Search Results (1,007)

Type II collagen is a primary fibrillar component of articular cartilage, and its early degradation is a key biomarker of joint-degenerative disorders such as osteoarthritis, rheumatoid arthritis, gout, etc. Reliable detection at low concentrations remains challenging due to limited assay accessibility, complex analytical procedures, and nonspecific responses in multicomponent biological matrices. This research reports the development of a Molecularly Imprinted Polymer (MIP)–based electrochemical sensor engineered for the selective recognition of type II collagen. A series of monomer formulations were evaluated, and the 1AAM:2VP composition produced a well-defined imprinted layer on screen-printed carbon electrodes, yielding the highest electrochemical sensitivity and linearity. The optimized sensor exhibited strong anodic and cathodic responses proportional to increasing collagen concentrations, with a calibration slope corresponding to an R² value of 0.9394. Minimal signal interference was observed, confirming high molecular selectivity. The limit of detection (LOD) was calculated to be approximately 0.065 µg/mL. These characteristics demonstrate that the proposed MIP sensor provides a low-cost, accessible, and highly selective analytical platform suitable for early-stage cartilage degeneration monitoring. Full article

This review explores the advancements and applications of β-hairpin peptide hydrogels, starting from the paradigmatic case of MAX1 and its highly versatile analogue MAX8. MAX1 (H-VKVKVKVKV^DPPTKVKVKVKV-NH₂) has been identified as the first synthetic β-hairpin peptide for the preparation of stimuli-responsive peptide-based hydrogels. At low ionic strength or neutral pH, MAX1 remains unfolded and soluble. However, under physiological conditions, it folds into a β-hairpin structure, then producing a self-supporting matrix within minutes. The formed gel is shear-thinning and self-healing, making it suitable for injectable therapies. To explore MAX1 molecular space and enhance its practical clinical use, the primary sequence was engineered via chemical modification, with specific single amino acid substitution and relative net charge alteration. This approach generates MAX1 analogues, differing in gelation kinetics, mechanical response and biological performances. The β-hairpin peptide hydrogels are categorized into five different groups: MAX1, MAX1 analogues, MAX8, MAX8 analogues and non-MAX peptides sequences. Collectively, the review outcomes demonstrate the use of β-hairpin peptide matrices as tunable platforms for the development of predictable and stable biomaterials for advanced tissue engineering and drug delivery applications. Full article

Protein phosphorylation is a crucial post-translational modification that regulates protein activity, cellular signaling, transcriptional regulation, and cell cycle control. However, the analysis of phosphoproteins in biological samples is often compromised by complex sample matrices and interference from high-abundance proteins. While the top-down phosphoproteomics strategy enables comprehensive analysis of post-translational modifications based on intact proteins, its requirement for higher protein purity due to low protein ionization efficiency poses stern challenges. Consequently, developing appropriate enrichment methods for phosphoproteins in practical samples becomes essential. Immobilized metal ion affinity chromatography (IMAC) represents a common strategy for phosphorylated protein separation and enrichment. Among metal ions, Ti⁴⁺ has gained widespread application as IMAC chelating ligands due to its capacity to form multiple coordination networks and its high selectivity for phosphorylated protein enrichment, leveraging the strong chelating ability of phosphate groups toward metal ions. This paper presents the design and preparation of a novel magnetic Ti-IMAC nanocomposite, MNP@MPTMS–VPA–Ti(IV). The material is modified with phosphate groups via facile thiol-ene click chemistry and then immobilizes Ti⁴⁺, enabling selective enrichment of intact phosphoproteins through IMAC affinity. The efficiency of enrichment was evaluated using subsequent matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for detection and analysis. This Ti-IMAC material-based magnetic solid-phase extraction (MSPE)-MALDI-TOF MS protocol has been successfully applied to enrich intact phosphoproteins in milk and eel mucus with high selectivity, sensitivity, and suitability. Full article

Background: Cigarette burns represent a well-established forensic indicator of inflicted injury, frequently encountered in cases of domestic violence. Clinical significance: Their morphological consistency and anatomical distribution offer valuable elements for differentiating between intentional and accidental trauma. Case Presentation: In this study, we report the case of a 40-year-old woman who presented with multiple cutaneous lesions attributed to repeated assaults by her intimate partner. The forensic medical examination revealed five discrete scars characterized by sharply demarcated borders, circular to oval shapes, and dimensions ranging from 0.7 to 1.5 cm. These lesions were anatomically located in regions not typically accessible for self-infliction. To reinforce the diagnostic interpretation and assess reproducibility, a controlled experimental protocol was conducted using porcine skin matrices. Cigarette burns were recreated under variable conditions of contact pressure and exposure duration. The lesions produced on the biological substrate exhibited morphological features consistent with those observed in the patient, suggesting compatibility with cigarette-induced thermal injury. Conclusions: These findings provide circumstantial support for the forensic interpretation but must be considered within the limitations of the experimental model. This integrated approach underscores the relevance of combining clinical forensic documentation with experimental validation to support medico-legal conclusions in cases of suspected interpersonal violence. Full article

