Search Results (34)

The Group-1 carcinogen Helicobacter pylori (H. pylori) secretes the serine protease high-temperature requirement A (HtrA), which is directly involved in the disruption of the epithelial barrier in the stomach. HtrA cleaves the extracellular domains of junctional proteins, including E-cadherin (CDH1), claudin-8, occludin, or desmoglein-2, to open intercellular adhesions, allowing H. pylori to transmigrate to subepithelial regions of the gastric mucosa. In our previous work, we found that Zn²⁺ and Cu²⁺ ions efficiently blocked the HtrA activity. However, the impact of other divalent ions on HtrA activity is rather unknown. In this report, we unexpectedly found a stimulating effect through Mn²⁺, Ni²⁺ and Co²⁺ ions on HtrA oligomerization and activity. In contrast to other tested ions, increasing concentrations of Mn²⁺, Ni²⁺ and Co²⁺ strongly enhanced HtrA multimerization as determined in SDS-PAGE under non-reducing conditions and in casein zymography. Increased proteolytic activity of HtrA was further assessed in in vitro cleavage experiments using casein and CDH1 as substrates. Mechanistically, divalent ions bound to HtrA and induced an active conformation, which strongly increased CDH1 cleavage in vitro. The importance of enhanced HtrA activity was finally underlined by the analysis of CDH1 cleavage in H. pylori infection experiments, showing that Ni²⁺ potentiated HtrA-mediated CDH1 shedding. In summary, this study demonstrates that divalent ions exhibit different effects on HtrA activity and that Ni²⁺ and Co²⁺ enhance proteolytic activity by promoting oligomerization, suggesting that metal availability in the gastric environment affects H. pylori virulence. Full article

The effective use of natural casein-based adhesives requires the reduction of shrinkage phenomena associated with the evaporation of water, which is largely used for preparation. After the procedure optimization of a casein natural glue by aid of an alkaline solution, it was modified by the addition of two different sugars with long and short chains—chitosan and dextrose, respectively—at different weight concentration levels to absorb and retain water. The thermal decomposition and degradation kinetics of prepared sugar-based casein glues have been analyzed by performing thermogravimetric TGA characterization at different heating rates. Experimental results and the evaluation of thermal degradation activation energy by Kissinger analysis evidenced that the chitosan and dextrose could be efficient and sustainable additives to control and mitigate the degradation mechanisms of casein glues. Further, vertical flammability tests (UL 94 standards) on the sugar-modified casein materials with the highest sugar content confirmed the positive effect of chitosan and dextrose addition under flame exposure too. Full article

Water-based (meth)acrylic (co)polymer dispersions are produced on a large scale for various applications including coatings, adhesives, paints, and construction materials. A major benefit of waterborne polymer dispersions as compared to more traditional solvent-based alternatives is the low volatile organic compound (VOC) content, which results in an improved environmental profile. Following the trend of sustainability that has driven the growth of acrylic dispersions, recent research has focused on further enhancing the properties of these products by incorporating biobased materials such as polysaccharides (e.g., cellulose, starch, chitin, and chitosan), and proteins (e.g., casein, soy protein, and collagen). Amongst a large number of benefits, the incorporation of biomaterials can serve to decrease the amount of petroleum-based polymers in the formulation and can also contribute to enhance the physical properties of the resulting bio-composites. In this review, the beneficial role of these biopolymers when combined with waterborne acrylic systems is summarized. Recent advances in the use of these biobased and biodegradable materials are covered, aiming to provide guidance for the development of more sustainable, high-performance latex-based bio-composites with minimal environmental impact. Full article

