Wool keratin/zeolitic imidazolate framework-8 composite shape memory sponge with synergistic hemostatic performance for rapid hemorrhage control.

Uncontrollable hemorrhage and subsequent wound infection pose severe threats to life, especially in the case of deep, non-compressible, massive bleeding. Here, a wool keratin/zeolitic imidazolate framework-8 (WK/ZIF-8) composite shape memory sponge is prepared by incorporating ZIF-8 nanoparticles into wool keratin. The combination of keratin and ZIF-8 particles not only reduces the effect of ZIF-8 particles on cell viability but also bolsters the mechanical properties of the keratin sponge and endows it with antibacterial efficacy. Due to the synergistic effect of the excellent hemostatic performance of keratin and Zn2+ release from ZIF-8 nanoparticles, the porous structure suitable for blood cell adhesion and the shape recovery ability of sponges, the WK/ZIF-8 composite sponge exhibits superior hemostatic performance to commercial medical sponges in SD rat and rabbit hemorrhage models. In addition, in vitro and in vivo antibacterial experiments demonstrate the anti-infection activity of the composite sponge. Overall, the WK/ZIF-8 composite sponge provides a promising approach to rapidly control bleeding and promote wound healing.

Gelatin Methacryloyl-Based Sponge with Designed Conical Microchannels for Rapidly Controlling Hemorrhage and Theoretical Verification.

It remains a challenge to develop effective hemostatic products in battlefield rescue for noncompressible massive hemorrhage. Some previous research had concentrated on the modification of different materials to improve the hemostasis ability of sponges. Herein, to investigate the relationship between the taper of microchannels and hemostatic performance of porous sponges, gelatin methacryloyl-based sponges with designed conical microchannels and a disordered porous structure were prepared using the 3D printing method and freeze-drying technology. Experiments and theoretical model analysis demonstrated that the taper and distribution of microchannels in the sponge affected the water and blood absorption properties, as well as the expansion ability. In treatment of SD rat liver defect and SD rat liver perforation wound, GS-1 sponge with the taper (1/15) microchannels exhibited an excellent hemostatic effect with blood loss of 0.866 ± 0.093 g and a hemostasis time of 280 ± 10 s. Results showed that the hemostatic capacities of GelMA sponges were increased with the bottom diameter (taper) of conical microchannels. This is a potential strategy to develop designed taper sponges with designed taper microchannels for rapidly controlling hemorrhage.

Efficient Fractionation and Catalytic Valorization of Raw Biomass in ϵ-Caprolactone and Water.

Efficient fractionation and utilization of the whole biomass is particularly attractive but remains a great challenge, owing to the recalcitrance of biomass. In this study, a simple and efficient approach is developed to obtain high-purity cellulose with a delignification degree of 97.5 % in ϵ-caprolactone and water. FTIR spectroscopy reveals that ϵ-caprolactone and water act in synergy to remove lignin from raw biomass and afford cellulose with clear macrofibrils. A linear positive correlation between the contents of hemicellulose and lignin is observed for the separated cellulose pulp. This mixed solvent exhibits good performance for the removal of lignin from various agricultural and forestry wastes. Moreover, nearly complete transformation of the whole biomass constituents is achieved with Ni-Al catalyst.

Catalytic production of low-carbon footprint sustainable natural gas.

Natural gas is one of the foremost basic energy sources on earth. Although biological process appears as promising valorization routes to transfer biomass to sustainable methane, the recalcitrance of lignocellulosic biomass is the major limitation for the production of mixing gas to meet the natural gas composition of pipeline transportation. Here we develop a catalytic-drive approach to directly transfer solid biomass to bio-natural gas which can be suitable for the current infrastructure. A catalyst with Ni2Al3 alloy phase enables nearly complete conversion of various agricultural and forestry residues, the total carbon yield of gas products reaches up to 93% after several hours at relative low-temperature (300 degrees Celsius). And the catalyst shows powerful processing capability for the production of natural gas during thirty cycles. A low-carbon footprint is estimated by a preliminary life cycle assessment, especially for the low hydrogen pressure and non-fossil hydrogen, and technical economic analysis predicts that this process is an economically competitive production process.

Molybdenum-Catalyzed Deoxygenation Coupling of Lignin-Derived Alcohols for Functionalized Bibenzyl Chemicals.

