Mechanical Barrier Research Articles

Superior toughness Anticorrosion-Bioactive integrated multilayer coating with excellent adhesion for biodegradable Magnesium-Based stents

Biodegradable magnesium-based stents overcome the limitations of non-degradable stents and exhibit superior mechanical properties compared to biodegradable polymer counterparts, representing an inevitable trend in cardiovascular stent evolution. However, the excessively rapid degradation rate remains a pivotal factor that constrains their clinical application. In this work, an anticorrosion-bioactive integrated multilayer coating is developed for magnesium-based stents. By optimizing the molecular structure of poly(L-lactide-co-ω-caprolactone) (PLCL), a biodegradable coating material with excellent mechanical properties and effective barrier performance is obtained. To enhance the wettability and adhesion strength between the highly surface-energy magnesium and the low-polarity PLCL, a silane-based transition layer and an intermediate connecting layer of covalently bonded PLCL chains are sequentially constructed on the magnesium substrate. Furthermore, bioactive polymer brush consists of poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) and Arg-Glu-Asp-Val (REDV) peptide is fabricated on the PLCL anticorrosion coating. The combined in vitro and in vivo experiments confirm that the multilayer coating exhibits commendable anti-corrosion performance, and is beneficial to anticoagulation and endothelialization, thereby making the degradation process of magnesium-based stents more compatible with the vascular remodeling process. The anticorrosion-bioactive multilayer composite coating developed in this study has the potential to overcome the corrosion resistance limitations of magnesium-based implants, thus promoting their clinical application.

Using a simple coating strategy to evolve polylactic acid into sand-fixation material with nutrient-rich reservoir by strong H-bonding interaction at phase interface

Developing simple and eco-friendly methods for polylactic acid (PLA) modification and establishing strong interfacial interactions between phases are still worthwhile research topics. Only by enabling sand barriers to continuously provide water and fertilizer for sand-fixing plants can effective control of desertification be truly achieved. Herein, a simple and eco-friendly coating functionalmodification strategy for PLA was introduced, involving in-situ curing of urea-aldehyde (UF)/polyacrylic acid (PAA) prepolymer after coating on PLA and then continuous rolling. During the preparation process, –NH in the amide group and –OH in the carboxyl group of UF/PAA form strong intermolecular H-bonding with C = O of PLA, resulting in high interfacial bonding strength and significant improvement in mechanical and hydrophilic properties of the modified PLA mesh. Wind erosion resistance, water absorption and holding capacity, nutrient content, and plant growth of the treated sand all display a very positive response. Effective surface coating modification evolves PLA into a “nutrient-rich reservoir” for sand-fixing plants without affecting its performances, thus truly achieving the desired but never achieved effective combination of natural sand fixation and mechanical sand barrier fixation, exhibiting great significance for further improving application performances and expanding applying fields of PLA through surface functional modification that is easy to industrialize.

Influence of Epilobium parviflorum Herbal Extract on Physicochemical Properties of Thermoplastic Starch Films.

In this study, for the first time, Epilobium parviflorum Schreb. (E, hoary willowherb) aqueous extract was introduced into edible biopolymer films and its influence on physicochemical properties of the final products were investigated. Potato starch was gelatinized in the herbal tea to obtain thermoplastic starch (TPS) films via the casting method. The characterization of the films included mechanical, antioxidative, water (WVTR, contact angle, swelling degree) and UV radiation barrier properties as well as microstructure analysis (SEM). Obtained results indicated that the presence of the extract (rich in phenolic compounds) in the films acted as a co-plasticizer for starch and led to a higher elongation at break, up to 70%, with a parallel increase in tensile strength up to ca. 9 MPa. Moreover, TPS films with E exhibited lower WVTR values and absorption of UV light in comparison with the control TPS film. DPPH scavenging activity of TPS E films immersed in methanol was ca. 92%, and it was related to the release of the extract into liquid media. Novel TPS E films are characterized by multifunctional properties that can be used, e.g., in the active packaging sector.

