Plant polysaccharide-derived edible film packaging for instant food: Rapid dissolution in hot water coupled with exceptional mechanical and barrier characteristics.

A comprehensive multiscale analysis was conducted to explore the effects of different ratios of these materials on its properties. The results show that KC played a crucial role in controlling solution viscosity and gel and sol temperatures. The dissolution time at high water temperatures primarily decreased with an increase in SA content. Higher KC and CS content increased tensile strength (TS) and elongation at break (ε), while also exhibiting better thermal stability. Water vapor transmission (WVT) and permeability (PV) initially decreased, then increased with the increase of SA and CS contents. Finally, an SA:KC:CS ratio of 1:3:2 showed optimal comprehensive properties, with a dissolution time of about 60.0 ± 3.8 s, TS of 23.80 ± 0.29 MPa, ε of 18.61 ± 0.34 %, WVT of 21.74 ± 0.62 g/m2·24h, and PV of 5.39 ± 0.17 meq/kg. Meanwhile, the SA:KC:CS edible food packaging only introduced minimal effects on food after dissolution, and the total bacterial count met regulatory standards.

Preparation, antibacterial activity, and structure-activity relationship of low molecular weight κ-carrageenan.

κ-Carrageenan (KC) is a polysaccharide widely used in food industry. It has been widely studied for its excellent physicochemical and beneficial properties. However, the high molecular weight and high viscosity of KC make it difficult to be absorbed and to exert its' biological activities, thus limit its extensive industrial application. In order to solve this problem, five low molecular weight κ-carrageenans (DCPs) were prepared by the degradation of KC using hydrogen peroxide (H2O2) and ascorbic acid (AH2). The chemical compositions and structure characteristics of the DCPs were then determined. The results showed that H2O2 and AH2 could effectively degrade KC to DCPs, and DCPs remained the basic skeletal structure of KC. DCPs showed good antibacterial activities against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis. The Minimum Inhibitory Concentration (MIC) of DCPs with the highest antibacterial effects were 5.25, 4.5, 5.25, and 4.5 mg/mL, respectively. This is due to the underlying mechanism of DCPs that bind to the bacterial membrane proteins and change the membrane permeability, thus exerting antibacterial activity. In addition, Spearman's rank correlation and Ridge regression analysis revealed that the molecular weight and the contents of 3,6-anhydro-D-galactose, aldehyde group, carboxyl, and sulfate were the main structural characteristics affecting the antibacterial activity. Our findings reveal that the H2O2-AH2 degradation treatment could significantly improve the antibacterial activity of KC and provide insights into the quantitative structure-activity relationships of the antibacterial activity of DCPs.

Multifunctional fish-skin collagen-based hydrogel sealant with dual-dynamic-bond cross-linked for rapid hemostasis and accelerated wound healing.

Collagen (COL) is the most widespread functional protein. Designing and developing dual-dynamic-bond cross-linked COL adhesive hydrogel sealants with multifunctional is highly advantageous for achieving a superior wound closure effect and hemostasis. In this study, we developed hybrid hydrogels consisting of fish-skin COL, oxidized sodium alginate (OSA), borax and polyvinyl alcohol (PVA) to enhance full-thickness wound healing. The hydrogels were furnished with first-rate self-healing capabilities through the dual-dynamic-bond cross-linking of dynamic Schiff base bonds (COL-OSA) and diol boric acid bonds (OSA-borax) with reversible breakage and re-formation. Moreover, the incorporation of PVA stimulated the formation of hydrogen bonds in the system, bolstering the stability of the hydrogel framework. The prepared hydrogel manifests self-healing, injectability, multifunctional adhesiveness and biodegradability. In vivo assessment of the hemostatic capacity of COSP20 hydrogel was superior to gauze both in the mice liver injury model and mice tail amputation model. In addition, a full-thickness skin wound model in mice revealed that the COSP20 hydrogel facilitated faster wound closure by accelerating reepithelialization, COL deposition and angiogenesis. These findings illustrate the potential of hybrid fish-skin COL-based hydrogels to enhance wound healing and promote rapid tissue repair, and provide new possibilities for the effective utilization of marine fishery resources.

