Membrane Formation Research Articles

In-Situ Formation of Three-Dimensional Network Intrinsic Microporous Ladder Polymer Membranes with Ultra-High Gas Separation Performance and Anti-Trade-Off Effect.

The global quest for clean energy and sustainable processes makes advanced membrane extremely attractive for energy-intensive industrial gas separations. Here, we disclosed a series of ultra-high-performance gas separation membranes (PIM-3D-TB) from novel network polymers of intrinsic microporosity (PIM) that combine the advantages of solution processible PIM and small pore size distribution (PSD) of porous organic polymers (POP), which was synthesized by in situ copolymerization of triptycene-2,6-diamine as linear part and triptycene-2,6,13(14)-triamine (TTA) as crosslinker. The resulting PIM-3D-TB membranes demonstrated outstanding separation properties that outperformed the latest trade-off lines for H2/CH4 and O2/N2. They also showed an anti-trade-off effect by simultaneously enhancing gas permeability and gas-pair selectivity with increasing TTA content. The TTA crosslinking node increased the microporosity, and, shifted the PSD from the ultramicropore (<7 Å) toward the more size sieving submicropore (<4 Å) region. The post-treated TTA-75 displayed an exceptional H2 permeability of 8000 Barrer and H2/CH4 selectivity of 208. These PIM-3D-TB membranes and their design protocol have unparalleled potential in the next generation of membranes for hydrogen purification and air separations.

Spatiotemporal pattern formation of membranes induced by surface molecular binding/unbinding.

Nonequilibrium membrane pattern formation is studied using meshless membrane simulation. We consider that molecules bind to either surface of a bilayer membrane and move to the opposite leaflet by flip-flop. When binding does not modify the membrane properties and the transfer rates among the three states are cyclically symmetric, the membrane exhibits spiral-wave and homogeneous-cycling modes at high and low binding rates, respectively, as in an off-lattice cyclic Potts model. When binding changes the membrane spontaneous curvature, these spatiotemporal dynamics are coupled with microphase separation. When two symmetric membrane surfaces are in thermal equilibrium, the membrane domains form 4.8.8 tiling patterns in addition to stripe and spot patterns. In nonequilibrium conditions, moving biphasic domains and time-irreversible fluctuating patterns appear. The domains move ballistically or diffusively depending on the conditions.

3D Covalent Organic Framework Membrane with Interactive Ion Nanochannels for Hydroxide Conduction.

Crystalline porous materials, known for their ordered structures, hold promise for efficient hydroxide conductivity in alkaline fuel cells with limited ionic densities. However, the rigid cross-linking of porous materials precludes their processing into membranes, while composite membranes diminish materials' conductivity advantage due to the interrupted phases. Here, we report a self-standing three-dimensional covalent organic framework (3D COF) membrane with efficient OH-transport through its interconnected 3D ionic nanochannels. The large-area, homogeneously connected COF membrane, with an 8 cm diameter and 20 μm thickness, was prepared using an interface polymerization strategy assisted by sacrificial templates of a polyacrylonitrile membrane. At the microscopic level, the introduction of imidazolium salt-building units resulted in a noninterpenetrated structure of 3D COF, creating a 3D interactive continuous hydrophilic channel for OH--conduction. The 3D COF membrane demonstrated high conductivity (169 mS/cm at 80 °C, 100% humidity) and achieved a peak power density of 160 mW/cm2 in H2/O2 single-cell tests. This COF interface polymerization strategy brings new possibilities to address the challenges of porous material membrane formation and is expected to advance their practical applications in the field of ion transport.

Morphometrics and First Ultrastructural Characterizations of Intra-Erythrocytic Stages of So-Called Haemogregarina damiettae Ramadan etal. (1996) With Special Reference to Its Cytopathological Effects on the Infected Erythrocytes.