The aim of this study was to develop a chilled, texture-modified salmon product for dysphagia patients, enriched with dairy and fish hydrolysate proteins. The challenge was to create a product with appealing sensory qualities and texture that meets level 5 (minced & moist) of the IDDSI framework. Atlantic salmon (Salmo salar) was heat-treated (95 °C/15 min), blended, and reconstructed by adding texture modifiers, casein and whey protein, and enzymatically derived fish hydrolysate. The products were packaged in oxygen-free plastic trays, heat-treated to a core temperature of 95 °C for 15 min, chilled and stored at 4 °C for 29 days and analyzed for microbiology, instrumental texture, and sensory properties. The texture analyses showed that products with fish protein hydrolysate were softer than those only with casein and whey protein, a result also confirmed by the IDDSI fork pressure test. Quantitative descriptive analysis of salmon products revealed significant differences (p < 0.05) in sensory attributes within flavour (fish flavour), and texture (softness and adhesiveness) but there was no significant change in bitterness. The shelf-life study at 4 °C showed good microbiological quality of the product, and safety after 29 days with appealing sensory and textural properties, i.e., a product at IDDSI level 5 for age care facilities and commercial production was obtained. Full article

This study investigates the rheological behavior of cellulose microfiber suspensions derived from kahili ginger stems (Hedychium gardnerianum), an invasive species, in two adhesive matrices: a commercial water-based adhesive (Coplaseal^®) and a casein-based adhesive made from non-food-grade milk, referred to as K and S samples, respectively. Rheological analyses were performed using oscillatory and rotational shear tests conducted at 25 °C, 50 °C, and 75 °C to assess the materials’ viscoelastic properties more comprehensively. Oscillatory tests across a frequency range of 1–100 rad/s assessed the storage modulus (G′) and loss modulus (G″), while rotational shear tests evaluated apparent viscosity and shear stress across shear rates from 0.1 to 1000 s⁻¹. Fiber-free samples consistently showed lower moduli than fiber-containing samples at all frequencies. The incorporation of fibers increased the dynamic moduli in both K and S samples, with a quasi-plateau observed at lower frequencies, suggesting solid-like behavior. This trend was consistent in all tested temperatures. As frequencies increased, the fiber network was disrupted, transitioning the samples to fluid-like behavior, with a marked increase in G′ and G″. This transition was more pronounced in K samples, especially above 10 rad/s at 25 °C and 50 °C, but less evident at 75 °C. This shift from solid-like to fluid-like behavior reflects the transition from percolation effects at low frequencies to matrix-dominated responses at high frequencies. In contrast, S samples displayed a wider frequency range for the quasi-plateau, with less pronounced moduli changes at higher frequencies. At 75 °C, the moduli of fiber-containing and fiber-free S samples nearly converged at higher frequencies, indicating similar effects of the fiber and matrix components. Both fiber-reinforced and non-reinforced suspensions exhibited pseudoplastic (shear-thinning) behavior. Fiber-containing samples exhibited higher initial viscosity, with K samples displaying greater differences between fiber-reinforced and non-reinforced systems compared to S samples, where the gap was narrower. Interestingly, S samples exhibited overall higher viscosity than K samples, implying a reduced influence of fibers on the viscosity in the S matrix. This preliminary study highlights the complex interactions between cellulosic fiber networks, adhesive matrices, and rheological conditions. The findings provide a foundation for optimizing the development of sustainable biocomposites, particularly in applications requiring precise tuning of rheological properties. Full article

Background: This study looks at the clinical applications of nanotechnology in dentistry, with an emphasis on implantology, preventive care, orthodontics, restorative dentistry, and endodontics. Methods: Following PRISMA criteria and registered in PROSPERO (ID: CRD 564245), a PubMed, Scopus, and Web of Science search was conducted for studies from January 2014 to April 2024. The criteria were English-language research on nanotechnology in dental coatings, with a focus on clinical trials and observational studies. The electronic database search yielded 8881 publications. Following the screening process, 17 records were selected for qualitative analysis. Results: Nanotechnology has revolutionized dentistry. In orthodontics, nanoparticles improve antibacterial characteristics, durability, and biocompatibility, lowering bacterial colonization and plaque. In preventative care, Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) combined with stannous fluoride (SnF₂) and nano-sized sodium trimetaphosphate (TMPnano) substantially remineralizes enamel. Nanostructured surfaces in dental implants, particularly those containing calcium, improve osseointegration and stability. Nanoparticles in restorative dentistry improve composite and adhesive strength, aesthetics, and longevity. Conclusions: Nanotechnology improves dental materials and equipment, resulting in better treatment outcomes and increased patient comfort. Its integration provides more effective treatments, which improves dental care and patient outcomes. More research is needed to overcome present problems and expand nanotechnology’s medicinal applications. Full article

