Search Results (1,881)

Aim: The aim of this study was to comparatively evaluate the shear bond strengths between different calcium silicate-based biomaterials and glass ionomer-based restorative materials. Materials and Methods: In this in vitro study, a total of 96 acrylic blocks were prepared, each containing a standardized cylindrical cavity measuring 4 mm in diameter and 2 mm in depth. Four different calcium silicate-based biomaterials (ProRoot MTA, Biodentine, TheraCal LC, and MTA BioRep) were placed into the cavities according to the manufacturers’ instructions. Three different glass ionomer restorative materials (Fuji II LC, Equia Forte HT, and Riva Self Cure) were then applied onto the biomaterial surfaces using molds measuring 2 mm in diameter and 2 mm in height, resulting in 12 experimental groups (n = 8). After storage at 37 °C for 24 h, the shear bond strengths were measured using a universal testing machine. The data were analyzed using the Kruskal–Wallis and Mann–Whitney U tests with Bonferroni correction (p < 0.05). Results: The highest bond strength was observed in the TheraCal LC–Fuji II LC combination, whereas the lowest value was obtained in the MTA BioRep–Equia Forte HT group. Both the type of biomaterial and type of glass ionomer cement had a statistically significant effect on the bond strength (p < 0.05). Conclusions: The combination of calcium silicate-based biomaterial and glass ionomer-based restorative material influenced the early shear bond strength. These findings suggest that material selection may play an important role in early bonding behavior at the biomaterial–restorative material interface. Full article

The transition toward a circular economy is accelerating the development of high-performance, sustainable polymeric materials derived from renewable resources. Medium-chain-length polyhydroxyalkanoates (mcl-PHAs) represent a versatile class of biodegradable polyesters with inherent flexibility and tunable side-chain chemistry, making them attractive candidates for advanced polymer applications. Here, we report a novel class of bio-based polyurethanes (PUs) incorporating mcl-PHAs as soft segments, marking their first application in polyurethane synthesis and shifting towards greener PU synthesis. Polyurethane networks were prepared using castor oil (CO) and mcl-PHAs as polyols, with hexamethylene diisocyanate (HMDI) as a hard segment. Material properties were systematically tuned by varying the mcl-PHA/CO ratio (100/0 to 0/100), enabling precise control over structure–property relationships. Comprehensive characterization confirmed urethane bond formation and revealed predominantly amorphous materials with tunable thermal and mechanical behavior. Increasing mcl-PHA content enhanced elasticity and influenced phase organization, underscoring its role as a flexible, bio-derived soft segment. The resulting materials exhibited competitive mechanical performance alongside adjustable swelling behavior and morphology. Importantly, in vitro biocompatibility (MRC-5 fibroblasts) and eco-toxicological evaluation (Caenorhabditis elegans) confirmed the absence of toxicity. These findings highlight the potential of mcl-PHAs as sustainable building blocks for advanced polyurethane systems. Full article

Background: Persistent intraradicular infection and biofilm survival remain major challenges in endodontic treatment, particularly because residual microorganisms may remain within dentinal tubules despite chemomechanical preparation. The antimicrobial efficacy of sealers may be insufficient against resistant bacteria. This study evaluated the effect of incorporating red and black iron oxide nanoparticles into BioRoot RCS on its antimicrobial activity and cytocompatibility. Methods: BioRoot RCS was modified with red or black iron oxide nanoparticles at 0.5 wt% and 2.0 wt%, generating 5 groups: unmodified sealer, 0.5% red, 2.0% red, 0.5% black, and 2.0% black. Surface morphology was analyzed using scanning electron microscopy, while elemental composition was determined by energy-dispersive X-ray spectroscopy. Antibacterial activity against Enterococcus faecalis and Fusobacterium nucleatum was assessed using a direct contact test, antibiofilm activity by colony-forming unit reduction on infected dentin discs, and cytocompatibility using human gingival fibroblasts and the AlamarBlue assay. Results: Iron was detected in the modified formulations, and elemental mapping showed homogenous distribution of calcium and iron. The 2.0% formulations showed significantly higher antibacterial and antibiofilm effects than the corresponding 0.5% groups (p < 0.05), with 2.0% black showing the lowest bacterial counts. Cytocompatibility differed at 1 and 3 days but not at 7 days, and all groups remained close to the control level with no significant difference (p > 0.05). Conclusions: Within the limitations of this in vitro study, experimental modification of BioRoot RCS with iron oxide nanoparticles, particularly at 2.0 wt%, improved the antimicrobial and antibiofilm efficacy of BioRoot RCS while maintaining acceptable cytocompatibility. However, physicochemical and handling properties must be evaluated before the clinical relevance of this modification can be determined. Full article

