Search Results (7,902)

In this study, polylactic acid (PLA) was blended with poly(ε-caprolactone) (PCL) and reinforced with nanosilica (SiO₂) to tailor surface characteristics and improve adhesion in biopolymer-based printed packaging applications. The surface microstructure and topography were analyzed using FTIR-ATR, SEM, and surface profilometry. Surface wettability and surface free energy (SFE), along with the adhesion properties of printed ink layers on polymer blends, were assessed, and the optical properties of the substrates and prints were evaluated. SEM revealed that PLA/PCL blends exhibited phase-separated morphologies with PCL droplet domains, whereas incorporation of 3 wt% SiO₂ resulted in finer dispersion and reduced surface irregularities. Surface roughness (Ra) increased from 1.92 µm for PLA/SiO₂ 100/3 to 4.45 µm for PLA/PCL/SiO2 50/50/0, while water contact angle decreased from 70.9° for neat PLA to 43.4° for PLA/SiO₂ 100/3 surface, reflecting enhanced hydrophilicity. SFE components ranged from 26 to 40.7 mJ/m² (dispersive) and 3.2 to 21.5 mJ/m² (polar). Adhesion parameters (interfacial tension ranging from 0.01 to 5.54 mJ/m², work of adhesion from 76.9 to 97.3 mJ/m², and wetting coefficient from 3.04 to 11.1 mJ/m²) indicated favorable ink compatibility for most blends, and optical density of the printed layers (1.85–2.35) confirmed potential for good printability. These findings demonstrate that PLA/PCL/SiO₂ blends allow controlled tuning of surface morphology, wettability, and adhesion, providing a promising approach for biodegradable and print-ready packaging substrates. Full article

This study addresses the limited adsorption efficiency of traditional vacuum suction cups used in applications such as unmanned aerial vehicles (UAVs) and robotic systems. Inspired by the adhesion mechanism of the abalone muscular foot, we propose a novel suction cup design. The design incorporates optimization of the groove geometry, groove distribution, and the positioning of the sealing ring. To assess the mechanical performance of these designs, finite element analysis (FEA) is employed. A prototype exhibiting the most promising simulation results is fabricated and subjected to tensile testing. The experimental results show strong agreement with the simulation outcomes, thereby validating the accuracy and reliability of the FEA. The biomimetic suction cup demonstrates superior adsorption performance compared to the baseline design. Specifically, the maximum von Mises stress is reduced by 5.9%, the maximum pressure is increased by 498%, and the maximum frictional stress rises by 498%. Moreover, the maximum sliding distance is reduced by 38%, while the maximum total circumferential deformation is increased by 21%. This innovative design enhances the stress distribution across the bottom surface of the suction cup, mitigates inward edge contraction, and delays the communication between the inner cavity and the external environment, thereby improving the overall adsorption efficiency of the suction cup. Full article

Insect hemocytic cell lines offer substantial advantages over primary, in vivo hemocyte cultures, fundamentally transforming experimental approaches in cellular immunology and related fields. Selected Malacosoma disstria cell lines were characterized for optimal growth temperatures, morphogenesis, blebbing, extracellular enzyme profiles, and their interactions with material (polystyrene) and microbial (Bacillus subtilis) surfaces. The adhesive hemocyte lines UA-Md221 and Md108 showed optimal growth at 28 °C, whereas UA-Md203 and Md66 grew best at 21 °C, with Md66 tolerating 21–28 °C. Md108 demonstrated a broader temperature tolerance than other adherent cultures. Both Md108 and UA-Md221 adhered to polystyrene within 24 h post-subculturing, although protease-induced morphological changes in modified Grace’s medium continued through 48 h and 72 h, respectively. Culture quality was monitored by assessing the release of multiple enzymes, including alkaline and acid phosphatases, esterases and lipases, aminopeptidases, proteases, glycosidases, and hydrolases from the cell lines at 50% confluency in modified Grace’s medium. Fetal bovine serum showed elevated esterase lipase (C8) and phosphoamidase activities when diluted in Grace’s medium and phosphate buffered saline (PBS). Exposure to dead B. subtilis suspended in PBS induced quantitative and qualitative alterations in the enzyme secretion profiles of Md66 and Md108 cultures. We conclude that semi-quantitative assessments of hemocytic cell lines can provide valuable insights for the time window of each enzyme release, revealing immune and metabolic signaling patterns. Full article

