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Nowadays, many studies are conducted on multilayer hydrogels for wound dressing. On the other hand, considering the emergence of bacterial resistance to common antibiotics, studies on the use of natural essential oils and their derivatives that have antibacterial and antioxidant activity can be useful. Herein, a novel bilayer hydrogel developed from polyvinyl alcohol and chitosan with the incorporation of Saqez essential oil (SEO) was synthesized. The results showed a gel-type structure with specific compression and flexibility, while the microscopic images confirmed the formation of a bilayer hydrogel. Further, the data showed that increasing the concentration of SEO reduces the swelling and water vapor permeability and increases the water retention and hydrophobicity of the hydrogel surface. The effects of the combination of SEO in the bilayer hydrogel led to a strong antioxidant property and increased antimicrobial activity. Also, the in vitro results demonstrated that the bilayer hydrogels are biocompatible, non-toxic, and blood compatible. Finally, the results of the in vivo tests showed that these bilayer hydrogels had good homeostatic efficiency. Overall, the obtained results indicate that these bilayer hydrogels are promising candidates for wound dressing. [Display omitted] [ABSTRACT FROM AUTHOR]

Double-layer dermal substitutes (DS) generally provide more effective therapeutic outcomes than single-layer substitutes. The architectural design of DS incorporates an outer layer to protect against bacterial invasions and maintain wound hydration, thereby reducing the risk of infection and the frequency of dressing changes. Moreover, the outer layer is a mechanical support for the wound, preventing undue tension in the affected area. A 3D-printed polycaprolactone (PCL) membrane was utilized as the outer layer to fabricate DS wound dressing. Simultaneously, a polyvinyl alcohol/chitosan/sildenafil citrate (PVA/CS/SC) scaffold was electrospun onto the PCL membrane to facilitate cellular adhesion and proliferation. Scanning electron microscopy (SEM) analysis of the PCL filaments revealed a consistent cross-sectional surface and structure, with an average diameter of 562.72 ± 29.15 μm. SEM results also demonstrated uniform morphology and beadless structure for the PVA/CS/SC scaffold, with an average fiber diameter of 366.77 ± 1.81 nm for PVA/CS. The addition of SC led to an increase in fiber diameter while resulting in a reduction in tensile strength. However, drug release analysis indicated that the SC release from the sample can last up to 72 h. Animal experimentation confirmed that DS wound dressing positively accelerated wound closure and collagen deposition in the Wistar rat skin wound model. [Display omitted] [ABSTRACT FROM AUTHOR]

Thymol (Th) and d -limonene (L) exhibit low stability and are prone to oxidation when exposed to air, light, humidity, and high temperatures. This study examined the coencapsulation of Th and L into Ferula assafoetida gum (AFG) microparticles. Scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analyzer (TGA) were done to characterize the obtained complexes. Furthermore, the encapsulation efficiency, antibacterial properties, cytotoxicity, and anticancer properties of both the free and encapsulated forms of L and Th were measured. For all samples, by increasing the percentage of bioactive compound (L, Th, and L-Th) from 2.5 to 5 % w/w, the EE was increased. FTIR and XRD analysis results demonstrated that Th and L were successfully incorporated into the AFG. Additionally, thermogravimetric analysis showed that in the thermal graphs of all samples, the first weight loss occurred between 30 °C and 160 °C, which was due to the evaporation of water. In the free L and Th graph, a sharp reduction peak was observed in which 80 % of compounds were lost. These reduction peaks disappeared in the thermal graphs of L: AFG and Th: AFG revealing that the thermal stability of Th and L was significantly increased upon their incorporation into the AFG. The inclusion of Th into the AFG also led to an increase in its antibacterial activity, while L exhibited acceptable antibacterial activity, albeit not as high as Th. Additionally, according to the MIC results, Th: AFG had the best antibacterial activity among all compounds, especially on gram-positive bacteria. According to the result of the MTT assay, there was a significant difference between the IC 50 of free Th (123.4 μg/ml) and Th: AFG (2312 μg/ml), and free L (1762 μg/ml) and L: AFG (2480 μg/ml) showing that encapsulated Th and L into the AFG has decreased the cytotoxicity of free compounds against L929 cell line. Also, Th: AFG had the best anticancer activity against Hella and CT26 cell lines among all compounds. Finally, the flow cytometry analysis demonstrated that the encapsulated particles effectively eliminated cancer cells. The outcomes imply that AFG can be employed as a suitable delivery system to enhance the use of Th and L into the food and pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Lysine Specific Demethylase 1 (LSD1) has been identified as a chromatin-modifying enzyme implicated in various cancer pathogeneses, highlighting the potential for novel epigenetic cancer treatments through the development of effective inhibitors. We employed 3D-QSAR pharmacophore modeling, molecular docking, and molecular dynamics simulations to identify a promising drug candidate for LSD1 inhibition. RMSD, RMSF, H-bond, and DSSP analysis demonstrated that ZINC02599970 (Arformoterol) and ZINC13453966 exhibited the highest LSD1 inhibitory potential. Experimental validation using MCF-7 and MDA-MB-231 cell lines revealed that Arformoterol displayed potent antiproliferative activity with IC 50 values of 12.30 ± 1.48 μM and 19.69 ± 1.15 μM respectively. In contrast, the IC 50 values obtained for the control (tranylcypromine) in exposure to MCF-7 and MDA-MB-231 cells were 104.6 ± 1.69 μM and 77 ± 0.67 μM, respectively. Arformoterol demonstrated greater LSD1 inhibitory potency in MCF-7 cells compared to MDA-MB-231 cells. Also, the expression of genes involved in chromatin rearrangement (LSD1), angiogenesis (VEGF1), cell migration (RORα), signal transduction (S100A8), apoptosis, and cell cycle (p53) were investigated. Arformoterol enhanced apoptosis and induced cell cycle arrest at the G2/M phase, both in MCF-7 and MDA-MB-231 cancer cells. Based on our findings, we propose that Arformoterol represents a promising candidate for breast cancer treatment, owing to its potent LSD1 inhibitory activity. • LSD1 acts as a dual transcriptional repressor and activator based on its target residue. • LSD1 directly and indirectly related to the expression of 102 genes. • Arformoterol exhibits strong LSD1 inhibitory potential (anti proliferative activity). • With availability of Arformoterol concerns about clinical trial costs is diminished. [ABSTRACT FROM AUTHOR]

As a serious neurodegenerative disorder, the prevalence of Parkinson's disease is predicted to dramatically increase in the coming decades. Despite the development of numerous drugs for its treatment, oral administration of levodopa has remained the simplest and most effective pharmacological approach in the management of Parkinson's disease. In this research, the levodopa-imprinted hydrogel was synthesized by reverse emulsion polymerization in the presence of levodopa followed by modification with polypyrrole. The antioxidant activity of amphiphilic non-levodopa-imprinted hydrogel was studied by 2,2-Diphenyl-1-picrylhydrazyl active radicals, which indicated 100% efficiency in the applied amount. Amphiphilic non-levodopa-imprinted hydrogel cytotoxicity was evaluated by MTT assay, which confirmed no significant toxicity after 24 and 48 h even at high concentrations. Moreover, in vitro releasing property of the levodopa-imprinted hydrogel was studied in the pH range of 4 to 7.4, which reached 60 and 80% within 160 h, respectively. [ABSTRACT FROM AUTHOR]

An easy-to-use food packaging label with pH and ammonia sensitivity was developed by adding betacyanin (5, 10 and 15 mg per g of starch) from flowers of paperflower (Bougainvillea glabra) to potato starch film made using the solvent casting method. The betacyanin was well dispersed into the starch matrix and formed new interactions with it as revealed by FTIR. The film containing 15 mg/g of betacyanin showed a color change from light pink to yellow as a response to pH adjustment of between 2 to 13. It was also able to detect the presence of ammonia in a range of 0.1 and 0.01 mg of ammonia per ml of water. Surface hydrophobicity and water vapor barrier capacity of the starch film increased by addition of the betacyanin, yet their mechanical strength decreased in the presence of the betacyanin. The ability of the film in the real-time indication of fish quality as a label was also evaluated during the storage of Caspian sprat at 4 °C. A visual change in the color of the packaging label from pink to yellow in parallel with the increase in the total volatile basic nitrogen (TVB-N), microbial count of the fish samples was detected. The starch/betacyanin film could be a novel intelligent label for application in food packaging. • A pH/ammonia sensor was developed by adding betacyanin to starch film. • Color of the film changed from red to yellow at pH > 9. • The film showed a color response to 0.01–0.1 mg/ml of ammonia. • The betacyanin reduced water sensitivity of the starch film. • The sensor visually alarmed the loss of fish quality as a label. [ABSTRACT FROM AUTHOR]