Improving the productivity and stability of winter wheat under increasingly variable climatic conditions remains a major challenge for sustainable agriculture. This study evaluated the effects of pre-sowing seed treatment with a microbial preparation (Nando BioExpert) and a biostimulant (Vitazyme), applied individually and in combination, on crop establishment, yield components, and grain yield of winter wheat under unstable moisture conditions in the Right-Bank Forest-Steppe of Ukraine. A three-year field experiment demonstrated that both treatments positively influenced plant growth, while their combined application produced a pronounced synergistic effect. Seed treatment enhanced plant establishment, increasing plant density at emergence from 242 plants m⁻² in the control to 372 plants m⁻² under the combined treatment. This improvement contributed to increased stand-level productive tiller density per unit area. Consequently, grain yield was consistently improved across years, with the combined treatment producing the highest average yield (6.04 t ha⁻¹), corresponding to a 37% increase relative to the control. The results indicate enhanced winter wheat resilience to environmental stress under biological seed treatment. Overall, integrating microbial inoculants with biostimulants represents an effective strategy for improving winter wheat productivity under moisture-limited conditions and supports the transition toward sustainable and resource-efficient crop production systems. Full article

This study presents a wood modification process using Fast Pyrolysis Bio-Oil (FPBO) as a fully biobased alternative to conventional, fossil-based and potentially toxic preservatives such as copper salts, organic biocides, and creosote. Standard FPBO was used in the development of 10 formulations, which were systematically characterized in terms of pot life, viscosity evolution, density, and pH. Radiata pine samples were subsequently impregnated using a bench-scale reactor, with specimens prepared in multiple geometries to assess treatment performance across different dimensions. The modified wood was comprehensively characterized with respect to moisture uptake, dimensional stability, density, mechanical strength, fixation efficiency, biological durability, and VOC emissions. Additional screening focused on properties relevant to outdoor applications, including aesthetic appearance and colour uniformity after UV exposure. The results enabled the identification of three top-performing formulations, treatments H, A, and E, which exhibited the most favourable balance between durability, environmental performance, and structural integrity. Overall, the findings demonstrate the strong potential of FPBO-based impregnation as a sustainable, multifunctional, and high-performance alternative for advanced wood protection systems. Full article

There is growing interest in the development of sustainable thermal insulating materials from renewable resources, a strategy which can stand as an alternative to conventional petroleum-based insulating materials. In this study, bio-based porous insulating materials derived from partially hydrolyzed collagen (rabbit-skin) and containing ammonium polyphosphate (APP) as flame retardant and miscanthus fibers as reinforcement are prepared. Four freeze-dried formulations were prepared: pure partially hydrolyzed collagen (COL), partially hydrolyzed collagen with APP (COL-APP), partially hydrolyzed collagen with miscanthus particles (COL-M) and a ternary formulation that included both additives (Col-APP-M). The density, porosity, thermal conductivity, specific heat capacity, compressive mechanical properties and fire behavior were evaluated. The neat collagen foam had the lowest density (122 kg·m⁻³), highest porosity (91%), and lowest thermal conductivity (0.045 W·m⁻¹·K⁻¹). The addition of APP and/or miscanthus increased density and showed limited change in thermal conductivity, which remains comparable with insulating materials (0.0445–0.0510 W·m⁻¹·K⁻¹). Specific heat capacities of partially hydrolyzed collagen foams were also relatively high (1319–1390 J·kg⁻¹·K⁻¹) as compared to some other typical insulating materials. Mechanical experiments demonstrated that APP had considerably improved the compression stiffness and strength through the physical crosslinking and densification effects in the partially hydrolyzed collagen network. Analysis of fire behavior with both Pyrolysis Combustion Flow Calorimetry (PCFC) and cone calorimetry further indicated that the addition of APP yielded improved flame retardancy with a very low heat release. These results showed that partially hydrolyzed collagen-based foams reinforced by APP and lignocellulosic particles are sustainable thermal insulation materials with desired thermal performances, improved mechanical stability, and enhanced flame retardancy. Full article