Pseudomonas fluorescens is a primary spoilage bacterium in aquatic products. Due to its strong ability to adhere to surfaces and form persistent biofilm, it poses a persistent challenge to food safety. Therefore, developing strategies to effectively inhibit biofilm formation holds significant research value. Dubosiella newyorkensis, a recently identified probiotic, has gained growing attention for its distinctive physiological features and potential functional benefits. Although various probiotic-derived cell-free supernatants (CFSs) have been explored for food preservation, the application of D. newyorkensis CFS against aquatic spoilage bacteria, and particularly its specific mechanism against P. fluorescens biofilm, has not been previously reported. Increasing evidence indicates that CFS from probiotic can influence microbial behavior, including biofilm development. In this study, we investigated the ability of D. newyorkensis CFS to inhibit P. fluorescens biofilm formation. The CFS treatment impaired bacterial growth and motility, lowered surface hydrophobicity, reduced self aggregation, and consequently hindered biofilm formation. Furthermore, CFS markedly decreased bacterial adhesion to food and contact surfaces. RT-qPCR analysis revealed that key genes associated with biofilm regulation were also significantly suppressed. Taken together, these results demonstrate that D. newyorkensis CFS exerts both antibacterial and antibiofilm effects against P. fluorescens. These findings provide a sound basis for exploring its application as a natural biopreservative to enhance the microbial safety and extend the shelf life of aquatic food products. Full article

Titanium-based implants are widely used in orthopedic and trauma surgery; however, postoperative infections remain a major cause of implant failure due to early bacterial adhesion. Localized antibiotic delivery from surface coatings offers a promising strategy to prevent initial colonization during the critical postoperative period. In this study, a self-organized TiO₂ nanotubular oxide layer was fabricated on Ti-407 by electrochemical anodization in a glycerol/NH₄F electrolyte at 40–60 V. SEM revealed vertically aligned single-walled nanotubes with diameters and lengths of ~80 nm and ~10 µm respectively. XPS analysis verified TiO₂ formation with Al–O, V–O, and fluorine incorporation. Ceftriaxone was successfully loaded into the nanotubular structure, as identified by FT-IR. UV–Vis measurements showed a biphasic release profile consisting of an initial burst followed by sustained release determined by nanotube geometry. In vitro antibacterial activity was evaluated against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli using optical density, CFU quantification, and an agar diffusion assay. Unloaded surfaces showed no inhibition, whereas ceftriaxone-loaded nanotubes significantly reduced bacterial growth up to ~6% and generated clear inhibition zones. These findings demonstrate, for the first time, that TiO₂ nanotubular coatings derived from Ti-407 support drug loading and demonstrate effective in vitro antibacterial activity, highlighting their potential for infection-resistant orthopedic implants. Full article

Mucins are high-molecular-weight glycoproteins that form the main structural component of the mucus covering epithelial surfaces in the gastrointestinal, respiratory, and urogenital tracts. They support epithelial integrity by protecting against microbial invasion, dehydration, and mechanical or chemical insults, while facilitating the transit of luminal contents. Beyond their structural function, mucins play key roles in molecular recognition. Their extensive glycosylation enables interactions with a wide range of molecules and allows the discrimination between pathogenic and commensal microorganisms at mucosal surfaces. Mucins help maintain mucosal homeostasis by preventing pathogen adhesion and colonization, while simultaneously providing nutrients to commensal species, supporting their stability, and maintaining spatial segregation from epithelial surfaces. Aberrant expression of mucin subtypes or alterations in their glycosylation patterns are associated with numerous diseases, including a wide spectrum of cancers and inflammatory disorders. The immunological relevance of the esophageal mucosa has only recently been recognized. Advances in the study of the esophageal mucosa-associated immune surveillance system and its interactions with structural components of this organ’s surface, including mucins, have shed light on unique pathological processes in the esophagus, such as Barrett’s esophagus, gastroesophageal reflux disease, and eosinophilic esophagitis. This review focuses on the role of esophageal mucins in inflammation, compiling current evidence to provide an integrated overview of mucin-driven inflammatory mechanisms. Full article