Virtual Screening of Potential RoxS Inhibitors and Evaluation of Their Antimicrobial Activity in Combination with Antibiotics against Clinically Resistant Bacteria.

Pseudomonas aeruginosa with difficult-to-treat resistance has been designated as an urgent or serious threat by the CDC in the United States; therefore, novel antibacterial drugs and combination strategies are urgently needed. The sensor kinase RoxS is necessary for the aerobic growth of Pseudomonas aeruginosa. This study aimed to screen candidate RoxS inhibitors and evaluate their efficacy in treating multi-drug-resistant and extensively drug-resistant Pseudomonas aeruginosa in combination with meropenem and amikacin to identify promising combination strategies. RoxS protein structures were constructed using homology modeling and potential RoxS inhibitors, including Ezetimibe, Deferasirox, and Posaconazole, were screened from the FDA-approved ZINC drug database using molecular docking and molecular dynamics simulations. MIC and checkerboard assays were used to determine the in vitro antimicrobial efficacy of the three drugs in combination with antibiotics. The results of in vitro experiments showed an additive effect of 100 µg/mL Deferasirox or 16 µg/mL Posaconazole in combination with meropenem and a synergistic effect of 1.5 µg/mL Deferasirox and amikacin. In summary, these three drugs are potential inhibitors of RoxS, and their combination with meropenem or amikacin is expected to reverse the resistance of P. aeruginosa, providing new combination strategies for the treatment of clinically difficult-to-treat Pseudomonas aeruginosa.

Sodium alginate/carboxymethyl starch/κ-carrageenan enteric soft capsule: Processing, characterization, and rupture time evaluation.

Although gelatin has good characteristics in preparing soft capsules, its noticeable shortcomings force researchers to further develop substitutes for gelatin soft capsules. In this paper, sodium alginate (SA), carboxymethyl starch (CMS) and κ-carrageenan (κ-C) were used as matrix materials, and the formula of the co-blended solutions was screened through rheological method. In addition, films of the different blends were characterized by thermogravimetry analysis, SEM, FTIR, X-ray, water contact angle and mechanical properties. The results showed that κ-C had strong interaction with CMS and SA, and the mechanical properties of capsule shell were greatly improved by the addition of κ-C. When the ratio of CMS/SA/κ-C was 2:0.5:1.5, the microstructure of the films was more dense and uniform. In addition, this formula had the best mechanical properties and adhesion properties, and was more suitable for the production of soft capsules. Finally, a novel plant soft capsule was successfully prepared by dropping method, and its appearance and rupture properties met the requirements of enteric soft capsules. In simulated intestinal fluid, the soft capsules were almost completely degraded within 15 min, and they were superior to the gelatin soft capsules. Therefore, this study provides an alternative formula for preparing enteric soft capsules.

Drying Process of HPMC-Based Hard Capsules: Visual Experiment and Mathematical Modeling.

Using plant-based polysaccharide gels to produce hard capsules is a novel application of this technology in the medicinal field, which has garnered significant attention. However, the current manufacturing technology, particularly the drying process, limits its industrialization. The work herein employed an advanced measuring technique and a modified mathematical model to get more insight into the drying process of the capsule. Low field magnetic resonance imaging (LF-MRI) technique is adopted to reveal the distribution of moisture content in the capsule during drying. Furthermore, a modified mathematical model is developed by considering the dynamic variation of the effective moisture diffusivity (Deff) according to Fick's second law, which enables accurate prediction of the moisture content of the capsule with a prediction accuracy of ±15%. The predicted Deff ranges from 3 × 10-10 to 7 × 10-10 m2·s-1, which has an irregular variation with a time extension. Moreover, as temperature increases or relative humidity decreases, there is an increased acceleration of moisture diffusion. The work provides a fundamental understanding of the drying process of the plant-based polysaccharide gel, which is crucial for enhancing the industrial preparation of the HPMC-based hard capsules.

Homocysteine Modulates Social Isolation-Induced Depressive-Like Behaviors Through BDNF in Aged Mice.

