Food-derived peptides unleashed: emerging roles as food additives beyond bioactivities.

Innovating food additives stands as a cornerstone for the sustainable evolution of future food systems. Peptides derived from food proteins exhibit a rich array of physicochemical and biological attributes crucial for preserving the appearance, flavor, texture, and nutritional integrity of foods. Leveraging these peptides as raw materials holds great promise for the development of novel food additives. While numerous studies underscore the potential of peptides as food additives, existing reviews predominantly focus on their biotic applications, leaving a notable gap in the discourse around their abiotic functionalities, such as their physicochemical properties. Addressing this gap, this review offers a comprehensive survey of peptide-derived food additives in food systems, accentuating the application of peptides' abiotic properties. It furnishes a thorough exploration of the underlying mechanisms and diverse applications of peptide-derived food additives, while also delineating the challenges encountered and prospects for future applications. This well-time review will set the stage for a deeper understanding of peptide-derived food additives.

Nanotechnology-based optical sensors for Baijiu quality and safety control.

Baijiu quality and safety have received considerable attention owing to the gradual increase in its consumption. However, owing to the unique and complex process of Baijiu production, issues leading to quality and safety concerns may occur during the manufacturing process. Therefore, establishing appropriate analytical methods is necessary for Baijiu quality assurance and process control. Nanomaterial (NM)-based optical sensing techniques have garnered widespread interest because of their unique advantages. However, comprehensive studies on nano-optical sensing technology for quality and safety control of Baijiu are lacking. In this review, we systematically summarize NM-based optical sensor applications for the accurate detection and quantification of analytes closely related to Baijiu quality and safety. Furthermore, we evaluate the sensing mechanisms for each application. Finally, we discuss the challenges nanotechnology poses for Baijiu analysis and future trends. Overall, nanotechnological approaches provide a potentially useful alternative for simplifying Baijiu analysis and improving final product quality and safety.

Reducing the background interference of liquid-liquid extraction method during Baijiu aroma analysis.

Liquid-liquid extraction coupled with gas chromatography-mass spectrometry (LLE-GC/MS) is a useful methodology for Baijiu aroma analysis. However, the background problems caused by LLE have rarely been investigated. In the present study, synthetic Baijiu was analyzed by traditional LLE-GC/MS to assess background problems, and a series of ghost peaks of some compounds were detected within the retention time of 47.0-60.0 min, including 2,4-di-tert-butylphenol (2,4-DTBP), palmitic acid and oleanitrile. 2,4-DTBP, which has a phenolic odor, is an important component in both strong and light-flavor Baijiu. Single-factor experiments confirmed that 2,4-DTBP is not a constituent of Baijiu but migrates from sodium sulphate and sodium chloride, and, high-temperature baking was an effective approach to eliminate these compounds. A combined strategy using standard cleaning coupled with high-temperature baking was proposed to reduce the background problems during LLE. Furthermore, more trace compounds could be identified through this process in the future.

Marker-Independent Food Identification Enabled by Combing Machine Learning Algorithms with Comprehensive GC × GC/TOF-MS.

Reliable methods are always greatly desired for the practice of food inspection. Currently, most food inspection techniques are mainly dependent on the identification of special components, which neglect the combination effects of different components and often lead to biased results. By using Chinese liquors as an example, we developed a new food identification method based on the combination of machine learning with GC × GC/TOF-MS. The sample preparation methods SPME and LLE were compared and optimized for producing repeatable and high-quality data. Then, two machine learning algorithms were tried, and the support vector machine (SVM) algorithm was finally chosen for its better performance. It is shown that the method performs well in identifying both the geographical origins and flavor types of Chinese liquors, with high accuracies of 91.86% and 97.67%, respectively. It is also reasonable to propose that combining machine learning with advanced chromatography could be used for other foods with complex components.

MicroRNA-92b promotes cell proliferation and invasion in osteosarcoma by directly targeting Dickkopf-related protein 3.

[This retracts the article DOI: 10.3892/etm.2017.5356.].

MicroRNA-137 acts as a tumor suppressor in osteosarcoma by targeting enhancer of zeste homolog 2.

[This retracts the article DOI: 10.3892/etm.2017.4435.].

RAB31 is targeted by miR-26b and serves a role in the promotion of osteosarcoma.