Peri-implantitis is an inflammatory disease caused by bacterial colonization that leads to progressive bone loss around dental implants. Implantoplasty is widely used for biofilm removal; however, it alters the titanium surface, generating particle release and impairing surface properties. This study evaluated whether a citric acid-based solution supplemented with collagen and magnesium cations could enhance hard and soft tissue regeneration following implantoplasty. Three surfaces were analyzed: physiological saline (Ctr), 25% citric acid (AC), and citric acid with collagen and magnesium nitrate hexahydrate (AC500/Mg). Surface roughness and wettability were assessed on titanium discs. Cytocompatibility, cell adhesion, and proliferation were evaluated using fibroblasts and osteoblasts up to 21 days, and mineralization was analyzed by alkaline phosphatase. In vivo studies were conducted in New Zealand rabbits with implants placed in the femur and muscle tissue. Surface roughness did not differ among treatments, while wettability significantly increased with citric acid-based solutions. All treatments showed good cytocompatibility. AC500/Mg significantly enhanced cell adhesion, proliferation, and osteoblast mineralization, showing threefold higher activity than controls at 21 days. In vivo, AC500/Mg exhibited greater bone contact (67%) and direct muscle integration, whereas AC and Ctr showed lower bone contact and fibrotic encapsulation. These results indicate that AC500/Mg improves soft and hard tissue responses without altering roughness, suggesting its potential as a regenerative strategy following implantoplasty. Full article

This paper provides a systematic review of urushiol-based antibacterial coatings for lacquer art applications, focusing on three key dimensions: molecular mechanisms, durability, and safety. Natural lacquer films form a dense three-dimensional network through laccase-catalyzed oxidative cross-linking, endowing them with excellent mechanical properties and corrosion resistance, while the catechol structure in urushiol confers broad-spectrum antibacterial potential. The article elaborates on the synergistic antibacterial mechanisms of urushiol, including covalent reactions with bacterial proteins via quinone intermediates, induction of oxidative stress, and metal ion chelation. It also reveals the dynamic change pattern of coating antibacterial activity over time, characterized by “high initial efficiency- gradual mid-term decline—long-term stabilization,” a process influenced collectively by side-chain unsaturation, degree of curing, and environmental factors such as temperature, humidity, and light exposure. From an application perspective, this review examines modification approaches such as silver/titanium dioxide composite systems, structurally regulated sustained-release strategies, and anti-adhesion surface designs, while pointing out current limitations in artistic compatibility, long-term durability, and safety assessment. Particularly in scenarios involving food contact and cultural heritage preservation, migration risks from unreacted urushiol monomers and metal nanoparticles, as well as the inherent sensitization potential of urushiol, remain critical challenges for safe application. Accordingly, this paper proposes the establishment of a holistic research framework covering “material design–process control–performance evaluation” and advocates for the development of functional coating systems with low migration, high biocompatibility, and preserved aesthetic value. Such advances are essential to promote the sustainable development and safe application of urushiol-based antibacterial coatings in fields such as cultural heritage conservation, daily-use utensils, and high-end decorative arts. Full article

To address the inherent defects in the fabrication of AlCrN titanium alloy coatings and enhance interfacial bonding strength as well as tribological performance, an AlCrN coating was employed as an absorption layer and subjected to laser shock processing to form an AlCrN/TC4 transition layer. Subsequently, a secondary AlCrN coating was deposited to construct a gradient coating architecture. The surface and cross-sectional morphologies and elemental distributions under varying laser energies were systematically investigated, and the influence of laser energy on the adhesion and wear resistance of the gradient coatings was analyzed. The results demonstrate that with increasing laser impact energy, the thickness of the AlCrN/TC4 transition layer gradually decreases from 3.75 μm to 1.32 μm, accompanied by significant changes in elemental distribution across the surface and cross-section. The interfacial bonding strength of the gradient coating increases substantially from 13.6 N to 43.3 N, while the average friction coefficient rises from 0.436 to 0.507. Concurrently, the wear track depth is reduced, and the wear rate decreases from 86.46 × 10⁻⁵ mm³/(N·m) to 7.67 × 10⁻⁵ mm³/(N·m). Laser shock peening promotes elemental diffusion, enabling the formation of a diffusion-aided interlayer. The incorporation of this diffused zone facilitates the successful construction of a high-quality TC4 titanium alloy gradient coating, effectively broadening the film–substrate interface, enhancing surface hardness, and significantly improving both interfacial adhesion and wear resistance. Full article

