Search Results (9,556)

Background/Objectives: The functionalization of various forms of graphene, such as graphene nanoplatelets, graphene oxide, and reduced graphene oxide, in biomaterials is a promising strategy in dentistry, particularly regarding their antimicrobial potential. However, conclusive studies on the toxicity and biocompatibility of graphene-based materials remain limited, and standardized guidelines for their production, handling, and dental applications are still lacking. This scoping review aims to map the available studies on various types of graphene, synthesize evidence on their antimicrobial effectiveness, and describe the main biological responses when functionalized in dental biomaterials. Methods: An electronic search was conducted in the Clarivate, PubMed, and Scopus databases using the descriptors as follows: ‘graphene’ AND ‘antimicrobial effect’ AND ‘bactericidal effect’ AND (‘graphene oxide’ OR ‘dental biofilm’ OR ‘antibacterial properties’ OR ‘dental materials’). Article screening and eligibility assessment were performed based on predefined inclusion and exclusion criteria, following the PRISMA-ScR guidelines. Results: The search identified 793 articles. After removing duplicates, applying the eligibility criteria, and performing a full-text analysis of 64 articles, 21 studies were included in the review. Graphene oxide, particularly at low concentrations, was the most commonly studied graphene variant, demonstrating significant antimicrobial efficacy against S. mutans, S. faecalis, E. coli, P. aeruginosa, and C. albicans. Both mechanical and chemical mechanisms have been linked to the biological responses of graphene-doped biomaterials. The biocompatibility and cytotoxicity of these compounds remain controversial, with some studies reporting favorable outcomes, while others raise significant concerns. Conclusions: Graphene shows great promise as an antimicrobial agent in dental biomaterials. Despite encouraging results, more in vitro and in vivo studies are needed to better understand its biocompatibility and cytotoxicity in dental applications. Additionally, standardized production protocols, clearly defined clinical applications in dentistry, and regulatory guidelines from the World Health Organization concerning handling procedures and occupational risks remain necessary. Full article

Although cemented carbides have been manufactured by the powder metallurgy (P/M) technology for over a century now, systematic developmental efforts are still underway. In the present study, tool life improvements in metal grooving applications are the key objective. Four PVD-coated cemented carbides compositions, dedicated to groove steel, stainless steel, cast iron, and aluminium alloys, have been newly designed, along with their manufacturing conditions. Physical, mechanical and chemical characteristics—such as sintered density, modulus of elasticity, hardness, fracture toughness, WC grain size, and the chemical composition of the substrate material, as well as the chemical composition, microhardness, structure, and thickness of the coatings—have been studied. A series of grooving tests have also been conducted to assess whether modifications to the thus far marketed tool materials, tool geometries, and coatings can improve cutting performance. In order to compare the laboratory and application properties of the investigated materials with currently produced by reputable companies, commercial inserts have also been tested. The experimental results obtained indicate that the newly developed grooving inserts exhibit excellent microstructural characteristics, high hardness, fracture toughness, and wear resistance and that they show slightly longer tool life compared to the commercial ones. Full article

The paradigm-shift idea of murburn concept is no hypothesis but developed directly from fundamental facts of cellular/ecological existence. Murburn involves spontaneous and stochastic interactions (mediated by murzymes) amongst the molecules and unbound ions of cells. It leads to effective charge separation (ECS) and formation/recruitment of diffusible reactive species (DRS, like radicals whose reactions enable ATP-synthesis and thermogenesis) and emission of radiations (UV/Vis to ELF). These processes also lead to a chemo-electromagnetic matrix (CEM), ascertaining that living cell/organism react/function as a coherent unit. Murburn concept propounds the true utility of oxygen: generating DRS (with catalytic and electrical properties) on the way to becoming water, the life solvent, and ultimately also leading to phase-based macroscopic homeostatic outcomes. Such a layout enables cells to become simple chemical engines (SCEs) with powering, coherence, homeostasis, electro-mechanical and sensing–response (PCHEMS; life’s short-term “intelligence”) abilities. In the current review, we discuss the coacervate nature of cells and dwell upon the ways and contexts in which various radiations (either incident or endogenously generated) could interact in the new scheme of cellular function. Presenting comparative evidence/arguments and listing of systems with murburn models, we argue that the new perceptions explain life processes better and urge the community to urgently adopt murburn bioenergetics and adapt to its views. Further, we touch upon some distinct scientific and sociological contexts with respect to the outreach of murburn concept. It is envisaged that greater awareness of murburn could enhance the longevity and quality of life and afford better approaches to therapies. Full article