Chitosan (CS) and poly (ε-caprolactone) (PCL) are two most usable polymers in biomedical applications. In this study, chitosan has been modified and incorporated with poly (ε-caprolactone) to fabricate bone tissue engineering scaffold. Moreover, hydroxyapatite nanoparticles were added to enhance bioactivity and mechanical properties of scaffold. Bulk and fibrous comparative results showed significant effect of fiber diameter and distribution on mechanical properties. Moreover, the incorporation of chitosan-g-poly (ε-caprolactone) (CS-g-PCL) significantly decreases fiber diameter of pure PCL scaffold. Furthermore, both CS-g-PCL and nHA enhance mineralization and degradation of the scaffold soaked in simulated body fluid (SBF) and phosphate buffered saline (PBS), respectively. In vitro cytocompatibility assays also confirmed high cell viability and proliferation on the samples. Taken together, the results suggest that the microfabricated nanocomposite scaffolds could be used in bone tissue engineering. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, encoding sequence of a new type 2 RIP (pebulin) was isolated and cloned from dwarf elder (Sambucus ebulus L.) native to the northern regions of Iran. The nucleotide sequence of pebulin was ligated to the pET-28a(+) expression plasmid and cloned into the E. coli strain BL21 (DE3) in order to express heterologously of recombinant protein. The recombinant pebulin protein was mainly produced in the form of insoluble inclusion bodies probably because to absence of N-glycosylation process in E. coli. Therefore, in order to increase the expression of recombinant protein in soluble form, co-expression of the target protein with the pG-Tf2 chaperone plasmid and incubation of bacterial culture under low temperature were used to enhance solubility and accumulation of recombinant protein. After purification of the recombinant protein using affinity chromatography method, the bioactivity of pebulin was analyzed by hemagglutination, anticancer, and antifungal assays. The results of the hemagglutination assay showed that purified pebulin agglutinated erythrocytes in all human blood groups. In addition, pebulin considerably inhibited the proliferation of cancer cell lines MCF-7 and HT-29 in a time- and dose-dependent manner and indicated remarkably growth-inhibiting effect against the plant pathogenic fungi such as Alternaria solani and Fusarium oxysporum. [ABSTRACT FROM AUTHOR]

The present study was conducted with the aim of fabricating smart bilayer polymers based on carboxymethyl cellulose-cellulose nanocrystals film and poly(lactic acid)- Viola odorata extract nanofibers (CMC-CNC and PLA-VOE) for freshness monitoring of Pacific white shrimps, minced lamb meat, chicken fillets, and rainbow trout fillets, during refrigerated storage conditions. The fabricated indicators based on CMC-PLA-VOE 5%, CMC-CNC 1%-PLA-VOE 5%, and CMC-CNC 3%-PLA-VOE 5% presented remarkable color changes in pH 1–12 buffer solutions, including red at pH 1–6, violet at pH 7–8, green at pH 9–10, and brown at pH 11–12. Significantly lower water vapor permeability and oxygen transmission rate of prepared polymers were found in comparison with the control groups (P < 0.05). Regarding the monitoring of food samples in real-time, the samples spoiled after 3 days, evidenced by total viable count, psychrotrophic bacterial count, total volatile basic nitrogen, and pH values of 7.17–7.54 log CFU/g, 5.68–6.23 log CFU/g, 25.14–28.12 mg N/100 g, and 7.10–7.66, respectively. Meanwhile, the noticeable color change of prepared indicators from white to violet (day 3) and finally dark violet (day 7) was observed, indicating a potential application in intelligent packaging for real-time control of the freshness of perishable food samples. • Poly(lactic acid)- Viola odorata anthocyanins nanofibers had excellent sensitivity to pH 1–12 and NH 3. • The color indicators changed from white to dark violet during food spoilage. • The indicators identified spoilage in the refrigerated shrimps, minced lamb meat, chicken fillets, and rainbow trout fillets. • V. odorata anthocyanins had antimicrobial and antioxidant activities. • The water and oxygen permeability properties of polymers reduced using V. odorata extract and cellulose nanocrystals. [ABSTRACT FROM AUTHOR]

Abstract Laccase was immobilized using a combinatorial strategy of cross-linking and entrapping in mesoporous silica to prepare entrapped enzyme species including simply adsorbed, entrapped cross-linked enzyme (E-CLE) and entrapped cross-linked enzyme aggregate (E-CLEA) to explore their potential in phenol removal. Parameters including pH, temperature, time and cross-linker concentration were optimized to achieve an immobilized product with highest laccase specific activity. Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the immobilization products. The storage and operational stability analysis were also carried out. Accordingly, E-CLEAs showed improved thermal and pH stabilities and activity retention in hydrophobic and hydrophilic solvents. Moreover, based on the resulted half-lives (t 1/2) for free and insoluble laccases, the improved storage stability is reported for E-CLEAs at 1.71 and 20.88 days for them, respectively. In addition, the immobilized biocatalyst exhibited good operational stability and reusability through maintaining up to 79% of its initial activity after 20 cycles of successive operations. In conclusion, E-CLEAs have catalytic potential in efficient phenol removal and advantages of the insolubilized form of laccase as E-CLEAs make it an appealing system in applications such as possible treatment of phenol-contaminated wastewater. Highlights • Enzyme immobilization achieved through entrapping of cross-linked protein aggregates in a meso-porous silica • Dephenolization can be achieved using immobilized Laccase as E-CLEA • E-CLEA displays an improved half-life against free enzyme • The immobilization product is reusable and shows improved competency in phenol removal [ABSTRACT FROM AUTHOR]

In this study, we synthesized thermo-responsive chitosan (TCTS) hydrogels, and loaded with different concentrations of antimicrobial peptide (AMP) (0, 4, 8 and 16 μg·ml−1) to fabricate an antibacterial wound dressing against resistant clinical isolates. Physico-chemical properties, release behavior, cytobiocompatibility and antibacterial activity of the AMP-TCTS hydrogels against standard strain and resistant Acinetobacter baumannii were fully determined in vitro. The TCTS-40% β-glycerolphosphate hydrogels showed a gelation time of 15 min at 37 °C. 80% weight loss at day 35 with no changes in pH value was observed. AMP-TCTS hydrogels showed a burst release of AMP (around 40%) at day 1, and a controlled release up to day 7. A dramatic water uptake was observed at first 4 h, and then continued for 10 h in a steady manner. All the AMP-TCTS hydrogels showed excellent cytobiocompatibility for human fibroblasts. The TCTS showed no antibacterial activity against both standard strain and clinical isolates. All the AMP-TCTS hydrogels had strong antibacterial activity against standard strains, but only 16 μg·ml−1 showed antibacterial behavior against resistant A. baumannii. Our results strongly suggest the 16 μg·ml−1 AMP-TCTS hydrogel as an excellent antibacterial wound dressing against resistant A. baumannii , and now promises to proceed with pre-clinical investigations. [ABSTRACT FROM AUTHOR]

Removal of chondroitin sulfate proteoglycans (CSPGs) with chondroitinase ABC I (ChABC) facilitates axonal plasticity, axonal regeneration and remyelination, following injury to the central nervous system (CNS). However, the ChABC rapidly undergoes thermal inactivity and needs to be injected repeatedly. Here this limitation was overcame by immobilizing the ChABC on porous silicon (PSi) nanoparticles (ChABC@PSi). The efficacy of immobilized ChABC on CSPGs level and the demyelination insult was assessed in mice corpora callosa demyelinated by 6 weeks cuprizone (CPZ) feeding. ChABC@PSi was able to reduce the amount of CSPGs two weeks after animals treatment. CSPGs digestion by ChABC@PSi reduced the extent of demyelinated area as well as the astrogliosis. Furthermore, ChABC@PSi treatment increased the number of newly generated oligodendrocyte lineage cells which imply for enhanced myelin repair. Our results showed that effective CSPGs digestion by ChABC@PSi enhanced remyelination in CPZ model. Accordingly, ChABC@PSi may have a great potential to be used for treatment of diseases like multiple sclerosis and spinal cord injury by promoting the regeneration of damaged nerves. Unlabelled Image • ChABC loaded on PSi (ChABC@PSi) was stable, in vitro and in vivo. • ChABC@PSi decreased CSPGs deposition in an animal model of multiple sclerosis. • ChABC@PSi reduced CPZ-induced reactive astrogliosis and the extent of demyelination in CC. • ChABC@PSi promoted remyelination by increasing the generation of oligodendrocyte lineage cells. [ABSTRACT FROM AUTHOR]