Applicability of Phosponated Poly(pentafluorostyrene) Fiber Reinforced Nafion Composite Membranes in Low-Temperature Fuel Cells

Reducing the fuel crossover of proton exchange membranes (PEMs) is an important measure to improve the fuel efficiency and performance of fuel cells and electrolyzers 1, 2. Additionally, the long-term stability and safety of PEM-based systems increase with a reduction in the gas crossover 1, 3, 4. A possible approach for reducing the gas crossover of a PEM is the implementation of fiber meshes to form a composite membrane 5. Furthermore, fiber-reinforced composite membranes can also increase the mechanical properties of PEMs and therefore enable the utilization of thinner membranes without sacrificing the mechanical integrity of the membrane or causing safety risks 6.In this work, we demonstrate the successful fabrication of electrospun fibers of a partially phosophonated, conductive polymer (phosponated poly(pentafluorostyrene); PWN70) and its non-phosphonated and, therefore, non-conductive equivalent (poly(pentafluorostyrene); PPFSt). Two different loadings of both fiber meshes were successfully infiltrated with Nafion, analyzed mechanically and electrochemically, and compared to a non-reinforced Nafion reference. We show that the mechanical properties of both fiber-reinforced composite membranes are superior to the reference membrane. The electrochemical analysis of the membrane electrode assemblies (MEAs) shows a reduction in performance with the incorporation of the non-conductive PPFSt fibers. An increase in the high-frequency resistance (HFR) of the MEAs containing the non-conductive PPFSt fibers explains the reduced performance and scales with fiber loading. In contrast, the MEAs with the proton conductive PWN70 fiber reinforcement maintained the same HFR and performance as the reference, independently of the fiber loading. Additionally, hydrogen crossover measurements revealed a significantly reduced hydrogen crossover of the MEAs composed of the conductive PWN70 fiber-reinforced membranes (between 30 and 40 % less than the reference). We hypothesize that PWN70 shows a decreased diffusivity for hydrogen compared to Nafion, and therefore, the fibers in the Nafion matrix increase the tortuosity of the membrane for fuel crossover.In summary, we developed a fiber-reinforced Nafion membrane with improved mechanical and gas barrier properties while maintaining the membrane's proton conductivity compared to the same membrane without reinforcement.References Q. Tang, B. Li, D. Yang, P. Ming, C. Zhang and Y. Wang, Int. J. Hydrog. Energy, 46(42), 22040–22061 (2021).M. Schalenbach, M. Carmo, D. L. Fritz, J. Mergel and D. Stolten, Int. J. Hydrog. Energy, 38(35), 14921–14933 (2013).B. Wu, M. Zhao, W. Shi, W. Liu, J. Liu, D. Xing, Y. Yao, Z. Hou, P. Ming, J. Gu and Z. Zou, Int. J. Hydrog. Energy, 39(26), 14381–14390 (2014).C. Klose, P. Trinke, T. Böhm, B. Bensmann, S. Vierrath, R. Hanke-Rauschenbach and S. Thiele, J. Electrochem. Soc., 165(16), F1271-F1277 (2018).J. Choi, K. M. Lee, R. Wycisk, P. N. Pintauro and P. T. Mather, Macromolecules, 41(13), 4569–4572 (2008).J. B. Ballengee and P. N. Pintauro, Macromolecules, 44(18), 7307–7314 (2011).

Dietary taurine effect on intestinal barrier function, colonic microbiota and metabolites in weanling piglets induced by LPS.

