Inhibitory effects of nobiletin-mediated interfacial instability of bile salt emulsified oil droplets on lipid digestion.

Previous lipase inhibitors studies mainly focus on the binding between inhibitors and lipase, ignoring the impact of inhibitors on the oil-water interface of lipid droplets. This study aimed to investigate the effect of nobiletin (NBT) from Citri Reticulatae Pericarpium on the oil-water interface properties and lipid digestion. Here, we found that NBT could destroy bile salt (BS)-stabilized lipid droplets and thus inhibited free fatty acid release, owing to the interaction between NBT and BS at the oil-water interface, and reducing the stability of the oil-water interface (the stability index decreased from 91.15 ± 2.6 % to 66.5 ± 3.6 %). Further, the molecular dynamics simulation and isothermal titration calorimetry revealed that NBT could combine with BS at oil-water interface through intermolecular interactions, including hydrogen bonds, Van der Waals force, and steric hindrance. These results suggest that the interfacial instability of NBT mediated BS emulsified oil droplets may be another pathway to inhibit lipid digestion.

An elastic MOF/graphene aerogel with high photothermal efficiency for rapid removal of crude oil.

Due to the frequent spill accidents during crude oil exploration and transport, to rapidly cleanup crude oil and eliminate the environmental pollution of oil spill is in high demand. In this work, a three-dimensional graphene aerogel (MEGA) with high elasticity, photothermal conversion capacity and adsorption capacity was prepared for rapid removal of crude oil. The results showed that the as-prepared MEGA exhibited a layered structure, the octahedral HKUST-1 nanoparticles and hydrophobic polydimethylsiloxane (PDMS) coatings were uniformly deposited on the surface. Such a hierarchical micro-nano porous structure not only improved the aerogel's hydrophobicity (water contact angle in air up to 152.7°), but also endowed it with strong oil adsorption capacity (41-118 times of its own weight). Especially, the MEGA showed excellent photothermal conversion capacity. Under light irradiation, its temperature raised to 80 â„ƒ from room temperature in 100 s. As a result, the adsorption for one drop of crude oil by MEGA was shortened from 5 h to 40 s, comparing with that in dark condition. In addition, the MEGA showed remarkable elasticity and mechanical stability, it could maintain more than 90% efficiency after 10 adsorption-compression cycles. This study suggests that the prepared MEGA has great potential for rapid removal of crude oil.

Enhanced air filtration performances by coating aramid nanofibres on a melt-blown nonwoven.

Nanofibre membranes with a small diameter and a large specific surface area are widely used in the filtration field due to their small pore size and high porosity. To date, aramid nanofibres (ANFs) have received extensive research interest because of their high stiffness and excellent temperature resistance. However, the preparation of ANFs usually takes a long time, which greatly hampers the practical application of these fibres. Herein, we report the preparation of ANFs by a modified deprotonation method at elevated temperature. Owing to the increase of temperature, the preparation cycle of ANFs was shortened to 8 hours. The resulting ANF dispersion was further coated on a polypropylene melt-blown nonwoven to form a composite nonwoven filter. With the submicron porous structure, the filtration efficiency, pressure drop and quality factor of the filter were 95.61%, 38.22 Pa and 0.082 Pa-1, respectively. Compared to the pristine nonwoven, the filtration, mechanical, and heat insulation properties of the composite filter were also significantly improved. This work may offer a simple and efficient way for enhancing the air filtration performances of current filters.

Protection of agarwood essential oil aroma by nanocellulose-graft-polylactic acid.

Essential oil products are often volatile, and their aromas cannot be effectively preserved over long periods of time. In this study, nanocellulose crystals were modified, and an amphiphilic copolymer was prepared by ring-opening polymerisation to produce wall materials. A nanocellulose crystal-grafted polylactic acid copolymer was successfully synthesised and characterised using nuclear magnetic resonance spectrometry, Fourier transform infrared spectrometry, X-ray diffraction, and thermogravimetric analysis. Because of the amphiphilic properties of the synthesised copolymer, an agarwood essential oil nanoemulsion system was prepared. Using transmission electron microscopy and dynamic laser light scattering, the nanoemulsion was observed to have an apparent shell-core structure. The nanoemulsion was uniformly distributed, and the system had good stability. Finally, the electronic nose results showed that the nanocellulose crystal-grafted polylactic acid copolymer micelle effectively protected agarwood essential oil aromas.