Here, we have studied the role of a histidine residue with the lowest solvent accessibility among other histidine residues at the end of a short connecting structure ( 189 AEL H 192 ) of the catalytic domain of the exo-inulinase through creation of H192A mutant. Site-directed mutagenesis method was applied to create the mutant enzyme. Molecular dynamics (MD) simulations, spectroscopic, calorimetric and kinetics analysis were used to study the structural and functional consequences of His192 substitution. Accordingly, the thermo-stabilities and catalytic performance were decreased upon H192A mutation. In silico and experimental approaches evidently confirm that His192 residue of exo-inulinase possesses structural and functional importance regardless of the lack of direct interaction with the substrate or involvement in the catalytic activity of exo-inulinase. [ABSTRACT FROM AUTHOR]

Inulinases are classified as hydrolases and widely used in the food and medical industries. Here, we report the deletion of a six-membered adjacent active site loop fragment ( 74 YGSDVT 79 sequence) from third Ω-loop of the exo-inulinase containing aspartate residue from Aspergillus niger to study its structural and functional importance. Site-directed mutagenesis was used to create the mutant of the exo-inulinase (Δ6SL). To investigate the stability of the region spanning this loop, MD simulations were performed 80 ns for 20-85 residues. Molecular docking was performed to compare the interactions in the active sites of enzymes with fructose as a ligand. Accordingly, the functional thermostability of the exo-inulinase was significantly decreased upon loop fragment deletion. Evaluation of the kinetics parameters ( V max , K m , k cat and, k cat / K m ) and activation energy ( E a ) of the catalysis of enzymes indicated the importance of the deleted sequence on the catalytic performance of the enzyme. In conclusion, six-membered adjacent active site loop fragment not only plays a crucial role in the stability of the enzyme, but also it involves in the enzyme catalysis through lowering the activation energy of the catalysis and effective improving the catalytic performance. [ABSTRACT FROM AUTHOR]

Abstract The novel trinary bio-composite film based on Tragacanth/Hydroxypropyl methylcellulose/Beeswax reinforced silver nanoparticles (AgNPs) was developed. This study investigated the effect of AgNPs (2, 4 and 8%) on some physico–mechanical and antimicrobial properties of bio-composite film. It was discovered that AgNPs reduced the composite tensile strength from 33.64 to 16.12 MPa. However, water vapor permeability was improved by addition of the nanoparticles (4.57–2.16 × 10−13 g m/m2 s Pa). The use of AgNPs influenced the apparent color of bio-composite film. The microscopic surface structure and topography of the films were also examined by scanning electron microscopy and Fourier transform infrared, respectively. Dynamic mechanical thermal analysis results showed that the thermal stability of film was slightly decreased through incorporation with AgNPs. Finally, nano-composite films demonstrated strong antibacterial activity against tested pathogen bacteria in the contact surface zone. The antimicrobial results suggest that new nanocomposite film may be used as food active packaging. Highlights • The mechanical resistance of the film decreased slightly by adding AgNPs. • Thermal stability of silver nano-composite film was slightly decreased through incorporation with AgNPs. • FT-IR analysis exhibited no chemical bonding between biopolymer and AgNPs. • Nano-composite films demonstrated strong antibacterial activity against tested pathogen bacteria. [ABSTRACT FROM AUTHOR]

Abstract A sulfated polysaccharide (fucoidan) has been isolated from Nizamuddinia zanardinii using subcritical water extraction method (SCWE), and extraction conditions were optimised using the response surface methodology. The optimum extraction conditions were found to be: extraction time of 29 min, extraction temperature of 150 °C, and raw material-to-water ratio of 21 g/mL. The fucoidan yield under these optimum conditions was 25.98%, which was considerably higher than that of conventional solvent extraction (5.2%). Extraction time and temperature were the extraction variables that most significantly affected fucoidan yield. Chemical and monosaccharide composition, molecular weight, and the antioxidant, anticancer and immunomodulatory activities of the extract have also been investigated. The monosaccharide composition of fucoidan included fucose (34.13%), mannose (30.70%), galactose (23.19%), xylose (9.35%) and glucose (2.65%). The average molecular weight of the extracted fucoidan was 694 kDa. Antioxidant results revealed that SCWE-extracted fucoidan had appreciable ABTS radical scavenging (70.35%) and reducing power (0.182 Abs). The anticancer activity of fucoidan ranged from 24.60 to 49.46% for HeLa cells and from 23.95 to 46.78% for HepG 2 cells. The NO production of RAW264.7 cells was observed to be dose-dependent, while maximum NO production was found to be 34.82 μmol at a 50 μg/mL fucoidan concentration. Graphical abstract Unlabelled Image Highlights • Subcritical water extraction (SCWE) was used to extract fucoidan from N. zanardinii. • Response surface methodology was used for optimization of extraction process. • Extraction time and temperature were the most influential factors. • High extraction yield of 25.98% was obtained with SCWE method. • SCWE-extracted fucoidan has appropriate antioxidant, anticancer and immunomodulatory activity. [ABSTRACT FROM AUTHOR]

Abstract To date, the high cost of enzyme production, lack of enzyme reusability and operational stability are the main limitations of the enzyme's application in industry. In this work, inulinase was covalently immobilized on the surface of glutathione-coated gold magnetic nanoparticles (GSH-AuMNPs). The synthesized NPs were fully characterized. The effects of different restriction factors such as substrate concentration, temperature, and pH on the performance and stability of the enzyme were examined. The maximum activity and immobilization yield were estimated 83% and 93%, respectively. The immobilized inulinase showed maximum activity at pH 4.5 and 60 °C. The kinetic parameters of the immobilized enzyme were not changed significantly after the immobilization process. The reusability assessment indicated that approximately 78% of the initial activity of immobilized inulinase remained after ten times recycling. The storage stability of inulinase was improved by the immobilization process. The inulin hydrolysates were checked by HPLC and the end products only contained two components, 98% of fructose and up to 2% of glucose in both free enzyme and immobilized enzyme systems. This study introduced a simple, effective and inexpensive immobilization process, which is applicable in different biomedical, biotechnological and food industries. Graphical abstract Unlabelled Image Highlights • Successful synthesis of glutathione decorated gold magnetic nanoparticles (GSH-AuMNPs) was performed. • Inulinase was successfully immobilized onto the GSH-AuMNPs with a high enzyme activity recovery of 83%. • The immobilized inulinase retained 78% of initial activity after ten cycles of reuse. • The storage stability of inulinase was improved by immobilization process. • The end products contained high amount of fructose (98%) and only up to 2% of glucose. [ABSTRACT FROM AUTHOR]

Abstract In this study, the most important variables (incubation temperature, fermentation time and yeast extract concentration) responsible for the exopolysaccharides (EPSs) production by Lactobacillus acidophilus LA5 and Bifidobacterium animalis subsp. lactis BB12 were screened. The EPSs synthesize by LA5, BB12, and their co-culture were successfully optimized and were 349.82 ± 5.39, 146.83 ± 3.99 and 187.02 ± 1.54 mg/L, respectively. GC–MS analysis indicated that the purified EPSs are heteropolysaccharide and consisted of glucose, galactose, glucuronic acid, and xylose. The FT-IR analysis was used to investigate functional groups of purified EPSs and NMR analysis was used to study the structure of them. The DSC, TGA and DTG analysis of the extracted EPSs showed that they had high thermal stability and degradation temperature. The results of bioactivity analysis indicated that maximum DPPH and hydroxyl radicals scavenging activity were 59.30 ± 1.95, 56.76 ± 0.79, 62.33 ± 1.02% and 59.94 ± 1.68, 46.40 ± 0.73, 53.54 ± 0.76%, respectively for the EPSs of LA5, BB12, and their co-culture. Additionally, reducing power of the produced EPSs by LA5, BB12, and their co-culture were 1.047 ± 0.001, 1.270 ± 0.045 and 1.139 ± 0.018, respectively. Consequently, all these results showed that the EPSs produced by LA5, BB12, and their co-culture had a high potential as natural antioxidants or bioactive additive in the food industry. Highlights • Fermentation variables were optimized by Box Behnken and D-optimal mixture designs. • The statistical models of EPSs production by pure and mixed cultures of BB12 and LA5 were established. • Characteristics differences of produced EPSs by pure and mixed cultures of BB12 and LA5 were compared. • The GC–MS analysis identified glucose, galactose, xylose and glucuronic acid as components of EPSs. • The antioxidant activity of the produced EPSs investigated by three different assays. [ABSTRACT FROM AUTHOR]