Social isolation is an unpleasant experience associated with an increased risk of mental disorders. Exploring whether these experiences affect behaviors in aged people is particularly important, as the elderly is very likely to suffer from periods of social isolation during their late-life. In this study, we analyzed the depressive-like behaviors, plasma concentrations of homocysteine (Hcy), and brain-derived neurotropic factor (BDNF) levels in aged mice undergoing social isolation. Results showed that depressive-like behavioral performance and decreased BDNF level were correlated with increased Hcy levels that were detected in 2-month isolated mice. Elevated Hcy induced by high methionine diet mimicked the depressive-like behaviors and BDNF downregulation in the same manner as social isolation, while administration of vitamin B complex supplements to reduce Hcy alleviated the depressive-like behaviors and BDNF reduction in socially isolated mice. Altogether, our results indicated that Hcy played a critical role in social isolation-induced depressive-like behaviors and BDNF reduction, suggesting the possibility of Hcy as a potential therapeutic target and vitamin B intake as a potential value in the prevention of stress-induced depression.

Enhancing Pullulan Soft Capsules with a Mixture of Glycerol and Sorbitol Plasticizers: A Multi-Dimensional Study.

The plasticizer is crucial in the plant-based soft capsule. However, meeting the quality requirements of these capsules with a single plasticizer is challenging. To address this issue, this study first investigated the impact of a plasticizer mixture containing sorbitol and glycerol in varying mass ratios and the performance of the pullulan soft film and capsule. The multiscale analysis demonstrates that the plasticizer mixture exhibits superior effectiveness in enhancing the performance of the pullulan film/capsule compared to a single plasticizer. Furthermore, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy indicate that the plasticizer mixture enhances the compatibility and thermal stability of the pullulan films without altering their chemical composition. Among the different mass ratios examined, a 15:15 ratio of sorbitol to glycerol (S/G) is identified as the most optimal, leading to superior physicochemical properties and meeting the requirements for brittleness and disintegration time set by the Chinese Pharmacopoeia. This study provides significant insights into the effect of the plasticizer mixture on the performance of pullulan soft capsules and offers a promising application formula for future use.

Theabrownin of raw and ripened pu-erh tea varies in the alleviation of HFD-induced obesity via the regulation of gut microbiota.

PURPOSE: Pu-erh tea can be classified into raw pu-erh tea and ripened pu-erh tea. Theabrownin (TB) is one of the major components of pu-erh tea. The difference of the anti-obesity activity between raw pu-erh tea TB (R-TB) and ripened pu-erh tea TB (F-TB) has not been comprehensively investigated yet. Therefore, this article aimed to systemically study the anti-obesity activity and the underlying mechanism of R-TB and F-TB. METHOD: High-fat diet (HFD)-induced C57BL/6J mice with obesity were gavaged with R-TB or F-TB to assess the effect of R-TB and F-TB on the amelioration of obesity, the expression of lipid metabolism-related genes, and the regulation of gut flora imbalance. RESULTS: Administration of both R-TB and F-TB could suppress body weight gain, improve insulin sensitivity and glucose homeostasis, regulate the lipid level and reduce the chronic inflammation in obese mice. The underlying anti-obesity mechanism of R-TB and F-TB might involve the regulation of lipogenesis and lipolysis, amelioration of the gut microbiota disorder and promotion of microbial metabolism. Interestingly, R-TB was more efficient in the regulation of blood glucose, reduction of inflammation and suppression of partial adipogenesis-related genes and protein, while F-TB was more effective in the inhibition of lipolysis-related genes and protein. In addition, F-TB might be more effective in adjusting the dysbacteria caused by HFD back to normal by promoting the proliferation of the beneficial microbiota, such as Lactobacillus and Lachnospiraceae_NK4A136_group. CONCLUSION: Taken together, both R-TB and F-TB had the potential to be developed as beneficial dietary supplements or functional foods for ameliorating obesity and obesity-related metabolic disorders, but their effects and the ability to regulate the intestinal flora varied.

Neoagarotetraose alleviates high fat diet induced obesity via white adipocytes browning and regulation of gut microbiota.