Ras-related protein Rab-31 (RAB31), a small guanosine 5'-triphosphate-binding protein, is a member of the Rab family and has been demonstrated to serve an oncogenic role in several common types of human cancer. However, the function of RAB31 in osteosarcoma (OS) has not been previously studied. The present study identified that the expression levels of RAB31 were significantly higher in OS tissue samples compared with matched adjacent non-tumor tissue samples, and high RAB31 expression was associated with malignant progression and a poor prognosis for patients with OS. Furthermore, it was identified that the expression levels of RAB31 were increased in OS cell lines compared with normal osteoblast cells. Silencing of RAB31 expression significantly inhibited OS cell proliferation, cell cycle progression, migration and invasion, and significantly increased the rate of cell apoptosis. In addition, the present study used a luciferase reporter assay to demonstrate that RAB31 was a direct target gene of microRNA-26b (miR-26b), which is a known tumor suppressor in OS. The expression levels of RAB31 were negatively associated with miR-26b expression in OS cells. Finally, miR-26b was demonstrated to be significantly decreased in OS tissues compared with adjacent non-tumor tissues, and an inverse correlation was observed between the expression levels of RAB31 and miR-26b in OS tissues. In summary, to the best of our knowledge, the present study is the first to report that RAB31 is a target gene of miR-26b, and silencing of RAB31 may inhibit OS growth and progression.

Long-Noncoding RNA PCAT6 Aggravates Osteosarcoma Tumourigenesis via the MiR-143-3p/ZEB1 Axis.

INTRODUCTION: The long-noncoding RNA PCAT6 plays an important regulatory role in the development of several cancers. However, the expression pattern and underlying mechanisms of PCAT6 in osteosarcoma (OS) are yet unknown. METHODS: We used real-time PCR to measure PCAT6 expression in 106 tumor pairs and corresponding non-tumor tissues from OS patients. Statistical analyses were applied to evaluate the prognostic value and associations of PCAT6 expression with clinical parameters. Furthermore, the PCAT6 was silenced with siRNA in OS cells. Moreover, phenotype of PCAT6 silenced OS cells was measured using colony formation, CCK-8, cell migration and invasion assay. Finally, the molecular mechanism of PCAT6/miR-143-3p/ZEB1 axis in OS progression was explored. RESULTS: The expression level of PCAT6 in OS tissues was significantly elevated as compared with that in the adjacent normal bone tissues and that high PCAT6 expression closely correlated with the malignant phenotype and poor survival among patients with OS. Multivariate analyses revealed PCAT6 overexpression as an independent prognostic factor for the poor outcome of patients with OS. Functional assay results demonstrated that the knockdown of PCAT6 expression notably suppressed the proliferation, migration, and invasion of OS cells. An elevated PCAT6 level aggravated the malignant phenotype of OS cells via ZEB1 expression upregulation. Mechanistic studies revealed that PCAT6 could sponge endogenous miR-143-3p and inhibit its activity, resulting in an increase in ZEB1 level. Finally, we demonstrated that the tumour-promoting role of PCAT6 in OS was dependent on the regulation of the miR-143-3p/ZEB1 axis. CONCLUSION: These findings highlight the potential role of PCAT6, which could serve as a valuable prognostic indicator for patients with OS.

In situ generation of silver nanoparticles and nanocomposite films based on electrodeposition of carboxylated chitosan.

Herein, for the first time the electrodeposition of carboxylated chitosan is studied and utilized for the synthesis of silver nanoparticles (AgNPs) and generation of AgNPs/carboxylated chitosan nanocomposite films. Particularly, AgNPs are in situ synthesized on electrodes or substrates during the electrodeposition. Carboxylated chitosan not only acts as the green reducing agent and stabilizing agent for preparing AgNPs, but also serves as the main component in the electrodeposited nanocomposite film. The experimental results indicate that a smooth and homogeneous film is formed on the silver plate after electrodeposition, and the electrodeposited film can be detached from the silver plate as an independent film. The TEM observation and spectroscopic analysis results confirm the existence of AgNPs (the average size of 10 nm) in the nanocomposite film. The nanocomposite films with various shapes can be fabricated by the spatial selectivity of electrodeposition. In addition, the nanocomposite film containing AgNPs shows favorable antibacterial properties.

