Performance of Polydopamine Complex and Mechanisms in Wound Healing.

Polydopamine (PDA) has been gradually applied in wound healing of various types in the last three years. Due to its rich phenol groups and unique structure, it can be combined with a variety of materials to form wound dressings that can be used for chronic infection, tissue repair in vivo and serious wound healing. PDA complex has excellent mechanical properties and self-healing properties, and it is a stable material that can be used for a long period of time. Unlike other dressings, PDA complexes can achieve both photothermal therapy and electro activity. In this paper, wound healing is divided into four stages: antibacterial, anti-inflammatory, cell adhesion and proliferation, and re-epithelialization. Photothermal therapy can improve the bacteriostatic rate and remove reactive oxygen species to inhibit inflammation. Electrical signals can stimulate cell proliferation and directional migration. With low reactive oxygen species (ROS) levels, inflammatory factors are down-regulated and growth factors are up-regulated, forming regular collagen fibers and accelerating wound healing. Finally, five potential development directions are proposed, including increasing drug loading capacity, optimization of drug delivery platforms, improvement of photothermal conversion efficiency, intelligent electroactive materials and combined 3D printing.

Antibacterial Mechanism of Curcumin: A Review.

Curcumin is a plant-derived polyphenolic active substance with broad-spectrum antibacterial properties. Curcumin blocks bacterial growth owing to its structural characteristics and the generation of antioxidation products. Curcumin can inhibit bacterial virulence factors, inhibit bacterial biofilm formation and prevent bacterial adhesion to host receptors through the bacterial quorum sensing regulation system. As a photosensitizer, curcumin acts under blue light irradiation to induce phototoxicity and inhibit bacterial growth. Moreover, it can exert a synergistic antibacterial effect with other antibacterial substances. In this review, we summarize the research progress on the antibacterial mechanism of curcumin based on five targeting structures and two modes of action. Our discussion provides a theoretical basis and technical foundation for the development and application of natural antibacterial agents.

Preparation and characterization of ß-cyclodextrin-oregano essential oil microcapsule and its effect on storage behavior of purple yam.

BACKGROUND: Natural plant essential oils have antimicrobial properties; however, essential oils are difficult to maintain in a system because of their volatile nature. First, we prepared microcapsules from ß-cyclodextrin and oregano essential oil and characterized their properties. Second, the effect of microcapsules on the preservation of freshly cut purple yam was studied using an edible coating technique. Purple yams immersed in distilled water were used as control, and their characteristics were compared with yams coated with citric acid, citric acid + sodium alginate, and citric acid + sodium alginate + ß-cyclodextrin-oregano essential oil microcapsules (CA-SA-MC) and stored at 4 °C for 5 days. RESULTS: Microcapsules of oregano essential oil and ß-cyclodextrin solution were successfully prepared via the inclusion method, with an optimal encapsulation efficiency of 55.14%. Scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis showed strong bonds between ß-cyclodextrin and oregano essential oil. All edible coatings, particularly CA-SA-MC, significantly (P ≤ 0.05) maintained firmness, total soluble solids, ascorbic acid content, and anthocyanin content compared with control treatment. This treatment also prevented browning and extended the shelf life of purple yam. CONCLUSION: Oregano essential oil can be successfully encapsulated into cyclodextrin microcapsules. It has a great impact on the shelf life extension of purple yam and could be successfully applied to other fresh produce. © 2020 Society of Chemical Industry.

The roles of nuclear receptors in cholesterol metabolism and reverse cholesterol transport in nonalcoholic fatty liver disease.

As the most prevalent chronic liver disease globally, NAFLD encompasses a pathological process that ranges from simple steatosis to NASH, fibrosis, cirrhosis, and HCC, closely associated with numerous extrahepatic diseases. While the initial etiology was believed to be hepatocyte injury caused by lipid toxicity from accumulated triglycerides, recent studies suggest that an imbalance of cholesterol homeostasis is of greater significance. The role of nuclear receptors in regulating liver cholesterol homeostasis has been demonstrated to be crucial. This review summarizes the roles and regulatory mechanisms of nuclear receptors in the 3 main aspects of cholesterol production, excretion, and storage in the liver, as well as their cross talk in reverse cholesterol transport. It is hoped that this review will offer new insights and theoretical foundations for the study of the pathogenesis and progression of NAFLD and provide new research directions for extrahepatic diseases associated with NAFLD.

