Search Results (115)

Heavy metal pollution from coal gangue severely degrades mine soil structure and threatens landscape ecological stability. Particularly, γ-polyglutamic acid (γ-PGA), a green biopolymer, offers potential applications for pollution remediation while supporting ecological restoration. To evaluate γ-PGA’s efficacy in immobilizing Pb, Cd, and Zn in gangue-based soil and clarify its regulatory mechanism for landscape-friendly remediation, soil samples from a 3-year-weathered gangue hill in the Liupanshui mining area were subjected to indoor leaching experiments with different γ-PGA doses, combined with material characterization and Density Functional Theory (DFT) simulations. The results showed that the optimal γ-PGA dose was 6 g/kg, achieving 93.25% Pb immobilization and reducing Cd/Zn migration risk by over 30%; γ-PGA acted via carboxyl-amide dual-site chelation and hydrogen-bonded agglomeration, forming stable aggregates that inhibited metal migration. DFT calculations confirmed strong chelation for Cu²⁺ (−59.54 kcal/mol, BSSE-corrected: −57.23 kcal/mol), while Pb²⁺ and Cd²⁺ showed weaker binding (−8.32 kcal/mol and −5.67 kcal/mol, BSSE-corrected: −6.15 kcal/mol and −3.89 kcal/mol, respectively), indicating multi-pathway immobilization mechanisms. This study provides a theoretical basis for applying γ-PGA in mine landscape ecological restoration. Full article

Methotrexate (MTX) remains the first-choice treatment for rheumatoid arthritis (RA), but individual variability in response and adherence underscores the need for reliable biomarkers of long-term drug exposure. Intracellular methotrexate polyglutamates (MTXPGs), typically measured in red blood cells (RBCs), fulfill this role but require invasive venous sampling. This study aimed to develop and validate a multi-matrix LC–MS/MS method for measuring MTXPGs in capillary blood samples obtained via volumetric absorptive microsampling (VAMS) and dried blood spots (DBS), and to compare these methods with traditional matrices. The method was validated in accordance with ICH M10 guidelines across RBC, whole blood (WB), VAMS, and DBS samples. MTX and MTXPG_2–5 and total MTXPG were measured in 40 matched clinical samples. MTXPG_6–7 were not detected across the tested clinical samples. Validation using Passing–Bablok regression, Bland–Altman analysis, and Spearman correlation showed strong agreement between VAMS and DBS (slopes 0.95–1.07; bias −4.21% to 0.36%; SRCC ≥ 0.969), with up to 100% of samples within ±20% of the agreement limits for total MTXPG. Significant differences were observed between capillary matrices and RBCs, with higher MTXPG levels in erythrocytes (bias up to −28%). Whole blood showed closer agreement with microsampling methods. ISR pass rates ranged from 84% to 95%, and stability tests indicated matrix- and chain length-dependent degradation, particularly for long-chain MTXPGs. These findings show that VAMS and DBS yield comparable results and can be considered interchangeable within a capillary-sampling framework. However, interpretation must account for matrix-specific differences when relating measurements to RBC-based reference values. This validated method could support the analytical feasibility of decentralized MTXPG monitoring in RA. However, prospective studies linking matrix-specific thresholds with disease activity, adherence, and toxicity are required before implementation for therapeutic decision-making. Full article

A mixture of poultry litter (PL) and biochar (BC) was composted over 120 days in a bioreactor. To assess the impact on the stability of organic matter, the bioavailability of heavy metals, and ecotoxicity, the PL+BC biomass was supplemented with 0.5% (w/w) γ-polyglutamic acid (PGA), superphosphate (SPP) and smectite-silica clay (SSC) relative to the dry matter. Incorporating PGA, SPP, and SSC additives into PL+BC increased total carbon content by an average of 6%, compared to PL+BC without additives. The SSC additive proved to be more effective in increasing the humic acid carbon content, raising Cha by an average of 23% relative to PGA and SPP treatments. The incorporation of biochar into PL led to a substantial increase in nonhydrolizing carbon content, while the enrichment of composts with PGA, SPP, or SSC resulted in an escalation in this form of carbon by an average of over 7% compared to PL+BC. The lowest amounts of metals extracted with water and the lowest RAC values were obtained for PL+BC+SPP compost. The additives used stabilized the composts more quickly and reduced their toxicity. The classification of PL compost was designated as class III, whereas composts that incorporated additives were classified as class II toxicity. The study findings substantiated the necessity to incorporate additives during the biological processing of poultry litter. Full article