MicroRNA-92b promotes cell proliferation and invasion in osteosarcoma by directly targeting Dickkopf-related protein 3.

Deregulation of microRNA-92b (miR-92b) has been implicated in osteosarcoma. However, the underlying regulatory mechanism of miR-92b in osteosarcoma growth and metastasis remains largely unclear. In the present study, reverse transcription-quantitative polymerase chain reaction and western blotting were used to measure mRNA and protein expression. MTT and Transwell assays were conducted to determine cell proliferation and invasion, and a luciferase reporter assay was performed to confirm the association between miR-92b and Dickkopf3-related protein (DKK3). The results demonstrated that miR-92b was significantly upregulated in osteosarcoma tissues compared with matched adjacent non-tumor tissues. Additionally, high miR-92b levels were significantly associated with lung metastasis and advanced tumor, node, metastasis stage (P<0.05) but not with age, sex, tumor size, location, serum lactate dehydrogenase or serum alkaline phosphatase. miR-92b expression was also significantly upregulated in osteosarcoma cell lines compared with normal osteoblast cells. Knockdown of miR-92b significantly inhibited the proliferation and invasion of osteosarcoma U2OS cells (P<0.01). By contrast, overexpression of miR-92b significantly increased U2OS cell proliferation and invasion (P<0.01). DKK3 was identified as a target gene of miR-92b and it was demonstrated that DKK3 expression was negatively regulated by miR-92b in U2OS cells. Restoration of DKK3 expression abrogated the increased proliferation and invasion of U2OS cells induced by miR-92b overexpression. Notably, DKK3 was significantly downregulated in osteosarcoma tissues compared with adjacent non-tumor tissues and its expression was inversely correlated to miR-92b levels in osteosarcoma tissues. Taken together, these data indicate that miR-92b promotes cell proliferation and invasion in osteosarcoma by targeting DKK3. Therefore, miR-92b may become a potential therapeutic target for osteosarcoma.

MicroRNA-137 acts as a tumor suppressor in osteosarcoma by targeting enhancer of zeste homolog 2.

MicroRNA (miR) are short non-coding RNA that bind to the 3'-untranslational region of their target genes, inhibiting translation and causing mRNA degradation. miR deregulation has been implicated in human cancer; however, the detailed regulatory mechanism of miR-137 in osteosarcoma (OS) remains largely unknown. In the present study, miR-137 and enhancer of zeste homologue 2 (EZH2) mRNA and protein expression levels were analyzed using reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. MTT and transwell assays were performed to evaluate cell viability and invasion capacities and a luciferase reporter gene assay was used to determine the targeting relationship. The results of the current study indicated that miR-137 expression was significantly downregulated in OS tissues and cell lines (P<0.01). Moreover, it was observed that low miR-137 expression levels were significantly associated with lung metastasis and advanced TMN stage (P<0.05), but not associated with age, gender, tumor size, location, serum lactate dehydrogenase or serum alkaline phosphatase. Increasing levels of miR-137 significantly inhibited U2OS cell viability and invasion (P<0.01). By contrast, knockdown of miR-137 markedly increased U2OS cell viability and invasion. EZH2 was identified as a direct target gene of miR-137 in U2OS cells by luciferase reporter assay and EZH2 expression was found to be significantly increased in OS tissues and cell lines (P<0.01). EZH2 was significantly downregulated following miR-137 overexpression (P<0.01), and was upregulated following miR-137 knockdown in U2OS cells. Furthermore, EZH2 overexpression significantly attenuated the suppressive effects of miR-137 on U2OS cell viability and invasion (P<0.01), suggesting that miR-137 inhibits the viability and invasion of OS cells by targeting EZH2. Therefore, the results of the current study suggest that the miR-137/EZH2 axis may be a potential target for novel potential therapeutic strategies to treat OS.

Electrodeposition of chitosan/gelatin/nanosilver: A new method for constructing biopolymer/nanoparticle composite films with conductivity and antibacterial activity.

