Search Results (972)

Wooden waste railroad ties preserved with coal tar creosote oil represent a specific source of polluting substances. The aim of this study was to investigate and compare extraction capacity due to solvent extraction of fifteen frequently used organic solvents for the purpose of decontamination treatment of waste wooden railroad ties, while recovering wood for reuse. Pure organic solvents, ethanol 96%, propan-2-ol, deionized water, dichloromethane, acetone, n-hexane, mixture n-hexane/acetone (V/V = 1/1), cyclohexane, methanol, N,N-dimethyl formamide, toluene, ethyl acetate, acetonitrile, amyl acetate, medical gasoline, n-pentane and n-butyl acetate were for leaching pollutants from waste railroad ties. The highest extraction capacity was achieved using dichloromethane, where 7.50 to 7.89 wt.% of total sixteen polycyclic aromatic hydrocarbons were extracted from waste railroad tie chips. The most promising solvents for the treatment exhibited extraction efficiency which decreases in a series dichloromethane > n-hexane/acetone > acetone > methanol > ethanol 96% > propan-2-ol > cyclohexane > toluene > n-hexane. Solvent extraction represents a novel approach for treatment of wooden waste railroad ties. The experiments are based on the search for a management process for the treatment of wood waste railroad ties that is simple, low energy consumption, efficient and could potentially be applied for large scale. Full article

Regenerative medicine is increasingly leveraging the synergies between bioinspired conductive biomaterials and 3D/4D bioprinting to replicate the native electroactive and hierarchical microenvironments essential for functional tissue restoration. However, a critical gap remains in the intelligent integration of these technologies to achieve dynamic, responsive tissue regeneration. This review introduces a “bioinspired material–printing–function” triad framework to systematically synthesize recent advances in: (1) tunable conductive materials (polymers, carbon-based systems, metals, MXenes) designed to mimic the electrophysiological properties of native tissues; (2) advanced 3D/4D printing technologies (vat photopolymerization, extrusion, inkjet, and emerging modalities) enabling the fabrication of biomimetic architectures; and (3) functional applications in neural, cardiac, and musculoskeletal tissue engineering. We highlight how bioinspired conductive scaffolds enhance electrophysiological behaviors—emulating natural processes such as promoting axon regeneration cardiomyocyte synchronization, and osteogenic mineralization. Crucially, we identify multi-material 4D bioprinting as a transformative bioinspired approach to overcome conductivity–degradation trade-offs and enable shape-adaptive, smart scaffolds that dynamically respond to physiological cues, mirroring the adaptive nature of living tissues. This work provides the first roadmap toward intelligent electroactive regeneration, shifting the paradigm from static implants to dynamic, biomimetic bioelectronic microenvironments. Future translation will require leveraging AI-driven bioinspired design and organ-on-a-chip validation to address challenges in vascularization, biosafety, and clinical scalability. Full article

For more than a century, pathology has served as a cornerstone of modern medicine, relying primarily on static microscopic assessment of tissue morphology—such as H&E staining—which remains the “gold standard” for disease diagnosis. However, this conventional paradigm provides only a snapshot of disease states and often fails to capture their dynamic evolution and complex functional mechanisms. Moreover, animal models are constrained by marked interspecies differences, creating a persistent gap in translational research. To overcome these limitations, we propose the concept of New Pathophysiology, a research framework that transcends purely morphological descriptions and aims to resolve functional dynamics in real time. This approach integrates Organ-on-a-Chip (OOC) technology, multi-omics analyses, and artificial intelligence to reconstruct the entire course of disease initiation and to enable personalized medicine. In this review, we first outline the foundations and limitations of traditional pathology and animal models. We then systematically summarize more than one hundred existing OOC disease models across multiple organs—including the kidney, liver, and brain. Finally, we elaborate on how OOC technologies are reshaping the study of key pathological processes such as inflammation, metabolic dysregulation, and fibrosis by converting them into dynamic, mechanistic disease models, and we propose future perspectives in the field. This review adopts a relatively uncommon classification strategy based on pathological mechanisms (mechanism-based), rather than organ-based categorization, allowing readers to recognize shared principles underlying different diseases. Moreover, the focus of this work is not on emphasizing iteration or replacement of existing approaches, but on preserving past achievements from a historical perspective, with an emphasis on overcoming current limitations and enabling new advances. Full article