Background: The aim of this review is to summarize and evaluate the properties of antibacterial polysaccharides for application in dental implantology to identify knowledge gaps and provide new research ideas. Methods: The electronic databases PubMed, Medline, ProQuest, and Google Scholar were used to search for peer-reviewed scientific publications published between 2018 and 2025 that provide insights to answer research questions on the role of antibacterial polysaccharides in combating pathogens in dental implantology without triggering immune reactions and inflammation. Further research questions relate to the efficacy against various dental pathogens and the understanding of the antibacterial mechanism, which may enable the development of functionalized polysaccharides with long-term antibacterial activity. Results: Biomedical implants have revolutionized medicine but also increased the risk of infections. Implant infections are a major problem in implantology and lead to implant failure and replacement. An antibacterial coating could be an excellent strategy to extend the lifespan of implants and improve the quality of the patient’s life. Bacterial resistance to antibiotics poses significant challenges for researchers, forcing them to search for new ways to prevent bacterial infections in implantology. Antibacterial natural polymers have recently received considerable research attention due to their long-term antibacterial activity. Polysaccharides from marine sources, such as chitosan and alginate, or pectin, xanthan, etc., from various plants, appear to be promising biopolymers for such applications in implantology due to their antibacterial activity, biocompatibility, and osteogenic properties. The antibacterial activity of these natural biopolymers depends on their chemical and physical properties. Nanopolysaccharides exhibit higher antibacterial activity than conventional polysaccharides, but their toxicity to human cells must be considered. Their antibacterial activity is based on the disruption of bacterial DNA or RNA synthesis, increased cell wall permeability, membrane disruption, and cytoplasmic leakage. Conclusions: Polysaccharides are a class of natural polymers with a broad spectrum of biological activities. They exhibit antioxidant, immunomodulatory, anticoagulant, anticancer, anti-inflammatory, antibacterial, and antiviral activity. Furthermore, polysaccharides are non-cytotoxic and exhibit good biocompatibility with osteogenic cells. Bactericidal polysaccharides are attractive new antibacterial materials against implant infections and open up new perspectives in implantology. Full article

Bisphenol A (BPA), a prevalent endocrine-disrupting chemical, is widely found in various consumer products and poses significant health risks, particularly through hormone receptor interactions, oxidative stress, and mitochondrial dysfunction. BPA exposure is associated with reproductive, metabolic, and neurodevelopmental disorders. Melatonin, a neurohormone with strong antioxidant and anti-inflammatory properties, has emerged as a potential therapeutic agent to counteract the toxic effects of BPA. This review consolidates recent findings from in vitro and animal/preclinical studies, highlighting melatonin’s protective mechanisms against BPA-induced toxicity. These include its capacity to reduce oxidative stress, restore mitochondrial function, modulate inflammatory responses, and protect against DNA damage. In animal models, melatonin also mitigates reproductive toxicity, enhances fertility parameters, and reduces histopathological damage. Melatonin’s ability to regulate endoplasmic reticulum (ER) stress and cell death pathways underscores its multifaceted protective role. Despite promising preclinical results, human clinical trials are needed to validate these findings and establish optimal dosages, treatment durations, and safety profiles. This review discusses the wide range of potential uses of melatonin for treating BPA toxicity and suggests directions for future research. Full article