Electrodeposition of chitosan provides a controllable means to simultaneously assemble biological materials and nanoparticles for various applications. Here, we present a new method to construct biopolymer/nanoparticle composite films with conductivity and antibacterial activity by electrodeposition of chitosan/gelatin/nanosilver. Besides, this method can be employed to build biopolymer/nanoparticle composite hydrogels or coatings on various electrodes or conductive substrates. We initially use a simple approach to prepare the aqueous nanosilver that can be well-dispersed in water. Then, the codeposition mixture containing chitosan, gelatin and nanosilver is prepared, and it can be electrodeposited onto different electrodes or conductive substrates in response to imposed electrical signals. After electrodeposition, it is found that the deposited hydrogels and their dried films are smooth and homogeneous due to the elimination of H2 bubbles by addition of H2O2 in electrodeposition process. Importantly, the composite films are strong enough to completely and readily peel from the electrodes after they reacted with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), which can build a type of biopolymer/nanoparticle film for further applications. Furthermore, the electrodeposition technique is able to offer controllable and convenient method to construct the composite films with diverse shapes. The composite films display improved conductivity and in vitro antibacterial activity against Escherichia coli and Staphylococcus aureus, which may provide attractive applications in biomedical fields such as artificial muscles, skin biomaterials and neuroprosthetic implants.

Electrodeposition of a carbon dots/chitosan composite produced by a simple in situ method and electrically controlled release of carbon dots.

Carbon dots (CDs), a new type of fluorescent nanomaterial, have drawn considerable attention due to their attractive applications in biolabeling, bioimaging and fluorescent probes. Here, a CDs/chitosan composite that can be straightforwardly used for further electrodeposition and electrically controlled release of CDs, was produced by a simple and novel in situ method based on a one-step microwave treatment of a chitosan solution. We choose the chitosan solution as the only reactant for producing the CDs/chitosan composite, because chitosan can not only serve as the precursor for preparing the CDs, but can also be frequently used for the electrodeposition. Importantly, the prepared CDs/chitosan composite is not only endowed with multicolor fluorescence features coming from the CDs, but also retains the pH-responsive film-forming properties of chitosan. On the basis of these favorable properties, we can straightforwardly employ the CDs/chitosan composite to construct fluorescent coatings, as well as a variety of multicolor fluorescent patterns on different electrodes or substrates through the electrodeposition technique. More interestingly, the release of CDs in the electrodeposited coatings or patterns can be controlled by electrical signals. Consequently, this CDs/chitosan composite with straightforward applications in electrodeposition and electrically controlled release of CDs is promising for use in photoluminescent coatings, fluorescent patterns, fluorescent labeling, and controlled release.

Genome-wide analysis of Nilaparvata lugens nymphal responses to high-density and low-quality rice hosts.

The brown planthopper (BPH) Nilaparvata lugens is an economically important pest on rice plants. In this study, the higher population density and yellow-ripe stage of rice plants were used to construct adverse survival conditions (ASC) against BPH nymphs. Simultaneously, the low population density and tillering stage of rice plants were used to establish a suitable survival condition (SSC) as a control. Solexa/Illumina sequencing was used to identify genes of BPH nymphs responding to ASC. Significantly longer duration development of BPH nymphs and significantly lower brachypterous ratio of BPH adults were observed by ASC compared with SSC. A total of 2 544 differentially expressed genes (DEGs) were obtained and analyzed by BLASTx, Gene Ontology and KEGG Orthology. Gene ontology analysis revealed that the DEGs were mainly involved in categories of cell, cell part, cellular process, binding, catalytic, organelle and metabolic processes. 1 138 DEGs having enzyme commission numbers were assigned to different metabolic pathways. The largest clusters were neurodegenerative diseases (137, 12.0%), followed by carbohydrate metabolism (113, 9.9%), amino acid metabolism (94, 8.3%), nucleotide metabolism (76, 6.7%), energy metabolism (64, 5.6%), translation (60, 5.3%), lipid metabolism (58, 5.1%), and folding, sorting and degradation (52, 4.6%). Expressing profile of 11 DEGs during eight nymphal developmental stages of BPH were analyzed by quantitative real-time polymerase chain reaction. The 11 genes exhibited differential expression between ASC and SSC during at least one developmental stage. The DEGs identified in this study provide molecular proof of how BPH reconfigures its gene expression profile to adapt to overcrowding and low-quality hosts.

Effects of elevated CO2 on the nutrient compositions and enzymes activities of Nilaparvata lugens nymphs fed on rice plants.

