Preparation of PEG/P(U-AM-ChCl) composite hydrogels using ternary DES light polymerization and their properties.

Deep eutectic solvents (DES) were prepared using urea (U) and acrylamide (AM) as hydrogen bond donors (HBD) and choline chloride (ChCl) as hydrogen bond acceptor (HBA), and polyethylene glycol (PEG) was selected as a filler and uniformly dispersed in DES to prepare PEG/P(U-AM-ChCl) composite hydrogels by light polymerization. The composite hydrogels were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The effects of the content of PEG on the swelling properties, mechanical properties and fatigue resistance of the composite hydrogels were investigated. The results showed that the compressive strength and fatigue strength of the composite hydrogels were gradually enhanced with the increase of the PEG content in the composite hydrogels, in which the maximum compressive strength of the hydrogels with 1 wt% PEG added was increased by 1.86 times. The composite hydrogel had excellent swelling properties, and the equilibrium swelling degree of the hydrogel with 1 wt% PEG added reached 10.15. Meanwhile, the PEG/P(U-AM-ChCl) composite hydrogel had excellent self-healing properties, and the self-healing rate of the composite hydrogel with a PFG content of 1 wt% could reach 91.93% after 48 hours of healing. This study provides a convenient and efficient method to prepare composite hydrogels with superior swelling properties and self-healing properties.

Preparation and characterization of PA/P(AA-co-AM) composite hydrogels via photopolymerization.

The present study synthesized a deep eutectic solvent (DES) using acrylic acid (AA), acrylamide (AM), and choline chloride (ChCl), and added phytic acid (PA) as a filler. Subsequently, the PA/P(AA-co-AM) composite hydrogel was prepared under ultraviolet irradiation and used a photoinitiator. Characterization of the hydrogels was conducted using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The study aimed to investigate the impact of PA on the mechanical properties, fatigue resistance, and electrical conductivity of the composite hydrogel. The findings demonstrated that as the mass fraction of PA increased, the compressive strength of the composite hydrogel gradually decreased, yet the fatigue resistance of the composite hydrogel increased. Specifically, after 10 cycles of compression, the resilience recovery rate of FP0 dropped from 86.9% to 70.4%, the maximum stress recovery rate of FP1 dropped from 97.9% to 89.4%, the maximum stress recovery rate of FP2 dropped from 94.4% to 86.6%, and the maximum stress recovery rate of FP3 dropped from 97.3% to 93%. Overall, this study offers a straightforward and efficient method for producing composite hydrogels with both fatigue resistance and electrical conductivity.

Mechanistic study of the effect of potassium ferrate and straw fiber on the enhancement of strength in cement-based solidified municipal sludge.

The high content of organic matter in sludge is the primary reason for the poor solidifying effect and excessive dosage of the cement base. In this study, potassium ferrate and straw fiber are utilized to synergistically enhance the solidifying effect of the cement and elaborate the strength mechanisms. Among them, potassium ferrate was selected to oxidize and crack the structure of organic matter in sludge and consume part of organic matter; straw fiber was used as an adsorption material to absorb some of the organic material and reduce its interference with the cement hydration reaction; the skeleton function of straw fiber in solidified sludge was used to improve the final solidified sludge strength. It is shown that the presence of these two additives significantly improved the cement solidification strength and reduced the moisture content of the solidified body. Moreover, the moisture content and strength followed an obvious linear relationship (adjusted R2 = 0.92), with the strength increasing as the moisture content decreased. After pretreatment with potassium ferrate, the free water content in the dewatered sludge increased by 4.5%, which was conducive to the adequate hydration reaction with cement. The analysis using X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS), and mercury intrusion porosimetry (MIP) revealed potassium ferrate synergizes with straw fibers to promote the production of hemihydrate gypsum and gismondine. However, hemihydrate gypsum, calcium carbonate, and gismondine resulted in structural swelling, which was confirmed by the microscopic morphology and pore structure analysis. However, the adverse effects due to swelling were offset by the increase in strength brought by the above crystalline substances.

Preparation of novel ß-CD/P(AA-co-AM) hydrogels by frontal polymerization.

In this paper, betaine (Bet) was used as a hydrogen bond acceptor (HBA), and acrylic acid (AA) and acrylamide (AM) were used as hydrogen bond donors (HBD) and mixed to form a deep eutectic solvent (DES). Different concentrations of ß-cyclodextrin (ß-CD) were dispersed in the DES, and a novel ß-CD/P(AA-co-AM) hydrogel was prepared by frontal polymerization (FP). The characteristic structure and morphology of the hydrogels were analyzed using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), and the properties of the hydrogels were investigated. The results show that the mechanical properties of the hydrogel were improved by ß-CD acting as a second cross-linking agent in the polymerization process, thus increasing the cross-link density of the hydrogel. Because the carboxyl groups contained in the acrylic acid dissociate under alkaline conditions, the composite hydrogel shows excellent pH responsiveness under alkaline conditions. Tetracycline hydrochloride was used as a drug model to test the drug loading and drug release performance of the hydrogels. With the increase of ß-CD content, the loading capacity of the hydrogels for tetracycline hydrochloride gradually increased. The data of drug release indicated that the hydrogel has good drug delivery performance and has promising applications in drug delivery systems and other areas.