Diarrhea in piglets is one of the most important diseases and a significant cause of death in piglets. Preliminary studies have confirmed that taurine reduces the rate and index of diarrhea in piglets induced by LPS. However, there is still a lack of relevant information on the specific target and mechanism of action of taurine. Therefore, we investigated the effects of taurine on the growth and barrier functions of the intestine, microbiota composition, and metabolite composition of piglets induced by LPS. Eighteen male weaned piglets were randomly divided into the CON group (basal diet + standard saline injection), LPS group (basal diet + LPS-intraperitoneal injection), and TAU + LPS group (basal diet + 0.3% taurine + LPS-intraperitoneal injection). The results show that taurine significantly increased the ADG and decreased the F/G (p < 0.05) compared with the group of CON. The group of TAU + LPS significantly improved colonic villous damage (p < 0.05). The expression of ZO-1, Occludin and Claudin-1 genes and proteins were markedly up-regulated (p < 0.05). Based on 16s rRNA sequencing analysis, the relative abundance of Lactobacilluscae and Firmicutes in the colon was significantly higher in the LPS + TAU group compared to the LPS group (p < 0.05). Four metabolites were significantly higher and one metabolite was significantly lower in the TAU + LPS group compared to the LPS group (p < 0.01). The above results show that LPS disrupts intestinal microorganisms and metabolites in weaned piglets and affects intestinal barrier function. Preventive addition of taurine enhances beneficial microbiota, modulates intestinal metabolites, and strengthens the intestinal mechanical barrier. Therefore, taurine can be used as a feed additive to prevent intestinal damage by regulating intestinal microorganisms and metabolites.

Preparation and improving mechanism of PBAT/PPC-based micro-layer biodegradable mulch film with excellent water resistance and mechanical properties

The utilization and implementation of biodegradable mulch film represent a highly effective approach to address the persistent pollution caused by non-degradable mulch film. However, the poor water resistance and insufficient mechanical properties strongly restrict its practical application. Here the PBAT/PPC-based multilayer biodegradable mulch films including 3-, 17-, 65-, and 257-layer, were manufactured successfully using a self-developed micro-layer blown film technology. The 65-layer film showed significant improvements in its mechanical and barrier properties, outperforming contrast the blend the film by 148 %, 168 %, and 203 % respectively in terms of puncture energy, tear energy, and water vapor barrier. The results obtained from DSC, WAXD, and SAXS analyses demonstrated a significant similarity in the crystalline structure of PBAT in various micro-layer films and the blend contrast film. Consequently, the robust mechanical and water barrier properties can be attributed to the ultrathin micro-layer structure, which dissipated energy during mechanical breakage by promoting substantial plastic deformation and blocked the water by forming a larger and more continuous phase of high barrier PPC. Briefly, the micro-layer mulch films, based on PBAT/PPC and fabricated using the self-developed micro-layer blown film technology, demonstrate exceptional mechanical strength and water resistance properties. Consequently, this research has the potential to garner interest within the biodegradable mulch film sector.

Green halochromic smart and active packaging materials based on chitosan film loading nanoparticles: Functionality, physicochemical properties and application

Despite extensive commercial and regulatory interventions, food spoilage and plastic packaging contamination continue to have large ramifications on human health and the global economy. Intelligent active packaging that can both monitor food freshness in real-time and improve food quality is needed. In this study, curcumin-zein- quercetin-chondroitin sulfate nanoparticles (CZQC NPs) with ammonia/acetic acid sensitivity and antioxidant activity were prepared and then loaded within a chitosan film to give a smart film. The effect of NPs loading upon the structure and physicochemical characteristics of the chitosan based films were studied. The scanning electron microscopy confirmed that the NPs had good compatibility with chitosan and filled the void in the film matrix. The NPs were uniformly integrated inside the chitosan film, which significantly improved its mechanical properties (tensile strength from 26 to 62 MPa; elongation at break from 35 to 61%), oxygen and water barriers and ultraviolet light protection. The NPs films showed significant antibacterial efficacy, antioxidant activity and a beneficial ammonia/acetic acid/pH-sensitivity. Thus, the NPs composite film could sensitively detect fillets freshness with discernible color changes. Therefore, the NPs composite films may potentially be applied to indicate and extend the freshness of packaged foods.