Wastewater containing such inorganic contaminants, especially phosphate and nitrate ions, has to be treated thoroughly before disposal into natural environments. This is a precautionary measure to avoid adverse effects on public health, which are exacerbated when these two pollutants are present in an aqueous system. The present research investigated how the adsorption process is influenced by factors such as the effect of ion composition, contact time, temperature and competitive adsorption behavior in multi-anion systems using Ternary Biopolymer–Bentonite Beads. This study used five isotherms and four kinetic models to investigate phosphate ions removal on prepared natural Clay-Bio-polymer composite beads. The results indicate that the pseudo-second-order (PSO) kinetic model provides the most accurate description of the adsorption process. Moreover, the correlation coefficients (R²) obtained for both the Langmuir and Freundlich isotherm models are nearly equal to 1, confirming their strong reliability in fitting the experimental data. The strong fit of both the Langmuir and Freundlich models indicates that the adsorption process exhibits mixed behavior, with both monolayer adsorption on relatively homogeneous sites and multilayer adsorption on heterogeneous sites. This mixed-behavior system is typical of composite adsorbents with diverse surface properties. The Redlich-Peterson model, a hybrid of Langmuir and Freundlich, showed the best overall correlation (R² = 0.990 for H₂PO₄⁻ and 0.998 for NO₃⁻). The applicability of the Sips and Toth isotherm models, which account for both uniform and non-uniform adsorption behaviors, validated the experimental results. In the competitive binary system, the maximum adsorption capacities achieved by the composite were 121.844 mg/g for H₂PO₄⁻ and 27.979 mg/g for NO₃⁻. The results indicate strong competition between H₂PO₄⁻ and NO₃⁻ ions for the available active sites, reflecting an antagonistic adsorption. A positive value of ∆H° verifies that the adsorption process is endothermic and primarily physical, consistent with the experimental observations. The negative ∆G° values demonstrate that the adsorption occurs spontaneously, whereas the positive ∆S° indicates an increase in randomness at the solid–liquid interface during the uptake of phosphate ions. Full article

Tung cake, a by-product of Vernicia fordii oil extraction, is an underutilized biomass residue rich in natural bioactive constituents and therefore shows potential for the development of sustainable protective formulations. In this study, tung cake-derived systems, including the aqueous extract, fermentation broth, and extract–ethanol mixtures with different ethanol volume fractions, were prepared and systematically evaluated as a unified protective system on two representative biological surfaces, namely rubberwood and fresh fruit. For rubberwood, the formulations were assessed in terms of uptake behavior, antifungal efficacy against Aspergillus niger, resistance to moisture swelling, and physicochemical characteristics using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). For fruit surfaces, preservation performance was evaluated through weight loss, decay rate, and color retention during storage. The results showed that formulation performance depended strongly on the preparation route and extract–ethanol mixture. In rubberwood, the 60–90% mixtures and the extract displayed showed better performance antifungal activity, with the 60%, 80%, and 90% mixtures reaching a control efficacy of 75.00% and the extract achieving 68.75%. The treatments also improved the dimensional stability of wood, and the water-saturated volumetric swelling rate decreased from 8.98% in the control to 5.63% in the extract-treated group. FTIR and XRD analyses indicated that the basic lignocellulosic chemical framework and cellulose-related diffraction features of rubberwood were largely retained after treatment, while treatment-dependent qualitative spectral and apparent diffraction differences were observed. SEM provided more direct evidence of surface-associated covering and reduced fungal attachment. A comparable protective tendency was also observed on fruit surfaces. In oranges, the 80% extract–ethanol mixture showed the most favorable preservation performance under the tested storage conditions, maintaining a decay rate of 0 throughout 10 days of storage, reducing weight loss to 17.76%, and preserving surface color more effectively than the control. Overall, the 80% ethanol mixture achieved the best balance between antimicrobial activity and barrier-related protection across both rubberwood and fruit surfaces. These findings demonstrate that tung cake waste can be converted into a bio-based protective system with potential mold-inhibiting and preservation functions across different biological substrates. Full article