Efficient microbial assimilation of high-concentration ammonium nitrogen and its conversion into value-added bioproducts represent a pivotal yet underexplored strategy for sustainable nitrogen management. Here, we report a newly isolated Bacillus velezensis strain, GY1, with a robust intrinsic capacity for simultaneous NH₄⁺-N assimilation and γ-polyglutamic acid (γ-PGA) biosynthesis. Under optimized conditions (37 °C, pH 7.0, C/N = 12:1), GY1 achieved 76.5% removal of ammonium nitrogen (400 mg/L) with negligible nitrite accumulation (<0.02 mg/L), indicating assimilation rather than nitrification. Transcriptomic analysis revealed a coordinated metabolic flux wherein the glutamine synthetase - glutamate synthase pathway GS-GOGAT pathway supplies glutamate for γ-PGA synthesis, while polymerization further facilitates ammonium sequestration via electrostatic interactions. GY1 produced up to 612.8 mg/L γ-PGA, and genetic overexpression of capB synchronized these pathways, enhancing both ammonium assimilation (87.4%) and γ-PGA yield (843.9 mg/L). Notably, this metabolic coupling remained resilient in complex substrates, achieving 68.8% ammonium removal and 220.7 mg/L γ-PGA production in untreated biogas slurry. Together, these findings establish GY1 as a metabolically robust platform linking nitrogen assimilation with biopolymer synthesis, offering a mechanistic framework for circular nitrogen economies. Full article

Aging is closely associated with oxidative stress, which contributes to functional decline and increased vulnerability to neurodegenerative diseases. Natural antioxidants, such as Chlorella Growth Factor (CGF) and γ-polyglutamic acid (γ-PGA), possess antioxidant and anti-aging properties; however, their combined effects remain unknown. This study investigated the potential synergistic effects of CGF and γ-PGA supplementation in senescence-accelerated mouse-prone 8 (SAMP8) mice, a model characterized by early cognitive decline, locomotor deficits, and elevated oxidative DNA damage. Three-month-old male SAMP8 mice (n = 40) were divided into four groups: control, CGF (49.2 mg/kg BW/day), γ-PGA (20.5 mg/kg BW/day), and combined CGF + γ-PGA (69.7 mg/kg BW/day), and were treated for 13 weeks. Behavioral and physiological assessments included locomotor activity, aging index, and cognitive function (passive and active avoidance tests). Biochemical analysis focused on brain 8-hydroxy-2′-deoxyguanosine (8-OHDG) as a biomarker of oxidative DNA damage. Supplementation with CGF and γ-PGA, particularly in combination, significantly improved locomotor activity, aging scores, and cognitive functions. Notably, the combined treatment yielded the greatest reduction in brain 8-OHDG levels. These findings indicate that CGF and γ-PGA, when administered together, exert enhanced protective effects against functional and molecular aging. In conclusion, long-term supplementation with CGF and γ-PGA protects against aging-related decline in SAMP8 mice. This study highlights the potential of CGF and γ-PGA as safe, natural candidates for the development of functional foods or nutraceuticals aimed at promoting healthy aging and reducing oxidative stress-associated disorders. Full article