With the growing demand for sustainability and reducing CO2 footprint, lignocellulosic biomass has attracted much attention as a renewable, carbon-neutral and low-cost feedstock for the production of chemicals and fuels. To realize efficient utilization of biomass resource, it is essential to selectively alter the high degree of oxygen functionality of biomass-derivates. Herein, we introduced a novel procedure to transform renewable lignin-derived alcohols to various functionalized bibenzyl chemicals. This strategy relied on a short deoxygenation coupling pathway with economical molybdenum catalyst. A well-designed H-donor experiment was performed to investigate the mechanism of this Mo-catalyzed process. It was proven that benzyl carbon-radical was the most possible intermediate to form the bibenzyl products. It was also discovered that the para methoxy and phenolic hydroxyl groups could stabilize the corresponding radical intermediates and then facilitate to selectively obtain bibenzyl products. Our research provides a promising application to produce functionalized aromatics from biomass-derived materials.

Sustainable synthesis of 1,2,3,4-cyclohexanetetracarboxylate from sugar-derived carboxylic acids.

Herein, we report a sustainable route for the synthesis of 1,2,3,4-cyclohexanetetracarboxylate from sugar-derived muconic acid and fumaric acid. The key Diels-Alder reaction constructed a cyclohexene framework substituted by four ester groups. The isolated yield of tetramethyl 5-cyclohexene-1,2,3,4-tetracarboxylate was up to 95.5% without any catalyst used. And the hydrogenation reaction of the cycloadduct was catalyzed by commercial RANEY® Ni at room temperature and nearly 100% yield of the cyclohexyl target products was obtained.

Production of Plant Phthalate and its Hydrogenated Derivative from Bio-Based Platform Chemicals.

Direct transformation of bio-based platform chemicals into aromatic dicarboxylic acids and their derivatives, which are widely used for the manufacture of polymers, is of significant importance for the sustainable development of the plastics industry. However, limited successful chemical processes have been reported. This study concerns a sustainable route for the production of phthalate and its hydrogenated derivative from bio-based malic acid and erythritol. The key Diels-Alder reaction is applied to build a substituted cyclohexene structure. The dehydration reaction of malic acid affords fumaric acid with 96.6 % yield, which could be used as the dienophile, and 1,3-butadiene generated in situ through erythritol deoxydehydration serves as the diene. Starting from erythritol and dibutyl fumarate, a 74.3 % yield of dibutyl trans-4-cyclohexene-1,2-dicarboxylate is obtained. The palladium-catalyzed dehydrogenation of the cycloadduct gives a 77.8 % yield of dibutyl phthalate. Dibutyl trans-cyclohexane-1,2-dicarboxylate could be formed in nearly 100 % yield under mild conditions by hydrogenation of the cycloadduct. Furthermore, fumaric acid and fumarate, with trans configurations, were found to be better dienophiles for this Diels-Alder reaction than maleic acid and maleate, with cis configuration, based on the experimental and computational results. This new route will pave the way for the production of environmental friendly plastic materials from plants.

[In vivo anti-tumor effect and in vitro anti-angiogenic effect of alcohol extract from Euphorbia prostrata].

The study was designed to investigate the anti-tumor and anti-angiogenic effects of alcohol extract from Euphorbia prostrata. The alcohol extract of E. prostrata was prepared, and the tolerated dosage was determined in mice by the test for acute toxicity. Then, MTT method was used to study the anti-proliferation effect of E. prostrata on normal cells and tumor cells. The rat aortic endothelial cells(RAECs) were primarily cultured. Subsequently, in vitro cell proliferation, migration and tubule formation assays were performed to detect the effect of alcohol extract of E. prostrata on proliferation, migration and angiogenesis. Western blot analysis was performed to detect the protein expressions of Akt, p-Akt, eNOS, p-eNOS, TGF-ß1 and Smad3 in RAECs treated with E. prostrata. In addition, an in vivo transplanted hepatocellular carcinoma model in nude mice was established to detect nude mass, tumor volume and tumor weight. The contents of vascular endothelial growth factor(VEGF) and the platelet-derived growth factor-BB(PDGF-BB) in blood serum were detected by using ELISA kits. HE staining was performed to study the morphology of tumor tissues. The tolerated dosage of alcohol extract of E. prostrata in mice was 94.29 g•kg⁻¹. Alcohol extract of E. prostrata showed no inhibitory effect on L6 cells, but significantly inhibited the proliferations of HepG-2, PC12, A549, and Hela cells with the following order： HepG-2>Hela>PC12>A549. Meanwhile, alcohol extract of E. prostrata markedly inhibited the proliferation, migration and tube formation of RAECs, and enhanced the expressions of phosphorylated Akt and eNOS and increased the expressions of TGF-ß1 and Smad3. In addition, E. prostrata notably inhibited the tumor growth in mice, and decreased the amount of VEGF, but increased the amount of PDGF-BB factor in serum of nude mice. The alcohol extract of E. prostrata may show an inhibitory effect on tumor growth and angiogenesis, which may contribute to its anti-tumor effect.