Background/Objectives: Ulcerative colitis (UC) is an inflammatory bowel disease and a major cause of ulcers and chronic inflammation in the colon and rectum. Recurring symptoms include abdominal pain, rectal bleeding, and diarrhoea, and patients with UC are at a higher risk of developing comorbidities such as colorectal cancer and poor mental health. In UC, the decreased diversity and changed metabolic profile of gut microbiota, along with a diminished mucus layer, leads to disruption of the underlying epithelial barrier, with an ensuing excessive and detrimental inflammatory response. Treatment options currently rely on drugs that reduce the inflammation, but less emphasis has been placed on improving the resilience of the epithelial barrier. Macrolide antibiotics exhibit epithelial barrier-enhancing capacities unrelated to their antibacterial properties. Methods: We investigated two novel barriolides, macrolides with reduced antibacterial effects in common bacterial strains. Gut epithelial cell barrier resistance in the Caco-2 cell line, with and without co-culture with mucus-producing HT-29 cells, was increased when treated with barriolides. Using ^AXGut-on-Chip technology with inflammatory cytokine-stimulated Caco-2/HT-29 co-cultures, the effectiveness of the barriolides was confirmed. Lastly, we reveal the barrier-enhancing and inflammation-reducing effects of the barriolides in a dextran-sulphate sodium (DSS)-induced colitis mouse model. Results: We show the predictive power of the novel ^AXGut-on-Chip system and the effectiveness of the novel barriolides. Indications include reduced inflammatory response, increased epithelial barrier and decreased overall clinical score. Conclusions: The results of this study indicate the notion that barriolides could be used as a treatment option for UC. Full article

Atherosclerosis remains a leading cause of cardiovascular mortality despite advances in pharmacological and interventional therapies. Current treatment approaches face limitations including systemic side effects, inadequate local drug delivery, and restenosis following vascular interventions. Gel-based technologies offer unique advantages through tunable mechanical properties, controlled degradation kinetics, high drug-loading capacity, and potential for stimuli-responsive therapeutic release. This review examines gel platforms across multiple scales and applications in atherosclerosis research and intervention. First, gel-based in vitro models are discussed. These include hydrogel matrices simulating plaque microenvironments, three-dimensional cellular culture platforms, and microfluidic organ-on-chip devices. These devices incorporate physiological flow to investigate disease mechanisms under controlled conditions. Second, therapeutic strategies are addressed through macroscopic gels for localized treatment. These encompass natural polymer-based, synthetic polymer-based, and composite formulations. Applications include stent coatings, adventitial injections, and catheter-delivered depots. Natural polymers often possess intrinsic biological activities including anti-inflammatory and immunomodulatory properties that may contribute to therapeutic effects. Third, nano- and microgels for systemic delivery are examined. These include polymer-based nanogels with stimuli-responsive drug release responding to oxidative stress, pH changes, and enzymatic activity characteristic of atherosclerotic lesions. Inorganic–organic composite nanogels incorporating paramagnetic contrast agents enable theranostic applications by combining therapy with imaging-guided treatment monitoring. Current challenges include manufacturing consistency, mechanical stability under physiological flow, long-term safety assessment, and regulatory pathway definition. Future opportunities are discussed in multi-functional integration, artificial intelligence-guided design, personalized formulations, and biomimetic approaches. Gel technologies demonstrate substantial potential to advance atherosclerosis management through improved spatial and temporal control over therapeutic interventions. Full article