Better understanding the fate and transport of estuarine per- and polyfluoroalkyl substances (PFASs) requires coupling multiple matrix-specific biogeochemical roles, rather than relying on a single-matrix approach. We therefore evaluated sediment and biological matrices (blue mussels (BMs), Mytilus edulis; and hardshell clams (HSCs), Mercenaria mercenaria) as complementary indicators of PFAS contamination across three locations over a 240-day period following a spill event. A three-tiered analytical approach was applied: Tier 1 used non-parametric statistics to assess the broad-spectrum detection patterns for a total of 40 PFASs (n = 47 samples); Tier 2 employed generalized regression (adaptive Elastic Net), random forest, and artificial neural networks to model the concentrations of the most frequently detected PFASs (PFOS, PFOA, PFHxA, and PFOSA) (n = 188 observations); and Tier 3 implemented a system dynamics model to mechanistically couple the PFOS and 5:3 FTCA fate. The results suggest that the sediment acted as a long-term sink for legacy long-chain compounds (99.3%, primarily PFOS), while the biota, particularly BMs, acted as sensitive recorders of acute pulses and hydrophilic precursors, uniquely accumulating 5:3 FTCA during spring pulses (p < 0.001). All the models identified the matrix type as the dominant driver of the most prevalent PFAS concentrations. A reliance on sediment monitoring alone may fail to capture the majority of the active contamination burden sequestered in the biota, suggesting that effective risk assessment necessitates an integrated view. Full article

Background. Determining the cause and manner of death in scenes involving multiple and putrified bodies found in the same environment is a real challenge for forensic pathologists. While common scenarios include fires, vehicle crashes, and natural disasters, one of the most common causes is drug intoxication or poisoning, and the scene must be carefully evaluated based on circumstantial evidence. Carbon monoxide (CO) (also called “the silent killer”) remains one of the leading agents capable of producing simultaneous fatalities. In multi-body scenes, distinguishing between homicide–suicide, double suicide, and accidental deaths adds further complexity. The aim of this study is to highlight the limitations of toxicological and pathological investigations in advanced putrefaction and to emphasize the role of scene investigation in the interpretation of suspected CO-related deaths. Methods. The authors report a case of suspected CO intoxication involving two bodies in an advanced stage of decomposition recovered from the same room. The scene investigation, coupled with the presence of a malfunctioning combustion source, raised suspicion of CO exposure; however, analytical interpretation was severely constrained by the altered condition of biological samples. Results. Advanced decomposition magnifies these challenges. Putrefactive changes can mimic traumatic injuries, hide hypostasis, and compromise both macroscopic and microscopic evaluations due to autolysis and gas formation. Toxicological investigations are frequently hindered by the degradation or absence of key biological matrices such as blood, cavity fluids, or vitreous humor, rendering carboxyhaemoglobin quantification unreliable or impossible. These limitations may lead to incorrect medico-legal conclusions. Conclusions. Determining the cause and manner of death in complex multi-body scenes requires careful evaluation of circumstantial evidence and scene investigation, particularly when advanced decomposition compromises biological analyses and toxicological interpretation. Full article

Titanium dioxide (TiO₂) nano- and submicrometric particles’ widespread use in different sectors raised concerns about human and environmental exposure. The validation of analytical methods is essential to ensure reliability in risk assessment studies. In this study, a single-particle inductively coupled plasma mass spectrometry (spICP-MS) method was validated for the detection, quantification, and dimensional characterization of TiO₂ particles in biological tissues. Tissue samples collected after exposure to TiO₂ particles underwent mild acidic digestion using a HNO₃/H₂O₂ mixture to achieve complete matrix decomposition while preserving particle integrity. The resulting digests were analyzed by ICP-MS operated in single-particle mode to quantify and size TiO₂ particles. Method validation was conducted according to ISO/IEC 17025:2017 and included linearity, repeatability, recovery, and detection limit assessments. The limit of detection for TiO₂ particles was 0.04 µg/g, and 55.7 nm was the size the detection limit. Repeatability was within 0.5–11.5% for both TiO₂ mass concentrations and particle size determination. The validated method was applied to tissues from inhalation-exposed subjects, showing TiO₂ levels of 80 ± 20 µg TiO₂/g and particle number concentrations of 5.0 × 10⁵ ± 1.2 × 10⁵ part. TiO₂/mg. Detected TiO₂ particles’ mean diameter ranged from 230 to 330 nm. The developed and validated spICP-MS method provides robust and sensitive quantification of TiO₂ particles in biological matrices, supporting its use in human biomonitoring and exposure assessment studies. 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