Obesity is nowadays a serious public health issue. Neoagarotetraose (NA4) is a marine oligosaccharide produced by the enzymatic hydrolysis of agar by ß-agarase. The present study is aimed to determine the effect of NA4 on high-fat diet (HFD)-induced obesity in mice and uncover the regulating role of gut microbiota and microbial metabolites. The results showed that the intervention of NA4 significantly reduced the body weight gain, insulin resistance, hepatic adipose accumulation, serum lipid levels, oxidative damages, and inflammation responses in HFD-induced obese mice. NA4 also promoted lipolysis and browning of white adipose tissue, inhibit lipogenesis, and protect the integrity of gut barrier. Moreover, NA4 restructured the altered gut microbiota and enhanced the content of short-chain fatty acids (SCFAs) in the feces with compared with the HFD group. Cumulatively, these findings suggest that NA4 can relieve obesity by stimulating white adipose tissue browning, regulating intestinal flora, and promoting microbial metabolism.

A bifocal compound liquid lens with continuous zoom based on selective wettability.

In this paper, a tunable zoom bifocal liquid lens based on selective wettability is proposed. This lens consists of internal and external immiscible coaxial droplets surrounded by immiscible ambient liquid. Since curvatures and refractive indexes of the internal and external droplets are different, the system forms a long focus and a short focus, respectively. By applying different voltages, the curvatures of the internal and external droplets change exerting continuous movement of a long/short focal point in a certain range. To verify the feasibility and practicability of this concept, a prototype of the bifocal compound lens is fabricated in experiment, and the modulation ability of its long/short focal length is detected. The short focal length of our proposed lens varies from 15.46 mm to 17.47 mm, while the relative long focal length ranges from 96.25 mm to 70.31 mm driven by 200 V.

Preparation and intrinsic kinetics study of the scale-up production of hydroxypropyl agar by heterogeneous hydroxypropylation reaction.

Hydroxypropylation is effective in modifying the structure and properties of agar. So far, the industrial scale-up production of hydroxypropylated agar has not been evaluated. Therefore, the large-scale production of the hydroxypropylation of agar using a heterogeneous reaction system was evaluated in the present this study. The structures and properties of the hydroxypropyl agar (HPA) product were measured and the intrinsic kinetics of the heterogeneous reaction were determined and analyzed. The results showed that the large-scale HPA had good thermal stability, and lower viscosity, gelling temperature and melting temperature compared with those of agar. The SEM indicated that the improvement of solubility of HPA was not only due to the hydrophilic effect of hydroxypropyl group, but also due to the formation of cluster structure and grid structure. The characteristic of heterogeneous hydroxypropylation reaction were determined by preliminary kinetic experiments, which demonstrated that the reaction order of propylene oxide was 2, while that for agar was approximately 0. The reaction activation energy of heterogeneous hydroxypropylation reaction was calculated to be 83.50 kJ/mol using the Arrhenius formula. Taken together, the results would provide guidances for the industrialization of hydroxypropyl agar.

Self-healing polysaccharide-based injectable hydrogels with antibacterial activity for wound healing.

Because the wound is difficult to heal, repeated bacterial infection will lead to complex clinical problems. Therefore, it is necessary to find an effective method to strengthen the healing process and resist bacterial infection. Hydrogels have many advantages, such as injectability and self-healing under physiological conditions, so they have been widely studied in recent years. Hydrogels can keep the wound moist and promote the wound healing. In addition, the growth of bacteria can be obviously inhibited by hydrogels themself or by doping some antibacterial active substances. Based on this, herein, this review highlighted the preparation and properties of different polysaccharide-based injectable hydrogels, and discuss their biological applications in antibacterial therapy for wound healing in recent years.

Phthalocyanine-based photoacoustic contrast agents for imaging and theranostics.