Optimizing calcium metabolism is crucial for skeletal development and overall productivity in growing ruminants. Twenty-four Sunite lambs were randomly assigned to four groups and fed 0, 0.6, 1.2, or 2.4 g/(d·head) of γ-PGA for 60 days. Growth performance, serum parameters, duodenal morphology and calcium transporter expression, bone microarchitecture, and duodenal microbiota were analyzed. Supplementation with 1.2 g/(d·head) of γ-PGA (the M group) yielded optimal results, significantly improving final body weight and size. It enhanced duodenal health, evidenced by increased villus height, crypt depth, and microvilli density. Crucially, this dose significantly upregulated the expression of key duodenal calcium transporters (TRPV5/6, CaBPD9k, PMCA, VDR, claudin-12) and altered systemic calcium-regulating hormones (elevated calcitriol, PTH, FGF23). Bone micro-CT analysis revealed changes in trabecular architecture indicative of active remodeling. 16S rRNA sequencing and weighted OTU co-expression network analysis (WOCNA) revealed that γ-PGA reshaped the duodenal microbiota and identified core microbial modules strongly associated with host phenotypes. Genera such as [Eubacterium]_ruminantium_group, Fusicatenibacter, and Prevotella emerged as central hubs. In conclusion, dietary γ-PGA at 1.2 g/(d·head) enhances calcium absorption and bone metabolism in lambs through a coordinated modulation of intestinal integrity and calcium transport, systemic endocrine responses, and the duodenal microbial community, with specific microbiota identified as potential key mediators associated with these effects. Full article

Background/Objectives: Methotrexate (MTX) is a cornerstone drug used to treat immune-mediated inflammatory diseases (IMIDs) in low doses (10–30 mg/week), and malignancies in high doses (5000 mg/m²/2 weeks). Its active metabolites, Methotrexate polyglutamates (MTX-PG_2–5), quantified in erythrocytes, are associated with efficacy. This study aimed to compare erythrocyte MTX-PG concentrations in patients with IMIDs and pediatric acute lymphoblastic leukemia (ped-ALL) treated with low-dose or high-dose MTX, respectively, and to identify clinical, demographic, and treatment-related factors influencing their concentration. Methods: A total of 567 patients with rheumatoid arthritis, juvenile idiopathic arthritis, Crohn’s disease, sarcoidosis, and ped-ALL were included. Erythrocyte MTX-PG concentration data was collected after 3 months (2.5 months for ped-ALL patients) of MTX-use. Multivariate linear regressing modelling adjusting for age, sex, body mass index (BMI), smoking status, starting MTX dose, route of MTX administration, use of predniso(lo)ne, disease-modifying anti-rheumatic drugs (DMARDs), and folic (or folinic) acid was performed. Results: Intravenous high-dose MTX increased MTX-PG_4&5 accumulation. Despite 50-fold higher doses in ped-ALL, MTX-PG_2–5sum concentrations were similar to those seen with subcutaneous low-dose MTX used in IMIDs. Age positively influenced MTX-PG concentrations, while DMARD use reduced MTX-PG_2–3&5 concentrations. Interestingly, predniso(lo)ne use was associated with higher MTX-PG_4&5 concentrations and folic (or folinic) acid with higher MTX-PG_3–5 concentrations. Conclusions: This is the first study to compare erythrocyte MTX-PG concentration in low-dose and high-dose patients. Intravenous high-dose MTX administration increased long-chain MTX-PG_4&5 concentrations, with MTX-PG_2–5sum concentrations similar compared to low-dose subcutaneous MTX use. This study demonstrated that route of administration, age, and concomitant therapies such as DMARDs, predniso(lo)ne, and folic (or folinic) acid significantly influence MTX-PG concentrations. Full article