Organ-on-a-Chip (OOC) platforms are microfluidic systems that recreate key features of human organ physiology in vitro via controlled perfusion. Fluid mechanical stimuli strongly influence cell morphology and function, making this important for cardiovascular OOC applications exposed to pulsatile blood flow. However, many existing OOC devices employ relatively simple chamber geometries and steady inflow assumptions, which may cause non-uniform shear exposure to cells, create stagnant regions with prolonged residence time, and overlook the specific effects of pulsatile perfusion. Here, we used computational fluid dynamics (CFD) to investigate how chamber geometry and inflow conditions shape the near-wall flow environment on a cell culture surface at a matched cycle-averaged volumetric flow rate. Numerical results demonstrated that pillarized chambers markedly reduced relative residence time (RRT) versus the flat chamber, and the small pillar configuration produced the most uniform time-averaged wall shear stress (TAWSS) distribution among the tested designs. Phase-resolved analysis further showed that wall shear stress varies with waveform phase, indicating that steady inflow may not capture features of pulsatile perfusion. These findings provide practical guidance for pillar geometries and perfusion conditions to create more controlled and physiologically relevant microenvironments in OOC platforms, thus improving the reliability of cell experimental readouts. Full article

Many emerging and re-emerging infectious diseases have been observed over the last few decades around the globe due to population growth, international travel, environmental changes, and microbial adaptation and evolution, despite advances in the medical field. The spread of these diseases is related to complex interactions between pathogens and their hosts. Accordingly, this review summarises current knowledge on infection development and discusses methods used for detection and modeling. Recent studies have revealed the limitations of two-dimensional models and increasingly rely on 3D systems, including spheroids, organoids, and organ-on-a-chip systems, that offer more realistic tissue environments, allowing researchers to more effectively study host–pathogen interactions. Overall, the integration of complementary approaches and the development of 3D models are crucial for enhancing diagnosis, developing new therapeutic approaches, and strengthening control strategies of emerging outbreaks. Full article

The FDA plans to gradually replace animal testing with organoid and organ-on-a-chip technologies for drug safety assessment, driving surging demand for gut-on-a-chip in food and drug safety evaluation and highlighting the need for efficient, precise chip designs. Oxygen gradients are central to these devices because they shape epithelial metabolism, microbial co-culture, and overall gut homeostasis. We coupled machine learning with finite element analysis to build a parametric COMSOL Multiphysics model linking channel geometry, transport coefficients, and cellular oxygen uptake to the resulting oxygen field. For numerical prediction, three models—Random Forest (RF), XGBoost, and MLP—were employed, with XGBoost achieving the highest accuracy (RMSE = 1.68%). SHAP analysis revealed that medium flow rate (39.7%), external flux (26.9%), and cellular oxygen consumption rate (24.8%) contributed most importantly to the prediction. For oxygen distribution mapping, an innovative Boundary-Guided Generative Network (BG-Net) model was employed, yielding an average concentration error of 0.012 mol/m³ (~4.8%), PSNR of 33.71 dB, and SSIM of 0.9220, demonstrating excellent image quality. Ablation experiment verified the necessity of each architectural component of BG-Net. This pipeline offers quantitative, data-driven guidance for tuning oxygen gradients in gut-on-a-chip. Future work will explore extensions including real experimental data integration, real-time prediction, and multi-task scenarios. Full article

Reliable models of the lung environment are important for research on inhalation products, drug delivery, and how aerosols interact with tissue. pH fluctuations frequently accompany real physiological processes in pulmonary environments, so monitoring pH changes in lung-on-a-chip devices is of considerable relevance. Presented here are flexible, miniaturized, inkjet-printed pH sensors that have been developed with the aim of integration into lung-on-a-chip systems. Different types of functional pH-sensitive materials were tested: hydrogen-selective plasticized PVC membranes and polyaniline (both electrodeposited and dropcast). Their deposition and performance were evaluated on different flexible conducting substrates, including screen-printed carbon electrodes (SPE) and inkjet-printed graphene electrodes (IJP-Gr). Finally, a biocompatible dropcast polyaniline-modified IJP was selected and paired with an inkjet-printed Ag/AgCl quasireference electrode. The printed potentiometric device showed Nernstian sensitivity (58.8 mV/pH) with good reproducibility, reversibility, and potential stability. The optimized system was integrated with a developed lung-on-a-chip model with an electrospun polycaprolactone membrane and alginate, simulating the alveolar barrier and the natural mucosal environment, respectively. The permeability of the system was studied by monitoring the pH changes upon the introduction of a 10 wt.% acetic acid aerosol. Overall, the presented approach shows that electrospun-hydrogel materials together with integrated microsensors can help create improved models for studying aerosol transport, diffusion, and chemically changing environments that are relevant for inhalation therapy and respiratory research. These results show that our system can combine mechanical behavior with chemical sensing in one platform, which may be useful for future development of lung-on-a-chip technologies. Full article