Background: Advanced glycation end products (AGEs) play a pivotal role in various human pathologies, including aging and metabolic diseases, and their formation may have significant physiological consequences for human health. Fructoselysine (FL) is an intermediate in the formation of AGEs, and its accumulation has been associated with detrimental health effects. Although several chromatographic methods have been developed for AGEs detection and quantification, no mass spectrometry-based approach has previously been established to quantify FL in different human biological matrices. Methods: In this study, we present a novel UHPLC-HRMS/MS method for the identification and quantification of this compound in various biological matrices, including plasma, feces, and urine. Results: The method demonstrates excellent linearity, accuracy, and precision, with limit of detection (LOD) of 0.02 µM and limit of quantification (LOQ) of 0.06 µM. Recovery rates ranged from 95% to 109% and intra- and inter-day relative standard deviations (RSDs) were below 10%, indicating robust analytical performance. The validated method was successfully applied to quantify FL in plasma, feces, and urine samples from healthy individuals. Additionally, given the known association between AGEs and diabetes, we analyzed a small cohort of prediabetic patients and observed elevated circulating levels of FL compared to healthy controls. Conclusions: This study introduces a sensitive and reliable method for the specific detection and quantification of FL in biological samples and provides new insights into early molecular changes associated with prediabetic condition to improve early diagnosis in aging related diseases. Full article

Human exposure to persistent organic pollutants such as polychlorinated biphenyls (PCB) and brominated flame retardants (BFR), including both legacy and emerging compounds, remains a concern due to their bioaccumulative nature and potential health effects. Comprehensive analytical methods are necessary to monitor these substances in complex biological matrices, such as human serum. A gas chromatography–mass spectrometry (GC-MS) method was developed for the simultaneous determination of 44 analytes, encompassing PCB and a broad spectrum of BFR with diverse physicochemical properties. The extraction procedure and GC-MS parameters were optimized using a design of experiments approach to maximize performance while minimizing analysis time. The method demonstrated high sensitivity, precision, and accuracy, thereby meeting internationally recognized validation criteria for biomonitoring applications. To further ensure analytical reliability, compound confirmation was achieved using gas chromatography–high-resolution mass spectrometry, providing enhanced selectivity and confidence in identification, particularly for low-level analytes. Key advantages of the method include its applicability to analytes with significantly different chemical behaviors and its capacity to quantify a large number of target compounds simultaneously. This makes it a powerful tool for assessing human exposure to both regulated and emerging halogenated contaminants. Full article

Recent advances in biomaterials, immunomodulation, stem cell therapy, and biofabrication are reshaping maxillofacial surgery, shifting reconstruction paradigms toward biologically integrated and patient-specific tissue regeneration. This review provides a comprehensive synthesis of current and emerging strategies for bone and soft-tissue regeneration in the craniofacial region, with particular emphasis on bioactive ceramics, biodegradable polymers, hybrid composites, and stimuli-responsive smart materials. We further examine translational technologies such as extracellular vesicles, decellularized extracellular matrices, organoids, and 3D bioprinting, highlighting key challenges such as bioink standardization, perfusion limitations, and regulatory classification. Maxillofacial surgery is positioned for a paradigm shift toward personalized, biologically active, and clinically scalable regenerative solutions. Full article

Canine ehrlichiosis, caused by Ehrlichia canis, represents a relevant challenge in veterinary medicine, particularly in resource-limited settings where access to laboratory-based diagnostics may be constrained. This pilot and exploratory study aimed to evaluate the feasibility of a portable electronic olfactometer as a non-invasive screening approach, based on the analysis of volatile organic compounds (VOCs) present in breath, saliva, and hair samples from dogs. Signals were acquired using an array of eight metal-oxide (MOX) gas sensors (MQ and TGS series). After preprocessing, principal component analysis (PCA) was applied for dimensionality reduction, and the resulting features were analyzed using supervised machine-learning classifiers, including AdaBoost, support vector machines (SVM), k-nearest neighbors (k-NN), and Random Forests (RF). A total of 38 dogs (19 PCR-confirmed infected cases and 19 controls) were analyzed, generating 114 samples evenly distributed across the three biological matrices. Among the evaluated models, SVM showed the most consistent performance, particularly for saliva samples, achieving an accuracy, sensitivity, and precision of 94.7% (AUC = 0.964). In contrast, breath and hair samples showed lower discriminative performance. Given the limited sample size and the exploratory nature of the study, these results should be interpreted as preliminary; nevertheless, they suggest that electronic olfactometry may represent a complementary, low-cost, non-invasive screening tool for future research on canine ehrlichiosis, rather than a standalone diagnostic method. Full article

