Good Barrier Research Articles

Wearable System for Continuous Estimation of Transepidermal Water Loss

To maintain skin moisture, we need to maintain good stratum corneum barrier function, which prevents moisture evaporation from the inside of the skin. Transepidermal water loss (TEWL), the amount of water that evaporates from the skin, indicates the state of barrier function. The barrier function of facial skin is easily damaged in daily life, and the condition of the skin becomes worse without us noticing. We should constantly monitor TEWL to prevent worsening skin conditions. In this paper, we propose a wearable device that continuously measures TEWL. We estimate TEWL using machine learning from temperature and humidity values of water evaporation from the skin and parameters that affect TEWL, such as skin surface temperature and galvanic skin response. We experimented with the prototype device in a controlled environment. We confirmed that the prototype device could estimate TEWL accurately enough to judge the skin’s condition in stationary and conversational situations. Then, we experimented to verify the environmental conditions for estimating TEWL using the prototype device. The prototype device could estimate TEWL with sufficient precision in an office without airflow. However, we could not estimate TEWL in the office with airflow and outdoor.

Engineered environment-friendly multifunctional food packaging with superior nonleachability, polymer miscibility and antimicrobial activity

This study was conducted primarily to develop an environment-friendly food packaging boasting several advantages, including good water vapor barrier, UV resistance, antimicrobial activity, non-leachability, and polymer miscibility. Initially, the starch-based antimicrobial agent (OCSI) was synthesized through a simple esterification reaction between oxidized corn starch (OCS) and indoleacetic acid (IAA). Subsequently, OCSI was further blended separately with environmentally-friendly materials (PVA, PBAT, PCL), and a series of environment-friendly packaging films were successfully prepared. The resulting films exhibited desirable thermal stability and 100 % barrier against both UV-A and UV-B rays. Moreover, the films presented effective barriers against water vapor, antioxidant, and antimicrobial activity against E. coli and S. aureus. Meanwhile, the films could significantly inhibit the deterioration of fresh fruits and prolong shelf life, considerably expanding their utilization in safe packaging. The environment-friendly packaging not only realized the sustainable utilization of green polymers, but also offered novel insights into the exploration of sustainable packaging.

Good Opportunities and Barriers to the Grain Trade in the Ports of the Western Black Sea Coast in the 1840s, Presented in the Reports of the European Consuls

Good Opportunities and Barriers to the Grain Trade in the Ports of the Western Black Sea Coast in the 1840s, Presented in the Reports of the European Consuls

Physico-chemical and thermal degradation characteristics of marine red macroalgae for sustainable packaging applications

This study aims to examine the characteristics of Eucheuma cottonii, Gracilaria verrucosa, and Acanthophora spicifera red macroalgae. Eucheuma cottonii showed an average particle size of 58 μm, while Gracilaria verrucosa and Acanthophora spicifera were 84 μm and 72 μm, respectively. Besides, Eucheuma cottonii presented the lowest band of hydroxyl groups, exhibiting the formation of greater intermolecular hydrogen bonds. The red macroalgae biopolymer films were fabricated via a solvent-casting technique. The optimum performance was achieved from Eucheuma cottonii macroalgae with the tensile strength, puncture resistance, and contact angle reached 27.38 MPa, 6.72 N, and 72.58°, respectively. The increase in storage time for six months resulted in a slight decrease in the water barrier and film transparency. It appears feasible to use these red macroalgae as promising sustainable marine biomasses for practical use in eco-friendly packaging materials since the red macroalgae films showed good mechanical, water barrier, and biodegradability properties.