Background/Objectives: Wound infections caused by multidrug-resistant Gram-negative bacteria, such as Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii, pose a major clinical challenge. This study evaluated the interactions between gamma-polyglutamic acid (γ-PGA), cefiderocol, and silver nanoparticles (AgNPs) within multilayer wound dressing configurations. The primary goal was to clarify the dual role of γ-PGA as a healing promoter and a potential protector of bacterial cells against antimicrobial agents. Methods: Multilayer dressing models were assembled in 96-well plates to simulate vertical stratification of antimicrobial layers4. Bacterial viability was assessed through relative OD₆₀₀ measurements following incubation with varying concentrations and spatial arrangements of cefiderocol, AgNPs, and γ-PGA. Data were analyzed using generalized linear modeling (GLM) with a gamma distribution and random forest regression to determine the relative importance of each factor in modulating bacterial survival. Results: γ-PGA concentration emerged as the dominant factor influencing bacterial viability, accounting for nearly 100% of variable importance in random forest analysis. Despite high antimicrobial pressure from cefiderocol and AgNPs, bacterial viability stabilized at approximately 40% in the presence of γ-PGA. The vertical positioning of γ-PGA significantly impacted survival; direct physical contact between the polymer and bacteria, particularly at high concentrations, enhanced bacterial persistence in P. aeruginosa and E. coli. Cefiderocol showed strain-specific potency, while AgNPs provided consistent growth inhibition. Conclusions: γ-PGA plays a paradoxical role in wound care by providing moisture retention while simultaneously acting as a cytoprotective agent that reduces antimicrobial efficacy, likely by facilitating biofilm formation. These findings underscore the necessity of optimizing the spatial layering and concentration of biopolymers in advanced dressings. Strategic design is crucial to balance regenerative benefits with maximal antimicrobial control to improve clinical outcomes in chronic wound management. Full article

Plant-based fermented foods are increasingly promoted for glycemic control, yet their mechanisms and clinical impact remain incompletely defined. This narrative review synthesizes mechanistic, preclinical, and human data for key matrices—kimchi and other fermented vegetables, tempeh/miso/natto, and related legume ferments, kombucha and fermented teas, plant-based kefir, and cereal/pulse sourdoughs. Across these systems, microbial β-glucosidases, esterases, tannases, and phenolic-acid decarboxylases remodel polyphenols toward more bioaccessible aglycones and phenolic acids, while lactic and acetic fermentations generate organic acids, exopolysaccharides, bacterial cellulose, γ-polyglutamic acid, γ-aminobutyric acid, and bioactive peptides. We map these postbiotic signatures onto proximal mechanisms—α-amylase/α-glucosidase inhibition, viscosity-driven slowing of starch digestion, gastric emptying and incretin signaling, intestinal-barrier reinforcement, and microbiota-dependent short-chain–fatty-acid and bile-acid pathways—and their downstream effects on AMPK/Nrf2 signaling and the gut–liver axis. Animal models consistently show improved glucose tolerance, insulin sensitivity, and hepatic steatosis under fermented vs. non-fermented diets. In humans, however, glycemic effects are modest and highly context-dependent: The most robust signal is early postprandial attenuation with γ-PGA-rich natto, strongly acidified or low-glycemic sourdough breads, and selected kombucha formulations, particularly in individuals with impaired glucose regulation. We identify major sources of heterogeneity (starters, process parameters, substrates, background diet) and safety considerations (sodium, ethanol, gastrointestinal symptoms) and propose minimum reporting standards and trial designs integrating metabolomics, microbiome, and host-omics. Overall, plant-based ferments appear best positioned as adjuncts within cardiometabolic dietary patterns and as candidates for “purpose-built” postbiotic products targeting early glycemic excursions and broader metabolic risk. Full article