The current study provides the first ultrastructural observations on the intraerythrocytic stages of so-called Haemogregarina damiettae and their cytopathological effects on the infected erythrocytes (IEs) in addition to the recording of new morphometric data. The intraerythrocytic stages are attributed to the immature forms or trophozoites (Ts), and mature gamonts (Gs). Ts are typically bowling-bottle shaped with nucleus (TN) occupying its globose part, while Gs are typically banana- shaped. Ts measure 9.60-13.77 (12.53 ± 0.95) × 3.29-5.72 (4.18 ± 0.52) μm, however, Gs measure 14.05-16.13 (15.15 ± 0.60) × 3.38-4.74 (4.06 ± 0.32). Parasite shape index, nuclear/body, and nuclear/cytoplasmic ratio are calculated for both Ts and Gs. Moreover, shape index, nuclear/erythrocytic ratio, nuclear/cytoplasmic ratio are determined for both uninfected erythrocytes (UIEs) and IEs. At ultrastructural level, the parasite exhibited numerous unique features such as the presence of unsutured covering capsule (Ca), intracytoplasmic membraneous structures (ICM), and electron-dense connecting structures (CS) between the degradable cytoplasmic mass (DC) of IEs and parasite itself which are postulated to perform a feeding function. The cytopathological effects on IEs include erythrocytic shape distortion, hypertrophy, dehemoglobinization, as well as nucleus size and shape changes. Erythrocytic karyolysis is confirmed by light and electron microscopy. In addition, all IEs showed characteristics two lateral polar projections or flape-like extensions (FE) supported by microtubules-like structures. Moreover, parasitophorous vacuole membrane (PVM) form in most cases a thick internal lining (IL) of homogenous electron-lucent materials at parasite-facing side and knob-like thickenings (K) of electron-dense materials on erythrocytic cytoplasm-facing side.

Hypoxia-Responsive Covalent Organic Framework Nanoplatform for Breast-Cancer-Targeted Cocktail Immunotherapy via Triple Therapeutic Switch Mechanisms.

Covalent organic frameworks (COFs), known for their exceptional in situ encapsulation and precise release capabilities, are emerging as pioneering drug delivery systems. This study introduces a hypoxia-responsive COF designed to encapsulate the chemotherapy drug gambogic acid (GA) in situ. Bimetallic gold-palladium islands were grown on UiO-66-NH2 (UiO) to form UiO@Au-Pdislands (UAPi), which were encapsulated with GA through COF membrane formation, resulting in a core-shell structure (UAPiGC). Further modification with hyaluronic acid (HA) created UiO@Au-Pdislands@GA-COF@HA (UAPiGCH) for enhanced tumor targeting. In the hypoxic tumor microenvironment, the COF collapses, releasing GA and UAPi, initiating a triple therapeutic response: nanozyme-catalyzed therapy, near-infrared II (NIR-II) mild photothermal therapy (mild-PTT), and chemotherapy. UAPi exhibits catalase (CAT)-like and peroxidase (POD)-like activities, generating oxygen to alleviate hypoxia and reactive oxygen species (ROS) for tumor destruction. GA acts as a chemotherapeutic agent and inhibits heat shock protein 90 (HSP90), enhancing photothermal sensitivity. In vitro and in vivo studies confirm UAPiGCH's ability to induce pyroptosis, stimulate dendritic cell maturation, and boost T cell infiltration, demonstrating its potential as a precise therapeutic nanoplatform. This strategy integrates multiple therapies into a hypoxia-responsive system, offering promising applications in cancer treatment.

The intervention of B. longum metabolites in Fnevs' carcinogenic capacity: A potential double-edged sword.

Colorectal cancer (CRC) ranks among the most prevalent malignant tumors globally. Fusobacterium nucleatum and its metabolites are effective biological targets for colon cancer promotion. Probiotics such as Bifidobacterium can block the occurrence and development of CRC by regulating the host intestinal mucosal immunity, eliminating carcinogens, and interfering with tumor cell proliferation and apoptosis. We selected six Bifidobacterium species to explore the inhibitory effect of their cell-free supernatant (CFS) on Fusobacterium nucleatum, and screened the best functional strain Bifidobacterium longum (B. longum) to explore its intervention effect on Fnevs infection of CRC cells. In the genus Bifidobacterium, B. longum-CFS can effectively inhibit the growth and membrane formation of Fusobacterium nucleatum. The metabolites of B. longum can inhibit the proliferation, migration and invasion of Fnevs-infected CRC cells. However, the transcriptomic analysis of Fnevs-infected CRC cells treated with Bl-CFS revealed that Bl-CFS exerted inhibitory effects on the expression of specific oncogenes (e.g., Myc, IL16, KCNN2, ACSBG1, Pum1, MET, NR5A2), while simultaneously promoting the expression of other oncogenes. This modulation potentially enhances the proliferation, epithelial-mesenchymal transition (EMT), stemness properties and other characteristics associated with CRC cells. Metabolomics also showed that Bl-CFS altered organic acid and lipid metabolism in Fnevs-infected CRC cells, and switched energy supply from aerobic glucose metabolism (TCA cycle) to anaerobic glycolysis, which increased the malignancy potential of CRC cells. The observed outcome may be attributed to the presence of both probiotics and toxic substances in the metabolites derived from Bifidobacterium longum. Therefore, this study concludes that the anti-colorectal cancer (CRC) effect of natural metabolites derived from Bifidobacterium longum is limited. Future investigations should focus on refining these natural substances and optimizing their composition ratios to extract their essence while eliminating impurities, thereby obtaining anticancer biologics with exceptional and consistent efficacy.