Microfluidics has emerged as a powerful enabling technology in plant science, offering unprecedented control over microscale environments for the cultivation, manipulation, and analysis of plant cells, tissues, and organs. This review provides a comprehensive overview of the development and application of microfluidic systems in plant physiology and development studies. We categorize the platforms based on their structural designs and biological targets—from single-cell trapping devices and droplet-based screening systems to organ-on-a-chip and root–microbe interaction modules. Key applications include live-cell imaging, real-time monitoring of stress responses, microenvironment simulation, and high-throughput phenotyping. Particular attention is given to microfluidic investigations of plant mechanobiology, chemotropism, and cell-to-cell communication, as well as their integration with biosensors, electrophysiological tools, and environmental control systems. We also examine current limitations related to material compatibility, device scalability, and biological complexity, and highlight emerging solutions such as modular design, interdisciplinary integration, and soil-on-a-chip systems. By addressing both fundamental research needs and practical agricultural challenges, microfluidic technologies offer a transformative path toward precision plant science and sustainable crop innovation. Full article

The human gut microbiota plays a key role in neurochemical communication, especially through the gut–brain axis. There is growing evidence that the gut microbiota influences dopamine metabolism through both production and consumption mechanisms. Two key bacterial enzymes are central to this process: tyrosine decarboxylase (TDC), which primarily catalyzes the decarboxylation of tyrosine to tyramine but can also act on L-DOPA to produce dopamine in certain bacterial strains, and aromatic L-amino acid decarboxylase (AADC), which can convert precursors such as L-DOPA, tryptophan, or 5-hydroxytryptophan into bioactive amines including dopamine, tryptamine, and serotonin. Identifying the bacterial families corresponding to TDC and AADC enzymes opens new avenues for clinical intervention, particularly in neuropsychiatric and neurodegenerative disorders, such as Parkinson’s disease. Moreover, elucidating strain-specific microbial contribution and host-microbe interactions may enable personalized therapeutic strategies, such as selective microbial enzyme inhibitors or tailored probiotics, to optimize dopamine metabolism. Emerging technologies, including biosensors and organ-on-chip platforms, offer new tools to monitor and manipulate microbial dopamine activity. This article explores the bacterial taxa capable of producing or consuming dopamine, focusing on the enzymatic mechanisms involved and the methodologies available for studying these processes in vivo. Full article

Microfluidic technologies have ushered in a new era in cardiac tissue engineering, providing more predictive in vitro models compared to two-dimensional culture studies. This review examines Organ-on-a-Chip (OoC) and Lab-on-a-Chip (LoC) platforms, with a specific focus on cardiovascular applications. OoCs, and particularly Heart-on-a-Chip systems, have advanced biomimicry to a higher level by recreating complex 3D cardiac microenvironments in vitro and dynamic fluid flow. These platforms employ induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), engineered extracellular matrices, and dynamic mechanical and electrical stimulation to reproduce the structural and functional features of myocardial tissue. LoCs have introduced miniaturization and integration of analytical functions into compact devices, enabling high-throughput screening, advanced diagnostics, and efficient pharmacological testing. They enable the investigation of pathophysiological mechanisms, the assessment of cardiotoxicity, and the development of precision medicine approaches. Furthermore, progress in multi-organ systems expands the potential of microfluidic technologies to simulate heart–liver, heart–kidney, and heart–tumor interactions, providing more comprehensive predictive models. However, challenges remain, including the immaturity of iPSC-derived cells, the lack of standardization, and scalability issues. In general, microfluidic platforms represent strategic tools for advancing cardiovascular research in translation and accelerating therapeutic innovation within precision medicine. Full article