Plasma enhanced chemical vapor deposition (PECVD) of SiOx thin films on Portuguese limestone: An experimental study

Plasma Enhanced Chemical Vapor Deposition (PECVD) of SiOx thin films has been applied to the stone surface under laboratory conditions in order to assess its feasibility as an alternative method for stone protection. SiOx thin layers were deposited on oolitic limestone lithologies known to have been used for the construction and restoration of the Batalha Monastery in Portugal surface by PECVD from tetraethoxysilane (TEOS) as the reaction precursor, in capacitively coupled parallel-plate reactor. The thickness, morphologies and chemical properties of the deposited film were characterized by attenuated total reflectance -Fourier transform infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM+EDS). Laboratory simulated decay and natural aging tests were implemented to evaluate the protective effect of the deposited micron-size SiOx thin films. Results suggested that, due to the good barrier effect, SiOx films were able to isolate the stones from aggressive acidic solution, thus reducing possible dissolution-related damage. Natural aging tests proved that SiOx thin films were also able to inhibit to a high extent bio-colonization while, at the same time reducing soiling of the stone appearance. Durability and wetting property of this SiOx thin film were preliminarily assessed. This research tested, for the first time, the feasibility of applying micron-size SiOx film quickly and directly via cold plasma deposition and its versatile protection performance on carbonate stone.

Evaluation of Rhus Tox, a homeopathic formulation for treatment of Parkinson’s and Alzheimer’s disease: a network pharmacology and ex-vivo approach

Rhus toxicodendron, commonly known as Rhus tox, is a potent homeopathic medication widely used in the treatment of rheumatoid arthritis and is claimed to have potential benefits for neurodegenerative disorders. Given the ability of homeopathic medications to address the root causes of diseases, our study aimed to evaluate Rhus tox for Parkinson’s Disease (PD) and Alzheimer’s Disease (AD) using in-silico, ex-vivo, and network pharmacology approaches to obtain comprehensive information on its multi-component and multi-target effects. Phytoconstituents of Rhus tox were collected from PubMed and screened for ADMET properties. Targets for these constituents were predicted using the Binding Database and DisGeNET, resulting in 61 targets for Parkinsonism and 85 targets for alzhiemer’s disease. Protein-protein interactions (PPIs) were analysed using the STRING database. A Venn diagram was constructed for all these targets, and 5 out of 13 common targets were selected for docking studies. From these analyses, kaempferol and quercetin were identified as promising neuroprotective agents with good blood-brain barrier (BBB) permeation. The docking studies validated these predictions as most of the constituents showed good binding affinity with EGFR, SNCA and MAO-B. It was further validated using MAO inhibition assay, in which Quercetin was found to be highly efficacious, with an IC50 value of 32.69 μg/mL among the other flavonoids studied for MAO inhibition assay. The Rhus Tox also showed MAO inhibition assay similar to the standard seligiline. To conclude, we can propose that Rhus Tox primarily acts on the dopaminergic pathway, serotonergic pathway, and EGFR signaling pathway. Further in vitro and in vivo studies are needed to confirm the mechanism action and efficacy of Rhus Tox for treatment of neurodegenerative diseases.

Nanocellulose as Sustainable Eco-friendly Nanomaterials: Production, Characterization, and Applications

Nanocellulose is a biodegradable nanomaterial derived from lignocellulosic biomass through mechanical, chemical, or enzymatic defibrillation processes to convert wood fibers into nanofibrils. This material consists of a network of cellulosic fibrils with a wide range of diameters, offering unique properties suitable for various functional applications. Nanocellulose can act as a substrate or coating, serving as an eco-friendly alternative to synthetic plastics. Despite having good barrier properties and strong mechanical strength, nanocellulose films are still not as effective as synthetic plastics. They are used in creating barrier materials, flexible electronics, and coatings for paper products.

A facile and sustainable strategy to construct recyclable paper with enhanced water and oil resistance for eco-friendly food packaging

As a potential substitute for petroleum-based plastics as food packaging material, application of paper is hampered by weak resistance to water and oil. In light of this, paper barrier coating was prepared based on sodium alginate and alkyl ketene dimer. The properties of the obtained SAKD emulsion were investigated and stabilizing mechanism was proposed. Furthermore, SAKD emulsion was applied on paper surface for enhancing barrier properties against both water and oil. After coated, oil resistance KIT was increased from 0 to 8, sizing degree increased by 3977 % and Cobb30 decreased by 66.08 % probably because a more closed structure formed with lower surface energy. Barrier properties to air, water vapor and organic solvents were also strengthened. Additionally, the coating exhibited good stability after folded repeatedly. Furthermore, SAKD coating layer did not negatively affected degradability of paper and the coated paper could be efficiently recycled via a facile treatment, confirming its eco-friendliness. This work demonstrates a sustainable and simple route to prepare paper with good barrier properties and provides the feasibility of developing eco-friendly paper packaging for food based on bio-based materials.