To address surface defects and enhance the wear resistance of 316L stainless steel parts fabricated by Selective Laser Melting (SLM), this study applied shot peening (SP) surface treatment to the SLM-processed samples. Ball-on-disk tribological tests were systematically conducted under water-lubricated conditions to investigate the evolution of surface morphology, microstructure, microhardness, and tribological performance before and after SP. The results indicate that SP induced severe plastic deformation in the surface layer, effectively refining the coarse columnar crystals and melt pool structures characteristic of SLM, and forming a crystalline hardened layer with a depth of 70–80 μm. Consequently, the surface microhardness increased by 21.97% compared to the un-peened samples. Under loads of 20 N and 30 N, the coefficient of friction (COF) of the SP-treated samples decreased by 16.36% and 12.4%, while the wear rate was reduced by 17.09% and 14.9%, respectively. In this load range, the samples primarily exhibited uniform plowing and localized adhesive wear, demonstrating significantly improved resistance to plastic deformation and crack initiation. However, when the load increased to 40 N, intense stress and thermal effects diminished the strengthening benefits of SP, resulting in no significant difference in tribological performance between the SP-treated and untreated samples. At this stage, the dominant wear mechanism transitioned to severe plastic deformation, extensive delamination, and thermally induced adhesion. Full article

The aetiology of invasive candidiasis is undergoing substantial changes; traditionally, these mycoses have been considered to originate from endogenous reservoirs; however, the increasing prevalence of non-Candida albicans species, such as Candida parapsilosis and Candida auris (also named Candidozyma auris), is a cause of concern as they demonstrate significant exogenous transmission. This challenges the long-standing paradigm of endogenous origin in hospital settings. Unlike previous reviews primarily focused on clinical epidemiology, this work adopts a multidisciplinary perspective combining microbiological evidence with biomaterials science. We analyse how surface roughness, hydrophobicity, and polymer composition within the hospital “plastisphere” influence Candida adhesion and the formation of dry surface biofilms (DSBs). In this specific context, in contrast to C. albicans, primarily associated with mucosal colonisation, C. auris and C. parapsilosis exhibit distinctive adaptations that promote survival in healthcare environments, including pronounced cell surface hydrophobicity and the capacity to form dense cellular aggregates, which facilitate prolonged adherence to synthetic polymers used in medical devices. We also explore the biological mechanisms underlying this resilience, with particular emphasis on the development of dry surface biofilms and viable but non-culturable states. These phenotypic traits confer tolerance to desiccation and resistance to conventional disinfectants, raising concerns that standard hygiene and decontamination protocols may be inadequate to prevent transmission. Understanding these mechanisms is essential for designing effective infection control strategies and mitigating the risk of invasive disease caused by these highly persistent species. Full article

Magnesium has attracted attention as an orthopedic implant material due to its excellent biocompatibility and biodegradability; however, rapid corrosion in physiological environments remains a major limitation. In this study, a polydopamine (PDA) intermediate layer and alginate/chitosan multilayer coating were formed on pure magnesium surfaces, with dexamethasone incorporation to simultaneously improve corrosion resistance and bioactivity. SEM observation revealed that uniform coating layers were formed on alginate/chitosan multilayer coated specimens, and the chemical structure of the coating layers was confirmed through FT-IR and XRD analyses. Electrochemical analysis revealed that the PDA/alginate/chitosan coating group exhibited higher corrosion potential (Ecorr: −0.7514 ± 0.022 V vs. −1.706 ± 0.001 V) and lower corrosion current density (icorr: 2.275 ± 0.15 × 10⁻⁷ A/cm² vs. 1.528 ± 0.47 × 10⁻⁴ A/cm²) compared to pure magnesium, with the highest impedance indicating superior corrosion resistance. In tape peel testing, the polydopamine-coated group demonstrated superior adhesion compared to the non-coated group, and sustained release of dexamethasone was confirmed. MC3T3-E1 cell culture results confirmed cell proliferation in all specimens, with the PDA/alginate/chitosan group exhibiting the highest ALP activity compared to other surface-treated groups. Based on these results, the PDA/alginate/chitosan multilayer coating was confirmed to be an effective surface modification method for corrosion control and promotion of osteoblast differentiation on magnesium. Full article