Failure Mechanism of the Corrugated Medium under Simulated Cold Chain Logistics.

It is necessary to develop corrugated medium food packaging, which is suitable for highly humid environments, to meet the demands of cold chain logistics. In this paper, we investigated the influence of the transverse ring crush index of different environmental factors of corrugated medium and the failure mechanisms during cold chain transportation. After freeze-thaw treatment of corrugated medium, XRD and DP showed a decrease in crystallinity and polymerization of 3.47 and 7.83%, respectively. Also, the FT-IR spectra of the paper showed that the number of intermolecular hydrogen bonds decreased by about 3.00% after freezing. SEM and XRD showed CaCO3 precipitation on the paper surface and a 26.01% increase in pore size. This study would be beneficial in further expanding the applications of cellulose-based paperboard cold chain transportation.

BAP18 facilitates CTCF-mediated chromatin accessible to regulate enhancer activity in breast cancer.

The estrogen receptor alpha (ERα) signaling pathway is a crucial target for ERα-positive breast cancer therapeutic strategies. Co-regulators and other transcription factors cooperate for effective ERα-related enhancer activation. Recent studies demonstrate that the transcription factor CTCF is essential to participate in ERα/E2-induced enhancer transactivation. However, the mechanism of how CTCF is achieved remains unknown. Here, we provided evidence that BAP18 is required for CTCF recruitment on ERα-enriched enhancers, facilitating CTCF-mediated chromatin accessibility to promote enhancer RNAs transcription. Consistently, GRO-seq demonstrates that the enhancer activity is positively correlated with BAP18 enrichment. Furthermore, BAP18 interacts with SMARCA1/BPTF to accelerate the recruitment of CTCF to ERα-related enhancers. Interestingly, BAP18 is involved in chromatin accessibility within enhancer regions, thereby increasing enhancer transactivation and enhancer-promoter looping. BAP18 depletion increases the sensitivity of anti-estrogen and anti-enhancer treatment in MCF7 cells. Collectively, our study indicates that BAP18 coordinates with CTCF to enlarge the transactivation of ERα-related enhancers, providing a better understanding of BAP18/CTCF coupling chromatin remodeling and E-P looping in the regulation of enhancer transcription.

Constructions of synergistic photothermal therapy antibacterial hydrogel based on polydopamine, tea polyphenols and polyvinyl alcohol and effects on wound healing in mouse.

Hydrogels with significant antibacterial efficacy have enormous potential in wound healing. This work reported a series of effective antibacterial and antioxidant hydrogels based on tea polyphenols (TP), polydopamine (PDA), and polyvinyl alcohol (PVA). PDA-TP molecular chains are formed from oxidized TP and PDA. These molecular chains, which were cross-linked with PVA by cyclic freeze-thaw (FT), formed the PVA/PDA-TP hydrogel (PPTP). The number of freezing-thawing cycles and the amount of TP would affect the mechanical properties and swelling properties of hydrogel. The PPTP hydrogel exhibited high photo thermal conversion efficiency, high antibacterial efficacy, antioxidant properties, good cellular compatibility and short wound closure time. The PPTP hydrogel leaded to wound closure in approximately 10 d in a full-thickness skin defect mouse model. The preparation method of hydrogel with non-chemical cross-linked and ability of rapid high temperature generation provided a new way to apply TP to wound healing and proved that synergistic chemical and photothermal therapy can effectively inhibit resistant bacteria and accelerate wound healing.

Effect of a novel shell material-Starch-protein-fatty acid ternary nanoparticles on loading levels and in vitro release of curcumin.

Preparation of ternary nanoparticles using high amylose complex, stearic acid, and soy protein isolate as shell materials and their encapsulation of curcumin were studied. The effect of curcumin in ternary nanostructures, loading capacity of the nanoparticles, its solubility and sustained release behavior in vitro are discussed. The encapsulation efficiency of the ternary nanoparticles was 87.14 ± 0.70%, and the loading rate was 16.81 µg/g. Qualitative analysis showed that curcumin addition increases the long-range and short-range ordered structure of ternary starch (TS) by changing its crystallinity. Fourier transform infrared spectroscopy showed that curcumin-TS is formed via hydrogen bonds and hydrophobic properties of the protein. An in vitro release test showed that TS particles can control the stable release of curcumin in simulated intestinal fluid. Our study provided a novel approach to high biomass encapsulation and sustained release of polyphenols.