Effects of alkaline pH and gallic acid enrichment on the physicochemical properties of sesame protein and common vetch starch-based composite films

In this study, sesame (Sesamum indicum L.) meal protein and common vetch (Vicia sativa L.) starch were extracted and used to obtain biodegradable composite films at different pH values (7, 9, and 11). Films were plasticized with glycerol (2.5 %) and enriched with gallic acid (0.25 %). Increasing pH promoted mechanical properties of the films with the developed barrier and thermal characteristics. Gallic acid addition at pH 7 resulted in lower tensile strength and higher elongation by reducing intermolecular forces, and a shift of diffraction peaks through lower angles due to crystal lattice expansion, as compared to neutral films without gallic acid. On the other hand, gallic acid-enriched films at neutral pH exhibited superior antioxidant properties. The mild alkalinity with gallic acid provided the lowest water vapor permeability, high thermal stability, improved mechanical properties and light barrier property due to deprotonation and subsequent interactions with biopolymers. The FTIR spectrum confirmed intense interactions, such as crosslinking and covalent bonding, promoted by mild alkalinity. Therefore, sesame protein and common vetch starch-based composite film with gallic acid incorporation at pH 9 can be recommended to be used in biodegradable active food packaging applications.

Acetylated cellulose nanofibers enhanced bio-based polyesters derived from 10-undecanoic acid toward recyclable and degradable plastics

The development of convenient technologies for green fabrication of bio-based polymers that are mechanically tough, recyclable and completely degradable in soil is an urgent demand. Herein, plant oil-based polyesters (PUD) were cost-effectively fabricated by polymerizing diene ester monomers derived from 10-undecanoic acid under mild solvent-free conditions with a yield of 92 %, making them environmentally friendly. Due to the presence of internal reversible forces, plant oil-based polyesters can be easily processed into various shapes and products. Plant oil-based polyester films exhibited a tensile strength of 10.0 MPa, while also being highly flexible, and water-resistant. Additionally, excellent recycling performance of polyester was achieved in a closed loop by solvent-assisted or hot-pressing depolymerization/repolymerization. Moreover, microorganisms and water in soil can completely degrade plant oil-based polyesters within 15 weeks. However, the mechanical properties and thermal stability of plant oil-based polyesters are still anticipated. Therefore, the addition of acetylated cellulose nanofibers (ACNF) to plant oil-based polyester matrix has obtained the production of biodegradable composites with excellent mechanical properties, thermal stability and barrier properties. The high-performance and eco-friendly nanocomposite has the potential to facilitate the multifunctional utilization of cellulose nanofibers and practical applications of plant oils.

Periostin regulates integrin expression in gingival epithelial cells

ObjectiveHuman gingival epithelial cells (HGECs) function as a mechanical barrier against invasion by pathogenic organisms through epithelial cell–cell junction complexes, which are complex components of integrin. Integrins play an important role in the protective functions of HGECs. Human periodontal ligament (HPL) cells regulate periodontal homeostasis. However, periodontitis results in the loss of HPL cells. Therefore, as replenishment, HPL cells or mesenchymal stem cells (MSCs) can be transplanted. Herein, HPL cells and MSCs were used to elucidate the regulatory mechanisms of HGECs, assuming periodontal tissue homeostasis. MethodsHuman gingival fibroblasts (HGFs), HGECs, HPL cells, and MSCs were cultured, and the conditioned medium was collected. With or without silencing periostin mRNA, HGECs were cultured under normal conditions or in a conditioned medium. Integrin and periostin mRNA expression was determined using real-time polymerase chain reaction. Integrin protein expression was analyzed using flow cytometry, and periostin protein expression was determined via western blotting. ResultsThe conditioned medium affected integrin expression in HGECs. Higher expression of periostin was observed in MSCs and HPL cells than in HGFs. The conditioned medium that contained periostin protein regulated integrin expression in HGECs. After silencing periostin in MSCs and HPL cells, periostin protein was not detected in the conditioned medium, and integrin expression in HGECs remained unaffected. ConclusionsIntegrins in HGECs are regulated by periostin secreted from HPL cells and MSCs. This result suggests that periostin maintains gingival cell adhesion and regulates bacterial invasion/infection. Therefore, the functional regulation of periostin-secreting cells is important in preventing periodontitis.

