Microbiota metabolite lithocholic acid in cancer: Mechanisms and therapeutic potential.

Retardation-induced porous geopolymer membranes for water treatment

Efficient solar-driven interfacial evaporation and hydrogen production of MoS2@hollow carbon microspheres coated hybrid porous membranes prepared by breath figure method

The integration of nanoscale hybridization between inorganic components and biopolymers, and the formation of hierarchical porous structures capable of efficiently including and activating cells and proteins, has not yet been achieved in the design of bone substitutes for tissue regeneration. We fabricated a porous nanohybrid membrane based on hyaluronic acid (HyAc) and citric acid-coordinated apatite nanoparticles (Cit/ApNPs) and proposed a scaffold material design that integrates a dense nanohybrid structure with a hierarchical porous structure. Specifically, the network structure of HyAc molecules was utilized as a reactive field (i.e., free space) for the hybridization of Cit/ApNPs, and the high dispersibility of Cit/ApNPs effectively induced the interfacial interactions between HyAc molecules and the NPs at the nanoscale, thereby achieving nanohybridization. This nanohybridization induced the spontaneous formation of mesopores and smaller macropores (i.e., 0.05-10 μm), and additionally, larger macropores (i.e., 10-800 μm) were constructed through the freeze-drying process while maintaining the nanohybridization state. As a result, a hierarchical porous structure with three types of pores that will contribute to protein adsorption, pseudopodia interaction/extension, and cell inclusion was successfully obtained, and the membrane was confirmed to maintain its structure and shape even after immersion in simulated body fluid (SBF). Therefore, we suggest a biomaterial design concept that integrates interfacial interaction and hierarchical pore structuring, which is expected to be an effective approach for the tissue regeneration.

ATG5, a key regulator of autophagy-associated inflammation, is markedly upregulated under inflammatory conditions. In this study, we observed significantly elevated ATG5 expression in the kidneys of patients with renal fibrosis and in mouse kidneys after unilateral ureteral obstruction (UUO), particularly in renal tubules and glomeruli. Recent studies suggest that enhanced ATG5-mediated autophagy in tubular epithelial cells targets the NF-κB pathway to alleviate renal injury. The glomerulus is a dense capillary network primarily composed of endothelial cells, which represent a key immune cell population in the kidney. However, whether endothelial ATG5 exerts a function similar to that of tubular ATG5 during the progression of renal fibrosis remains unclear. First, Sirius red staining, immunohistochemistry staining and other and pathological methods were used to analyze the expression of ATG5 in relation to the progression of renal fibrosis in patients and UUO model mice. We next observed the effects of endothelial-specific knockout of ATG5 in mice with renal fibrosis induced by the UUO model by ultrasound image assessment, HE staining, and Masson staining. Human umbilical vein endothelial cells (HUVECs) were isolated, and their regulation of inflammation and promotion of renal fibrosis were analyzed by overexpression and knockdown of ATG5 using in vitro synthetic mRNA and siRNA interference techniques. Transmission electron microscopy (TEM), qPCR and Western blotting were used to determine the effect of endothelial ATG5 on promoting inflammation-dependent pyroptosis in vitro and in vivo. Finally, the expression of GSDMD, a key pyroptosis gene, was examined in the kidneys of clinical renal fiber patients by immunohistochemistry staining. We successfully generated endothelial-specific ATG5 knockout (Tek-Cre ATG5 KO) mice and found that endothelial cell deletion of ATG5 attenuated UUO-induced renal fibrosis. Mechanistically, endothelial-specific ATG5 knockout suppressed pyroptosis and the release of inflammatory factors in the UUO model, primarily by inhibiting GSDMD expression and its cleavage into the N-GSDMD fragment during canonical NLRP3 inflammasome activation. Electron microscopy results showed that ATG5 mainly caused pyroptosis independent of plasma membrane pores in endothelial cells. Conditioned medium from human umbilical vein endothelial cells with ATG5 knockdown inhibited the expression of the key fibrotic marker TGF-β1 in renal tubular epithelial HK-2 cells. Consistent results were obtained when HK-2 cells were cocultured with serum from UUO mice with endothelial-specific ATG5 knockout. Furthermore, GSDMD expression was positively correlated with the degree of fibrosis in patients with renal fibrosis. Collectively, our findings demonstrate that ATG5 modulates the inflammatory response by mediating pyroptosis and exacerbates UUO-induced renal fibrosis in endothelial cells, which is in striking contrast to its role in renal tubular epithelial cells. These results highlight the cell-type-specific functions of ATG5 during renal fibrogenesis. Furthermore, our study provides a novel theoretical basis for the development of targeted therapeutic strategies against renal fibrosis in clinical practice.