Multifunctional role of surfactant in fabricating polyamide nanofiltration membranes for Li+/Mg2+ separation

Extracting Lithium from salt-lake brines can effectively alleviate global lithium scarcity. Separating the co-existing Mg2+ ions from Li+ ions in the brines is essential. While thin-film composite (TFC) nanofiltration (NF) membrane show potential for this separation, commercial NF membranes with negatively charged surfaces fail to meet the high rejection requirement for Mg2+ ions due to the electrostatic attractions between membranes and cations. Positively charged NF membranes fabricated by interfacial polymerization (IP) between aqueous phase polyethylenimine (PEI) and hexane phase trimesoyl chloride (TMC) have shown promise for Li+/Mg2+ separation. However, lithium extraction efficiency is greatly limited by the relatively low permeance and high lithium rejection of the membrane caused by an excessively cross-linked structure. Therefore, optimizing the pore size while maintaining the positive charge of PEI/TMC-based TFC membranes is necessary. We propose adding anionic surfactants to the aqueous PEI solution to modulate PEI/TMC-based NF membrane formation. Surfactants control PEI diffusion in IP through their interactions and improve reaction uniformity at the water-hexane interface. This results in a narrow pore size distribution of the PA network. In this study, three sulfate surfactants with varying alkyl chain lengths were used to control membrane formation. Results showed that sodium n-decyl sulfate (SDES), the shortest sulfate surfactant, improved membrane performance most effectively. The optimized membrane exhibited a crumpled surface and relatively loose pore structure with narrow pore size distribution. It demonstrated a pure water permanence of 5.65 L m−2 h−1 bar−1, high MgCl2 rejection of 92.6 %, and low LiCl rejection of 21.5 %. After filtering a Mg2+ and Li+ binary mixture solution, the Mg2+/Li+ ratio decreased significantly from 40 (feed) to 3.08 (permeate). This study provides an efficient strategy for preparing PEI/TMC-based NF membranes with favorable Li+/Mg2+ separation performance.

Lipid droplet specific BODIPY based rotors with viscosity sensitivity to distinguish normal and cancer cells: impact of molecular conformation.

Lipid droplets (LDs) are dynamic, multifunctional organelles critical for regulating energy balance, cell signaling, membrane formation, and trafficking. Recent studies have highlighted LDs as emerging cancer biomarkers, with cancer cells typically exhibiting a higher number and viscosity of LDs compared to normal cells. This discovery paves the way for developing molecular probes that can monitor intracellular viscosity changes within LDs, offering a powerful tool for early cancer diagnosis, recurrence monitoring, and therapeutic interventions. In this study, we designed and synthesized two series of donor-acceptor (D-A) conjugated BODIPY-cyanostilbene based fluorophores (5a-c and 6a-c) by fine-tuning the cyanostilbene unit with three distinct substituents (OMe, H, Cl) and modulating the molecular conformation via rigidifying the indacene core. While the terminal substituents had a minimal effect on the optical properties, changes in molecular conformation significantly impacted the photophysical behavior of the fluorophores. Compounds 5a-c function as molecular rotors, with the free rotation of the meso-biphenyl rings leading to non-radiative deactivation of the excited state, resulting in weak emission. Additionally, this structural feature makes them highly responsive to changes in viscosity. As the glycerol concentration increased from 0% to 99%, the fluorescence intensity of compounds 5a, 5b, and 5c increased dramatically by 17-fold, 78-fold, and 43-fold, respectively. In contrast, compounds 6a-c, with restricted phenyl ring rotation due to tetra-methyls on the indacene unit, showed only a modest 2-3-fold increment in fluorescence intensity under similar conditions. These fluorophores possess several key advantages, including high selectivity for LDs, good photostability, sensitivity to viscosity, and responsiveness to polarity and pH. Moreover, they effectively differentiate between normal and cancer cells, making them valuable tools for cancer diagnosis and potential therapeutic applications.

