro models represent valuable substitutes for animal experiments to assess the toxicity of mycotoxins. The complexities of the interactions between epithelial and innate immune cells, vital for upholding barrier integrity and averting infections, remain inadequately understood. In the current study, a co-culture model of bovine epithelial cells (MAC-T) and macrophages (BoMac) was used to investigate the impact of exposure to Fusarium mycotoxins, namely deoxynivalenol (DON), zearalenone (ZEN), enniatin B (ENB), and beauvericin (BEA), on the inflammatory response elicited by the bacterial lipopolysaccharide (LPS) endotoxin. The MAC-T cells and BoMac were seeded on the apical side of a Transwell membrane and in the lower chamber, respectively, and mycotoxin exposure on the apical side of the membrane was carried out with the different mycotoxins (LC20; concentrations that elicited 20% cytotoxicity) for 48 h followed by an LPS immunity challenge for 24 h. The culture supernatants were collected from the basolateral compartment and these samples were submitted for cytokine/chemokine multiplex analysis. RNA-Seq analysis was performed using total RNA extracted from the MAC-T cells to acquire a more detailed insight into their cellular functions. The multiplex analysis indicated that IFN-γ, IL-1α, IL-8, and MCP-1 were significantly induced post-DON treatment when compared to control cells, and levels of IL-1α and IL-8 were enhanced significantly in all mycotoxin-treated groups post-LPS challenge. Analysis of the sequencing results showed that there were 341, 357, and 318 differentially expressed MAC-T cell genes that were up-regulated in the DON, ENB, and BEA groups, respectively. Gene ontology and pathway analysis revealed that these DEGs were significantly enriched in various biological processes and pathways related to inflammation, apoptosis signaling, and Wnt signaling. These results provide a comprehensive analysis of the co-culture cytokine/chemokine production and MAC-T cells' gene expression profiles elicited by Fusarium mycotoxins, which further contributes to the understanding of early endotoxemia post-mycotoxin exposure.