The global population growth and the demand for agricultural food products have generated a significant volume of agro-industrial by-products which, inadequately managed, affect the quality of the environment. The construction industry, a large consumer of raw materials and energy, constitutes an important source of waste and greenhouse gas emissions. In this context, the circular economy provides the right framework for the valorization of such natural materials, allowing us to obtain innovative sustainable building materials. The paper presents experimental research that led to the development of twelve plasters incorporating rice husks that were characterized by means of thickness (2.71–6.26 mm, when applied on concrete, and 4.20–10.29 mm, when applied on plasterboards), adhesion to the concrete surface (0.18–0.65 N/mm²), thermal conductivity (0.072–0.083 W/m·K), and impact on indoor air quality, in terms of total volatile organic compounds (TVOCs) emissions (3272–9470 µg/m³). The determined levels of the emissions suggest the possibility that by extending the monitoring for at least seven days after application, the information is more relevant. The findings confirmed that using the rice husks for the obtaining of such plasters represents a possible direction of valorization in construction; additional research is necessary for a more precise delineation of the characteristics of these products. Full article

This research presents a comprehensive evaluation of semi-elastic polyurethane adhesives used for bonding wooden flooring, with a particular focus on both domestic (oak) and exotic hardwood species (teak, iroko, wenge, merbau). Given the increasing interest in sustainable construction practices and the growing use of diverse wood species in flooring systems, this study aimed to assess the mechanical, morphological, and surface properties of adhesive joints under both standard laboratory and thermally aged conditions. Mechanical testing was conducted according to PN-EN ISO 17178 standards and included shear and tensile strength measurements on wood–wood and wood–concrete assemblies. Specimens were evaluated in multiple aging conditions, simulating real-world application environments. Shear strength increased post-aging, with the most notable improvement observed in wenge (21.2%). Tensile strength between wooden lamellas and concrete substrates remained stable or slightly decreased (up to 18.8% in wenge), yet all values stayed above the 1 MPa minimum requirement, confirming structural reliability. Surface properties of the wood species were characterized through contact angle measurements and 3D optical roughness analysis. Teak exhibited the highest contact angle (74.9°) and the greatest surface roughness, contributing to mechanical interlocking despite its low surface energy. Oak and iroko showed high wettability and balanced roughness, supporting strong adhesion. Scanning electron microscopy (SEM) revealed stable adhesive penetration across all species and aging conditions, with no signs of delamination or interfacial failure. The study confirms the suitability of polyurethane adhesives for durable, long-lasting bonding in engineered and solid wood flooring systems, even when using extractive-rich or dimensionally sensitive tropical species. The results emphasize the critical role of surface morphology, wood anatomy, and adhesive compatibility in achieving optimal bond performance. These findings contribute to improved material selection and application strategies in flooring technology. Future research should focus on bio-based adhesive alternatives, chemical surface modification techniques, and in-service performance under cyclic loading and humidity variations to support the development of eco-efficient and resilient flooring systems. Full article

Achieving environmentally friendly, green, and non-toxic marine antifouling has long been a development goal of the modern coatings industry. However, in complex marine environments, non-toxic or low-toxic antifouling coatings often have a significantly reduced service life. Therefore, achieving stable antifouling performance on a low-toxic basis has always been a goal in this industry. By using fluorocarbon resin with low surface energy and spraying a well-mixed blend of alkaline earth metal oil-absorbing nanowires and nano zinc oxide particles that is under high pressure, half-embedded into the resin, and infiltrated with alkanes, the antifouling mechanism of these coatings is achieved by the slow release of oily components, creating a long-lasting liquid–liquid interface to separate biofouling from the coating. Thanks to this antifouling mechanism, the sample maintains a water contact angle of 100–110° for 42 days in static seawater, achieves over 98% resistance to bacterial adhesion, and reaches 99.9% resistance to protein and algae adhesion. This study provides a novel and promising solution for the strict implementation of low-toxic and harmless antifouling. Full article