Comparative Metabolomics in Liver Reveals Eggshell Translucency Formation Using LC-MS Analysis

Eggshell translucency is the common problem on eggshell that become more severe with age. They are important because it influence consumer preferences and the economic value of eggs. The reason for the eggshell translucency is currently believed to be the eggshell membrane (ESM). In this study, we screened translucency eggs and normal eggs and used metabolomics to study liver metabolism in different eggshell translucency and discuss important liver lipids and phosphatidyl metabolites. Liver samples were taken for Liquid Chromatograph Mass Spectrometer (LC-MS) during the formation of eggshell membranes in hens, that is, when eggs form eggshell membranes in the oviduct isthmus. The results showed that we identified two essential metabolic pathways through differential metabolite pathway analysis, which were glycine, serine, and threonine metabolism related to amino acids metabolism and the PPAR metabolic pathway related to lipid metabolism. Furthermore, this study helps us understand the process of translucency egg production in poultry. This laid the foundation for in-depth research on eggshell translucency. These results may and provide support for future breeding.

Bioenhanced remediation of dibutyl phthalate contaminated black soil by immobilized biochar microbiota

To address the contamination caused by DBP residues prevalent in black soils, this study developed a multifunctional bioremediation material (BHF@DK-P3) using humic acid and iron-modified corn stover biochar in combination with microbiota. The microbiota contained DBP-degrading bacteria (Enterobacterium sp. DNB-S2), phosphorus-solubilizing bacteria (Enterobacter sp. P1) and potassium-solubilizing bacteria (Paenibacillus sp. KT), and formed a good mutualistic symbiosis. In the biochar microenvironment, the microflora had lower DBP biotoxicity responses and more cell membrane formation. The addition of BHF@DK-P3 brought the structure of the DBP-contaminated black soil closer to the optimal three-phase ratio. The microbiota was able to perform their biological functions stably under both DBP stress and acid-base stress conditions. The stability of soil aggregates and the efficiency of N, P, K nutrients were improved, with available phosphorus increasing by 21.45%, available potassium by 12.54% and alkali-hydrolysable nitrogen by 14.74%. The relative abundance of copiotrophic bacterial taxa in the soil increased and the relative abundance of oligotrophic bacterial taxa decreased, providing a good mechanism for the conversion and utilization of soil nutrients. Biochar and microbiota jointly influenced soil carbon and nitrogen metabolism in response to DBP.

Clinical outcomes and significance of postoperative ultrasound biomicroscopy in patients with Boston type 1 keratoprosthesis.

To determine the clinical outcomes in patients after type 1 Boston keratoprosthesis surgery and the significance of ultrasound biomicroscopy imaging for postoperative follow-up. This retrospective analysis included 20 eyes of 19 patients who underwent corneal transplantation with type 1 Boston keratoprosthesis between April 2014 and December 2021. Data on patient demographics, preoperative diagnosis, visual acuity, and postoperative clinical findings were analyzed. Type 1 Boston keratoprosthesis implantation resulted in intermediate- and long-term positive outcomes. However, blindness and other serious complications such as glaucoma, retroprosthetic membrane formation, endophthalmitis, or retinal detachment also occurred. The use of ultrasound biomicroscopy imaging allowed for better evaluation of the back of the titanium plate, anterior segment structures, and the relationship of the prosthesis with surrounding tissues, which provided valuable postoperative information. Regular lifetime monitoring and treatment are necessary in patients who undergo Boston type 1 keratoprosthesis implantation for high-risk corneal transplantation. ultrasound biomicroscopy imaging can be a valuable imaging technique for the evaluation of patients with Boston type 1 keratoprosthesis, providing important information on anterior segment anatomy and potential complications. Further studies and consensus on postoperative follow-up protocols are required to optimize the management of patients with Boston type 1 keratoprosthesis.