A single-nucleotide polymorphism (SNP) is a genome-level trait that arises from a variation in a single nucleotide, leading to diversity in DNA sequences. SNP screening is commonly used to provide candidate genes for yak breeding efforts. Integrin Subunit Alpha 9 (ITGA9) is an integrin protein. It plays an important role in cell adhesion, signalling, and other processes. The aim of this study was to discuss the association between genetic polymorphisms in the ITGA9 gene and milk quality traits and to identify potential molecular marker loci for yak breeding quality. We genotyped 162 yaks using an Illumina Yak cGPS 7K liquid chip and identified the presence of polymorphisms at nine SNP loci in the ITGA9 gene of yaks. The results showed that the mutant genotypes in the loci g.285,808T>A, g.306,600T>C, and g.315,413C>T were positively correlated with the contents of casein, protein, total solids (TS), and solid nonfat (SNF) in yak milk. In other loci, heterozygous genotypes had a positive correlation with nutrient content in yak milk. Then, two ITGA9 haplotype blocks were constructed based on linkage disequilibrium, which facilitated a more accurate screening of ITGA9 as a candidate gene for yak milk quality improvement. In conclusion, we identified SNPs and haplotype blocks related to yak milk quality traits and provided genetic resources for marker-assisted selection in yak breeding. Full article

Dentine adhesives have demonstrated great success with permanent teeth. Though the results in primary teeth are not well documented, some studies have demonstrated lower values of bond strength in primary teeth than those found in permanent teeth. The aim of this study was to compare and evaluate the effect of grape seed extract (6.5%) (Herbal Bio Solutions, Delhi, India), glutaraldehyde (5%) (Loba Chemie PVT. LTD., Mumbai), hesperidin (0.5%) (Herbal Bio Solutions, Delhi, India), and casein phosphopeptide-amorphous calcium phosphate (tooth mousse) (GC Corporation, Alsip, IL, USA) on the shear bond strength of dentine of primary teeth and to evaluate the resin tags at the resin tooth interface. Seventy-five caries-free human primary molars were collected, and their occlusal surfaces were ground flat. Dentin surfaces were etched using phosphoric acid. Then teeth were randomly assigned in sequential order to five groups according to the dentinal treatment method: Group I (Control group) (no treatment), Group II (5% glutaraldehyde), Group III (6.5% grape seed extract), Group IV (0.5% hesperidin), and Group V (CPP-ACP). Ten teeth from each group were assigned for Shear Bond Strength and five for SEM analysis. ANOVA and a post hoc least significant difference test (p < 0.05) were used for statistical analysis of the collected data. The grape seed extract group showed significantly increased shear bond strength than the control group (p < 0.05), and the mean length of resin tags in different dentine bio modifiers groups was also statistically significant (p < 0.05). The use of dentin bio modifiers such as 5% glutaraldehyde, 6.5% grape seed extract, 0.5% hesperidin, and CPP-ACP in the bonding process for primary teeth did not improve the dentinal bond strength. Full article

Irritable bowel syndrome (IBS) is a common gastrointestinal disorder that affects 10–15% of the global population and presents symptoms such as abdominal discomfort, bloating and altered bowel habits. IBS is believed to be influenced by gut microbiota alterations and low-grade inflammation. Bovine kappa-casein glycomacropeptide (GMP), a bioactive dairy-derived peptide, possesses anti-adhesive, prebiotic and immunomodulatory properties that could potentially benefit IBS patients. This pilot study investigated the effects of daily supplementation with 30 g of GMP for three weeks on gut health in five people with IBS. We assessed alterations in gut microbiota composition, fecal and blood inflammatory makers, and gut-related symptoms before, during and after the GMP feeding period. The results revealed no changes in fecal microbiota, subtle effects on systemic and intestinal immune makers, and no changes in gut-related symptoms during and after the GMP supplementation. Further research is needed to assess the potential benefits of GMP in IBS patients, including the examination of dosage and form of GMP supplementation. Full article