As typical environmental hormones, endocrine-disrupting chemicals (EDCs) have become a global environmental health issue of high concern due to their property of interfering with the endocrine systems of organisms. As a commonly used substitute for bisphenol A (BPA), bisphenol E (BPE) has been frequently detected in environmental matrices such as soil and water in recent years. Existing research has unveiled the developmental and reproductive toxicity of BPE; however, only one in vitro cellular experiment has preliminarily indicated potential neurotoxic risks, with its underlying mechanisms remaining largely unelucidated in the current literature. Potential toxic mechanisms and action targets of BPE were predicted using the zebrafish model via network toxicology and molecular docking, with RT-qPCRs being simultaneously applied to uncover neurotoxic effects and associated mechanisms of BPE. A significant decrease (p < 0.05) in the frequency of embryonic spontaneous movements was observed in zebrafish at exposure concentrations ≥ 0.01 mg/L. At 72 hpf and 144 hpf, the larval body length began to shorten significantly from 0.1 mg/L to 1 mg/L, respectively (p < 0.01), accompanied by a reduced neuronal fluorescence intensity and a shortened neural axon length (p < 0.01). By 144 hpf, the motor behavior in zebrafish larvae was inhibited. Through network toxicology and molecular docking, HSP90AB1 was identified as the core target, with the cGMP/PKG signaling pathway determined to be the primary route through which BPE induces neurotoxicity in zebrafish larvae. BPE induces neuronal apoptosis and disrupts neurodevelopment by inhibiting the cGMP/PKG signaling pathway, ultimately suppressing the larval motor behavior. To further validate the experimental outcomes, we measured the expression levels of genes associated with neurodevelopment (elavl3, mbp, gap43, syn2a), serotonergic synaptic signaling (5-ht1ar, 5-ht2ar), the cGMP/PKG pathway (nos3), and apoptosis (caspase-3, caspase-9). These results offer crucial theoretical underpinnings for evaluating the ecological risks of BPE and developing environmental management plans, as well as crucial evidence for a thorough comprehension of the toxic effects and mechanisms of BPE on neurodevelopment in zebrafish larvae. Full article

Phosphogypsum, a byproduct of orthophosphoric acid production, is one of the large-tonnage wastes. Since phosphogypsum mainly consists of CaSO₄ 2H₂O, it can be considered as an alternative gypsum-bearing raw material in the production of gypsum binders. However, its features, such as particle morphology and the presence of impurities, can negatively affect the characteristics of phosphogypsum-based binders. Identification of these factors will allow us to develop methods for their minimization and increasing the efficiency of phosphogypsum use from the required source as a raw material for the production of phosphogypsum-based binders. In this regard, the manuscript contains a comprehensive and comparative analysis of phosphogypsum and natural gypsum, which makes it possible to establish their differences in chemical composition and structural and morphological features, which subsequently affect the properties of the phosphogypsum-based binder. It has been established that the key factor negatively affecting the strength of phosphogypsum-based paste (2.58 MPa) is its high water demand (0.89), which is due to the high values of the specific surface area of the particles and the presence of a large number of conglomerates with significant porosity in phosphogypsum. It has been suggested that preliminary grinding of phosphogypsum can help reduce the amount of water required to obtain fresh phosphogypsum-based paste with a standard consistency and improve its physical and mechanical properties. Full article

Nudibranchs have garnered increasing interest in biomedical research due to their complex chemical defense mechanisms, many of which are derived from their diet, including sponges, cnidarians, tunicates, and algae. Their remarkable ability to sequester dietary toxins and synthesize secondary metabolites positions them as a promising source of biologically active compounds with potential therapeutic applications, particularly in oncology. This study aimed to review and summarize the available literature on the bioactive potential of nudibranch-derived compounds, focusing mainly on their antitumor properties. Although research in this area is still limited, recent studies have identified alkaloids and terpenoids isolated from species such as Dolabella auricularia, Jorunna funebris, Dendrodoris fumata, and members of the genus Phyllidia. These compounds exhibit notable cytotoxic activity against human cancer cell lines, including those from colon (HCT-116, HT-29, SW-480), lung (A549), and breast (MCF7) cancer. These findings suggest that compounds derived from nudibranchs could serve as scaffolds for the development of more effective and selective anticancer therapies. In conclusion, nudibranchs represent a valuable yet underexplored resource for antitumor drug discovery, with significant potential to contribute to the development of novel cancer treatments. Full article