Tyrosinase (EC 1.14.18.1) is a key copper-containing metalloenzyme widely distributed in nature and plays determinant role in melanin biosynthesis. The enzyme manifests two unusual catalytic properties including oxidase and monooxygenase activities. Its inhibitors may be applied to efficiently treat of hyperpigmentation and widely used in pharmaceutical and cosmetic products, as well as food supplements and insecticides. The present study aims to evaluate the inhibitory effects of some novel azo-hydrazone tautomeric dyes (4a–e) including bioactive thiazolidinone moiety on the activity of the mushroom tyrosinase. When L-3,4-dihydroxyphenylalanine (L-Dopa) was used as the substrate for the enzyme, the compounds 4d, 4a, and 4e showed strong inhibitory effects against the activity of the enzyme (61%, 56%, and 49% inhibition in the presence of 60 μM of each compound, respectively). The IC 50 values of the synthetized compounds were measured and their inhibition properties were also visualized by zymography. According to tyrosinase inhibitory activity, the compounds 4a, 4c, 4d and 4e exhibited strong inhibitory activities with IC 50 values of 45.83, 140.25, 37.59, and 42.31 μM, respectively, compared to the positive control kojic acid (29.44 μM). Kinetic study of 4d compound (as the most potent inhibitor) revealed that the compound acts as a reversible competitive inhibitor of the enzyme with the Ki value of 31.0 μM. We also simulated the molecular docking with the compound 4d and the results confirmed that the compound strongly interacts with the mushroom tyrosinase residues. All results totally suggest that thiazolidine derivatives, especially 4d, 4a, and 4e, can be considered as safe and efficient tyrosinase inhibitors. They also have the potential to be used in the correspond fields. [ABSTRACT FROM AUTHOR]

Extremozymes have gained importance for their ability to efficiently develop the processes in rigorous industrial conditions with incidence in the recycling of especially robust natural wastes. The production of an extracellular laccase from the halophilic bacterium Chromohalobacter salexigens aided for the bio-delignification of almond shell was optimized using response surface methodology followed by one-factor-at-a-time, resulting in an 80-fold increase in the enzyme yield. Out of 10 different medium components, CuSO 4 , ZnSO 4 , glucose, and urea were shown to have the greatest effects on the laccase production. The crude laccase was surprisingly stable against the various solvents, salts, chemicals, pH ranges, and temperatures, and it exhibited a high catalytic efficiency to a wide range of phenolic and non-phenolic substrates. Laccase reduced the kappa number of the lignin of almond shell by approximately 27% without the aid of a mediator, and the delignification efficiency strengthened by up to 58% reduction in kappa number in the used harsh conditions. Due to the high potential of the enzyme in delignification, specifically under extreme conditions, laccase from C. salexigens can be considered as an ideal alternative for chemical treatment methods in cellulose fibres extraction of lignocellulosic bio-wastes or delignification of the lignin and lignin-derived industrial wastes. [ABSTRACT FROM AUTHOR]

Protein crucial function and flexibility directly depend on its whole structure which is determined by the native distribution of structural elements. Any disturbances in a protein architecture leads to many kind of abnormalities and intra- or extracellular accumulation of misfolded proteins which are the basis of conformational diseases. Glycation is one of the most important unwanted post-translational modifications (PTM) which modifies protein three dimensional decoration and triggers its abnormalities. In current review, we take a look at the brief history of protein glycation, its mechanism and kinetics, glycation consequences and toxic products and its involvement in protein chemical modification, aggregation amyloids and fibril formation and different mechanisms induced by such alterations. [ABSTRACT FROM AUTHOR]

In this study, the fabrication of vanillin incorporated almond gum/polyvinyl alcohol (PVA) nanofibers through electrospinning has been investigated. Electrospinning of only almond gum was proved impossible. It was found that the aqueous solution of almond gum/PVA (80:20, concentration = 7% (w/w)) containing 3% (w/w) vanillin could have successfully electrospun to uniform nanofibers with diameters as low as 77 nm. According to the thermal analysis, incorporated vanillin in almond gum/PVA nanofibers showed higher thermal stability than free vanillin, making this composite especially suitable for high temperature applications. XRD and FTIR analyses proved the presence of vanillin in the almond gum/PVA nanofibers. It was also found that vanillin was dispersed as big crystallites in the matrix of almond gum/PVA nanofibers. FTIR analysis showed almond gum and PVA had chemical cross-linking by etheric bonds between C OH groups of almond gum and OH groups of PVA. Also, in the nanofibers, there were no major interaction between vanillin and either almond gum or PVA. [ABSTRACT FROM AUTHOR]

Nanocrystalline cellulose (NCC) was prepared from microcrystalline cellulose (MCC) with particle size of 24.7 μm using sulfuric acid hydrolysis technique. The obtained NCC revealed size of 0–100 nm, which the major part of them was about 30 nm. Then different contents (2.5, 5 and 10 wt%) of these NCC incorporated in agar film solution and the morphology, structure, and properties of the nanocomposite films were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transforms infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), mechanical, physical and optical testing. Results showed that the water vapor permeability (WVP) and water solubility (WS) of the agar-based nanocomposite films significantly ( P < 0.05) decreased about 13% and 21%, respectively, upon increasing the NCC content to 10%. Tensile strength (TS) and Young's modulus (YM) values of nanocomposite films significantly increased ( P ≤ 0.05) with addition of NCC, whereas the elongation percent ( E %) decreased not significantly ( P > 0.05). In addition, swelling percentage, transparency and light transmission of the films were decreased by incorporating NCC into polymer matrix. [ABSTRACT FROM AUTHOR]

In this study, we report the first successful production of kefiran nanofibers through electrospinning process using distilled water as solvent. For this purpose, kefiran was extracted from cultured kefir grains, and homogenous kefiran solutions with different concentrations were prepared and then electrospun to obtain uniform nanofibers. The effect of main process parameters, including applied voltage, tip-to-collector distance, and feeding rate, on diameter and morphology of produced nanofibers, was studied. Scanning electron microscopy (SEM) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy were used to characterize electrospun mats. Rheological behavior of the kefiran solution was evaluated via a cone and plate rheometer too. The results exhibited that diameter of kefiran nanofibers increased with increasing polymer concentration, applied voltage, and polymer feeding rate, while tip-to-collector distance did not have significant effect on nanofiber diameter. ATR-FTIR spectra showed that kefiran has maintained its molecular structure during electrospinning process. Flow curves also demonstrated shear thinning behavior for kefiran solutions. [ABSTRACT FROM AUTHOR]

Abstract: Varieties of hemoglobin (Hb) forms exist in fish, which are usually well adapted to the different ecological conditions or various habitats. In the current study, Hbs from two Sturgeon species of the Southern Caspian Sea Basin were purified and studied upon interaction with n-dodecyl trimethylammonium bromide (DTAB; as a cationic surfactant) by various methods including UV–visible absorption, dynamic light scattering (DLS), and ANS fluorescence spectrophotometry. The chemometric analysis of Hbs was investigated upon interaction with DTAB under titration, using UV–visible absorption spectra. The chemometric resolution techniques were used to determine the number of the components and mole fraction of the oxidized Hbs. These results provided the evidence for the existence of three different molecular components including native (N), intermediate (I) and denatured (D) in sturgeon Hbs. According to the distribution of intermediates, which were broadened in a range of DTAB concentration, the aggregation states, DLS experiments, and thermal stability (T m obtained by differential scanning calorimetry (DSC)), the Acipenser stellatus Hb was more stable compared to Acipenser persicus Hb. These results demonstrate a significant relationship between the stability of fish Hbs and the habitat depth requirements. [Copyright &y& Elsevier]