Pyrethroids, synthetic analogues of natural pyrethrins, are extensively used in agriculture and household pest control due to their high insecticidal activity and relatively low toxicity to mammals. Due to the presence of multiple chiral centres, many pyrethroids exist as complex mixtures of stereoisomers with significantly different biological activities, toxicities, and environmental behaviours. Consequently, accurate determination of these stereoisomeric forms, particularly compounds such as cypermethrin, is critical for food safety monitoring. Determining pyrethroid residues in food matrices presents a significant analytical challenge due to the structural diversity and stereochemical complexity of these compounds. This study presents the development of an analytical method for determining the stereoisomeric forms of cypermethrin and other synthetic pyrethroids in food matrices using both LC-MS/MS and GC-MS/MS techniques. The method meets the performance criteria outlined in SANTE/11312/2021 v2, demonstrating satisfactory recovery rates (91.6%), precision (RSDR 1.9%), and low limits of quantification (LOQ 0.010 µg/kg) for the quantification of alpha-cypermethrin. This approach offers a reliable tool for regulatory monitoring and risk assessment of pyrethroid residues, especially those with complex stereochemistry. Full article

Reliable biological datasets, especially those integrating biotic indices such as the Saprobic Index, are scarce, limiting machine and deep learning applications in aquatic ecosystem assessments. This study evaluates Conditional Tabular Generative Adversarial Networks (CTGANs) for generating synthetic datasets that combine physico-chemical parameters with a biological index (Saprobic Index) from multiple monitoring stations in the lower Danube River. Beyond univariate distributional agreement, we assess whether ecologically meaningful multivariate relationships are preserved in the synthetic tables. To support this, we propose an ecology-oriented validation workflow that combines distributional tests with correlation structure and clustering diagnostics across stations. Real monitoring datasets were statistically modelled and recreated using CTGANs, then qualitatively assessed for realism. Comparisons between synthetic and real data employed box plots, Wilcoxon rank-sum tests, correlation matrices, and K-means clustering across stations. Stable variables, including pH, total dissolved solids, and chemical oxygen demand, were well replicated, showing no significant distributional differences (p > 0.05). Conversely, dynamic parameters such as dissolved oxygen, total nitrogen, and suspended solids exhibited notable discrepancies (p < 0.05). Correlation analyses indicated that several strong associations present in the observed data (e.g., total nitrogen–nitrate and total nitrogen–electrical conductivity) were substantially weaker in the synthetic dataset. Overall, a CTGAN can reproduce several marginal patterns but may fail to preserve key ecological linkages, which constrains its use in ecological relationship-dependent inference. While promising for exploratory modelling and general trend analysis, synthetic data should be applied cautiously for studies involving seasonally influenced, biologically significant parameters. Full article

Ochratoxin A (OTA), a fungal secondary metabolite, is frequently detected in grains, herbal products, and other agricultural commodities, posing potential food safety risks. Among existing detoxification strategies, biological degradation is considered both specific and environmentally sustainable. In this study, a novel OTA-degrading bacterium, Brevibacillus parabrevis S09T2, was isolated from soil using OTA as the sole carbon source. The strain exhibited no hemolytic activity and carried no virulence or antibiotic resistance genes, indicating a favorable safety profile. S09T2 efficiently degraded OTA, removing over 93% of 5–8 μg/mL OTA within 24 h at 37 °C, and almost completely degrading OTA concentrations up to 10 μg/mL within 72 h. UPLC-HRMS analysis identified ochratoxin α (OTα) and phenylalanine as the only degradation products, confirming detoxification via amide bond hydrolysis. The intracellular enzyme responsible for this reaction displayed notable thermostability, achieving near-complete degradation of 1 μg/mL OTA at 50 °C within 6 h. Moreover, the cell lysate significantly reduced OTA levels in Plumeria rubra extract, a widely consumed functional food, demonstrating applicability in complex food matrices. Collectively, these findings highlight S09T2 as a promising candidate for OTA detoxification and support its potential use in food and feed safety applications. Full article