Influence of Cobalt and Cobalt–Manganese Oxide Coating Thickness Deposited by DLI-MOCVD as a Barrier Against Cr Diffusion for SOC Interconnect

The influence of cobalt and cobalt–manganese oxide coating thickness on its ability to be a good diffusion barrier against Cr outward diffusion was investigated for stainless steel interconnects (AISI 441) of a solid oxide cell (SOC). The coatings were all synthesized using a DLI-MOCVD (Direct Liquid Injection-Metal Oxide Chemical Vapor Deposition) hot wall reactor. The study shows that a minimum cobalt oxide thickness of 300 nm was needed to be a good diffusion barrier against Cr for the 500-h exposure test. This observation was linked to the Mn concentration reached in the cobalt spinel during exposure. Indeed, during exposure at high temperature, Mn diffused from the substrate into the cobalt coating and transformed cobalt spinel into Co-Mn spinel. Whereas pure cobalt spinel was a good Cr diffusion barrier, cobalt-manganese spinel, Co3-xMnxO4, was not when x > 2. The thickness of the cobalt coatings must be chosen so that the Mn quantity coming into it from diffusion from the substrate does not degrade the protectiveness of the coating.

Shelf-Life Extension and Quality Changes of Fresh-Cut Apple via Sago and Soy-Oil-Based Edible Coatings

In-demand fresh-cut fruits are highly perishable and require shelf stability. Starch, such as sago, is a naturally available polysaccharide with good gas barrier properties. The study aimed to develop an edible coating and examine the effect of its application on the quality parameters of fresh-cut apples. The coating solution was prepared with sago and soy oil in concentrations of 3, 4, and 5% and 0, 0.25, and 0.50%, respectively. Lecithin (0.50%) was used as an emulsifier and glycerol (1.5%) as a plasticizer. Coated fresh-cut apples were evaluated for physicochemical properties (TSS, pH, non-enzymatic browning index, moisture content, weight loss, headspace gas, and color attributes) during a 12-day shelf-life study at 4 °C. Sensory analysis was also performed to assess consumer acceptability, and microbial analysis to investigate its inhibiting effect against yeast and mold. Compared to the control, developed coatings reduced browning, respiration rate, moisture, weight loss, and microbial load in fresh-cut apples. The study indicates that the blend of 5% sago and 0.5% soy oil produced the best coatings which were most effective for retaining the original quality attributes and in extending the shelf life of apple slices for 12 days in storage at 4 °C.

Poly(butylene 2,5-thiophenedicarboxylate-co-glycolate) copolyesters with good degradation and barrier properties

In this work, poly(butylene 2,5-thiophenedicarboxylate-co-glycolate) (PBTFGA) copolyesters were synthesized from 2,5-thiophenedicarboxylic acid, 1,4-butanediol and glycolic acid. The influence of the glycolic acid content on thermal properties, mechanical properties and degradation capacity of copolyesters was systematically investigated. The glass transition temperature of copolyesters closely matched that of poly(butylene 2,5-thiophenedicarboxylate) (PBTF). While also demonstrating good thermal stability. When the glycolic acid content was low, the copolyesters exhibited some crystallization capability, but they gradually became fully amorphous as the glycolic acid content increased. The tensile tests revealed that the young's modulus of the PBTFGA copolyesters ranged from 69.2 MPa to 221.4 MPa. With elongation at break exceeding 659%, outperforming most biodegradable packaging materials. Copolyesters exhibited excellent gas barrier properties to both oxygen (PO2 = 0.024 barrer) and carbon dioxide (PCO2 = 0.029 barrer), both of which are superior to poly(butylene 2,5-thiophenedicarboxylate). The incorporation of glycolic acid significantly reduced the crystalline content of the copolyesters, facilitating the interaction of water molecules with ester bonds in the polymer backbone. The weight of poly(butylene 2,5-thiophenedicarboxylate-co-glycolate) was decreased significantly during enzymatic hydrolysis, indicating excellent degradation performance