Elevated CO(2) may reduce the tolerance of Nilaparvata lugen (N. lugens) to adverse environmental factors through the biological and physiological degeneration of N. lugens. In an artificial climate box, under 375 and 750 µL L(-1) CO(2) levels, the rice stems nutrient content, the nutrient content and enzyme activities of N. lugens nymph fed on rice seedlings exposed to ambient and elevated CO(2) were studied. The results showed that rice stems had significantly higher protein and total amino acid levels under ambient than elevated CO(2) levels. Nymphs had significantly higher protein levels in the ambient CO(2) treatment, while their glucose levels were significantly lower under ambient CO(2) conditions. Significantly higher trypsin activity was observed in nymphs grown in elevated CO(2). Significantly lower activities of the protective enzymes total superoxide dismutase and catalase were observed in the nymphs under ambient CO(2). Meanwhile, the activity of the detoxification enzyme glutathione S-transferase was significantly higher in the ambient CO(2) treatment. Measuring how energy and resources were allocated to enzymes in N. lugens nymphs under elevated CO(2) conditions can provide a more meaningful evaluation of their metabolic tolerances to adverse climatic conditions.

Surface properties of polyurethanes modified by bioactive polysaccharide-based polyelectrolyte multilayers.

Lentinan, a mushroom polysaccharide, isolated from Lentinus edodes (Shiitake mushroom) was sulfated in dimethylsulfoxide to obtain a water-soluble derivative coded as LS. Then, two polysaccharide-based polyelectrolytes, polyanionic lentinan sulfate (LS) and polycationic chitosan (CS), were alternatively deposited onto the surfaces of polyurethane (PU) via layer-by-layer (LbL) assembly technique. The surfaces modified by polysaccharide-based multilayers were investigated by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angle measurements. The fibrinogen adsorption and platelet adhesion to the surfaces, cytocompatibility to L-929 cells, and antibacterial activity against Pseudomonas aeruginosa of unmodified PU and LbL-modified PU were tested in vitro, respectively. The results showed that the water contact angle decreased gradually during the successive buildup of the polysaccharide-based multilayers, and decreased slowly after four bilayers were assembled. The surface roughness of PU modified by five bilayers (LS as topmost layer) increased compared with that of unmodified PU. The fibrinogen adsorption on the surface decreased 81% after assembly of five bilayers (LS as topmost layer). The number of adherent platelets on the surface modified by five bilayers (LS as topmost layer) is reduced, in comparison with that of the unmodified PU. The tests of L-929 cells indicated that LbL-modified PU surfaces had better cytocompatibility than unmodified PU. In addition, PU modified by polysaccharide-based multilayers showed antibacterial activity against P. aeruginosa.

[Preparation and characterization of an extracellular matrix of artificial tendon tissue from natural macromolecules].

Collagen and chitosan are well natrual polymers to be used as extracellular matrix on tissue engineering because of their biocompatibility, certain mechanical strength and biodegradability. But there are some disadvantages when they are used to construct extracellular matrix respectively. This experiment utilized their complementary performances to prepare a composite extracellular matrix of artificial tendon tissue that had adequacy mechanics strength and good biocompatibility, cell affinity, biodegradability. Collagen and chitosan were covalently crosslinked using EDC and NHS to obtain a porous scaffold material that the porous was oriented under an external force. Then RGD peptide was covalently attached to scaffold material surface to improve its affinity with cells. The microstructure of scaffold material was observed under microscope and scanning electron microscope. Simultaneously, the physical performance, hydrophilicity, ecto-degradation rate and cell compatibility of scaffold material were measured in the experiments. The results showed that this scaffold material was soft and stretchy. Its tensile strength was 15.0 MPa, corresponding shape extension was 7.33%, and its porosity was 79.4%. Its water absorption rate and water retention rate were 772% and 206% respectively. Its degradation rate in RPM 1640 culture mediun with 10% fetal bovine serum and in human serum were 4.13% and 37.2% respectively after three weeks. These degradation rates are suitable for the rehab course of injured tendon. Moreover the degradation rates can be controlled by adjusting technological conditions and degree of cross linking. Significantly higher affinity with 3T3-Ll cell was detected on the scaffold material modified by RGD peptide. The various physical performances of this complex scaffold material are appropriate for constructing extracellular matrix of artificial tendon tissue or artificial skin. Moreover, it could be used as soft tissue slurry for plastic surgery.