Preparation and properties of CS/P(AM-co-AA) composite hydrogels by frontal polymerization of ternary DES.

A deep eutectic solvent (DES) was prepared from choline chloride (ChCl), acrylamide (AM) and acrylic acid (AA); chitosan (CS) was used as a filler, and CS/P(AM-co-AA) composite hydrogels were prepared by frontal polymerization (FP). The hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The mechanical properties, pH responsiveness and conductivity of the hydrogel were studied. The results showed that the mechanical properties of the hydrogel were significantly improved by adding CS, and the tensile strength and compressive strength were increased by 11.61 and 1.65 times respectively due to the increase in number of hydrogen bonds. At the same time, due to the presence of AA, the composite hydrogel has excellent pH response and super high swelling performance under alkaline conditions. The introduction of CS enhanced the conductivity of the hydrogel and gradually increased with the increase of CS content. The conductivity of the hydrogel with CS content of 10 wt% was nearly 160 times that of the hydrogel without CS. In this study, a more convenient and rapid method was proposed to prepare conductive composite hydrogels with excellent mechanical properties and pH responsiveness.

Rapid preparation of N-CNTs/P(AA-co-AM) composite hydrogel via frontal polymerization and its mechanical and conductive properties.

Deep eutectic solvent (DES) was prepared by using acrylic acid (AA) and acrylamide (AM) as hydrogen bonding donors (HBD) and choline chloride (ChCl) as hydrogen bonding receptors (HBA). Nitrogen-doped carbon nanotubes (N-CNTs) were dispersed in DES as fillers, and N-CNTs/P(AA-co-AM) composite hydrogels were prepared by FP. The interaction mode between the hydrogel and N-CNTs was characterized by Fourier infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The mechanical properties, pH response and electrical conductivity of the composite hydrogels were studied. The results showed that the mechanical properties of the hydrogel were significantly enhanced with the increase of N-CNT content. The tensile strength and compressive strength of the FP4 composite hydrogel reached 5.42 MPa and 4.29 MPa, respectively. Due to the dissociation of carboxyl groups in AA in an alkaline environment the composite hydrogel showed excellent pH response performance. The conductivity of the hydrogel was also found to be improved with the content of N-CNTs. When the content of N-CNTs is 1.0 wt%, the conductivity of the hydrogel was 4.2 times higher than that of the hydrogel without N-CNTs, and connecting it to a circuit can make an LED lamp emit bright light. In this study, a simple and green method was proposed to prepare composite hydrogels with excellent mechanical properties and electrical conductivity by FP of DES in less than 5 min.

Rapid preparation of ZnO nanocomposite hydrogels by frontal polymerization of a ternary DES and performance study.

A deep eutectic solvent (DES) was synthesized from urea (U), acrylamide (AM), and choline chloride (ChCl). ZnO was dispersed in the DES as a filler, and nanocomposite hydrogels (ZnO/P(U-AM-ChCl)) were successfully prepared by frontal polymerization (FP). The hydrogels were verified by Fourier infrared spectroscopy to contain ZnO nanoparticles (ZnO-NPs). The swelling behaviour, conductivity, and antibacterial properties of the ZnO nanocomposite hydrogels were investigated. The results showed that the ZnO/P(U-AM-ChCl) hydrogels had excellent antibacterial properties and exhibited super high inhibition rates of 81.87% and 88.42% against two basic colonies of Gram-negative and Gram-positive bacteria, respectively. The equilibrium swelling of the hydrogels was found to increase significantly from 9.30 to 12.29 with the addition of ZnO, while the ZnO/P(U-AM-ChCl) hydrogel conductivity exhibited good UV sensitivity. This study provides a rapid and low-energy method for the preparation of nanocomposite hydrogels with excellent antibacterial properties.

α-Hederin inhibits the growth of lung cancer A549 cells in vitro and in vivo by decreasing SIRT6 dependent glycolysis.