This study investigates the impact of microchannel geometrical parameters on the separation of glomerular ultrafiltrate in a non-cell-based microfluidic device. The analysis focuses on the device's ability to selectively separate plasma from other blood components, considering parameters such as the radius of curvature at the channel junction, the side channel angle, and the membrane pore shape. Among the configurations tested, a channel junction with radii of curvature Rc1=5 μm and Rc2=0 μm achieved the highest separation efficiency. A straight, perpendicular side channel outperformed other angular variations, while cylindrical membrane pores promoted laminar flow with minimal turbulence and shear stress, enhancing ultrafiltrate separation. The glomerular filtration fraction was observed to be around 20%, closely matching values reported for the human glomerulus under whole blood conditions. The proposed device functions as a glomerular ultrafiltration unit and can potentially be integrated with other modules to develop a complete artificial kidney. This numerical study provides insights into key microchannel design parameters that influence separation efficiency. Moreover, as the device does not rely on cultured cells, it is expected to have a longer operational lifespan and reduced maintenance costs by eliminating the need for cell cultivation.

Copper (Cu) is widely used as a growth-promoting trace element in swine feed, but excessive Cu causes liver toxicity and modulates innate immunity, with unclear molecular mechanisms. In this study, dietary Cu overload in pigs led to Cu accumulation and liver injury, elevated levels of reactive oxygen species (ROS), and decreased mitochondrial membrane potential (MMP). These changes were accompanied by increased VDAC oligomerization in the mitochondrial membrane and mitochondrial DNA (mtDNA) release, which activates the NLRP3 inflammasome and triggers hepatocyte pyroptosis. Mechanistically, the VDAC inhibitor VBIT-4 reduced Cu-induced VDAC oligomerization and mtDNA release. Furthermore, NLRP3 is essential for Cu-mediated pyroptosis. Combined VBIT-4 and the MCC950 (NLRP3 inhibitor) treatment further attenuated VDAC oligomerization, mtDNA release, and pyroptosis. Collectively, our results reveal that Cu exposure promotes VDAC oligomerization and mitochondrial membrane pore formation, leading to mtDNA release, NLRP3 inflammasome activation, and pyroptosis in hepatocytes. These findings provide new insights into Cu-induced hepatotoxicity.

Intercellular electrical coupling mediated by gap junctions plays a central role in signal transmission in many biological systems. Its disruption contributes to cardiac and neurological disorders, as well as impaired wound healing and tumor progression. Restoring direct electrical communication between cells, however, remains challenging, particularly without genetic manipulation or the delivery of preformed devices across cellular membranes and interfaces. The small conjugated molecule DTTO (2,6-diphenyl-3,5-dimethyl-dithieno[3,2-b:2',3'-d]thiophene-4,4-dioxide) self-assembles inside living cells into supramolecular nanofibers, which can extend between neighboring cells and connect their cytoplasm. Here, we show that these fibers also establish functional electrical coupling between cells: dual patch clamp recordings demonstrate restored signal transmission even when native gap junctions are pharmacologically suppressed, while control experiments show that the recovered signal transmission does not result from nonspecific membrane poration associated with fibers crossing the membrane. Electrical characterization of DTTO fiber networks shows that these structures support charge transport, while humidity-dependent measurements, impedance spectroscopy, and equivalent circuit modeling show that the observed electrical response is shaped by ionic and interfacial contributions from the surrounding environment. Collectively, this work establishes intracellular DTTO self-assembly as a nongenetic strategy to create functional bioelectrical connections in situ and restore electrical communication in diseased and engineered tissues.