Based on the background of the limited availability of raw materials in the forestry and timber industry, increased attention applies to sawmill by-products and their potential for future applications. Within the present research, the suitability of a natural binder based on different casein sources, superficially lean curd with different lime ratios, for the production of bark insulation panels from larch bark (Larix decidua) in fraction 12.5–4.0 mm with densities below 500 kg/m³ were discussed and physical and mechanical properties evaluated. In order to obtain a benchmark, control boards bound with powdery casein and urea-formaldehyde resin were fabricated. The evaluation of physical-mechanical characteristics indicated the lean curd panels to be competitive with the references and commercially available insulation materials, whereby higher values could be achieved consistently with a lower lime content of 20% compared to 31%. The best moisture resistance and water absorption were observed with a lime ratio of 31%, whilst thickness swelling and mechanical characteristics were best with a lime content of 20%. Particularly with regard to mechanical properties, panels containing a low proportion of lime in the lean curd blends delivered convincing results, e.g., with an average IB of 0.19 N/mm², MOR of 1.43 N/mm² and C of 1.70 N/mm². In terms of thickness swelling, lean curd adhesives generated unsurpassed values of approximately 11% compared to the casein and urea-formaldehyde references. Additionally, as described in the relevant literature, a considerable influence of density on the mechanical behavior of composite materials was observed. Partly, the lime content significantly influenced the panel properties. The study proved that natural binders based on lean curd and lime are suitable for the production of bark insulation boards and represent a serious alternative to synthetic, oil-based adhesive systems. The results are promising with regard to the market situation due to the availability and pricing of raw materials and technical requirements and demonstrated great potential for further research efforts. Full article

Degradation of the collagen fibrils at the dentin–resin interface by the enzymatic activity of matrix metalloproteinases (MMPs) has been known to permit some dental restoration complications, such as microleakage, secondary caries, and, ultimately, restoration failures. This study aimed to evaluate a modified adhesive by adding an MMP inhibitor from green tea extract with and without nanotube encapsulation to sustain the drug release. Epigallocatechin-3-gallate (EGCG) and Halloysite nanotubes (HNTs) were prepared to produce three variant combinations of modified adhesive (EGCG, EGCG-encapsulated HNT, and EGCG-free HNT). The drug loading efficiency and EGCG release over time were evaluated using UV-vis spectrometry. MMP-mediated β-casein (BCN) cleavage rate assays were used to determine the ability of the EGCG in eluates of the adhesive to inhibit MMP-9 activities. For up to 8 weeks, HNT encapsulation reduced release to a statistically significant level. MMP-mediated β-casein cleavage rate assays showed a significant decrease for the EGCG groups compared to the non-EGCG adhesive groups. Furthermore, the use of HNT for EGCG encapsulation to modify a dental adhesive helped slow down the rate of EGCG release without impacting its MMP inhibitory capabilities, which may help to maintain the dentin–resin interface’s integrity over the long term after dental restoration placement. Full article