The development of bio-based active packaging materials has gained increasing attention as a sustainable alternative to synthetic plastics. In this study, chitosan-based films incorporating yerba mate kombucha infusion (YMK-I) were developed and fully characterized. Films were prepared using different YMK-I concentrations (25–100% v/v) as solvent, with acetic acid-based chitosan films as controls. The infusion showed pH 2.5, titratable acidity of 3.5%, total solids of 6%, high phenolic content (1085 mg GAE/L), and reducing sugars (18.3 g/L). Acetic and lactic acids were identified by high-performance liquid chromatography (HPLC). Minimum Inhibitory Concentration (MIC) values ranged from 0.03 µg/mL for Staphylococcus aureus to 0.3 µg/mL for Escherichia coli and Pseudomonas aeruginosa. Rheological results indicated that YMK-I performed similarly to acetic acid as a solvent. Fourier Transformed Infrared with Attenuated Total Reflectance (FTIR-ATR) suggested interactions between chitosan and bioactive compounds. Thermal analyses showed that YMK-I acted as a plasticizer and introduced thermolabile components, altering glass transition and degradation behavior. Increasing YMK-I content reduced tensile strength and increased elongation, indicating greater flexibility, while water vapor permeability increased due to hydrophilic compounds. Films enriched with YMK-I exhibited high antioxidant activity (Radical Scavenging Activity > 85%) and strong antimicrobial effects (>98% inhibition) against E. coli and S. aureus. These results highlight the potential of chitosan–kombucha films as multifunctional materials for specialized applications. Full article

In recent years, synergistic effects between inorganic clay minerals (e.g., montmorillonite, sepiolite, kaolinite) and bio-based flame retardants (e.g., chitosan-based, lignin-based, phytate-based) have achieved certain progress in the area of polymer flame retardancy. The effects of bio-based flame retardants are exerted through mechanisms such as catalytic char generation and vapour-phase hindrance. However, they have limitations when used alone, including insufficient thermal stability and the need for a high dosage. Inorganic clays form physical barriers through their layered or tubular structures. The high thermal stability of these structures suppresses heat and mass transfer, thereby offsetting the shortcomings of bio-based flame retardants. This synergistic combination greatly improves the flame retardancy of polymer composites, often strengthening their mechanical performance in the process. It therefore offers great potential for the design of multifunctional, eco-friendly flame-retardant polymer composites. Nevertheless, a systematic review of the synergistic mechanisms, fabrication approaches and application progress of different inorganic clay minerals when combined with various bio-based flame retardants is still lacking. Therefore, this article offers a comprehensive review of the current developments of synergistic systems that incorporate various primary clays, such as sepiolite and montmorillonite, with bio-based flame retardants for usage in polymers. Before this, the synergistic flame-retardant mechanism and the key preparation techniques of the composite system were explained in detail. Finally, this article puts forward solutions to the current challenges and sets out prospects for innovation in the designing of flame-retardant materials and the optimisation of processes. The aim is to promote the sustainable growth of efficient, eco-friendly flame-retardant materials. Full article