Currently, asymmetric polymeric membranes exhibit numerous advantages for wound dressing applications. Usually, numerous systems allow the release of only one or several antibacterial drugs to fight against the bacteria present on the wound. However, to be efficient, it is necessary to disrupt biofilm formation in order to render the enclosed bacteria sensitive to the antibacterial agent. Here, we describe a system capable of achieving such goal via a double compartment asymmetric polymeric membrane designed for dual drug release. In view of elaborating our gradient-structured membrane for differential kinetic release of combined antibiofilm/antibiotic agents in the context of wound dressing applications, a previously electrospun poly(vinyl alcohol) (PVA) fibrous membrane (EFM) was combined with a renewable poly(butylene-succinate-co-adipate) (PBSA) asymmetric porous membrane (AM) via physical adhesion. Physical adhesion was promoted via surface modification of the PVA fibers involving complexation of the numerous PVA hydroxyl groups with phenyl boronic acid (PBA). This modification resulted in heightened hydrophobicity of the upper EFM layer with substantial contact angle increase up to 115° allowing for effective adhesion of the PVA based EFM onto the AM. No delamination was observed. Thus, thanks to surface modification, a gradient-structured double compartment asymmetric membrane (DCAM) was obtained consisting of a dense/macro-/micro-/nano-porous structure. Furthermore, as proof of concept, our study shows that PBA can be used as a pro-drug mimic pH sensitive system exhibiting release profiles in aqueous environment up to 3-fold higher in acidic compared to that for neutral or alkaline environments. Moreover, the BSA (Bovine Serum Albumin) use as a potential therapeutic model protein was encapsulated within the porous structure and its release profile was monitored over time showing maximum release attained within 24 h. Finally, the biocompatibility of our new DCAM was confirmed via the internationally recognized standard ISO 10993-5: 2009 assay for the in vitro cytotoxicity testing of medical devices. Our results are promising in that they provide a new structural substrate for the dual concomitant differential-controlled release of large amounts of high (antibiofilm and potentially other therapeutic proteins) and low molecular weight (antibacterial) bioactive agents.

Diabetes mellitus (DM) is increasingly recognized as a major risk factor for skeletal fragility, characterized by impaired bone quality and increased fracture susceptibility. Chronic hyperglycemia induces metabolic stress, oxidative injury, and low-grade inflammation, all of which disrupt normal bone remodeling. Accumulating evidence indicates that pyroptosis, a highly inflammatory form of programmed cell death, has emerged as a critical mechanistic link between diabetes and bone loss. Pyroptosis is driven by inflammasome activation, particularly the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome, leading to caspase-1 activation, gasdermin-mediated membrane pore formation, and the release of pro-inflammatory cytokines such as interleukin-1β (IL-1β) and interleukin-18 (IL-18). In the diabetic bone microenvironment, pyroptosis affects all major bone cell types. Osteoblast pyroptosis suppresses bone formation, osteoclast-associated pyroptotic signaling enhances bone resorption, and osteocyte pyroptosis disrupts mechanotransduction and microarchitectural integrity. Emerging data further reveal extensive crosstalk between pyroptosis, apoptosis, and necroptosis through PANoptotic signaling pathways, amplifying inflammatory bone damage. Experimental evidence from in vivo and in vitro models, together with emerging biomarker studies, consistently supports a central role for pyroptosis in diabetes-associated bone disease. Understanding the molecular regulation and temporal dynamics of pyroptosis in bone may provide novel therapeutic opportunities to preserve skeletal health in diabetic patients.

The analysis at hand discusses the creation and multifunctional testing of an electrospun nanofiber membrane completed from polyvinylidene fluoride (PVDF), chitosan (CS), and Al/Cu-layered double hydroxide (Al/Cu-LDH), which is meant for the simultaneous adsorption of Hg(II) ions and the testing of its biological properties. Thorough physicochemical characterization techniques such as FT-IR, XRD, BET surface area analysis, XPS, and SEM-EDS confirmed the effective incorporation of Al/Cu-LDH and CS into the PVDF matrix to arrangement a highly porous membrane with enriched hydroxyl and amino practical groups that are important in binding interactions with metal ions. Batch adsorption studies revealed an appreciable influence of adsorbent quantity, solution pH, and interaction time, with a maximum Langmuir monolayer adsorption capacity of 422.68mg.g⁻¹ at pH 6 after 100min and a quantity of 0.02g. Adsorption kinetics were best fitted to the pseudo-second-order model, whereas thermodynamic study reflected that the adsorption method was spontaneous and endothermic. Response Surface Methodology (RSM) using a Box-Behnken design (BBD) was applied for the statistical optimization of adsorption parameters with a desirability value of 0.99 and a respectable fit among experimental and projected results. The uptake of Hg(II) ions occurs through surface complexation and ion exchange pathways involving -OH and -NH₂ functional groups, as further validated by XPS investigations. Besides its adsorption abilities, the membrane showed significant biological efficiency, presenting dose-dependent cytotoxicity against MCF-7 (breast cancer) besides HePG-2 (liver cancer) cell lines, along with remarkable antioxidant activity in DPPH radical scavenging tests. These results highlight its potential for dual applications in environmental cleanup and biomedical fields. Altogether, the PVDF/CS-Al/Cu-LDH nanofiber membrane comes out as a high-capacity, regenerable, and biologically active material with future prospects for advanced water purification technologies plus multifunctional therapeutic applications.