CONTEXT: α-Hederin, a potent bioactive compound of Pulsatilla chinensis (Bunge) Regel (Ranunculaceae), has many pharmacological uses, but its effect on cancer cell metabolism is still unclear. OBJECTIVE: To elucidate the role of α-hederin in the glucose metabolism of lung cancer cells. MATERIALS AND METHODS: Cell Counting Kit 8 and colony formation assays were employed to assess the antiproliferative effects of α-hederin. Glucose uptake, ATP generation, and lactate production were measured. Glycolysis-related proteins were detected using western blotting, and a sirtuin 6 (SIRT6) inhibitor was used to verify A549 cell proliferation. Sixty male BALB/c nude mice were divided into normal control, 5-FU (25 mg/kg), and α-hederin (5 and 10 mg/kg) groups to assess the antitumor effect for 32 days. Glycolysis-related protein expression was evaluated using immunohistochemical analysis. RESULTS: α-Hederin inhibited A549 (IC50 = 13.75 µM), NCI-H460 (IC50 = 17.57 µM), and NCI-H292 (IC50 = 18.04 µM) proliferation; inhibited glucose uptake and ATP generation; and reduced lactate production. Furthermore, α-hederin (10 and 15 µM) markedly inhibited hexokinase 2, glucose transporter 1, pyruvate kinase M2, lactate dehydrogenase A, monocarboxylate transporter, c-Myc, hypoxia-inducible factor-1α, and activated SIRT6 protein expression. Using a SIRT6 inhibitor, we demonstrated that α-hederin inhibits glycolysis by activating SIRT6. A tumour xenograft mouse model of lung cancer confirmed that α-hederin (5 and 10 mg/kg) inhibits lung cancer growth by inhibiting glycolysis in vivo. DISCUSSION AND CONCLUSIONS: α-Hederin inhibits A549 cell growth by inhibiting SIRT6-dependent glycolysis. α-Hederin might serve as a potential agent to suppress cancer.

Anemoside B4 prevents acute ulcerative colitis through inhibiting of TLR4/NF-κB/MAPK signaling pathway.

Anemoside B4 (B4) is a compound extracted from Pulsatilla chinensis(P. chinensis). Pharmacological studies have proved that it has certain anti-inflammatory activity. Acute ulcerative colitis (ulcerative colitis) is a non-specific inflammatory disease whose pathogenesis is not completely known, and there is no effective drugs. The purpose of this study was to investigate the protective effect of B4 on ulcerative colitis and its mechanism. In this study, the C57BL/6 mice model of ulcerative colitis was established by DSS [3% (w/v)] and treated with intraperitoneal injection of B4 and oral administration of mesalazine, respectively. During the experiment, the clinical symptoms of the mice were scored by the disease activity index (DAI). Histopathological changes were observed by HE staining. In addition, the effect of LPS on Raw264.7 cells was also studied. In vivo studies showed that B4 could prevent DSS-induced colitis mice from losing weight, shortening colon length and improving pathological changes of colon tissues. B4 significantly reduced levels of inflammatory cytokines IL-1ß, IL-6, and TNF-α in colon tissues. In vitro experiments, B4 was almost nontoxic to Raw264.7 cells and could protect the Raw264.7 cells induced by LPS. In terms of mechanism, B4 significantly inhibited the activation of the TLR4 signaling pathway induced by DSS and down-regulate the expression of key proteins in the TLR4/NF-κB/MAPK signaling pathway in Raw264.7 cells induced by LPS. These findings suggest that the inhibition of B4 on ulcerative colitis may be through the TLR4/NF-κB/MAPK pathway. Therefore, B4 may be used as a potential drug for the treatment of ulcerative colitis.

Molecular mechanistic insight into the anti-hyperuricemic effect of Eucommia ulmoides in mice and rats.

CONTEXT: Eucommia ulmoides Oliver (Eucommiaceae) has various medicinal properties. Our previous studies revealed that Eucommia ulmoides has a protective effect on hyperuricaemia. OBJECTIVE: This study investigates the effect of Eucommia ulmoides cortex ethanol extract (EU) on hyperuricaemia and explores the underlying mechanism in Kunming mice and Sprague-Dawley rats. MATERIAL AND METHODS: Sixty mice and sixty rats were divided into normal control, hyperuricaemia, allopurinol (10 mg/kg) and three EU groups. The EU groups received intragastric EU at 80, 160, 320 mg/kg in mice and 100, 200, 400 mg/kg in rats for 7 days. Serum uric acid (SUA) was measured using a kit. mRNA and proteins were quantified by RT-qPCR and immunohistochemical assays (IHC), respectively. RESULTS: The Maximal Tolerable Dose (MTD) of EU administered intragastrically was 18 g/kg in mice. The intermediate (160 mg/kg) and high (320 mg/kg) EU treatment significantly reduced (p < 0.05) SUA levels to 130.16 µmol/L and 109.29 µmol/L, respectively, and markedly elevated the mRNA expression of organic anion transporters 1 (OAT1) and organic anion transporters 3 (OAT3), while significantly deceasing the mRNA levels of glucose transporter 9 (GLUT9) and uric acid transporter 1 (URAT1) in the mouse kidney (p < 0.05). In hyperuricemic rats, high EU (400 mg/kg) significantly reduced SUA levels to 253.85 µmol/L, and increased OAT1 and OAT3 levels, but decreased URAT1 and GLUT9, compared to the hyperuricaemia group (p < 0.05). DISCUSSION AND CONCLUSIONS: This study demonstrated the potential hyperuricaemia ameliorating effect of EU. Specific active ingredients in EU should be evaluated. These results are valuable for the development of antihyperuritic agents from EU.