Electroless ZnO Deposition on Mg-Al Alloy for Improved Corrosion Resistance to Marine Environments

Electroless ZnO (≈900 nm) was deposited on the surface of an Mg-Al alloy (AM60) to reduce its degradation in the marine environment. Uncoated and coated ZnO samples were exposed to an SME simulated marine solution for up to 30 days. The AFM and optical images revealed that the corrosion attack on the ZnO-AM60 surface was reduced due to an increase in the surface hydrophobicity of the ZnO coating (contact angle of ≈91.6°). The change in pH to more alkaline values over time was less pronounced for ZnO-AM60 (by ≈13%), whereas the release of Mg2+ ions was reduced by 34 times, attributed to the decrease in active sites on the Mg-matrix provided by the electroless ZnO coating. The OCP (free corrosion potential) of ZnO-AM60 shifted towards less negative values of ≈100 mV, indicating that electroless ZnO may serve as a good barrier for AM60 in a marine environment. The calculated polarization resistance (Rp), based on EIS data, was ≈3 times greater for ZnO-AM60 than that of the uncoated substrate.

Modified Chitosan-Based Coating/Packaging Composites with Enhanced Antibacterial, Antioxidant, and UV-Resistant Properties for Fresh Food Preservation.

Chitosan-based biomass packaging materials are a promising material for food preservation, but their limited solubility, antioxidant capacity, UV resistance, and mechanical properties severely restrict their application. In this study, we developed a novel chitosan-based coating/packaging composite (QCTO) using quaternary ammonium salt and tannic acid (TA)-modified chitosan (QCS-TA) and oxidized chitosan (OCS). The introduction of quaternary ammonium salt and TA effectively improves the water solubility and antibacterial, antioxidant, and UV-resistant properties of chitosan. The Schiff-base bond formed between OCS and QCS-TA, along with the TA-mediated multiple interactions, conferred the prepared composite film with good mechanical properties (69.9 MPa tensile strength) and gas barrier performance to water (14.3 g·h-1·m-2) and oxygen (3.5 g·mm·m-2·h-1). Meanwhile, the prepared QCTO composites demonstrate excellent biocompatibility and safety and are applied as coatings for strawberries and bananas as well as packaging films for mushrooms. These preservation experiments demonstrated that the prepared composites are able to effectively reduce weight loss, prevent microbial growth, maintain color, and significantly prolong the shelf life of fresh products (bananas, strawberries, and mushrooms extended shelf life by 6, 5, and 6 days, respectively). Therefore, the developed QCTO coating/packaging film shows great potential for applications in the field of food preservation and packaging.

Application of bio-based modified graphene oxide in epoxy composite coatings

This study focuses on the application of bio-based modified graphene oxide epoxy composite coatings and analyzes the coating properties, such as anticorrosive ability, hydrophobicity and self-healing properties, through experimental studies of modified graphene oxide using substances such as cashew nut phenol, lignin and glutamic acid. Summarizing the latest research progress, it is found that the materials such as cardanol, lignin and glutamic acid are from a wide range of sources, are green and have a wide range of application prospects, and it is also shown in the results of EIS analysis that the modified graphene oxide epoxy compliant coatings exhibit higher impedance values at low frequencies, and have good protective properties and barrier properties. The cashew phenol-modified graphene oxide epoxy coating has high densification, high barrier capacity and high hydrophobicity in addition to good coating healing ability using GO modification. The glutamate-modified graphene oxide epoxy coating can be desorbed by using HCL solution to make L-Glu/GO reusable, with good reusability and high application value.