Effects of cactus pear clone harvest seasons and times on the physicochemical and technological properties of resulting mucilage and biopolymeric films

Cactus pear cladodes, clones ‘Miúda’ (MIU) and ‘Orelha de Elefante Mexicana’ (OEM) were harvested at 6 am and 8 pm during the rainy-dry, dry and rainy seasons to evaluate the effect of type of clone and harvest seasons on the physicochemical and technological properties of mucilage as well as the optical, physicochemical, mechanical, thermal and microstructural characteristics of the films obtained. The mucilage of the OEM clone presented a higher content of phenolic compounds, compared to the Nopalea genus, regardless of the season and time of harvest. Furthermore, the dry period resulted in higher carbohydrate levels, regardless of the harvest time. The biopolymeric films produced from the OEM clone harvested in the rainy season and rainy-dry transition showed darker color, better mechanical properties, water barrier, compact microstructure and thermal stability when compared to the MIU clone. Furthermore, harvesting at 6 am provided improvements in the mechanical conditions, permeability and thermal stability of the films of both types of clones studied. These results showed strong environmental modulation, naturally incorporating important macromolecules such as carbohydrates and phenolic compounds, used in the industry in the production of nutraceutical foods, into the mucilage. Furthermore, harvesting cladodes at 6 am in the rainy and transitional (rainy-dry) periods provided better quality biopolymeric films and/or coatings.

NaOH protective layer for a stable sodium metal anode in liquid electrolytes

Sodium is known as a soft metal that can easily change its particle morphology. It can form outstretched and rolled fibers with plastic or brittle behavior, and cubes. In Na-batteries, metallic Na anodes demonstrate a high reactivity towards the majority of electrolyte solutions, volume change and a random deposition process from the electrolyte, accompanied by dendrite formation.In order to smooth the electrochemical Na deposition, we propose NaOH as a simple artificial protective layer for sodium, formed by its exposure to ambient conditions for a certain period of time. The formed NaOH layer on top of the metallic sodium suppresses the volume change and dendrite growth on the sodium surface. Additionally, the protected sodium does not change its morphology after a prolonged contact with carbonate-based electrolytes. In symmetric Na-batteries, the NaOH layer increases the lifetime of the electrochemical cell by eight times in comparison to non-protected Na.In the full-cell with a layered sodium oxide cathode, the NaOH-protected sodium anode also leads to a high cycling stability, providing 81 % of the initial cell capacity after 500 cycles with a 1C current rate. In contrast, batteries with a non-protected Na-anode reach only 20 % of their initial capacity under the same conditions. Therefore, the main benefits of the NaOH artificial layer are the chemical compatibility with the carbonate-based electrolytes, the protection of Na metal against reaction with the electrolyte solution, the rapid Na-ion diffusion through the layer and the formation of a mechanical barrier, mitigating Na-dendrite growth.This work presents an easily scalable method to protect sodium without any additional chemicals or a special environment for this reaction.

Qingchang Wenzhong Decoction ameliorates intestinal inflammation and intestinal barrier dysfunction in ulcerative colitis via the GC-C signaling pathway