This study analyzes the durability of brick-faced clay-core walls (BCWs) in the traditional residential architecture of Quanzhou—a UNESCO World Heritage City. Taking the northern gable of Ding Gongchen’s former residence as an example, the mechanical properties, microscopic structure, and changes in chemical symbol, oxides and minerals of the red bricks and clay-cores were analyzed using finite element mechanics analysis (FEM), scanning electron microscopy (SEM), X-ray fluorescence (XRF), and X-ray diffraction (XRD). The results indicate a triple mechanism: (1) The collaborative protection and reinforcement mechanism of “brick-wrapped-clay”. (2) The infiltration and destruction mechanism of external pollutants. (3) The material stability mechanism of silicate minerals. Therefore, the key to maintaining the durability of BCWs lies in the synergistic effect of brick and clay materials and the stability of silicate mineral materials, providing theoretical and methodological support for sustainable research into brick and clay constructions. Full article

The Maillard reaction refers to the reaction between carbonyl compounds with reducing properties and amino-containing compounds that undergo condensation and polymerization to produce melanoidins. In flour product processing, the Maillard reaction is a critical chemical reaction influencing color, flavor, nutrition, and safety. A moderate Maillard reaction contributes to desirable color and flavor profiles in flour products, whereas an excessive reaction leads to amino acid loss and the formation of harmful substances, posing potential health risks. This review summarizes the substrate sources, reaction stages, influencing factors, impact on quality, and mitigation strategies of harmful products, aiming to provide a reference for regulating the Maillard reaction in flour product processing. Currently, most existing mitigation strategies focus on inhibiting harmful products, while research on the synergistic optimization of color and flavor remains insufficient. Future research should focus on elucidating the molecular mechanisms of reaction pathways, understanding multi-factor synergistic effects, and developing composite regulation technologies to balance the sensory quality and safety of flour products. Full article

Titanium alloys such as Ti-6Al-4V are widely used in biomedical implants due to their excellent mechanical properties and biocompatibility, but their bioinert nature limits osseointegration and antibacterial performance. This study proposes a multifunctional surface coating system integrating a thermally oxidized TiO₂ interlayer with a hydroxyapatite (HAp) top layer synthesized via a green route using Hylocereus undatus extract. The HAp was deposited by electrophoretic deposition (EPD), enabling continuous coverage and strong adhesion to the pre-treated Ti-6Al-4V substrate. Structural, morphological, chemical, and electrical characterizations were performed using XRD, SEM, EDS, Raman spectroscopy, and impedance spectroscopy. Bioactivity was assessed through apatite formation in simulated body fluid (SBF), while antibacterial properties were evaluated against Staphylococcus aureus. The results demonstrated successful formation of crystalline TiO₂ (rutile phase) and calcium-rich HAp with good surface coverage. The HAp-coated surfaces exhibited significantly enhanced bioactivity and strong antibacterial performance, likely due to the combined effects of surface roughness and the bioactive compounds present in the plant extract. This study highlights the potential of eco-friendly, bio-inspired surface engineering to improve the biological performance of titanium-based implants. Full article

Metal–Organic Frameworks (MOFs) have emerged as advanced porous crystalline materials due to their highly ordered structures, ultra-high surface areas, fine-tunable pore sizes, and massive chemical diversity. These features, arising from the coordination between an almost unlimited number of metal ions/clusters and organic linkers, have resulted in significant interest in MOFs for applications in gas storage, catalysis, sensing, energy, and biomedicine. Beyond their stand-alone properties and applications, recent research has increasingly explored the integration of MOFs with other substrates, particularly electrodes, polymeric thin films, and glass surfaces, to create synergistic effects that enhance material performance and broaden application potential. Coating MOFs onto these substrates can yield significant benefits, including, but not limited to, improved sensitivity and selectivity in electrochemical sensors, enhanced mechanical and separation properties in membranes, and multifunctional coatings for optical and environmental applications. This review provides a comprehensive and up-to-date summary of recent advances (primarily from the past 3–5 years) in MOF coating techniques, including layer-by-layer assembly, in situ growth, and electrochemical deposition. This is followed by a discussion of the representative applications arising from MOF-substrate coating and an outline of key challenges and future directions in this rapidly evolving field. This article aims to serve as a focused reference point for researchers interested in both fundamental strategies and applied developments in MOF surface coatings. Full article

