Spray-drying and rehydration on ß-carotene encapsulated Pickering emulsion with chitosan and seaweed polyphenol.

The spray-drying process to generate microcapsules from Pickering emulsions needs high temperatures, leading to instability of emulsions and degradation of encapsulated thermosensitive compounds (ß-carotene). However, these effects may be attenuated by the introduction of seaweed polyphenols into the emulsion interfacial layers, although the effects underlying this protective mechanism have not been explored. This study evaluates the effects of spray-drying/rehydration on the morphology, encapsulation efficiency, redispersibility, and stability of ß-carotene loaded Pickering emulsions stabilized by chitosan (PESC) and Pickering emulsions stabilized by chitosan/seaweed polyphenols (PESCSP). The encapsulation efficiency of ß-carotene in PESCSP microcapsules (61.13 %) was higher than PESC (53.91 %). Rehydrated PESCSP exhibited more regular droplet size distribution, higher stability, stronger 3D network morphology, and lower redispersibility index (1.5) compared to rehydrated PESC. Analyses of interfacial layers of emulsions revealed that chitosan covalently bound fatty acids at their hydrophobic side. Polyphenols were linked to chitosan at the hydrophilic side of emulsions through hydrogen bonds, providing 3D network between droplets and antioxidant activities to inhibit the degradation of ß-carotene. This study emphasized the role of polyphenols in the interfacial layers of Pickering emulsions for the development of efficient delivery systems and protection of ß-carotene and other thermosensitive bioactive compounds during spray-drying and rehydration.

Scalable Photochromic Film for Solar Heat and Daylight Management.

The adaptive control of sunlight through photochromic smart windows could have a huge impact on the energy efficiency and daylight comfort in buildings. However, the fabrication of inorganic nanoparticle and polymer composite photochromic films with a high contrast ratio and high transparency/low haze remains a challenge. Here, a solution method is presented for the in situ growth of copper-doped tungsten trioxide nanoparticles in polymethyl methacrylate, which allows a low-cost preparation of photochromic films with a high luminous transparency (luminous transmittance Tlum = 91%) and scalability (30 × 350 cm2 ). High modulation of visible light (ΔTlum = 73%) and solar heat (modulation of solar transmittance ΔTsol = 73%, modulation of solar heat gain coefficient ΔSHGC = 0.5) of the film improves the indoor daylight comfort and energy efficiency. Simulation results show that low-e windows with the photochromic film applied can greatly enhance the energy efficiency and daylight comfort. This photochromic film presents an attractive strategy for achieving more energy-efficient buildings and carbon neutrality to combat global climate change.

Effects of environmental stimuli on the physicochemical and rheological properties of chitosan-macroalgal polyphenol stabilized Pickering emulsion.

In this study, Pickering emulsions stabilized by chitosan (CS), chitosan-Laminaria japonica polyphenols (CP) and chitosan-Ascophyllum nodosum polyphenols (CB) were fabricated. This study also evaluated the stability of CS, CP, and CB under different environmental factors including pH (2-9), NaCl concentrations (0-500 mM), heat treatments (50-100 °C) and storage period (0-8 weeks). The characterization on interfacial layer of emulsion droplets demonstrated that macroalgal polyphenols could combined with the amorphous regions of chitosan particles through hydrogen bond and electrostatic interactions, providing stronger dual wettability with enhanced ability of interfacial layer in stabilizing Pickering emulsions. All three emulsions showed best droplet distribution, highest emulsion stability and specific surface area at pH 6 and 0 mM NaCl concentration as fresh emulsion. Moreover, CS, CP, and CB exhibited the rheological behaviour of pseudoplastic fluids at different pH and NaCl concentration. It should be noted that CP and CB exhibited higher emulsion stability than CS under a variety of environmental stresses. Overall, this research proved that chitosan-macroalgal polyphenol co-stabilized Pickering emulsion had enhanced stability against various environmental stimuli, which could be utilized as potential delivery and protection system for hydrophobic bioactive compounds.

Pickering emulsions with chitosan and macroalgal polyphenols stabilized by layer-by-layer electrostatic deposition.

Due to the hydrophilic nature of chitosan, its use as stabilizers in Pickering emulsions requires of hydrophobic modifications that can be achieved by layer-by-layer electrostatic deposition. This study aims to explore and optimize the effects of multiple parameters (chitosan-polyphenol ratio, chitosan concentrations, oil-phase ratios, pH and NaCl concentrations) on the stability of Pickering emulsions stabilized by chitosan and macroalgal polyphenols. The binding mode of chitosan and polyphenols in co-stabilized Pickering emulsions was characterized by Fourier transform infrared spectroscopy (FTIR), confocal scanning laser microscopy (CLSM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle. The emulsions had the highest physical stability (95.67 %) and specific surface area (2.21 m2/g) at: chitosan-polyphenol ratio 9.5:1 (w:w), chitosan concentration 0.5 % (w/v), oil-phase ratio 5 % (v/v), pH 6, and NaCl concentration 0 mM. FTIR, CLSM, SEM, and AFM evidenced that chitosan and polyphenols were bound by hydrogen bonds and electrostatic interactions at oil-water interfacial layers of emulsions that had a contact angle of 87.8°, indicating that polyphenols combined with chitosan had better ability to stabilize Pickering emulsions compared to chitosan alone. This study broadens the potential applications of naturally extracted macroalgal polyphenols for the development of Pickering emulsions in nutraceutical and functional food industries.

Chitosan-based Pickering emulsion: A comprehensive review on their stabilizers, bioavailability, applications and regulations.