Vitiligo is an autoimmune skin disease characterized by the loss of epidermal melanocytes. Oxidative stress serves as a key initiating factor in its pathogenesis. Mitochondria, known as the powerhouse of the cell, perform multiple essential functions in eukaryotic cells and participate in melanocyte physiological processes. Lonp1 is a crucial mitochondrial matrix soluble protease involved in maintaining mtDNA stability, clearing aberrant proteins, and regulating mitochondrial homeostasis. Meanwhile, mitophagy serves as a crucial function within the mitochondrial quality control system, responsible for eliminating damaged mitochondria. Pyroptosis is a form of programmed cell death mediated by inflammasomes, accompanied by cell membrane pore formation and the release of inflammatory cytokines. This study confirmed that oxidative stress was associated with decreased Lonp1 in PIG1 cells, the human melanocyte line. This downregulation impairs mitochondrial homeostasis by suppressing the expression of PINK1, a key mitophagy-related protein, ultimately leading to activation of the NLRP3 inflammasome pathway, release of IL-1β, and induction of melanocyte pyroptosis.

Efficient localization of analytes near plasmonic hotspots remains a major challenge for surface-enhanced Raman scattering (SERS) detection in complex liquid-phase systems. Herein, an interlaced cellulose-based porous membrane composed of dissolving pulp fibers (DPFs), mechanically ground nanofibers (MGNFs), sodium alginate (SA), and Ag nanoparticles was developed as a molecular enrichment-assisted SERS platform for sweat biomarker determination. The hierarchical porous architecture provided interconnected transport channels and abundant interfacial adsorption sites, facilitating analyte retention and localized enrichment within the plasmonic region. Benefiting from the synergistic effects of porous confinement and uniformly distributed Ag nanoparticles, the optimized substrate exhibited sensitive and reproducible SERS performance with an enhancement factor of 4.36 × 10⁷, a relative standard deviation of 8.04%, and a detection limit down to 1.0 × 10⁻⁸ mol/L for Rhodamine 6G (R6G). Systematic adsorption experiments using molecules with different charge properties further demonstrated the broad molecular enrichment capability of the structured cellulose network. The developed platform enabled quantitative detection of lactate and urea within physiologically relevant sweat concentration ranges and showed satisfactory analytical performance in spiked sweat samples. More importantly, this work demonstrates a structure-engineered porous membrane strategy for integrating molecular enrichment with plasmonic sensing, providing new insight into cellulose-based SERS platforms for complex bioanalytical applications.

Water confined within nanofiltration (NF) membrane pores experiences a dielectric environment that differs substantially from that of bulk water, and this pore-scale dielectric constant is a key parameter in NF transport models such as the Donnan and steric partitioning model with dielectric exclusion (DSPM-DE). However, real polyamide NF membranes possess highly irregular and tortuous pore structures, and the dielectric properties of water under such realistic confinement remain poorly quantified. In this study, molecular dynamics simulations were performed using five polyamide models based on piperazine-TMC and diethylenetriamine-TMC to clarify how nanoscale pore morphology influences the dielectric response of confined water. In all models, confinement significantly reduced the dielectric constant relative to bulk water due to suppressed dipole moment fluctuations and hindered rotational mobility. Analysis of directional dielectric components and orientational distributions revealed that pore geometry and connectivity, rather than polymer hydrophilicity, predominantly govern the dielectric behavior. These findings provide physically grounded dielectric parameters for improving NF transport models and offer molecular-level insight into polarization phenomena within realistic polymeric membrane pores.