The gut–brain axis (GBA) interaction is important for human health and disease prevention. Organ chips are considered a solution for GBA research. Three-dimensional (3D) cultures and microfluidics engineered in an organ chip could improve the scientific knowledge in the GBA interactions field. In this study, a novel organ chip is developed, which achieves multicellular three-dimensional cultivation by utilizing a decellularized matrix. In addition, this paper reports the rapid prototyping process of the GBA microfluidic chip in polydimethylsiloxane (PDMS) using 3D printing interconnecting poly(ethylene/vinyl acetate) (PEVA) microchannel templates. In comparison to the static culture system of the transwell model, the intestinal epithelial barrier (IEB) and blood–brain barrier (BBB) models on our chip demonstrated superior barrier function and the efflux functionality of transporters under appropriate fluidic conditions. Additionally, it is observed that butyrate protected against BBB dysfunction induced by gut-derived lipopolysaccharide (LPS) via enhancing intestinal barrier function. These results demonstrate that this multicellular, three-dimensional cultivation integrated with a fluidic shear stress simulation chip offers a promising tool for gut–brain interaction study to predict therapy of intestinal and neurological disorders. Full article

Biomolecule–photosensitizer conjugates have rapidly evolved into one of the most powerful strategies for improving the selectivity, efficacy, and translational potential of photodynamic therapy (PDT). By integrating photosensitizers (PSs) with carbohydrates, amino acids, peptides, aptamers, proteins, cofactors, vitamins or antibodies, these constructs overcome long-standing limitations of classical PDT, including poor solubility, insufficient tumour accumulation, and strong dependence on oxygen availability. Beyond enhancing receptor-mediated uptake and enabling precise interactions with the tumour microenvironment (TME), bioconjugation also modulates aggregation, photochemical properties, intracellular accumulation, and immune system activation. A particularly transformative trend is the emergence of supramolecular architectures in which photosensitizers form defined nanostructured aggregates with peptides or proteins. Once considered an undesirable phenomenon, aggregation is now recognized as a tenable feature that governs photochemical behaviour. Engineered aggregates can undergo environment-triggered disassembly to monomeric, photoactive states, or operate as semiconductor-like nanodomains capable of Type I reaction through symmetry-breaking charge separation. This shift toward oxygen-independent radical pathways offers a promising solution to the challenge of hypoxia, a hallmark of the TME that severely compromises conventional Type II PDT. Parallel advances in 3D experimental platforms such as tumour organoids and organ-on-chip systems provide physiologically relevant validation of these conjugates, enabling the assessment of penetration, subcellular localization, immunogenic cell death, and therapeutic synergy within realistic TME conditions. Collectively, the integration of biomolecular targeting with controlled supramolecular design is redefining the landscape of PDT. Future progress will depend on designing conjugates that retain high activity under hypoxia, engineering dynamic aggregate states, and systematically validating these systems in advanced TME-mimetic models. Together, these developments position biomolecule–photosensitizer conjugates as a versatile and increasingly less oxygen-dependent class of next-generation phototherapeutic agents. Full article

Three-dimensional (3D) bioprinting is a rapidly evolving technology that uses complementary biomaterials to emulate native extracellular matrices, enabling the generation of finely patterned, multicellular tissue architectures. Autoimmune diseases (AD), which are characterized by chronic, often organ-specific, immune response, are ideally suited to these in vitro models. This review summarizes the current state of 3D bioprinting for modelling AD, focusing on rheumatoid arthritis (RA), type 1 diabetes (T1D) and inflammatory bowel disease (IBD), as well as applications to systemic lupus erythematosus (SLE), neuroinflammatory conditions such as multiple sclerosis (MS) and other AD. Bioprinting modalities, advances in immune competent bioinks, strategies for vascularization and approaches to the hybridization of printed tissues with organoids and organ-on-chip systems are reviewed. From a clinical perspective, this review focuses on applications with translational potential, including immune-competent models derived from patients for biomarker discovery, drug screening and treatment response prediction. The key challenges, notably the reconstitution of full immune complexity, stable and perfusable vasculature, and maintenance of long-term viability and function are highlighted. Finally, future directions are defined to enhance the clinical utility and impact of 3D bioprinting across preclinical development and precision medicine. Full article