BACKGROUND: Chitosan-based particles are one of the most promising Pickering emulsions stabilizers due to its cationic properties, cost-effective, biocompatibility, biodegradability. However, there are currently no comprehensive reviews analyzing the role of chitosan to develop Pickering emulsions, and the bioavailability and multiple uses of these emulsions. SCOPE AND APPROACH: This review firstly summarizes the types, preparation and functional properties of chitosan-based Pickering emulsion stabilizers, followed by in vivo and in vitro bioavailability, main regulations, and future application and trends. KEY FINDINGS AND CONCLUSIONS: Stabilizers used in chitosan-based Pickering emulsions include 6 categories: chitosan self-aggregating particles and 5 types of composites (chitosan-protein, chitosan-polysaccharide, chitosan-fatty acid, chitosan-polyphenol, and chitosan-inorganic). Chitosan-based Pickering emulsions improved the bioavailability of different compounds compared to traditional emulsions. Current applications include hydrogels, microcapsules, food ingredients, bio-based films, cosmeceuticals, porous scaffolds, environmental protection agents, and interfacial catalysis systems. However, due to current limitations, more research and development are needed to be extensively explored to meet consumer demand, industrial manufacturing, and regulatory requirements. Thus, optimization of stabilizers, bioavailability studies, 3D4D printing, fat substitutes, and double emulsions are the main potential development trends or research gaps in the field which would contribute to increase adoption of these promising emulsions at industrial level.

Total Bilirubin Level is Associated with the Risk of Left Atrial Appendage Thrombosis in Patients with Non-Valvular Atrial Fibrillation.

Objectives: There are some evidence suggesting that total bilirubin (TBIL) appears to be associated with stroke in patients with nonvalvular atrial fibrillation (NVAF). The left atrial appendage (LAA) is the most common orgin of thrombus in patients with NVAF. The purpose of this study was to assess a possible relationship between plasma TBIL levels and LAA thrombus in NVAF patients. Methods: We retrospectively screened 459 consecutive hospitalized patients with NVAF at three AF centers, who underwent transesophageal echocardiography or cardiac CT. According to the examination results, the patients were divided into either the LAA thrombosis group (41 cases) or the no LAA thrombosis group (418 cases). Independent sample t test, Mann-Whitney U-test and chi-square test were used to compare and analyze the general clinical data of the two groups. Multivariate Logistic regression was used to analyze whether TBIL was a risk factor for LAA thrombosis in patients with NVAF. Pearson correlation analysis was used to explore the correlation between TBIL and other influencing factors. The predictive value of TBIL for LAA thrombosis in patients with NVAF was evaluated by ROC curve. Results: A total of 459 patients were enrolled in this study. Compared with the group without LAA thrombosis, the level of TBIL in LAA thrombosis group was significantly increased (21.34 ± 9.34 umol/L vs. 13.98 ± 4.25 umol/L, P < 0.001). Multivariate logistic regression showed that TBIL level was a risk factor for LAA thrombosis (OR, 1.229; 95% CI, 1.122~1.345; P < 0.001). The AUC of the ROC curve is 0.801 (95% CI, 0.725~0.877; P < 0.001). At 17.4 umol/L of TBIL, the patient may have LAA thrombosis (sensitivity 73.2%; specificity 82.1%). Conclusions: In patients with NVAF, TBIL level is positively associated with LAA thrombosis, and TBIL level may be an index reflecting LAA thrombosis.

Photothermal Dual Passively Driven Liquid Crystal Smart Window.

Photochromic or thermochromic liquid crystal (LC) smart windows have attracted wide attention due to their spontaneous transmittance modulation under different environments. There remains a challenge for the LC smart windows that can be modulated with light and temperature simultaneously owing to the difficulty in selecting photothermal molecules. Herein, we selected a photothermal molecule, isobutyl-substituted diimmonium borate (IDI), which shows excellent characteristics of a photothermal material used in smart windows, such as transparency in the visible light range with a slight brown color, good compatibility with the LC system, and excellent photothermal effect compared with common photothermal materials. Thus, a photothermal dual-driven smart window is developed by doping IDI into chiral LC mixtures, which can efficiently modulate the transmittance at different temperatures (or light intensities) by varying the phase state from the homeotropically oriented smectic phase (transparent) to the focal conic cholesteric phase (opaque). The transmittance is high (70%) when the ambient temperature is low and the light intensity is weak, allowing more sunlight to enter the room. The transmittance is low (20%) when the ambient temperature is high and the light intensity is strong, which prevents sunlight from entering the room. The proposed smart window will have a promising application in terms of energy saving and personalized privacy protection.

MicroRNA-17 as a potential diagnostic biomarker in pulmonary arterial hypertension.

OBJECTIVE: This study aimed to detect circulating microRNA (miR)-17 and miR-20a levels in patients with pulmonary arterial hypertension (PAH), and to investigate whether circulating miR-17 levels are associated with PAH. METHODS: Thirty-five PAH patients and 20 healthy controls were enrolled in the study. Circulating miR-17 and miR-20a levels were measured using real-time PCR analysis. RESULTS: miR-17 levels were significantly increased in PAH patients compared with healthy controls. They were also higher in PAH patients at World Health Organization functional class (WHO FC) III-IV than WHO FC I-II PAH patients. There was no significant difference in miR-20a levels between PAH patients and controls. miR-17 had a high area under the corresponding receiver operating characteristic curve. Further, we found that circulating miR-17 levels correlated with the 6-minute walk distance, mean pulmonary artery pressure, and mean right atrial pressure in PAH patients. CONCLUSION: Circulating miR-17 levels may be associated with human PAH. Therefore, miR-17 could be used as a diagnostic index and prognostic factor for PAH patients.