Ethnopharmacological relevanceUlcerative colitis (UC) is an idiopathic, chronic inflammatory disorder of the colonic mucosa, accompanied with abdominal pain, and bloody diarrhea. Currently, clinical treatment options for UC are limited. Qingchang Wenzhong Decoction (QCWZD) is an effective prescription of traditional Chinese medicine for the treatment of UC. However, the mechanism of QCWZD in alleviating intestinal barrier dysfunction in UC has not been clearly explained. Aim of the studyTo determine the mechanism whereby QCWZD promotes the recovery of intestinal barrier dysfunction in UC. Materials and methodsA secondary analysis of colonic mucosa from UC patients acquired from a prior RCT clinical trial was performed. The effects of QCWZD on intestinal mucus and mechanical barriers in UC patients were evaluated using colon tissue paraffin-embedded sections from UC patients. The mechanism was further investigated by in vivo and in vitro experiments. UC mice were established in sterile water with 3.0% dextran sodium sulfate (DSS). Meanwhile, mice in the treatment group were dosed with QCWZD or mesalazine. In vitro, an intestinal barrier model was constructed using Caco-2 and HT29 cells in co-culture. GC-C plasmid was used to overexpress/knock down GC-C to clarify the target of QCWZD. HE, AB-PAS, ELISA, immunohistochemistry and immunofluorescence assays were used to assess the level of colonic inflammation and intestinal barrier integrity. Rt-qPCR, Western Blot were used to detect the expression of genes and proteins related to GC-C signaling pathway. Molecular docking was used to simulate the binding sites of major components of QCWZD to GC-C. ResultsIn UC patients, QCWZD increased mucus secretion, goblet cell number, and promoted MUC2 and ZO-1 expression. QCWZD accelerated the recovery of UC mice from DSS-induced inflammation, including weight gain, reduced disease activity index (DAI) scores, colon length recovery, and histological healing. QCWZD promoted mucus secretion and increased ZO-1 expression in in vivo and in vitro experiments, thereby repairing mucus mechanical barrier damage. The effects of QCWZD are mediated through regulation of the GC-C signaling pathway, which in turn affects CFTR phosphorylation and MUC2 expression to promote mucus secretion, while inhibiting the over-activation of MLCK and repairing tight junctions to maintain the integrity of the mechanical barrier. Molecular docking results demonstrate the binding of the main components of QCWZD to GC-C. ConclusionOur study demonstrated that QCWZD modulates the GC-C signaling pathway to promote remission of mucus-mechanical barrier damage in the UC. The clarification of the mechanism of QCWZD holds promise for the development of new therapies for UC.

Chronic exposure to polystyrene nanoplastics induces intestinal mechanical and immune barrier dysfunction in mice

Micro(nano)plastics are prevalent in the environment, and prolonged exposure to them represents a threat to human health. The goal of this study is to assess the health risk of long-term exposure to nanoplastics (NPs) at environmental concentrations on the intestinal mechanical and immune barrier in mice. In this study, mice were provided drinking water containing polystyrene NPs (PS-NPs; 0.1, 1, and 10 mg·L−1) for 32 consecutive weeks. The levels of endocytosis proteins caveolin and clathrin and of tight junctional proteins claudin-1, occludin, and ZO-1, and morphological changes, proportion of lymphocytes B in MLNs and lymphocytes T in IELs and LPLs were determined by immunohistochemistry, hematoxylin–eosin, and flow cytometry assays in the intestinal tissues of mice at 28 weeks. The activities or concentrations of ROS, SOD, MDA, and GSH-Px and inflammatory factors (IL-1β, IL-6, and TNF-α) in the intestinal tissues of mice were measured by ELISA at 12, 16, 20, 24, and 32 weeks. Compared with the control group, oral ingested PS-NPs entered the intestinal tissues of mice and upregulated expression levels of the clathrin and caveolin. The intestinal tissue structure of mice in the PS-NPs (1 and 10 mg·L−1) exposure groups showed significant abnormalities, such as villus erosion, decreased of crypts numbers and large infiltration of inflammatory cells. Exposure to 0.1 mg·L−1 PS-NPs decreased occludin protein levels, but not claudin-1 and ZO-1 levels. The levels of these three tight junction proteins decreased significantly in the 1 and 10 mg·L−1 PS-NPs exposed groups. Exposure to PS-NPs led to a significant time- and dose-dependent increase in ROS and MDA levels, and concurrently decreased GSH-Px and SOD contents. Exposure to PS-NPs increased the proportion of B cells in MLNs, and decreased the proportion of CD8+ T cells in IELs and LPLs. The levels of pro-inflammatory cytokines IL-6, TNF-α and IL-1β were markedly elevated after PS-NPs exposure. Long-term PS-NPs exposure impaired intestinal mechanical and immune barrier, and indicate a potentially significant threat to human health.