Mitigation of membrane fouling in dye wastewater using a ternary WO3/CNT/ZnO composite photocatalytic membrane

The membrane filtration has been widely utilized in the water reclamation due to its simplicity in operation and outstanding separation performance. Nevertheless, the membrane filtration always suffers from the fouling issue which deteriorate the permeability of membrane. This study targeted to diminish the membrane fouling using a photocatalytic membrane. A ternary tungsten trioxide/carbon nanotube/zinc oxide (WO3/CNT/ZnO) composite photocatalyst was applied to form a ternary WO3/CNT/ZnO composite photocatalytic membrane via a wet processing technique. The highest efficiency to photodegrade methylene blue (MB) were obtained using the M5 ternary composite photocatalytic membrane. The presence of CNT and WO3 intensifies the photocatalysis in the ternary photocatalytic membrane to degrade MB. The ternary composite photocatalyst in membrane form displayed a competitive effectiveness in degrading MB when compared to particle form. The ternary composite photocatalytic membrane demonstrated a decreased permeation flux, accompanied by an increased rejection toward the MB when increasing the loading of ternary composite photocatalyst in the photocatalytic membrane. The analysis on the antifouling behaviour of the ternary composite photocatalytic membrane showed that approximately 95% of flux recovery ratio (Rfr) and 5% of irreversible fouling ratio (Rif) were obtained.

Tailoring Polyelectrolyte Multilayer Nanofiltration Membranes by Aerosol-Assisted Printing: Insights into Membrane Formation Mechanisms.

Polyelectrolyte multilayer (PEM) membranes, with advantageous features of versatile chemistry and structures, are driving the development of advanced nanofiltration (NF) membranes with exceptional performance. While developing a printing method holds great promise for the eventual mass production of these membranes, reports on the printing method and the underlying mechanisms of membrane formation are currently scarce. Herein, we develop an aerosol-assisted printing (AAP) system for fabricating PEM NF membranes with highly tunable separation characteristics. Our study unveils the three stages of membrane formation from assembly of polyethylenimine (PEI) and poly(sodium 4-styrenesulfonate) (PSS): aerosol deposition, single PE layer formation, and PEM assembly. The droplet deposition is governed by inertial impaction, and the deposited PEs migrate/entangle to form a single PE layer. The thicknesses of the PE layer and PEM exhibit linear growth as the number of printing scan increases. Furthermore, PE interdigitation forms an effective polymeric network barrier, which increases the resistance to solute and water transport. By manipulating the PE deposition mass and layering, PEM membranes with tunable pore radii (0.40-0.56 nm) and water permeability (5-60 L·m-2·h-1·bar-1) were obtained for various water treatment applications, ranging from micropollutant removal to humic acid filtration. Our study offers valuable mechanistic insights into the PEM formation and precise structural adjustment via printing, thus facilitating scalable manufacturing and widespread applications of the PEM NF membranes.

Angstrom‐Scale Defect‐Free Crystalline Membrane for Sieving Small Organic Molecules

AbstractCrystalline membranes, represented by the metal‐organic framework (MOF) with well‐defined angstrom‐sized apertures, have shown great potential for molecular separation. Nevertheless, it remains a challenge to separate small molecules with very similar molecular size differences due to angstrom‐scale defects during membrane formation. Herein, a stepwise assembling strategy is reported for constructing MOF membranes with intrinsic angstrom‐sized lattice aperture lattice to separate organic azeotropic mixtures separation. The membrane is synthesized by redesigning the metal source, which reduces the coordination reaction rate to avoid cluster‐missing defects. Then, extra ligands are introduced to overcome the coordination steric hindrance to heal the linker‐missing defects. Ultralow‐dose transmission electron microscopy is used to realize a direct observation of the angstrom‐scale defects. For separating the challenging methanol‐containing ester or ether azeotropic mixtures with molecular size difference as small as &lt;1 Å, the angstrom‐scale defect‐free MOF membrane exhibits an outstanding flux of ≈3700 g·m−2 h−1 and separation factor of ≈247–524, far beyond the upper‐bound of state‐of‐the‐arts membranes. This study offers a feasible strategy for precisely constructing angstrom‐confined spaces for diverse applications (e.g., separation, catalysis, and storage).

Preclinical study of novel human allogeneic adipose tissue-derived mesenchymal stem cell sheets toward a first-in-human clinical trial for myopic chorioretinal atrophy.