In this paper, SiC and Si/SiC ceramics were fabricated using direct laser powder bed fusion with chemical vapor infiltration. Their microstructure, mechanical properties and the impacts of silicon addition were analyzed. The incorporation of silicon led to an increase in the relative density of the silicon carbide ceramics from 76.4% to 78.3% and the compression strength increased from 39 ± 13 MPa to 90 ± 8 MPa after laser powder bed fusion with chemical vapor infiltration. The melting and re-solidification of silicon allows the silicon to encapsulate the silicon carbide grains, changing the microstructure and the failure mechanism of the silicon carbide ceramics, resulting in a small amount of silicon residue. In the LPBF-CVI SiC ceramic specimen, the LPBF-formed SiC exhibits a microhardness of 24.2 ± 1.0 GPa. In LPBF-CVI Si/SiC, the spherical dual-phase structure displays a moderately increased hardness (25.9 ± 4.4 GPa), and the CVI-formed SiC exhibits a hardness of 55.3 ± 9.3 GPa. Full article

Lotus (Nelumbo nucifera Gaertn.) is a quintessential medicinal and edible plant, exhibiting marked differences in therapeutic effects among its various parts. The lotus seed constitutes a key component of this plant. Notably, the entire seed and the plumule display distinct medicinal properties. To investigate the “homologous plants with different effects” phenomenon in traditional Chinese medicine, this study established a Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging (MALDI-MSI) method. This study employed immature lotus seeds as the experimental material, diverging from the mature seeds conventionally used. Conductive double-sided tape was employed for sample preparation, and complete longitudinal sections of the seeds were obtained, followed by MALDI-MSI analysis to identify and visualize the spatial distribution of characteristic secondary metabolites within the entire seeds. The results unveiled the diversity of metabolites in lotus seeds and their differential distribution across tissues, with pronounced distinctions in the plumule. A total of 152 metabolites spanning 13 categories were identified in lotus seeds, with 134, 89, 51, and 98 metabolites discerned in the pericarp, seed coat, cotyledon, and plumule, respectively. Strikingly, young lotus seeds were devoid of liensinine/isoliensinine and neferine, the dominant alkaloids of mature lotus seed plumule, revealing an early-stage alkaloid profile that sharply contrasts with the well-documented abundance found in mature seeds and has rarely been reported. We further propose a biosynthetic pathway to explain the presence of the detected benzylisoquinoline and the absence of the undetected bisbenzylisoquinoline alkaloids in this study. These findings present the first comprehensive metabolic atlas of immature lotus seeds, systematically exposing the pronounced chemical divergence from their mature counterparts, and thus lays a metabolomic foundation for dissecting the spatiotemporal mechanisms underlying the nutritional and medicinal value of lotus seeds. Full article

The use of radiosensitizers is a beneficial approach in cancer radiotherapy treatment. However, the enhancement of radiation effects on cancer cells by radiosensitizers involves several different mechanisms, reflecting the chemical nature of the radiosensitizer. G-quadruplex (G4) DNA ligands have emerged in recent years as a potential new class of radiosensitizers binding to specific DNA sequences. Recently, we have shown that the Re(I) tricarbonyl complex PDF-Pz-Re and its pyrazolyl-diamine chelator PDF-Pz, carrying a N-methylated pyridostatin (PDF) derivative, act as G4 binders of various G4-forming DNA and RNA sequences. As described in this contribution, these features prompted us to evaluate PDF-Pz-Re and PDF-Pz as radiosensitizers of prostate cancer PC3 cells submitted to concomitant treatment with Co-60 radiation. The compound RHPS4 was also tested, as this G4 ligand was previously shown to exhibit strong radiosensitizing properties in other cancer cell lines. The assessment of the resulting radiobiological effects, namely through clonogenic cell survival, DNA damage, and ROS production assays, showed that PDF-Pz-Re and PDF-Pz were able to radiosensitize PC3 cells despite being less active than RHPS4. Our results corroborate that G4 DNA ligands are a class of compounds with potential interest as radiosensitizers, deserving further studies to optimize their radiosensitization activity and elucidate the mechanisms of action. Full article