A review on biodegradable polymers: Used as packaging Materials

In current years littering of plastics and the problem associated with their chronic inside the environment have end up a primary awareness in the each studies and information. There is high need of biodegradable polymers and especially in the discipline of packing and additionally want to create biodegradable polymers for traditional packaging material. The current review paper focuses towards the various types of biopolymer sources that are available in nature which are able to reduce the risk of environment damage through the use of alternative of plastics as a packaging material. This review present review of the exclusive biodegradable polymers and records about biodegradable polymers which are degraded by way of microorganisms and additionally include biodegradation technique. The excellent of biopolymers can be expressed as distinct properties like gas barrier, thermal and mechanical barrier, and moisture barrier properties. Biopolymers may be classified into classes in keeping with natural, synthetic and based totally on repeating units. Biodegradable polymers can be used as an approach to the troubles posed via plastics as they effortlessly degrade inside the surroundings and also mimic the properties of traditional polymers. Starch, cellulose based totally biodegradable zero waste plastics can update with non-renewable plastics with comparable packaging properties. Some of organic substances can be incorporated into biodegradable polymers materials with the maximum common being PLA, PCA, protein, starch cellulose etc. This overview additionally nation the biodegradable polymers bundle of food programs and utilized in other discipline and which merchandise are made from this.

Construction of a sustainable and hydrophobic high-performance all-green pineapple peel cellulose nanocomposite film for food packaging

The increasing global awareness of environmental issues has led to a growing interest in research on cellulose-based film. However, several limitations hinder their development and industrial application, such as hydrophilicity, inadequate mechanical properties and barrier properties, and a lack of activity. This study aimed to create a sustainable and hydrophobic high-performance all-green pineapple peel cellulose nanocomposite film for food packaging by incorporating natural carnauba wax and cellulose nanofibers (CNF) into a pineapple peel cellulose matrix. The results showed that adding carnauba wax to the cellulose matrix converted the surface wettability of the cellulose-based film from hydrophilic to hydrophobic (water contact angle over 100). Additionally, the film exhibited ultraviolet resistance and antioxidation properties. The incorporation of CNF further improved the barrier properties, mechanical properties, and thermal stability of the cellulose nanocomposite film. In applied experiments, the cellulose nanocomposite film delayed post-harvest deterioration and maintained storage quality of cherry tomatoes. Importantly, the cellulose nanocomposite film could be degraded in soil within 30 days. It can be concluded that the cellulose nanocomposite film has great potential to alleviate the environmental problems and human health problems caused by non-degradable petroleum-based plastic packaging.

Nanoplatforms for the Delivery of Nucleic Acids into Plant Cells.

Nanocarriers are widely used for efficient delivery of different cargo into mammalian cells; however, delivery into plant cells remains a challenging issue due to physical and mechanical barriers such as the cuticle and cell wall. Here, we discuss recent progress on biodegradable and biosafe nanomaterials that were demonstrated to be applicable to the delivery of nucleic acids into plant cells. This review covers studies the object of which is the plant cell and the cargo for the nanocarrier is either DNA or RNA. The following nanoplatforms that could be potentially used for nucleic acid foliar delivery via spraying are discussed: mesoporous silica nanoparticles, layered double hydroxides (nanoclay), carbon-based materials (carbon dots and single-walled nanotubes), chitosan and, finally, cell-penetrating peptides (CPPs). Hybrid nanomaterials, for example, chitosan- or CPP-functionalized carbon nanotubes, are taken into account. The selected nanocarriers are analyzed according to the following aspects: biosafety, adjustability for the particular cargo and task (e.g., organelle targeting), penetration efficiency and ability to protect nucleic acid from environmental and cellular factors (pH, UV, nucleases, etc.) and to mediate the gradual and timely release of cargo. In addition, we discuss the method of application, experimental system and approaches that are used to assess the efficiency of the tested formulation in the overviewed studies. This review presents recent progress in developing the most promising nanoparticle-based materials that are applicable to both laboratory experiments and field applications.