Mesenchymal stem cells may have neuroprotective and tissue regenerative capabilities and the potential to rescue retinal degeneration in chorioretinal diseases including myopic chorioretinal atrophy. Transplantation of human (allogeneic) adipose tissue-derived mesenchymal stem cell (adMSC) suspensions has been clinically conducted to treat retinal degenerative diseases. However, serious side effects including proliferative vitreoretinopathy and epiretinal membrane formation have been reported. PharmaBio Corporation fabricated novel adMSC sheets with a Bruch's membrane-like structure using our original method, potentially overcoming these problems. We evaluated the characteristics of newly developed adMSC sheets named PAL-222 and assessed their safety and efficacy in rats with congenital retinal degeneration (RCS rats) to obtain the proof-of-concept for the first-in-human clinical trial for myopic chorioretinal atrophy. We measured the viability of cells obtained from PAL-222, examined cell surface antigens by flow cytometry, measured the vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF) secretory ability, examined the expression of types I and IV collagen and elastin by immunostaining. We performed a transwell in vitro migration assay to evaluate durability and similarity to retinal pigment epithelium (RPE) and checked in vitro tumorigenicity. In an in vivo experiment, we transplanted PAL-222 into the subretinal space of RCS rats and evaluated the safety and efficacy. Viability of cells obtained from PAL-222 was 88.1%. The rate of positive markers such as CD90, CD73, CD105 and CD44 exceeded 90%; that of the negative markers such as CD34, CD11b, CD19, CD45 and HLA-DR was less than 2%. PAL-222 secreted significant amounts of VEGF and PEDF and expressed types I and IV collagen and elastin. The migration assay showed that PAL-222 preserved the sheet structure without cell migration. No chromosomal aberration or colony formation was observed in in vitro tumorigenicity tests. PAL-222 transplantation suppressed the progression of retinal degeneration by preserving the outer nuclear layer without negative changes in RCS rats, suggesting a retinoprotective effect. We confirmed the efficacy and safety of PAL-222 and are currently conducting a clinical trial to treat myopic chorioretinal atrophy. Transplantation of these novel adMSC sheets may be a promising therapy for myopic chorioretinal atrophy. ClinicalTrials.gov, Identifier: NCT05658237. URL: https://classic. gov/ct2/show/NCT05658237 .

Vertical ridge augmentation using deproteinized bovine bone material without covering with a membrane: a tunnel pouch technique- 4-year follow-up- A pilot clinical study.

The present pilot clinical trial was planned to evaluate the effect of particulate deproteinized bovine bone graft mixed with blood could be used as a vertical ridge augmentation material without covering with any form of collagen membrane in a tunnel pouch technique, resulting in sufficient bone formation to allow placement of dental implants, with maintenance of the newly formed bone after final restoration. Eight patients (three males and five females) were selected for this procedure and treated between February 2016 and December 2017. All these patients had a deficient vertical height of the posterior mandibular alveolar bone above the inferior alveolar canal. The particulate deproteinized an organic bovine bone graft (Bio Oss) mixed with blood was placed through the tunnel in the defected area and compacted firmly to form a dense pack. The average gain of alveolar bone in the first implant site after immediate post-op was 13.51±0.85, and in the second implant site was 13.84± 0.62. Histomorphometric analysis showed that about 70.31% of the area analyzed was occupied by the vital bone, the newly formed bone, whereas only 29.69% of the residual graft remained. In the present pilot study, the deproteinized bovine bone graft placed to enhance vertical and horizontal bone gain showed positive results in regaining the bone needed to place implants and maintaining the bone around restored implants for 4 years of follow-up.

Development of New Chitosan-Based Complex with Bioactive Molecules for Regenerative Medicine