The present study developed a novel complex coacervate based on succinyl mung bean protein (SMBP) and gum arabic (GA) to encapsulate curcumin. The optimum pH and succinylprotein/polysaccharide ratio for complex coacervation were 3.0 and 1:1, respectively, measured by turbidity evaluation. Fluorescence spectroscopy depicted that the curcumin was loaded in the hydrophobic core of SMBP/GA. The evaluated FTIR and XRD showed that the encapsulation of curcumin in the complex coacervate hydrophobic core was successful, followed by minor changes in SMBP conformation caused by the succinylation process. The zeta potential showed that the succinylation of MBP led to a decrease in the zeta potential of SMBP and confirmed that the SMBP/GA was produced successfully at pH 3.0. The EE and LA of c-SMBP/GA were 99.79 ± 0.03 % and 24.94 ± 0.05 μg·mg−1, respectively, which were significant. SMBP showed enhanced antioxidant activity compared with MBP, and c-MBP/GA showed significant antioxidant activity measured by ABTS and DPPH radical scavenging assays. SMBP is a biopolymer that can be used to encapsulate bioactive compounds like curcumin and shows enhanced antioxidant activity. The c-SMBP/GA is a promising tool for encapsulating curcumin in food matrices with enhanced dispersity characteristics and release behavior. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Naturally occurring polyamines are known to interact with a variety of biomolecules and critically involve in some important physiological processes. They have also been shown to influence protein aggregation in vitro in some cases. The aim of the present study was to investigate how polyamines may influence the structure and thermal stability of α-chymotrypsin and modulate alcohol-induced aggregation of this protein. Various techniques, including turbidity measurements, tensiometry, DSC, intrinsic fluorescence and far- and near-UV circular dichroism spectroscopy were used to examine the effect of putrescine and spermidine on α-chymotrypsin. While slight changes in the secondary and tertiary structure of the protein was observed, a clear stabilizing effect against its thermal unfolding was achieved. Moreover, the polyamines were found to inhibit TFE-induced aggregation at 32% TFE and promote formation of non-native α-helices in the protein structure. Based on the observed increase in surface tension induced by polyamines, it is suggested that their effects on enhancing thermal stability and alcohol-induced α-helices formation may be due to their kosmotropic properties. [Copyright &y& Elsevier]

Aflatoxins are common fungal toxins in foods that cause health problems for humans. The aim of this study was to use Saccharomyces cerevisiae and Lactobacillus rhamnosus cell walls immobilized on nano-silica entrapped in alginate as aflatoxin M 1 (AFM 1) binders. In this study, microbial walls were disrupted using a three-step mechanical technique including autoclave, thermal shock, and ultrasound. Dynamic light scattering (DLS) results proved size reduction in microbial walls ranging 75.8–91.4 nm. Disrupted walls were immobilized on nano-silica to enhance the efficiency of AFM 1 adsorption. Then, to prevent the release of the nano-silica or cell walls into the reaction medium, they were entrapped into alginate gel beads. Fourier transform infrared spectrometer (FT-IR) and scanning electron microscopy (SEM) micrographs confirmed the immobilization and entrapment process. Individual and mixtures of free cell walls, immobilized-entrapped walls, alginate bead and nano-silica were contacted with AFM 1 for 15 min and 24 h. AFM 1 reduction ability was evaluated using high performance liquid chromatography (HPLC). The results showed an AFM 1 reduction ranging 53–87% for free cell walls mixture at 15 min and alginate bead respectively. Also, it was possible to reuse immobilized-entrapped walls as binders with an efficiency of about 85%. [ABSTRACT FROM AUTHOR]

A novel bio-inspired electrically conductive nanofibrous scaffold based on PANI- co -(PDA- g -PLA) was fabricated using electrospinning technique and its physicochemical as well as biological characteristics toward bone tissue engineering were investigated extensively. • A novel conductive nanofibrous scaffold based on PANI- co -(PDA- g -PLA) was fabricated. • The scaffold exhibited proper electrical conductivity for especial type of tissue engineering applications. • The fabricated scaffold showed excellent biocompatibility and biodegradability. • The scaffold enhanced the adhesion and proliferation of osteoblast cells. A novel electrically conductive nanofibrous scaffold based on polyaniline- co -(polydopamine- grafted -poly(d , l -lactide)) [PANI- co -(PDA- g -PLA)] was fabricated using electrospinning technique and its physicochemical as well as biological characteristics toward bone tissue engineering (TE) were investigated extensively. In detail, PANI- co -PDA was synthesized via a one-step chemical oxidization approach. Then, d , l -lactaide monomer was grafted onto PDA segment using a ring opening polymerization (ROP) to afford PANI- co -(PDA- g -PLA) terpolymer. The successful synthesis of PANI- co -(PDA- g -PLA) terpolymer was confirmed using FTIR spectroscopy as well as TGA analysis. Finally, a solution of the synthesized terpolymer was electrospun to fabricate a conductive nanofibrous scaffold. Some physicochemical features such as mechanical, conductivity, electroactivity, hydrophobicity, and morphology as well as biological characteristics including biocompatibility, biodegradability, as well as enhancing the cells adhesion and proliferation were investigated. According to the above-mentioned experimental results, the fabricated electrospun nanofibers can be considered as a potential scaffold for TE application, mainly due to its proper physicochemical and biological properties. [ABSTRACT FROM AUTHOR]

Nowadays, tissue and organ failures resulted from injury, aging accounts, diseases or other type of damages is one of the most important health problems with an increasing incidence worldwide. Current treatments have limitations including, low graft efficiency, shortage of donor organs, as well as immunological problems. In this context, tissue engineering (TE) was introduced as a novel and versatile approach for restoring tissue/organ function using living cells, scaffold and bioactive (macro-)molecules. Among these, scaffold as a three-dimensional (3D) support material, provide physical and chemical cues for seeding cells and has an essential role in cell missions. Among the wide verity of scaffolding materials, natural or synthetic biopolymers are the most commonly biomaterials mainly due to their unique physicochemical and biological features. In this context, naturally occurring biological macromolecules are particular of interest owing to their low immunogenicity, excellent biocompatibility and cytocompatibility, as well as antigenicity that qualified them as popular choices for scaffolding applications. In this review, we highlighted the potentials of natural and synthetic polymers as scaffolding materials. The properties, advantages, and disadvantages of both polymer types as well as the current status, challenges, and recent progresses regarding the application of them as scaffolding biomaterials are also discussed. This review is the first up-to-date comprehensive overview regarding the employing of natural and synthetic polymers or their composites as well as copolymers for scaffolding. Unlabelled Image • An overview of synthetic and natural polymers-based scaffolding biomaterials • Physicochemical and biological features of scaffolding biomaterials • Fundamentals and general characteristics of natural and synthetic polymers • Modification approaches of synthetic and natural polymers for scaffolding • An impetus for the development of novel multifunctional scaffolding biomaterials [ABSTRACT FROM AUTHOR]

The pH-sensitive and magnetic-triggered release ensures the effective delivery of drugs. Chitosan carries amine pendants that encourage the fabrication of pH-responsive carriers. Montmorillonite (MMt), an attractive nano-clay in drug delivery possessing high encapsulation properties, was magnetized through the co-precipitation of Fe3+/Fe2+ ions. The study aimed to integrate the magnetic montmorillonite (mMMt) into the chitosan matrix and crosslinked by citric acid (CA) to achieve the nanocomposite carrier with double-responsive features for effective drug delivery. The release evaluation revealed that coating the mMMt with CA-crosslinked chitosan prevented the burst release of Ciprofluxcacin (Cip). The nanocomposite showed a high sustained release, and the release rate in the neutral environment (pH 7.4) was remarkably higher than in acidic media (pH 5.8). The new nanocomposite carrier showed high encapsulation efficiency to Cip (about 98 %). The study was developed by investigating external magnetic effects on the release rate, which lead to an increase in the release rate. The kinetics studies confirmed the diffusion mechanism for Cip release in all experimental media. The Cip-loaded nanocomposite carriers showed antibacterial activity against E. coli and S. aureus. • The prepared core-shells showed high encapsulation efficiency to Cip. • The release amount was higher in the neutral environment than in acidic media. • Using an external magnetic field increased the release amount of Cip. [ABSTRACT FROM AUTHOR]

Abstract In the present study, a novel 5FU and OXA co-loaded PHBV/PLGA NPs was developed which induced apoptosis in cancer cells. NPs were prepared by the double emulsion method and their preparation was optimized using D-optimal design of response surface methodology (RSM). 5FU-OXA loaded NPs were evaluated by SEM, DSC and DLS. NPs were spherical as shown by SEM and the results of DSC indicated that both drugs successfully entrapped into NPs. 5FU-OXA loaded NPs exhibited higher cytotoxicity effect than free drugs on cancer cells. For the first time to our knowledge, these results showed that more ROS generation and stronger activation of the ROS-dependent apoptotic pathway were induced by 5FU and OXA delivered by NPs. Furthermore, it was observed that NPs were hemocompatible. Co-loaded NPs exhibited significantly higher antitumor efficiency compared to free drugs combination, indicating this co-delivery system provides great potential in cancer therapy. The results of present study also confirmed that PHBV/PLGA NPs can be served as a promising platform for the co-delivery of antitumor drugs and present a new view for treatment of cancer with reducing side effect of drugs. [ABSTRACT FROM AUTHOR]