Legumain (LGMN), a lysosomal cysteine protease, is crucial for tumor progression, invasion, and metastasis, making it a promising target for cancer imaging and therapy. This study developed novel ⁶⁷Ga-labeled 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA)-conjugated LGMN-cleavable peptide probes ([⁶⁷Ga]Ga-NOTA-LCPs) composed of polyarginine and polyglutamic acid sequences linked by LGMN-cleavable sites for nuclear medicine imaging of LGMN activity. The probes were synthesized via fluorenylmethoxycarbonyl solid-phase peptide synthesis and radiolabeled in high radiochemical yields. In vitro assays with HCT116 cells showed significantly higher uptake of [⁶⁷Ga]Ga-NOTA-LCPs compared to non-cleavable controls, confirming efficient cleavage and cellular uptake. In vivo studies in tumor-bearing mice revealed rapid renal clearance, low non-specific binding, and favorable tumor-to-blood ratios, particularly for [⁶⁷Ga]Ga-NOTA-LCP-1. These results demonstrate the potential of [⁶⁷Ga]Ga-NOTA-LCPs as effective LGMN-responsive imaging agents, with further optimization needed to improve tumor specificity and reduce off-target accumulation. Full article

Background: Various thiolactones are known as biologically active compounds, capable of stimulating the development of several human diseases and quorum sensing of Gram–positive bacteria. The enzymatic hydrolysis of thiolactones represents a promising approach to preventing their action. Methods: Thirteen enzymes, including various lactonases and serine hydrolases were studied in this work using several substrates including the homocysteine thiolactone (HTL), and its derivatives the N–acetylhomocysteine thiolactone (C₂–HTL) and the isobutyryl–homocystein thiolactone (i–but–HTL). The potential interactions of the ligands with the surface of enzymes molecules were predicted in silico using computational modeling and checked in wet experiments in vitro. Results: Based on the data obtained several enzymes were selected with localization of the thiolactones near their active sites, indicating the possibility of effective catalysis. The lactonase (AiiA), metallo-β-lactamase (NDM-1) and the organophosphate hydrolase with hexahistidine tag (His₆–OPH) were among them. Determination of catalytic characteristics of enzymes in the hydrolytic reactions with the HTL and the C₂–HTL revealed the maximal value of catalytic efficiency constant for the NDM-1 in the hydrolysis of the HTL (826 M⁻¹ s⁻¹). The maximal activity in the hydrolysis of C₂–HTL was established for AiiA (137 M⁻¹ s⁻¹). The polyaspartic (PLD₅₀) and the polyglutamic (PLE₅₀) acids were used to obtain polyelectrolyte complexes with enzymes. The further combination of these complexes with the clotrimazole and polymyxin B possessing antimicrobial properties resulted in notable improvement of their action in relation to Staphylococcus cells. Conclusions: It was revealed that the antimicrobial activity of the polymyxin B is enhanced by 9–10 times against bacteria and yeast when combined with the His₆–OPH polyelectrolyte complexes. The antimicrobial activity of clotrimazole was increased by ~7 times against Candida tropicalis cells in the case of the AiiA/PLE₅₀/Clotrimazole combination. These results make the obtained biology attractive and promising for their further advancement to practical application. Full article

Background: Methotrexate (MTX) is the most used anti-rheumatic drug for the treatment of early rheumatoid arthritis (ERA) patients, with an adequate response rate of only 30–40%. Thus, early detection of response failure is very crucial to prevent permanent disability. Objectives: We aimed to provide an update on the current evidence of potential predictive biomarkers of MTX treatment response (MTX-TR) in patients with ERA. Materials and Methods: PubMed/MEDLINE, Scopus, EBSCO, and Cochrane Library were searched for studies that investigated a multitude of predictive metabolites of MTX-TR in ERA patients during the 2000–2024 period. This study was registered in PROSPERO (ID: CRD42024547651). Results: We determined that 31 out of 102 metabolites studied were the best predictive of MTX-TR in ERA, using clinical response (DAS28-ESR score). Our results on serum protein profiles revealed that higher pre-treatment levels of myeloid-related proteins, MTX–polyglutamates, choline, inosine, hypoxanthine, guanosine, nicotinamide, and diglyceride, and lower pre-treatment levels of N-methyl isoleucine, 2,3-dihydroxy butanoic acid, nor-nicotine, glucosylceramide, and itaconic acid, were associated with a good MTX-TR. However, lower baseline plasma itaconate and its derivatives and haptoglobin, but a higher baseline level of galactosylated glycans (FA2G) of IgG1, were associated with a good response to MTX. The results on immune cell biology indicated that higher pre-treatment of regulatory B cells, lower pre-treatment of Treg, and RDW were correlated with a good MTX-TR. The results on inflammatory biomarkers showed that a lower IL-1ra/IL1B ratio and IL-6 levels after MTX indicated a good response. Conclusions: This study provides an update on the current evidence of the potential predictive metabolites for the best MTX-TR in ERA patients. We revealed that few biomarkers resulted in a remission state of patients with ERA. These biomarkers are promising but not yet ready for routine clinical use; they warrant validation in larger prospective trials. We recommend that, for the implementation of personalized medicine, these biomarkers should be the first-line biomarkers for use in routine clinical practice after validation. Full article