Graphene-modified CePO4 nanorods effectively treat breast cancer-induced bone metastases and regulate macrophage polarization to improve osteo-inductive ability.

BACKGROUND: Breast cancer bone metastasis has become one of the most common complications; however, it may cause cancer recurrence and bone nonunion, as well as local bone defects. METHODS: Herein, In vitro, we verified the effect of bioscaffold materials on cell proliferation and apoptosis through a CCK8 trial, staining of live/dead cells, and flow cytometry. We used immunofluorescence technology and flow cytometry to verify whether bioscaffold materials regulate macrophage polarization, and we used ALP staining, alizarin red staining and PCR to verify whether bioscaffold material promotes bone regeneration. In vivo, we once again studied the effect of bioscaffold materials on tumors by measuring tumor volume in mice, Tunel staining, and caspase-3 immunofluorescence. We also constructed a mouse skull ultimate defect model to verify the effect on bone regeneration. RESULTS: Graphene oxide (GO) nanoparticles, hydrated CePO4 nanorods and bioactive chitosan (CS) are combined to form a bioactive multifunctional CePO4/CS/GO scaffold, with characteristics such as photothermal therapy to kill tumors, macrophage polarization to promote blood vessel formation, and induction of bone formation. CePO4/CS/GO scaffold activates the caspase-3 proteasein local tumor cells, thereby lysing the DNA between nucleosomes and causing apoptosis. On the one hand, the as-released Ce3+ ions promote M2 polarization of macrophages, which secretes vascular endothelial growth factor (VEGF) and Arginase-1 (Arg-1), which promotes angiogenesis. On the other hand, the as-released Ce3+ ions also activated the BMP-2/Smad signaling pathway which facilitated bone tissue regeneration. CONCLUSION: The multifunctional CePO4/CS/GO scaffolds may become a promising platform for therapy of breast cancer bone metastases.

Magnetic lanthanum-doped hydroxyapatite/chitosan scaffolds with endogenous stem cell-recruiting and immunomodulatory properties for bone regeneration.

Generally, the addition of exogenous stem cells and host-to-scaffold immune responses restricts the clinical applications of hydroxyapatite (HA)/chitosan (CS) scaffolds for bone regeneration. To achieve "facilitated endogenous tissue engineering", magnetic M-type hexagonal ferrite (SrFe12O19) nanoparticles were incorporated into bone scaffolds to recruit endogenous stem cells. Then, lanthanum incorporation was utilized to regulate host-to-scaffold immune responses and to provide a pro-regenerative environment for recruited endogenous stem cells. Here, we first fabricated and characterized magnetic lanthanum-doped HA/CS scaffolds. The MLaHA/CS scaffolds were demonstrated to be effective at recruiting rat bone marrow mesenchymal stem cells (rBMSCs) and modulating host-to-scaffold immune responses by promoting macrophage polarization into the anti-inflammatory phenotype (M2) in vitro. By further examining the underlying mechanism, we found that MLaHA/CS scaffolds could promote the osteogenic differentiation of rBMSCs by upregulating the phosphorylation of the Smad 1/5/9 pathway. When MLaHA/CS scaffolds were implanted into rat calvarial defects, the incorporation of magnetic nanoparticles and lanthanum significantly promoted the new bone regeneration, as revealed by micro-CT assays and histological staining. Our findings suggest that MLaHA/CS shows great potential for use as a cell-free and biocompatible scaffold for bone regeneration.

Transforming Nanofiber Mats into Hierarchical Scaffolds with Graded Changes in Porosity and/or Nanofiber Alignment.