Phthalocyanine, as an organic dye, has attracted much attention due to its high molar absorption coefficient in the near-infrared region (NIR). It is precisely because of this advantage that phthalocyanine is very beneficial to photoacoustic imaging (PAI). At present, many different strategies have been adopted to design phthalocyanine-based contrast agents with photoacoustic (PA) effect, including increasing water solubility, changing spectral properties, prolonging the circulation time, constructing activatable supramolecular nanoparticles, increasing targeting, etc. Based on this, this minireview highlighted the above ways to enhance the PA effect of phthalocyanine. What's more, the application of phthalocyanine-based PA contrast agents in biomedical imaging and image-guided phototherapy has been discussed. Finally, this minireview also provides the prospects and challenges of phthalocyanine-based PA contrast agents in order to provide some reference for the application of phthalocyanine-based PA contrast agents in biomedical imaging and guiding tumor treatment.

Pu-erh tea ameliorates obesity and modulates gut microbiota in high fat diet fed mice.

Obesity is regarded to be associated with fat accumulation, chronic inflammation, and gut microbiota dysbiosis. Raw and ripened pu-erh tea extract (PETe) have the effect of reducing body weight gain and fat accumulation, which are associated with gut microbiota. However, little is known about the difference of raw and ripened PETe on the regulation of gut microbiota. Here, our results suggested that supplementation of raw and ripened PETe displayed similar anti-obesogenic effect in high fat diet (HFD)-induced obesity mice, by attenuating the body weight gain, fat accumulation, oxidative injury, and low-grade inflammation, improving the glucose tolerance, alleviating the metabolic endotoxemia, and regulating the mRNA and protein expression levels of the lipid metabolism-related genes. 16S rRNA sequencing of fecal samples indicated that raw and ripened PETe intervention displayed different regulatory effect on the HFD-induced gut microbiota dysbiosis at different taxonomic levels. The microbial diversity, the relative abundance of Firmicutes and Bacteroidetes as well as F/B ratio were reversed more closer to normal by ripened PETe. Phylotypes of Bacteroidaceae, Ruminococcaceae, Lachnospiraceae, Muribaculaceae, and Rikenellaceae which are negatively correlated with obesity were enhanced notably by the intervention of ripened PETe, while Erysipelotrichaceae and Lactobacillaceae which have positive correlation with obesity were decreased dramatically. In addition, the treatment of ripened PETe had better effect on the increase of benefical Bacteroides, Alistipes, and Akkemansia and decrease of obesity associated Faecalibaculum and Erysipelatoclostridium (p < 0.05). These findings suggested that pu-erh tea especially ripened pu-erh tea could serve as a great candidate for alleviation of obesity in association with the modulation of gut microbiota.

Drying Behavior and Kinetics of Drying Process of Plant-Based Enteric Hard Capsules.

The drying process is a significant step in the manufacturing process of enteric hard capsules, which affects the physical and chemical properties of the capsules. Thus, the drying characteristics of plant-based enteric hard capsules were investigated at a constant air velocity of 2 m/s in a bench scale hot-air dryer under a temperature range of 25 to 45 °C and relative humidity of 40 to 80%. Results indicate that the drying process of the capsules mainly occur in a falling-rate period, implying that moisture transfer in the capsules is governed by internal moisture diffusion rate. High temperature and low relative humidity reduce drying time but increase the drying rate of the capsules. Investigation results of the mechanical properties and storage stability of the capsules, however, reveal that a fast drying rate leads to plant-based enteric hard capsules of low quality. Scanning electron microscopy further demonstrates that more layered cracks appear in capsules produced under a faster drying rate. The Page model yielded the best fit for describing thin-layer drying of the capsules based on the coefficient of determination and reduced chi-square. Moreover, it was established that the effective moisture diffusivity of the capsules increases with an increase in drying temperature or reduction in relative humidity.

Design and Characteristics of an Optofluidic Phase Modulator Based on Dielectrowetting.

In this paper, an optofluidic phase modulator based on dielectrowetting is designed and fabricated to adjust the optical phase. Two liquids are filled in the device, and a transparent sheet is employed at the liquid interface to keep the interface flat. When different voltages are applied to the modulator, the flat interface moves up and down, leading to the variation of the optical phase. A theoretical model is constructed to predict the optical phase shift quantitatively, and the phase regulation ability is also tested experimentally. Our modulator realizes continuous adjustment of the optical phase in a certain range by the operation of voltage adjustment. When the voltage is increased to 150 V, the optical phase modulation range of our proposed modulator can reach 9.366 π.