TRPC5 channel modulates endothelial cells senescence.

As a Ca2+-permeable cationic channel, canonical transient receptor potential 5 channel (TRPC5) has been known to be involved in various functions of cells. Although TRPC5 is abundantly expressed in vascular endothelium, it remains unknown whether TRPC5 plays a role in regulating endothelial senescence. In the present study, we investigated the involvement of TRPC5 in the senescence of mouse aortic endothelial cells (MAECs). Meanwhile, the regulatory role of TRPC5 in the endothelial dysfunction in aged mice was also studied. Results showed that the endothelium-dependent relaxations were significantly promoted but the endothelium-dependent contractions were markedly attenuated in aortic rings from aged mice with TRPC5 gene knocked out compared with those from aged C57BL/6J mice. Meanwhile, the nuclear telomerase activity and nitric oxide generation were notably enhanced but the reactive oxygen species production was significantly inhibited in aged mice or in hydrogen peroxide-induced senescent MAECs lacking the TRPC5 gene. In addition, by performing the senescence-associated ß-galactosidase staining the oxidative stress-induced premature senescence was markedly depressed in MAECs with TRPC5 gene deficient. Expressions of endothelial nitric oxide synthase and silent information regulator protein 1 (SIRT1) were significantly up-regulated but those of P53 and P21 were markedly down-regulated both in aged mice and in hydrogen peroxide-treated MAECs in the absence of the TRPC5 gene. These results of our study uncover novel functions of TRPC5 in regulating vascular aging.

Vasodilatory effects and underlying mechanisms of the ethyl acetate extracts from Gastrodia elata.

The objective of this study was to assess the ethyl acetate extracts of Gastrodia elata Blume (GEB) on vascular tone and the mechanisms involved. GEB was extracted with 95% EtOH followed by a further extraction with ethyl acetate. The effects of GEB and its ingredients on the isometric tensions of the aortic rings from rats were measured. The ethyl acetate extract of GEB induced a vasodilatory effect on rat aorta, which was partially dependent on endothelium. Four chemical compounds isolated from GEB were identified as 3,4-dihydroxybenzaldehyde (DB), 4-hydroxybenzaldehyde (HB), 4-methoxybenzyl alcohol (MA), and 4,4'-dihydroxydiphenyl methane (DM), respectively. All of these compounds induced vasodilatations, which were dependent on the endothelium to different degrees. After pretreatment with Nω-nitro-l-arginine methyl ester, indomethacin, or methylene blue, the vasodilatations induced by DB, HB, and MA were significantly decreased. In addition, the contractions of the rat aortic rings due to Ca2+ influx and intracellular Ca2+ release were also inhibited by DM. Furthermore, the administration of DB significantly enhanced the productions of nitric oxide (NO) and the activities of the endothelial NO synthase in aorta and in endothelial cells. Thus, GEB may play an important role in the amelioration of hypertension by modulating vascular tones.

High Yield Production of Natural Phenolic Alcohols from Woody Biomass Using a Nickel-Based Catalyst.

Efficient depolymerization of woody biomass to produce natural phenolic alcohols not only preserves the original structure of lignin, but also makes the depolymerization process atom-efficient. Here, high yield production of natural phenolic alcohols (38.7 wt %) from woody biomass has been achieved using a Ni/C catalyst in a methanol-water co-solvent. The Ni-based catalyst can efficiently etherify the Cα -OH group in lignin ß-O-4 motifs under hydrogen atmosphere, which can break the hydrogen bond between the Cß -O oxygen and the Cα -OH proton to facilitate the Cß -O cleavage. It was reported that water can also accelerate the etherification of raw lignin with methanol through in situ formation of acid. Our results suggest that breaking the intramolecular hydrogen bonds can accelerate the Cß -O cleavage, keeping the original structure of lignin unchanged. This work highlights the significance of structure modification in lignin depolymerization and displays a clear potential for the valorization of whole biomass.