A method for generating hierarchical scaffolds with graded changes in porosity and/or fiber alignment through solution-masked, vapor-induced welding of electrospun poly(lactic-co-glycolic acid) (PLGA) nanofibers is reported. The success of this method relies on the fact that the PLGA nanofibers are swollen and welded more slowly by ethanol when immersed in its aqueous solution relative to direct exposure to its vapor. For a mat composed of random nanofibers, the treatment generates a gradation in porosity (both surface and bulk), with the over-welded region evolving from a highly porous mat into a dense film. If uniaxially aligned nanofibers are involved, however, graded changes are observed in both surface porosity and fiber alignment. When bone marrow stem cells are cultured on such a scaffold, they exhibit highly organized and random morphologies on the regions of uniaxially aligned nanofibers and dense film, respectively, with gradual changes in between. Such a scaffold shows promise in mimicking the connective tissue, such as the tendon-to-bone insertion, that relies on a graded transition in cell morphology from uniaxially aligned to random.

Gadolinium-doped mesoporous calcium silicate/chitosan scaffolds enhanced bone regeneration ability.

Chitosan (CTS) and mesoporous calcium silicate (MCS) have been developed for bone defect healing; however, their bone regeneration capacity still does not satisfy the patients with bone diseases. Gadolinium (Gd) is accumulated in human bones, and plays a beneficial role in regulating cell performance and bone regeneration. We firstly constructed Gd-doped MCS/CTS (Gd-MCS/CTS) scaffolds by a lyophilization technology. The interconnected arrangement of CTS films lead to forming macropores by using ice crystals as templates during the lyophilization procedure, and the Gd-MCS nanoparticles dispersed uniformly on the macropore walls. The biocompatible chemical components and hierarchical pores facilitated the attachment and spreading of rat bone marrow-derived mesenchymal stem cells (rBMSCs). Interestingly, the Gd dopants in the scaffolds effectively activated the Wnt/ß-catenin signaling pathway, resulting in excellent cell proliferation and osteogenic differentiation capacities. The osteogenic-related genes such as alkaline phosphatase (ALP), runt-related transcription factor 2 (Runx2) and collagen type1 (COL-1) were remarkably up-regulated by Gd-MCS scaffolds as compared with MCS scaffolds, and their expression levels increased in a positive correlation with Gd doping amounts. Moreover, in vivo rat cranial defect tests further confirmed that Gd-MCS/CTS scaffolds significantly stimulated collagen deposition and new bone formation. The exciting finding suggested the beneficial effects of Gd3+ ions on osteogenic differentiation and new bone regeneration, and Gd-MCS/CTS scaffolds can be employed as a novel platform for bone defect healing.

OMS-2-based catalysts with controllable hierarchical morphologies for highly efficient catalytic oxidation of formaldehyde.

Cryptomelane-type octahedral molecular sieve (OMS-2) catalysts are currently attracting tremendous attention due to their low-cost and remarkable thermo-catalytic activity. However, it is still difficult for OMS-2 catalysts to completely degrade formaldehyde at relatively low or even ambient temperature. In this work, OMS-2 catalysts with different ratios of length to diameter were prepared and the OMS-2-s with the minim ratio of length to diameter (1-3) exhibited the best catalytic performance than the other samples. Then, the optimized OMS-2-s nanorods were loaded on the SiO2 nanofibers via a simultaneous electrospining-spray strategy. The evaluation for the dynamic catalytic activities of the samples showed that, the T50 (HCHO conversion reached to 50%) for the OMS-2/SiO2 nanofibrous membranes was decreased by 24 °C than the OMS-2-s nanorods. Furthermore, in the static experiment of HCHO decomposition, the composite membrane could achieve a catalytic efficiency of 52.3% at 25 °C, much higher than that of the OMS-2-s nanorods (45.9%). This work offers a new strategy to improve the catalytic efficiency of OMS-2 by controlling the morphology and loading of OMS-2 nanorods, and also designs a kind of advanced nano OMS-2-based nanofibrous membranes with hierarchical nanostructures for the highly efficient formaldehyde elimination during the practical application.