Preparation and properties of lignin-based polyurethane materials

In this paper, lignin-based polyurethane (LPU) films were successfully prepared by tape casting using modified alkaline lignin instead of partial polycarbonate diol (PCDL) in reaction with isophorone diisocyanate (IPDI), with diethylene glycol (DEG) as chain extender and dibutyltin dilaurate (DBTDL) as catalyst. The factors influencing the hydroxylation modification of alkali lignin were discussed, and the optimal reaction conditions were determined: reaction temperature of 50 °C, reaction time of 60 min, hydrogen peroxide to lignin mass ratio of 1.2:1, and iron hydroxide to alkali lignin mass ratio of 2 %. The lignin-based polyurethane films with different R values were also prepared by changing the ratio of isocyanate groups to hydroxyl groups (R-value), and the effects of different R values on the polyurethane properties were investigated. It was characterized by Fourier transform infrared spectroscopy (FTIR), mechanical property tests, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), moisture and oxygen permeability property tests, and UV spectroscopy tests. The results show that changing the R-value can improve the mechanical properties, thermal stability, barrier properties, and UV shielding properties of polyurethane materials. When the R-value is 1.8, the lignin-based polyurethane film material has the best performance.

Agaricus blazei Polysaccharide Alleviates DSS-Induced Colitis in Mice by Modulating Intestinal Barrier and Remodeling Metabolism

Ulcerative colitis (UC) is a chronic noninfectious intestinal disease that severely affects patients’ quality of life. Agaricus blazei Murrill polysaccharide (ABP) is an effective active ingredient extracted from Agaricus blazei Murrill (ABM). It has good efficacy in inhibiting tumor cell growth, lowering blood pressure, and improving atherosclerosis. However, its effect on colitis is unclear. The aim of this study was to analyze the protective effects and potential mechanisms of ABP against dextran sulfate sodium (DSS)-induced acute colitis in mice. The results showed that dietary supplementation with ABP significantly alleviated DSS-induced colitis symptoms, inflammatory responses, and oxidative stress. Meanwhile, ABP intervention was able to maintain the integrity of the intestinal mechanical barrier by promoting the expression of ZO-1 and Occludin tight junction proteins and facilitating mucus secretion. Moreover, 16S rRNA sequencing results suggested that ABP intervention was able to alleviate DSS-induced gut microbiota disruption, and nontargeted metabolomics results indicated that ABP was able to remodel metabolism. In conclusion, these results demonstrate that dietary supplementation with ABP alleviated DSS-induced acute colitis by maintaining intestinal barrier integrity and remodeling metabolism. These results improve our understanding of ABP function and provide a theoretical basis for the use of dietary supplementation with ABP for the prevention of ulcerative colitis.

White-berried grapevines as hosts for polyphagous aphids: analysis of probing behavior, plant leaf anatomy and allelochemicals

Aphids (Hemiptera: Aphididae) are herbivorous insects which deprive plants of nutrients by feeding on the phloem sap and transmission of plant viruses. In the present study, the susceptibility of selected white-berried grapevine (Vitis spp.) cultivars “Aurora”, “Bianca”, “Muskat Letni” and “Solaris” to the black bean aphid (Aphis fabae Scop.) and the green peach aphid (Myzus persicae (Sulz.) was evaluated using the Electrical Penetration Graph (EPG) technique. The content of major flavonoids and stilbenoids in grapevine leaves and leaf anatomy parameters that might have affected aphid probing were also analyzed. Based on the success rate in reaching the phloem vessels and feeding on phloem sap, the studied grapevine cultivars can be assigned to various groups of susceptibility. Cultivars “Bianca” and “Muskalt Letni” are susceptible to A. fabae and M. persicae, respectively (aphids reach phloem phase and show short bouts of sap ingestion); “Muskat Letni” shows low susceptibility to A. fabae, while “Aurora” and “Bianca” to M. persicae (only 50% aphids reach phloem phase and no sap ingestion occurs); “Solaris” is resistant to A. fabae and M. persicae (no phloem phase present). Anatomical structure of leaves was similar in all cultivars and no mechanical barriers for aphid probing were observed. However, the content of individual flavonoids and silbenoids differed among cultivars. We hypothesize that the high content of piceid in the leaves of “Solaris” may be responsible for the rejection of this cultivar by both aphid species. The study demonstrated that the risk of the direct damage due to A. fabae and M. persicae feeding on grapevines is low. However, considering the intense aphid probing activity within leaf epidermis and mesophyll, A. fabae and M. persicae may pose a serious threat as vectors of non-persistent and semi-persistent viruses to white-berried grapevines.