Membrane-active peptides (MAPs) disrupt lipid bilayers through mechanisms that depend sensitively on amino acid sequence, yet the molecular determinants governing membrane pore formation remain incompletely understood. The spider-venom peptide M-lycotoxin exhibits strong membrane-disruptive activity, whereas a single substitution of Leu17 with glutamate (L17E) markedly reduces cytotoxicity. Here, we employed microsecond-scale all-atom molecular dynamics simulations to investigate how this mutation alters the membrane disruption pathway. The wild-type (WT) peptide preserves strong amphiphilicity and stable α-helicity, enabling deep insertion into the membrane. In multiple independent simulations, WT peptides spontaneously nucleated membrane defects that evolved into toroidal pores stabilized by inward bending of lipid headgroups and cooperative insertion of a small number of peptides. These pores contain continuous water columns and permit transient ion permeation. In contrast, the L17E mutation disrupts amphiphilicity and reduces helical stability, weakening peptide-membrane coupling. As a result, spontaneous pore formation is not observed. Under an applied electric field used to accelerate rare membrane penetration events in simulations, the mutant adopts only a largely nonconductive transmembrane configuration that does not develop into cooperative pore assemblies. These results indicate that the L17E mutation shifts the membrane disruption pathway from cooperative toroidal pore formation to a nonconductive transmembrane state, providing a molecular explanation for the reduced cytotoxicity of the mutant.

MLKL pseudokinase is a critical executioner of necroptotic cell death. MLKL drives necroptosis by forming pores in the cell membrane. A growing body of data indicates that, in addition to this well-established role, MLKL can promote cell survival in certain contexts. Moreover, pharmacological or genetic MLKL inhibition was shown to suppress in vivo growth of several tumor types. It was found that MLKL protects cancer cells from various cell death-inducing stimuli by promoting autophagy or preserving the mitochondrial function of the cells. It was proposed that both of these MLKL effects prevent parthanatos, a cell death type mediated by hyperactivation of PARP1 and subsequent PARP1-dependent chromosomal DNA degradation. In addition, MLKL was found to protect tumor cells from the death receptor-induced demise and trigger the secretion of the growth-promoting cytokines by the cells. Notably, MLKL-deficient mice are healthy, while pharmacological MLKL inhibitors are not significantly toxic to mice. Hence, targeting MLKL in vivo to block MLKL-dependent cancer cell survival is feasible. The mechanisms of the pro-survival MLKL effects is the subject of this review.

Delivering proteins into subcellular compartments can significantly enhance their therapeutic potential. However, such delivery is largely restricted due to poor cell uptake and lysosomal trafficking/degradation of delivered proteins. The direct membrane penetrating nanocarrier-based nonendocytic approach offers new opportunities for subcellular delivery of proteins. Here, we report histidine-terminated 2 nm gold nanoparticles as carriers for nucleus delivery of proteins via direct membrane penetration and temporary membrane pore formation while bypassing endosomal/lysosomal trafficking. It has been observed that successful nucleus delivery requires modular protein-carrier assembly of <50 nm size. Thus, nucleus delivery performance is sensitive to protein molecular weight and the ratio of protein to carrier concentration. Results show that nuclear delivery of proteins offers ∼2 times enhanced therapeutic performance as compared to their cytosolic delivery via the endocytic approach. The presented approach can be adapted to other therapeutic proteins and macromolecules for more efficient therapy.

Machine learning-guided predictive modeling and optimization of polyamide-based thin-film nanocomposite reverse osmosis membranes.

Ajugol attenuates acute gouty arthritis by enhancing mitophagy to suppress chondrocyte pyroptosis.

The transport of individual entities through interconnected structures is a process of practical relevance both in biology and technology. Examples are given by diffusive dynamics of molecules in porous structures. In soft environments, this transport can be strongly influenced by fluctuations of the porous structure itself. Here, we focus on triply periodic membrane structures found both in cell organelles and in synthetic amphiphilic systems. We theoretically study the effect of a complex three-dimensional fluctuating environment on the diffusive motion of a test object, using a phase field approach. The rigid spherical test object is energetically forced to not penetrate the membrane. Generally, the pores of the membrane structure can be smaller than the diffusing object. Yet, fluctuations of the membrane can intermittently widen its pores, still allowing for the motion of the larger particles through them. Thus, the object stays trapped for a while inside one cavity formed by the membrane, before an appropriate fluctuation event widens a membrane pore in the right moment so that the object can jump into the next cavity. The process is reflected by a pronounced plateau in the time evolution of the mean squared displacement. We think that the described scenario should be directly observable, for instance, in protein diffusion through biological environments.