In response to the limitations of hyaluronic acid (HA)—such as its high cost, short durability, and instability—in anti-aging aesthetic applications, this study developed a novel injectable micelle system, with a triple network structure. It is the particle size of approximately 400 nm and the elevated potential that enhance the crosslinking density and mechanical strength of the hydrogel. Importantly, following ultrafiltration and purification processes, the material’s hemolysis rate measured by spectrophotometry was only 3.25%, and endotoxin levels measured by the LAL assay were less than 0.5 EU/mL (test conditions: 37 °C, pH = 7, detection limit: 0.125 EU/mL). Building on this safe and stable material platform, we further designed an antibacterial wound dressing by functionalizing γ-PGA with penicillin or benzalkonium chloride. It reduced the cellular activity of Staphylococcus aureus by 78.9% and 84.2%, respectively. The outstanding safety profile, combined with customizable functionality, positions this γ-PGA-based platform as a promising multifunctional biomaterial meeting practical standards for both aesthetic medicine and wound care applications. Full article

Poly-γ-glutamic acid (γ-PGA), also known as polyglutamate, is a naturally derived polymer produced by Bacillus species that has demonstrated antiviral properties. Growing evidence from preclinical and clinical studies supports its therapeutic potential against various viral infections, highlighting both effective antiviral activity and a favorable safety profile. This review emphasizes current findings on the antiviral mechanisms of γ-PGA, including its ability to interfere with viral entry and to activate serial immune signaling pathways, with additional insights from structural biology. Collectively, γ-PGA represents a promising biomaterial for the development of future broad-spectrum antiviral strategies and applications. Full article

Superabsorbent polymers (SAPs) are increasingly applied in agriculture to enhance soil water retention, reduce nutrient loss, and mitigate drought stress—challenges expected to intensify under global climate change. While their benefits for crop growth are well documented, much less is known about their influence on free-living microorganisms. Here, we examined the effects of three SAP chemistries—potassium polyacrylate (DCM Aquaperla^®), starch-based polyacrylamide (Zeba Plus SP^®), and γ-polyglutamate (Stockosorb^® 660 Medium)—on the growth and pigment composition of Chlorella vulgaris Beijerinck across three initial cell densities (22.8 × 10³, 228 × 10³, and 2.228 × 10⁶ cells/mL). Six spectral indices, derived from weekly absorbance measurements over seven weeks, were used to track biomass and pigment allocation. Nonparametric repeated-measures analysis and principal component analysis revealed strong effects of SAP type, algal density, and time. Zeba consistently maintained biomass comparable to the control while enhancing carotenoid- and xanthophyll-sensitive indices, suggesting pigment reallocation without growth suppression. Stockosorb produced intermediate responses, whereas Aquaperla frequently reduced biomass-related measures, particularly at high density. Pigment allocation was also density-dependent, with low-density cultures investing proportionally more in carotenoids. Overall, these results show that SAP–microbe interactions are strongly influenced by polymer chemistry and starting biomass, with implications for biotechnology, environmental risk assessment, and sustainable crop production systems that aim to support both algal and plant resilience under drought. Full article