Abstract Bacterial cellulose (BC) is gaining considerable attention due to its unique physicochemical and mechanical properties. In this study, BC production by Gluconacetobacter xylinus PTCC 1734 in sugar beet molasses, cheese whey and standard Hestrin–Schramm (HS) media was evaluated. The synthesized BC was hydrolyzed by sulfuric acid to prepare bacterial cellulose nanocrystals (BCNC). The results showed that treated sugar beet molasses led to the highest BC concentration and productivity, followed by treated cheese whey. Structural analysis of BC and BCNC was carried out by Fourier Transform Infrared (FTIR) spectroscopy. The crystallinity index of the BCNC determined by X-ray diffraction (XRD) was higher than BC. The morphological analysis carried out by FE-SEM showed that microfibrils diameter decreases with acid treatment. TEM images confirmed the formation of rod like cellulose nanocrystals having an average diameter and length of 25 ± 5 and 306 ± 112 nm, respectively. In conclusion, food industrial byproducts can be used as cost-effective culture media to produce BC for large-scale industrial production and isolated cellulose nanocrystals are useful in the fabrication of bio-nanocomposite films for food packaging applications. Highlights • The use of beet molasses and cheese whey media not only decrease the production cost of BC but also upgrade these by products • Highest BC concentration and productivity was obtained in molasses medium • Bacterial cellulose nanocrystals (BCNC) was synthesized by sulfuric acid hydrolysis • FTIR analysis showed the increasing of crystalline regions after chemical treatment process • FE-SEM micrographs confirmed that the average diameter of BC microfibrils decreased as the result of acid treatment. [ABSTRACT FROM AUTHOR]

Abstract Enzyme immobilization is a way to increase efficiency of the enzyme and facilitate its recovery. The aim of this study was to immobilize α-amylase on chitosan-montmorillonite nanocomposite beads. Nanocomposite beads were prepared as the carrier for the enzyme stabilization and their surface was modified by Glutaraldehyde. Alpha-amylase was immobilized on nanocomposite beads by covalent bonding. The results of scanning electron microscopy (SEM) showed that particle size range of montmorillonite was 10–30 nm. This study indicated that the enzyme immobilization efficiency was 87%. The activity of free and immobilized enzyme during 40 days of storage at 4 °C decreased 95% and 36%, respectively. The results showed that the immobilized enzyme activity after reusing five times decreased about 47%. This study indicated that the immobilized enzyme activity was higher than the free enzyme at different temperatures. Also the immobilized enzyme was more stable than the free enzyme at lower pH. The results of kinetic parameters showed that K m values of the immobilized enzyme (9.12 μmol/ml) were higher than free enzyme (6.80 μmol/ml). The V max values for the free and immobilized enzyme were 1.30 and 0.629 μmol/mg·min, respectively. Highlights • α-Amylase enzyme was covalently immobilized on chitosan-montmorillonite nanocomposite beads. • The size of montmorillonite nanoparticles used in the preparation of the beads was 10–30 nm. • FTIR confirmed enzyme immobilization and connections between carrier components. • Enzyme immobilization efficiency of 86% was obtained. • Immobilized enzyme exhibited high thermal and pH stability and retained 64% of its initial activity after 40 days. [ABSTRACT FROM AUTHOR]

In this study, thyme essential oil (TEO) nanoemulsion was immobilized within composite films based on almond gum (AG), polyvinyl alcohol (PVA), and chitosan (CS). The physical, mechanical, water barrier, microstructural and antimicrobial properties of composite films were assessed. Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis confirmed the intermolecular interactions in the composite film matrix. The results indicated that the incorporation of TEO into the composite films increased thickness, moisture content, and water vapor permeability, while it reduced light transmittance and transparency value. The antimicrobial activity of films against gram-negative and gram-positive bacteria was tested using a disc diffusion method. The effect of composite on the microbiological properties of chicken breast fillets was investigated during refrigerated storage for 21 days. The microbial populations of total mesophilic, psychrotrophic, and lactic acid bacteria of the samples that were coated with the composite containing TEO were lower than the permitted limit after 21 days while for blank samples they were higher than 7 log CFU/g after 7 days which is considered as the maximum acceptable total count limit. Results disclosed that AG/PVA/CS composite films containing TEO nanoemulsion can be applied as eco-friendly active food packaging to enhance the shelf-life of food products. [Display omitted] • Almond gum/chitosan/polyvinyl alcohol composite films containing thyme essential oil (TEO) nanoemulsion were prepared • The composite containing TEO nanoemulsion enhanced the shelf-life of chicken breast fillets • The addition of TEO decreased the tensile strength and elongation at break of the composite films • The composite films showed effective barriers against both UV and visible light. [ABSTRACT FROM AUTHOR]

Active nanocomposites based on carboxymethyl cellulose-chitosan-oleic acid (CMC-CH-OL) incorporated with different concentrations (0.5–2 wt.%) of zinc oxide nanoparticles (ZnO NPs) were produced by casting method. The effects of ZnO NPs on the morphological, mechanical, thermal, physical and antifungal properties of the films were studied. New interaction between ZnO NPs and polymer matrix were confirmed by Fourier Transform infrared. After addition of ZnO NPs, tensile strength, lightness (L*) and thermal stability decreased however, elongation at break, contact angle, a* (greenness) and b* (yellowness) of the nanocomposite films increased in comparison to the films without nano-filler. UV transmittance at 280 nm decreased from 17.3% to 0.2, 0.1 and 0.1 for the nanocomposite films containing 0.5, 1 and 2 wt.% ZnO NPs, respectively, suggesting higher UV blocking properties. Disc diffusion test showed considerable antifungal properties of the active nanocomposite films against Aspergillus niger , especially in CMC-CH-OL-ZnO 2 wt.% by more than 40% fungal growth inhibition. [ABSTRACT FROM AUTHOR]

In this study, acidic extraction (citric acid) was used for the extraction of pectin from melon peel. A central composite design (CCD) was applied to study the effect of temperature (35–95 °C), time (40–200 min), pH (1–3) and solvent to sample ratio (10–50 v/w) on the yield and degree of esterification (DE). The results showed that the yield and DE ranged from 2.87 to 28.98% and 1.33–29.33%, respectively. Also, the highest extraction yield (29.48 ± 1.7%) was obtained under optimal conditions (pH of 1, temperature of 95 °C and ratio of 10 v/w after 200 min). The protein, ash, carbohydrate and galacturonic acid content of pectin obtained under optimal conditions were about 1.5, 3.5, 10 and 48%, respectively. Rheological experiments determined that melon peel pectin dispersions behaved as a weak gel at concentrations of 1%w/v. The emulsifying activity was 35% and also, the emulsion stability was higher at 4 °C than at 23 °C. [ABSTRACT FROM AUTHOR]

Multi-layer film structures of poly(lactic acid) (PLA) and fish gelatin (FG), prepared using the solvent casting technique, were studied in an effort to produce bio-based films with low oxygen (OP) and water vapor permeability (WVP). The scanning electron microscopy (SEM) images of triple-layer film showed that the outer PLA layers are being closely attached to the inner FG layer to make continuous film. The OP of multi-layer film (5.02 cm 3 /m 2 day bar) decreased more than 8-fold compared with that of the PLA film, and the WVP of multi-layer film (0.125 g mm/ kPa h m 2 ) also decreased 11-fold compared with that of the FG film. Lamination with PLA profoundly increased the water resistance of the bare gelatin film. Meanwhile, the tensile strength of the triple-layer film (25 ± 2.13 MPa) was greater than that of FG film (7.48 ± 1.70 MPa). At the same time, the resulting film maintains high optical clarity. Differential scanning calorimetry (DSC) analysis also revealed that the materials were compatible showing only one T g which decreased with FG deposition. This material exhibits an environmental-friendliness potential and a high versatility in food packaging. [ABSTRACT FROM AUTHOR]