Biodegradable and antioxidant films with barrier properties to visible and ultraviolet light using Hass avocado (Persea americana Mill.) by-products

The search for renewable sources that can be used to develop products as alternatives to traditional polymers in the future, without affecting food safety, represents a challenge for the food industry. In this context, agro-industrial waste has emerged as an interesting alternative. This study evaluated biodegradable films made from Hass avocado seed flour without (Control film; PC) and with antioxidant extracts (PExBIO and PExIND) derived from the epicarp of the same fruit. The results showed that all the films blocked visible (over 96 %) and ultraviolet light (99.9 %), which was mainly attributed to perseorangine, a compound generated by the action of polyphenol-oxidase. The films also exhibited good water vapor barrier properties. PExIND showed the highest mechanical strength (Young's modulus = 901.8 ± 33.4 MPa; tensile strength = 9.1 ± 1.0 MPa; elongation = 3.5 ± 0.5 %), correlating with the highest crystallinity index (14.9 %). The incorporation of extracts increased the content of phenolic compounds and antioxidant capacity in PExBIO and PExIND compared to PC, with no significant differences between them. Moreover, the biodegradation test indicated that the films showed high biodegradability. Therefore, Hass avocado residues could be used to produce biodegradable antioxidant films, suitable for packaging light-sensitive and low-moisture products.

Embedding Biomimetic Vascular Networks via Coaxial Sacrificial Writing into Functional Tissue.

Printing human tissues and organs replete with biomimetic vascular networks is of growing interest. While it is possible to embed perfusable channels within acellular and densely cellular matrices, they do not currently possess the biomimetic architectures found in native vessels. Here, coaxialsacrificial writing into functional tissues (co-SWIFT) is developed, an embedded bioprinting method capable of generating hierarchically branching, multilayered vascular networks within both granular hydrogel and densely cellular matrices. Coaxial printheads are designed with an extended core-shell configuration to facilitate robust core-core and shell-shell interconnections between printed branching vessels during embedded bioprinting. Using optimized core-shell ink combinations, biomimetic vessels composed of a smooth muscle cell-laden shell that surrounds perfusable lumens are coaxially printed into granular matrices composed of: 1) transparent alginate microparticles, 2) sacrificial microparticle-laden collagen, or 3) cardiac spheroids derived from human induced pluripotent stem cells. Biomimetic blood vessels that exhibit good barrier function are produced by seeding these interconnected lumens with a confluent layer of endothelial cells. Importantly, it is found that co-SWIFT cardiac tissues mature under perfusion, beat synchronously, and exhibit a cardio-effective drug response in vitro. This advance opens new avenues for the scalable biomanufacturing of vascularized organ-specific tissues for drug testing, disease modeling, and therapeutic use.

Preparation of biodegradable poly(lactic acid)/poly[(butylene diglycolate)‐co‐furandicarboxylate] blends with excellent toughness and gas barrier performance

AbstractPoly(lactic acid) (PLA) is known as one of the most promising biodegradable polyesters, while inherent brittleness and insufficient gas barrier performance limit its potential application as a film material. Herein, poly[(butylene diglycolate)‐co‐furandicarboxylate] (PBDF) with excellent flexibility and good gas barrier properties was synthesized and then melt‐blended with PLA. Compared with neat PLA, the elongation at break of the PLA/PBDF20 blend increased more than 40 times and reached over 176.7%. In addition, its O2, CO2 and H2O permeability coefficients decreased by 21.3%, 50.8% and 46.3%, respectively. Moreover, the PLA/PBDF20 blend also exhibited better biodegradability, with a weight loss rate increasing from 2.7% of neat PLA to 19.0% after 5 weeks of composting. Notably, incorporation of a multifunctional epoxy compatibilizer (Joncryl ADR®‐4368) into the PLA/PBDF blends further enhanced their toughness and gas barrier performance, which could be attributed to the improvement of the miscibility between PLA and PBDF. © 2024 Society of Chemical Industry.