Fucoidan Isolated from Saccharina japonica Inhibits LPS-Induced Inflammation in Macrophages via Blocking NF-κB, MAPK and JAK-STAT Pathways.

Fucoidan has been reported to have a variety of biological activities. However, different algae species, extraction methods, harvesting seasons, and growth regions lead to the structural variation of fucoidan, which would affect the bioactivities of fucoidan. To date, the anti-inflammatory properties and the underlying mechanism of fucoidan from brown alga Saccharina japonica (S. japonica) remain limited. The aims of the present study were to investigate the structure, the anti-inflammatory properties, and the potential molecular mechanisms of fucoidan isolated from S. japonica (SF6) against lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. SF6 was characterized using high performance liquid gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR), and observed to be rich in fucose, galactose, and sulfate. Additionally, results showed that SF6 remarkably inhibited LPS-induced production of various inflammatory mediators and pro-inflammation cytokines, including nitric oxide (NO), NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), interleukin-ß (IL-ß), and interleukin-6 (IL-6). A mechanism study showed that SF6 could effectively inhibit inflammatory responses through blocking LPS-induced inflammation pathways, including nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), and Janus kinase (JAK)-2 and signal transducer and activator of transcription (STAT)-1/3 pathways. These results suggested that SF6 has the potential to be developed as an anti-inflammatory agent applied in functional food.

Effect of Gellan Gum and Xanthan Gum Synergistic Interactions and Plasticizers on Physical Properties of Plant-Based Enteric Polymer Films.

The mechanical and barrier properties of plant-based enteric polymer films were enhanced by synergistic interactions between binary gum mixtures and adding plasticizers. The results indicated that the best ratio of gellan gum (GG) and xanthan gum (XG) was 7:3 by comparing tensile strength, tensile elongation, transmittance, and water vapor permeability of plant-based enteric polymer films and rheological properties of solutions. Polyethylene glycol 400 (PEG-400) was an effective plasticizer in improving plasticity and water vapor barrier property of the plant-based enteric polymer film. Rheology measurement and different characterization methods, including Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy, were used to explain interactions between GG and XG as well as PEG-400 and components of the film. The new mixed system, composed of GG/XG mixture with ratio of 7:3 as a novel gelling agent and PEG-400 as a plasticizer, was applied to prepare plant-based enteric hard capsules, which have potential applications in medicines and functional food preparations.

Separation, purification, structural analysis and immune-enhancing activity of sulfated polysaccharide isolated from sea cucumber viscera.

A novel sulfated polysaccharide (SCVP-1) was isolated from sea cucumber viscera and purified to elucidate its structure and immune-enhancing ability. SCVP-1 was found to be a homogeneous polysaccharide with a relative molecular weight of 180.8 kDa and composed of total sugars (60.2 ±â€¯2.6%), uronic acid (15.3 ±â€¯1.8%), proteins (6.8 ±â€¯0.8%), and sulfate groups (18.1 ±â€¯0.9%). SCVP-1 consisted of mannose, glucosamine, glucuronic acid, N-acetyl-galactosamine, glucose, galactose and fucose at an approximate molar ratio of 1.00:1.41:0.88:2.14:1.90:1.12:1.24. The fourier transform infrared spectra (FT-IR) and nuclear magnetic resonance (NMR) analyses showed that SCVP-1 was a kind of glycosaminoglycan. And the sulfation patterns of the fucose branches were Fuc2,4S, Fuc3,4S and Fuc0S. The surface morphology of SCVP-1 presented loose and irregular sheet structure formed by aggregation of polysaccharide molecules with spherical structure. Moreover, SCVP-1 promoted the production of nitric oxide (NO) and cytokines (IL-1ß, IL-6 and TNF-α) by RAW264.7 cells as well as the expression of related genes (iNOS, IL-1ß, IL-6 and TNF-α) and also enhanced their phagocytic activity through TLR4-mediated activation of the MAPKs and NF-κB signaling pathways. This study suggests that sea cucumber viscera are good sources of polysaccharides and SCVP-1 might be a novel immunomodulator.