The purpose of this study was to compare four activation solutions (AS)—Woynarovich, Lahnsteiner, Kucharczyk, and Perchec—with the addition of 0.5% bovine serum albumin (BSA) for ide (Leuciscus idus) sperm activation and analysis with a CASA system. It was found that ide sperm can be activated using each AS within a pH range of 7.4–9.0 and an osmolality range of 160–200 mOsm kg⁻¹. The effect of Woynarovich and Perchec solutions supplemented with BSA and casein at concentrations of 0.25, 0.5, 1.0, and 2.0% were also analyzed during the experiment. These two AS without protein supplementation (pure solutions) were the controls. Woynarovich and Perchec solutions supplemented with the minimum BSA concentration (i.e., 0.25%) significantly improved sperm motility (89.05% and 86.63%, respectively) compared to the controls (20.39 and 28.48%, respectively). Similar increases were also noted in progressively motile sperm (PRG, %), the curvilinear velocity of sperm (VCL, µm s⁻¹), and the amplitude of lateral head displacement (ALH, µm). A similar trend in CASA parameters was also noted when casein was added to Woynarovich and Perchec solutions at a concentration of 0.25%. We concluded that 0.25% doses of each of the proteins were sufficient to prevent sperm adhesion to glass slides, and they can be used in research on ide sperm motility measurements. Full article

Effects of two high pressure processing treatments and various levels of konjac glucomannan (KGM) and sodium caseinate (SC) on texture properties, water-holding capacity, and ultra-structure of gels of rabbit myosin protein were investigated. The two high pressure processing treatments were as follows: (1) mean pressure (200 MPa), low temperature (37 °C), and holding for a short time (5 min) followed heating (80 °C for 40 min) (gel LP + H), and (2) high pressure (500 MPa), high temperature (60 °C), and holding for a long time (30 min) (gel HP). Gel LP + H have better gel properties (increased hardness, springiness, gumminess, adhesiveness, cohesiveness, and water binding capacity) than gels HP. Above all, gels myosin + SC:KGM (2:1) have best gel properties. KGM and SC both significantly improved the gel texture properties and water binding capacity. Full article

A considerable body of work has studied the involvement of osteopontin (OPN) in human physiology and pathology, but comparably little is known about the interaction of OPN with prokaryotic cells. Recently, bovine milk OPN has been proposed as a therapeutic agent to prevent the build-up of dental biofilms, which are responsible for the development of caries lesions. Bioactive milk proteins are among the most exciting resources for caries control, as they hamper bacterial attachment to teeth without affecting microbial homeostasis in the mouth. The present work investigated the ability of OPN to prevent the adhesion of three dental biofilm-forming bacteria to saliva-coated surfaces under shear-controlled flow conditions in comparison with the major milk proteins α-lactalbumin, β-lactoglobulin, αs1-casein, β-casein and κ-casein, as well as crude milk protein. OPN was the most effective single protein to reduce the adhesion of Actinomyces naeslundii, Lactobacillus paracasei subsp. paracasei and Streptococcus mitis. β-casein and crude milk protein also had a pronounced effect on all three species, which suggests binding to different microbial surface structures rather than the blocking of a specific bacterial adhesin. Bioactive milk proteins show potential to delay harmful biofilm formation on teeth and hence the onset of biofilm-related oral disease. Full article

Sustainable coating solutions that function as a fire retardant for wood are still a challenging topic for the academic and industrial sectors. In this study, composite coatings of casein protein mixed with mica and aluminum trihydroxide (ATH) were tested as fire retardants for wood and plywood; coating degradation and fire retardancy performance were assessed with a cone calorimeter, and a thermogravimeter was used for the thermal stability measurement. The results indicated that casein–mica composites were beneficial as coatings. The heat release rate (HRR) and the total heat released (THR) of the sample coated with casein–mica composite were reduced by 55% and 37%, respectively; the time to ignition was increased by 27% compared to the untreated sample. However, the TTI of the sample coated with the casein–mica–ATH composite was increased by 156%; the PHR and THR were reduced by 31% and 28%, respectively. This is attributed to the yielded insulating surface layer, active catalytic sites, and the crosslink from mica and endothermic decomposition of ATH and casein producing different fragments which create multiple modes of action, leading to significant roles in suppressing fire spread. The multiple modes of action involved in the prepared composites are presented in detail. Coating wear resistance was investigated using a Taber Abrader, and adhesion interaction between wood and a coated composite were investigated by applying a pull-off test. While the addition of the three filler types to casein caused a decrease in the pull-off adhesion strength by up to 38%, their abrasion resistance was greatly increased by as much as 80%. Full article