The interfacial behavior of hybrid nanoparticles on biological substrates governs their functional performance. Here, we investigate how surface properties and colloidal stability dictate the pH-dependent adhesion of oxybenzone-loaded palygorskite nanohybrids to hair—a model biological interface. A series of hybrids with 5–50% oxybenzone loadings were prepared via melt impregnation. XRD and FTIR analyses confirm hydrogen bonding between oxybenzone and palygorskite, forming stable organic–inorganic hybrids. The colloidal stability of these nanohybrids varies non-monotonically with oxybenzone loading, governed by surface hydrophilicity and zeta potential, exhibiting a network-like behavior upon pH change. Optimal stability is achieved at an intermediate loading with a favorable balance of surface properties. While pristine hybrids show no affinity for hair, surface modification with cationic polyquaternium-7 (PQ-7) or non-ionic polyvinylpyrrolidone (PVP) enables effective deposition through distinct pH-dependent mechanisms: PQ-7 operates optimally at pH 10 via electrostatic attraction, whereas PVP performs best at pH 4 through hydrogen bonding, forming a protective coating layer on the hair surface. Deposition fails for PVP-modified hybrids at 50% loading due to excessive surface hydrophobicity. The deposited hybrids provide exceptional UV protection, significantly mitigating cuticle damage, suppressing photo-yellowing, and minimizing protein oxidation. Among the hybrids, hybrid-35 exhibited the best colloidal stability, whereas PQ-7-modified hybrid-50 gave the highest UV protection (color difference ΔE reduced from 10.51 to 1.60). The adhesion rates of the two best-performing hybrids were 2.70% and 2.85%, respectively. Beyond hair protection, we evaluate the environmental interface of these materials. While free oxybenzone is highly toxic to Chlorella vulgaris, hybridization drastically reduces its ecotoxicity. Remarkably, palygorskite and the hybrids promote algal growth, likely by acting as nutrient adsorbents and attachment sites. This work provides fundamental insights into particle–biointerface interactions and offers a strategy for designing functional hybrid materials with tailored surface properties for bio-related applications. Full article

The conventional production of waterborne polyurethane (WPU) typically relies on organic solvents to regulate viscosity; additionally, traditional ionic WPU systems still utilize volatile neutralizers, raising environmental and health concerns. To overcome these limitations and reduce dependence on petrochemical resources, this study presents a solvent-free approach for WPU synthesis using isophorone diisocyanate (IPDI), polytetrahydrofuran (PTMG), and the nonionic PEG derivative Ymer^TM A-130. In addition, castor oil (CO), a renewable and hydroxyl-rich bio-based material, was incorporated as a partial substitute for PTMG to improve both sustainability and material performance. The effects of varying substitution ratios of castor oil on the physical properties of the resulting dispersions, dried films, and coatings were initially investigated. The results indicate that increasing the castor oil content from 0 wt% to 11.8 wt% led to an enhancement in tensile strength, rising from 1.45 MPa to 2.40 MPa. Concurrently, the temperature at 5% weight loss (Td_5%) shifted upward from 263.84 °C to 285.36 °C, indicating a favorable trend in thermal stability. Furthermore, the preliminary solvent resistance, surface wetting characteristics, and environmental durability of the prepared coatings were evaluated and discussed. Full article

The effect of biopreparations containing rhizobial nod factors (lipochitooligosaccharides, LCOs) on pea growth and yield was tested under field conditions. Experiments were conducted using Pisum sativum cv. Batuta as a model, which was grown on two different soils in very similar weather conditions. Rhizobial metabolites were applied at three different concentrations and the effect of the treatment was studied at flowering and at full maturity of plants. At both sites an increase in the root nodule number and mass, acceleration of the plant growth rate, and increase in the mass of roots and aboveground parts of plants after the application of preparations containing LCOs were observed. Despite adverse climatic conditions (low rainfall from flowering to maturity), the application of preparations with LCOs resulted in a significant increase in the pea yield, ranging from 11 to 16%, which supports the use of such preparations in pea field cultivation. Full article

Despite major advances in polymer composites for Fused Filament Fabrication (FFF), designing environmentally sustainable materials from bio-based resources remains a key research priority. The objective of this study is to check the processability and properties of sustainable PETG/cork composites processed via FFF technology. Filaments with 5 and 10% of cork were created using a twin-screw extruder. Samples from these filaments were printed by FFF technology, and subsequently subjected to morphological, thermal and mechanical testing. As a result of the study, it was proved that the 3D-printing process did not result in a tensile strength decrease with an increasing cork percentage, as observed in mechanical testing of the filament. The addition of cork significantly increased plasticity without decreasing tensile strength when introducing 10% of cork particles. The interfacial temperatures of the prepared composites did not differ much from the polymer matrix and were 79.55 °C, 77.56 °C, 76.67 °C for PET-G, PET-G + 5% cork, and PET-G + 10% cork, respectively. Thermal conductivity decreased significantly as the percentage of cork increased. This work shows that FFF technology is one of the most suitable manufacturing options for PETG + 10% cork composites to produce things with low conductivity and the same thermal and mechanical properties as pure PETG. Full article