Design, synthesis and biological evaluation of N-salicyloyl tryptamine derivatives as multifunctional neuroprotectants for the treatment of ischemic stroke

Ischemic stroke (IS) is a disease of high death and disability worldwide with few medications in clinical treatment. Neuroinflammation and oxidative stress are considered as crucial factors in the progression of IS. In our previous studies, N-salicyloyl tryptamine derivative (NST) L7 exhibited promising anti-inflammatory properties and is considered a potential clinical therapy for IS but had limited antioxidant capacity. Here, we have designed, synthesized, and biologically evaluated 30 novel NSTs for their neuroprotective effects against cerebral ischemia-reperfusion (CI/R) injury. To identify a multifunctional neuroprotectant with enhanced antioxidant and anti-inflammatory capacity, as well as an effective therapeutic agent for CI/R damage. Among them, M11 exhibited synergistic highly anti-oxidant, anti-inflammatory, anti-ferroptosis, and anti-apoptosis effects and surpassed the parent compound L7. Further studies demonstrated that the synergistic and efficient neuroprotective role of M11 was mainly achieved by activating Nrf2 and stimulating its downstream target HO-1/GCLC/NQO1/GPX4. In addition, M11 possessed good blood-brain barrier permeability. Moreover, M11 effectively reduced cerebral infarct volume and improved neurological deficits in MCAO/R mice. Its hydrochloride form, M11·HCl, exhibited better pharmacokinetic properties, high safety, and a significant reduction in infarct volume, which is comparable to Edaravone. In conclusion, our findings suggested that M11 capable of activating Nrf2, could represent a promising candidate agent for IS.

A Review of Recent Developments in Edible Films and Coatings-Focus on Whey-Based Materials.

Packaging for food products is particularly important to preserve product quality and shelf life. The most used materials for food packaging are plastic, glass, metal, and paper. Plastic films produced based on petroleum are widely used for packaging because they have good mechanical properties and help preserve the characteristics of food. However, environmental concerns are leading the trend towards biopolymers. Films and coatings based on biopolymers have been extensively studied in recent years, as they cause less impact on the environment, can be obtained from renewable sources or by-products, are relatively abundant, have a good coating and film-forming capacity, are biodegradable and have nutritional properties that can be beneficial to human health. Whey protein-based films have demonstrated good mechanical resistance and a good barrier to gases when at low relative humidity levels, in addition to demonstrating an excellent barrier to aromatic compounds and especially oils. The use of whey proteins for films or coatings has been extensively studied, as these proteins are edible, have high nutritional value, and are biodegradable. Thus, the main objective of this document was to review new methodologies to improve the physicochemical properties of whey protein films and coatings. Importance will also be given to the combinations of whey proteins with other polymers and the development of new techniques that allow the manipulation of structures at a molecular level. The controlled release and mass transfer of new biomaterials and the improvement of the design of films and packaging materials with the desired functional properties can increase the quality of the films and, consequently, broaden their applications.

Fully Bio-Based Blends of Poly (Pentamethylene Furanoate) and Poly (Hexamethylene Furanoate) for Sustainable and Flexible Packaging.

In the present study, bio-based polymeric blends have been prepared for applications in the field of sustainable food packaging, starting from two furan-based homopolymers, poly(hexamethylene 2,5-furanoate) (PHF) and poly(pentamethylene 2,5-furanoate) (PPeF). PHF and PPeF were synthesized by two-step melt polycondensation-a solvent-free synthetic strategy-and then binary physical mixtures, PHF/PPeF, with different weight compositions were prepared by dissolution in a common solvent. The blends were processed into compression-moulded films, and molecular, morphological, structural, thermal, and mechanical characterizations were subsequently carried out. Blending did not negatively affect the thermal stability of the parent homopolymers, and good compatibility between them was observed. This strategy also allowed for the modulation of the chain rigidity as well as of the crystallinity, simply by acting on the relative weight amount of the homopolymers. From a mechanical point of view, the presence of PPeF led to a reduction in stiffness and an increase in the elongation at break, obtaining materials with an elastomeric behaviour. Evaluation of the gas barrier properties confirmed that the good barrier properties of PHF were preserved by blending. Finally, lab-scale composting tests confirmed a greater weight loss of the mixtures with respect to the PHF homopolymer.