Increasing the temperature by just a few degrees may lead to structural perturbation or unfolding of the protein and consequent loss of function. The concepts of flexibility and rigidity are fundamental for understanding the relationships between function, structure and stability. Protein unfolding can often be triggered by thermal fluctuations with flexible residues usually on the protein surface. Therefore, identification and knowledge of the effect of modification to flexible regions in protein structures are required for efficient protein engineering and the rational design of thermally stable proteins. The most flexible regions in protein are loops, hence their rigidification is one of the effective strategies for increasing thermal stability. Directed evolution or rational design by computational prediction can also lead to the generation of thermally stable proteins. Computational protein design has been improved significantly in recent years and has successfully produced de novo stable backbone structures with optimized sequences and functions. This review discusses intramolecular and intermolecular interactions that determine the protein structure, and the strategies utilized in the mutagenesis of mesophilic proteins to stabilize and improve the functional characteristics of biocatalysts by describing efficient techniques and strategies to rigidify flexible loops at appropriate positions in the structure of the protein. • The mutation of a few residues, or even a single residue, in a non-functional loop can affect thermal stability. • Loop alteration is one possible strategy for modifying the enzyme activity. • Directed evolution or rational design by computational prediction can lead to the generation of thermally stable proteins. • The thermal stability is increased by overall rigidity of a protein structure. • The rigidifying flexible loops at appropriate sites of proteins should enhance the thermal stability. [ABSTRACT FROM AUTHOR]

Interaction of methyl tert -butyl ether (MTBE) with proteins is a new look at its potential adverse biological effects. When MTBE is released to the environment it enters the blood stream through inhalation, and could affect the properties of various proteins. Here we investigated the interaction of MTBE with insulin and its effect on insulin structural changes. Our results showed that insulin formed a molten globule (MG)-like structure in the presence of 8 μM MTBE under physiological pH. The insulin structural changes were studied using spectroscopy methods, viscosity calculation, dynamic light scattering and differential scanning calorimetry. To delineate the mechanisms involved in MTBE-protein interactions, the formation of reactive oxygen specious (ROS) and formation of protein aggregates were measured. The chemiluminscence experiments revealed an increase in ROS production in the presence of MTBE especially in the MG-like state. These results were further confirmed by the aggregation tests, which indicated more aggregation of insulin at 40 μM MTBE compared with 8 μM. Thus, the formation of initial aggregates and exposure of the hydrophobic patches upon formation of the MG-like state in the presence of MTBE drives protein oxidation and ROS generation. [ABSTRACT FROM AUTHOR]

Antigen presenting cells (APCs)-derived exosomes are nano-vesicles that can induce antigen-specific T cell responses, and possess therapeutic effects in clinical settings. Moreover, dendritic cells (DCs)-based vaccines have been developed to combat human immunodeficiency virus-1 (HIV-1) infection in preclinical and clinical trials. We investigated the immunostimulatory effects (B- and T-cells activities) of DCs- and exosomes-based vaccine constructs harboring HIV-1 Nefmut-Tat fusion protein as an antigen candidate and heat shock protein 70 (Hsp70) as an adjuvant in mice. The modified DCs and engineered exosomes harboring Nefmut-Tat protein or Hsp70 were prepared using lentiviral vectors compared to electroporation, characterized and evaluated by in vitro and in vivo immunological tests. Our data indicated that the engineered exosomes induced high levels of total IgG, IgG2a, IFN-γ, TNF-α and Granzyme B. Moreover, co-injection of exosomes harboring Hsp70 could significantly increase the secretion of antibodies, cytokines and Granzyme B. The highest levels of IFN-γ and TNF-α were observed in exosomes harboring Nefmut-Tat combined with exosomes harboring Hsp70 (Exo-Nefmut-Tat + Exo-Hsp70) regimen after single-cycle replicable (SCR) HIV-1 exposure. Generally, Exo-Nefmut-Tat + Exo-Hsp70 regimen can be considered as a promising safe vaccine candidate due to high T-cells (Th1 and CTL) activity and its maintenance against SCR HIV-1 exposure. [Display omitted] [ABSTRACT FROM AUTHOR]

We developed an effective and eco-friendly strategy using chitosan gel-molten salt to achieve high loading (2.23 At. %) of single Fe-N X as assistive active sites. These sites were combined with small NiCo alloy NPs distributed on porous carbon aerogels to boost the ORR performance. The FeSAs-NiCo alloy@N-C sphere exhibits exceptional mass activity and specific activity of 3.705 A.mg−1 and 8.79 mA.cm−2 (ECSA) , respectively, at 0.85 V versus RHE. It has a superior onset potential of 1.08 V versus RHE, surpassing that of its nanoparticle Fe counterpart and NiCo alloy@N-C sphere. The significant improvement in ORR performance of the FeSAs-NiCo alloy@N-C sphere could be attributed to the positive effects of increased lattice strain due to the single atoms of Fe-N X hybridized with small NiCo alloy NPs. The chitosan gel-assisted molten salt strategy and assistive active sites of Fe-N X hybridized with NiCo alloy NPs regulate the electronic properties of the FeSAs-NiCo alloy@N-C sphere, both geometrically via lattice strain mismatch and electronically through shifting of the d-band center. This could influence the binding energies for oxygen and/or oxygen reduction intermediate adsorption/desorption. The additional improvement in the ORR performance of the FeSAs-NiCo alloy@N-C sphere also benefits from having a lower electrochemical activation energy. [Display omitted] • The coexistence of alloy nanoparticles with single atoms can enhance the performance of ORR, by tuning geometric and electronic properties. • An effective and eco-friendly chitosan gel assistive molten salt strategy was reported for designing high-loading single Fe–N X as assistive active sites that are further hybridized with small NiCo alloy NPs. • FeSAs-NiCo alloy@N-C sphere demonstrated exceptional mass activity (MA) and specific activity (SA) of 3.705 A mg-1 and 8.79 mA cm ECSA -2, respectively, at 0.85 V versus RHE. • Constructing single atom assistive active sites hybridizing with small NiCo alloy NPs can enhance dual functionality simultaneously for ORR activities. [ABSTRACT FROM AUTHOR]

Utilizing plant-based scaffolds has pulled in the consideration of tissue engineers. Plant tissues own different structures with particular porosity and structure. In this study, the stem of the Alstroemeria flower was designated for decellularization to fabricate a new scaffold. The stems were decellularized and called AFSP and then modified by chitosan and named AFSPC. Osteoblast precursor cell line was employed to assess the biological potential of the final scaffolds. The results uncovered that AFSP owns linear microchannels with a smooth surface. AFSPC delineated uniform chitosan coating on the walls with appropriate roughness. AFSPC showed higher potential in swelling, degradation, diffusion, and having a porous structure than AFSP. Modification with chitosan improved mechanical behavior. Biological assays depicted no cytotoxicity for AFSP and AFSPC. AFSPC showed good cell attachment, proliferation, and migration. In conclusion, modified tissue plants can be a good candidate for tissue engineering of both soft and hard tissues. [Display omitted] • Stems of plants own linear microchannels that can act as vessels in scaffolds. • Decellularized plant was modified with chitosan for biological properties improvement. • Modification with chitosan promoted the mechanical behavior. • MC3T3 cells could migrate into the central zones due to the microchannel. • This type of plant-based scaffold can be a good candidate for bone tissue engineering. [ABSTRACT FROM AUTHOR]

A category of very uncommon systemic inflammatory blood vessel illnesses known as vasculitides. The pathogenesis and etiology of vasculitis are still poorly known. Despite all of the progress made in understanding the genetics and causes behind vasculitis, there is still more to learn. Epigenetic dysregulation is a significant contributor to immune-mediated illnesses, and epigenetic aberrancies in vasculitis are becoming more widely acknowledged. Less than 2 % of the genome contains protein-encoding DNA. Studies have shown that a variety of RNAs originating from the non-coding genome exist. Long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs) have attracted the most attention in recent years as they are becoming more and more important regulators of different biological processes, such as diseases of the veins. Extracellular vehicles (EVs) such as exosomes, are membrane-bound vesicular structures that break free either during programmed cell death, such as apoptosis, pyroptosis, and necroptosis or during cell activation. Exosomes may be involved in harmful ways in inflammation, procoagulation, autoimmune reactions, endothelial dysfunction/damage, intimal hyperplasia and angiogenesis, all of which may be significant in vasculitis. Herein, we summarized various non-coding RNAs that are involved in vasculitides pathogenesis. Moreover, we highlighted the role of exosomes in vasculitides. [ABSTRACT FROM AUTHOR]