Background/Objectives: The development of new materials incorporating bioactive molecules for tissue regeneration is a growing area of interest. The objective of this study was to develop a new complex specifically designed for bone and skin tissue engineering, combining chitosan, ascorbic acid-2-magnesium phosphate (ASAP), and β-tricalcium phosphate (β-TCP). Methods: Chitosan and the complexes chitosan/ASAP and chitosan/ASAP/β-TCP were prepared in membrane form, macerated to a particulate format, and then subjected to characterization through Fourier transform infrared (FTIR) spectroscopy, optical and scanning electron microscopy (SEM), zeta potential, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Cell viability was evaluated through a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and with fluorescein diacetate (FDA) and propidium iodide (PI) staining in stem cells obtained from deciduous teeth. Statistical analyses were performed using analysis of variance (ANOVA), followed by Tukey’s test. Results: The FTIR results indicated the characteristic bands in the chitosan group and the complexation between chitosan, ASAP, and β-TCP. Microscopic characterization revealed a polydisperse distribution of micrometric particles. Zeta potential measurements demonstrated a reduction in surface charge upon the addition of ASAP and β-TCP to the chitosan matrix. TGA and DSC analyses further indicated complexation between the three components and the successful formation of a cross-linked structure in the chitosan matrix. Stem cells cultured with the particulate biomaterials demonstrated their biocompatibility. Statistical analysis revealed a significant increase in cell viability for the chitosan/ASAP and chitosan/ASAP/β-TCP groups compared to the chitosan control. Conclusions: Therefore, the chitosan/ASAP complex demonstrated potential for skin regeneration, while the chitosan/ASAP/β-TCP formulation showed promise as a biomaterial for bone regeneration due to the presence of β-tricalcium phosphate.

Development and optimisation of the biosensor for aspartate aminotransferase blood level determination.

This work presents the development and optimisation of an amperometric biosensor for determining aspartate aminotransferase (AST) activity in blood serum, using glutamate oxidase and platinum disc electrodes. AST is a key biomarker for diagnosing cardiovascular and liver diseases. The biosensor's bioselective membrane composition and formation protocol and the working solution (aspartate 8mM, α-ketoglutarate 2mM, pyridoxal-5-phosphate 100µM) were optimised. The sensor demonstrated high selectivity, stability (70% retention over 2months at - 18°C), and sensitivity (2.37 nA min⁻1 per 10 U L⁻1), with a dynamic range of 0-500 U L⁻1 and a limit of detection of 1 U L⁻1. Comparative analysis showed the calibration curve method outperforms the standard addition method for AST measurement in serum samples. Additionally, a reference spectrophotometric technique was adapted for AST level determination, showing a strong correlation (r = 0.989) with the biosensor results. This research offers a fast, affordable, and accurate tool for early check-ups of liver and heart conditions. The biosensor's flexibility and ease of use make it suitable for further development into point-of-care testing and personalised healthcare techniques.

IL-6 Does Not Influence the Expression of SLC41A1 and Other Mg-Homeostatic Factors.

Together with chronic inflammation, disturbed magnesium homeostasis is a factor accompanying chronic disease which thus contributes to a reduced quality of human life. In this study, our objective was to examine the possible IL-6-mediated chronic inflammation-dependent regulation of nine magnesiotropic genes encoding for constituents of magnesium homeostasis of the cell. We used three cell lines (HepG2, U-266, and PANC-1), all characterized by high expression of the IL6R gene and the presence of a membrane form of IL-6R capable of responding to human IL-6. Despite the confirmed activation of the IL-6R/JAK/STAT3 pathway after hIL-6 treatment, we observed no biologically relevant changes in the transcription intensity of the studied magnesiotropic genes. This, however, does not exclude the possibility that IL-6 can affect magnesium homeostasis at levels other than through modified transcription.

Cellular Compartmentalization as a Physical Regulatory Mechanism of Signaling Pathways

Cells compartmentalize biochemical processes using physical barriers in the form of membranes. Eukaryotes have a wide diversity of membrane-based compartments that can be used in this context, with the main ones being the extracellular membrane, which separates the inside from the outside of the cell, and the nuclear membrane, which separates the nucleus from the cytoplasm. The nuclear membrane not only isolates and protects the DNA and the transcription and replication processes from the other processes that are occurring in the cytoplasm but also has an active role in the regulation of cellular signaling. The TGF-β pathway is one of the most important and conserved signaling cascades, and it achieves compartmentalization using a well-tuned balance between the import and export rates of the active and inactive forms of key proteins. Thus, compartmentalization serves as an additional regulatory mechanism, physically isolating transcription factors from their targets, influencing the dynamics and strength of signal transduction. This contribution focuses on this biophysical layer of regulation, using the TGF-β pathway to illustrate the molecular mechanisms underlying this process, as well as the biological consequences of this compartmentalization. We also introduce a simplified mathematical formulation for studying the dynamics of this process using a generalized approach.