Despite of growing interest in use of carbon-based nanomaterials as carriers of functional proteins, less attention has been paid to the effects of these nanomaterials on the structure and function of the proteins. In this study, with the aim of shedding light on the mechanisms of interaction between carbon-based nanomaterials and proteins, the interactions of carbon quantum dots (CQDs) containing amine (CQD-NH 2) or carboxyl groups (CQD-COOH) with Photinus pyralis firefly luciferase enzyme were investigated by experimental and computational approaches. The structural changes and reduction in activity of the luciferase upon treatment with CQDs were experimentally proved. CQD-NH 2 induced more reduction in enzyme activity (15 %) compared to CQD-COOH (7.4 %). The interactions CQD-NH 2 with luciferase led to higher affinity of the enzyme for its substrate. It was found by molecular dynamic simulations that CQD-NH 2 binds to multiple regions on the surface of luciferase. Secondary structure analysis showed that CQD-NH 2 had more profound effects on the active site amino acids, the adjacent amino acids to the active site and the residues involved in ATP binding site. In addition, CQD-NH 2 interactions with luciferase were suggested to be stronger than CQD-COOH based on the number of hydrogen bonds and the binding energies. [Display omitted] [ABSTRACT FROM AUTHOR]

The current Coronavirus Disease 19 (COVID-19) pandemic, caused by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) shows similar pathology to MERS and SARS-CoV, with a current estimated fatality rate of 1.4%. Open reading frame 10 (ORF10) is a unique SARS-CoV-2 accessory protein, which contains eleven cytotoxic T lymphocyte (CTL) epitopes each of nine amino acids in length. Twenty-two unique SARS-CoV-2 ORF10 variants have been identified based on missense mutations found in sequence databases. Some of these mutations are predicted to decrease the stability of ORF10 in silico physicochemical and structural comparative analyses were carried out on SARS-CoV-2 and Pangolin-CoV ORF10 proteins, which share 97.37% amino acid (aa) homology. Though there is a high degree of ORF10 protein similarity of SARS-CoV-2 and Pangolin-CoV, there are differences of these two ORF10 proteins related to their sub-structure (loop/coil region), solubility, antigenicity and shift from strand to coil at aa position 26 (tyrosine). SARS-CoV-2 ORF10, which is apparently expressed in vivo since reactive T cell clones are found in convalescent patients should be monitored for changes which could correlate with the pathogenesis of COVID-19. [ABSTRACT FROM AUTHOR]

The present study investigated the effects of composite coatings made of chitosan (CS), tragacanth gum (TG), and polyvinyl alcohol (PVA) containing cinnamon essential oil (CEO) on the shelf-life of refrigerated chicken breast fillets. The samples were treated with different coating dispersions, and coded as: T 1 (distilled water as control), T 2 (blank composite coating), and T 3 (composite coating containing CEO). Results showed that incorporating CEO into CS/TG/PVA coatings could significantly increase the quality of chicken fillets. The obtained results showed that after 21 days, the total microbial population of lactic acid bacteria (LAB), psychrotrophic and mesophilic bacteria in T 3 samples was less than T 1 and T 2 samples. In addition, the highest antioxidant activity (48.04 %) and total phenolic content (TPC) values (2.458 mg gallic acid /g), the best sensory characteristics and the lowest pH (5.73), total volatile basic nitrogen (TVB-N) (21.89 mg N/100 g), thiobarbituric acid reactive substances (TBARS) (1.678 mg malondialdehyde equivalent/kg) and percentage of cooking loss (30 %) were related to T 3. Results disclosed that this composite coating is a promising technology to improve the shelf life of chicken fillets during storage. [Display omitted] • Cinnamon essential oil (CEO) nanoemulsion was incorporated in chitosan/tragacanth gum/polyvinyl alcohol composite coating. • CEO nanoemulsion increased the antioxidant and antimicrobial activity of the composite coating. • Chicken fillets coated with composite coating containing CEO had better sensory attributes compared to control sample. • The coating loaded with CEO nanoemulsion improved the shelf-life of chicken breast fillets. [ABSTRACT FROM AUTHOR]

Osteogenic properties of phenolated alginate (1.2 %) hydrogel containing collagen (0.5 %)/nano-hydroxyapatite (1 %) were studied on human mesenchymal stem cells in vitro. The phenolation rate and physical properties of the hydrogel were assessed using nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), swelling ratio, gelation time, mechanical assay, and degradation rate. The viability of encapsulated cells was monitored on days 7, 14, and 21 using an MTT assay. Osteoblast differentiation was studied using western blotting, and real-time PCR. Using PCR array analysis, the role of the Wnt signaling pathway was also investigated. Data showed that the combination of alginate/collagen/nanohydroxyapatite yielded proper mechanical features. The addition of nanohydroxyapatite, and collagen reduced degradation, swelling rate coincided with increased stiffness. Elasticity and pore size were also diminished. NMR and FTIR revealed suitable incorporation of collagen and nanohydroxyapatite in the structure of alginate. Real-time PCR analysis and western blotting indicated the expression of osteoblast-related genes such as Runx2 and osteocalcin. PCR array revealed the induction of numerous genes related to Wnt signaling pathways during the maturation of human stem cells toward osteoblast-like cells. In vivo data indicated that transplantation of phenolated alginate/collagen/nanohydroxyapatite hydrogel led to enhanced de novo bone formation in rats with critical-sized calvarial defects. Phenolated alginate hydrogel can promote the osteogenic capacity of human amniotic membrane mesenchymal stem cells in the presence of nanohydroxyapatite and collagen via engaging the Wnt signaling pathway. [ABSTRACT FROM AUTHOR]

The magnetic nanocarriers containing chitosan/hyaluronic acid complexed with κ -carrageenan were synthesized by solution method, as the drug delivery system. Doxorubicin (DOX) was used as the model drug. Characterization assessments were performed to identify the functional groups, determine the structure and morphology, and magnetic properties of nanodelivery system. Furthermore, their impacts on MCF-7 and MDA-MB-237 cell lines were evaluated by MTT assay. Analyses confirm polymers physical interaction, chemical bonding in the structure, moreover presence of spherical shape magnetic nanoparticles in the 100-150 nm range. The DOX loading was 74.1 ± 2.5 %. Results indicate that the drug loading was raised to 83.0 ± 2.2 % by increasing the amount of κ -carrageenan in specimens. The swelling of samples in the acidic environment (e.g. pH 5.5) was verified by the Dynamic Light Scattering analysis. Consequently, pH stimulus-responsive drug release in the sustained stream and a considerable amount of DOX release (84 ± 3.1 %) was detected as compared to a higher pH medium (27 ± 1.5 % at pH 7.4). According to the MTT assay results, MNPs showed no inhibitory effect on both cell lines. Also, 10 and 15 μg/ml of MNPs-DOX was considered as IC 50 value on MDA-MB-237 and MCF-7 cells, respectively. The DOX 25 μg/ml caused 50 % antiproliferative activity in both cell lines. • Magnetic chitosan/hyaluronic acid/ κ -carrageenan drug delivery is synthesized. • The drug carrier system benefits from a pH-sensitive characteristic. • Doxorubicin is used as a model drug for loading into the nanocarrier. • Increasing κ -carrageenan concentration is effective and improves drug loading. • At acidic environment drug release is promising that indicate enhanced performance. [ABSTRACT FROM AUTHOR]

The present study investigated the effects of composite coatings made of chitosan (CS), tragacanth gum (TG), and polyvinyl alcohol (PVA) containing cinnamon essential oil (CEO) on the shelf-life of refrigerated chicken breast fillets. The samples were treated with different coating dispersions, and coded as: T 1 (distilled water as control), T 2 (blank composite coating), and T 3 (composite coating containing CEO). Results showed that incorporating CEO into CS/TG/PVA coatings could significantly increase the quality of chicken fillets. The obtained results showed that after 21 days, the total microbial population of lactic acid bacteria (LAB), psychrotrophic and mesophilic bacteria in T 3 samples was less than T 1 and T 2 samples. In addition, the highest antioxidant activity (48.04 %) and total phenolic content (TPC) values (2.458 mg gallic acid /g), the best sensory characteristics and the lowest pH (5.73), total volatile basic nitrogen (TVB-N) (21.89 mg N/100 g), thiobarbituric acid reactive substances (TBARS) (1.678 mg malondialdehyde equivalent/kg) and percentage of cooking loss (30 %) were related to T 3. Results disclosed that this composite coating is a promising technology to improve the shelf life of chicken fillets during storage. [Display omitted] • Cinnamon essential oil (CEO) nanoemulsion was incorporated in chitosan/tragacanth gum/polyvinyl alcohol composite coating. • CEO nanoemulsion increased the antioxidant and antimicrobial activity of the composite coating. • Chicken fillets coated with composite coating containing CEO had better sensory attributes compared to control sample. • The coating loaded with CEO nanoemulsion improved the shelf-life of chicken breast fillets. [ABSTRACT FROM AUTHOR]