Protective mechanism of quercetin compounds against acrylamide-induced hepatotoxicity

Quercetin compounds have antioxidant,anti-inflammatory and anticancer pharmacological functions.Longterm exposure to acrylamide(AA)can cause liver injury and endanger human health.However,whether quercetin compounds can attenuate AA-induced liver injury and the specific mechanism are not clear.Here,we studied the mechanism and structure-activity relationship of quercetin compounds in reducing AA-induced hepatotoxicity in vivo and in vitro.In vivo studies found that quercetin-like compounds protect against AAinduced liver injury by reducing oxidative stress levels,activating the Akt/m TOR signaling pathway to attenuate autophagy,and improving mitochondrial apoptosis and endoplasmic reticulum stress-mediated apoptosis.In vitro studies found that quercetin compounds protected Hep G2 cells from AA by attenuating the activation of AA-induced autophagy,lowering reactive oxygen species(ROS)levels by exerting antioxidant effects and thus attenuating oxidative stress,increasing mitochondrial membrane potential(MMP),and improving apoptosis-related proteins,thus attenuating AA-induced apoptosis.Furthermore,the conformational differences between quercetin compounds correlated with their protective capacity against AA-induced hepatotoxicity,with quercetin showing the best protective capacity due to its strongest antioxidant activity.In conclusion,quercetin compounds can protect against AA-induced liver injury through multiple pathways of oxidative stress,autophagy and apoptosis,and their protective capacity correlates with antioxidant activity.

A Polyvinyl Alcohol/Acrylamide Hydrogel with Enhanced Mechanical Properties Promotes Full-Thickness Skin Defect Healing by Regulating Immunomodulation and Angiogenesis Through Paracrine Secretion

Hydrogel-based tissue-engineered skin has attracted increased attention due to its potential to restore the structural integrity and functionality of skin.However,the mechanical properties of hydrogel scaffolds and natural skin are substantially different.Here,we developed a polyvinyl alcohol(PVA)/acrylamide based interpenetrating network(IPN)hydrogel that was surface modified with polydopamine(PDA)and termed Dopa-gel.The Dopa-gel exhibited mechanical properties similar to native skin tissue and a superior ability to modulate paracrine functions.Furthermore,a tough scaffold with tensile resistance was fabricated using this hydrogel by three-dimensional printing.The results showed that the interpenetration of PVA,alginate,and polyacrylamide networks notably enhanced the mechanical properties of the hydrogel.Surface modification with PDA endowed the hydrogels with increased secretion of immunomodulatory and proangiogenic factors.In an in vivo model,Dopa-gel treatment accelerated wound closure,increased vascularization,and promoted a shift in macrophages from a proinflammatory M1 phenotype to a prohealing and anti-inflammatory M2 phenotype within the wound area.Mechanistically,the focal adhesion kinase(FAK)/extracellular signal-related kinase(ERK)signaling pathway may mediate the promotion of skin defect healing by increasing paracrine secretion via the Dopa-gel.Additionally,proangiogenic factors can be induced through Rho-associated kinase-2(ROCK-2)/vascular endothelial growth factor(VEGF)-mediated paracrine secretion under tensile stress conditions.Taken together,these findings suggest that the multifunctional Dopa-gel,which has good mechanical properties similar to those of native skin tissue and enhanced immunomodulatory and angiogenic properties,is a promising scaffold for skin tissue regeneration.

Procyanidin A_1 and its digestive products alleviate acrylamide-induced IPEC-J2 cell damage through regulating Keap1/Nrf2 pathway

Our previous study has revealed that procyanidin A_(1)(A_(1))and its simulated digestive product(D-A,)can alleviate acrylamide(ACR)-induced intestine cell damage.However,the underlying mechanism remains unknown.In this study,we elucidated the molecular mechanism for and D-A_(1) to alleviate ACR-stimulated IPEC-J2 cell damage.ACR slightly activated nuclear factor erythroid 2-related factor 2(Nrf2)signaling and its target genes,but this activation could not reduce intestine cell damage.A_(1) and D-A_(1) could alleviate ACR-induced cell damage,but the effect was abrogated in cells transiently transfected with Nrf2 small interfering RNA(siRNA).Further investigation confirmed that A_(1) and D-A_(1) interacted with Ketch-like ECH-associated protein 1(Keapl),which boosted the stabilization of Nrf2,subsequently promoted the translocation of Nrf2 into the nucleus,and further increased the expression of antioxidant proteins,thereby inhibiting glutathione(GSH)consumption,maintaining redox balance and eventually alleviating ACR-induced cell damage.Importantly,there was no difference between A_(1) and D-A_(1) treated groups,indicating that A_(1) can tolerate gastrointestinal digestion and may be a potential compound to limit the toxicity of ACR.

ZnO Incorporated Acrylamide Grafted Chitosan Based Composite Film for Advanced Wound Healing Applications

This study was carried out to prepare ZnO nanoparticles incorporated acrylamide grafted chitosan composite film for possible biomedical application especially drug loading in wound healing. ZnO nanoparticles were prepared by co-precipitation method from zinc acetate di-hydrate and incorporated in acrylamide grafted chitosan. FT-IR and TGA of the prepared composite film confirmed the successful incorporation of ZnO nanoparticles in the acrylamide-grafted polymer matrix. SEM images showed that the ZnO nanoparticles were homogeneously distributed on the porous matrix of the composite film. Water uptake and buffer uptake analysis revealed that the composite film could hold water and buffer sufficiently, which facilitated the absorption of exudate from the wound site. Amoxicillin was loaded in the prepared composite film and the maximum loading efficiency was found to be 67.33% with drug concentration of 300 ppm. In vitro studies showed greater antimicrobial activity of drug-loaded composite film compared to both pure film and standard antibiotic disc. Finally, the In vivo mouse model showed maximum healing efficiency compared to conventional gauge bandages because the loading of antibiotic in the film produced a synergistic effect and healing time was reduced.

Preparation and Antibacterial Activity of Copolymer of Methacryloxyethyldimethyl Dodecyl Ammonium Bromide/Acrylamide

Copolymers PMDAB-co-AA with excellent antibacterial activity were designed and prepared（MDAB/AA=methacryloxyethyldimethyl dodecyl ammonium bromide with acrylamide）.The chemical structures of the copolymers were characterized by Fourier transform infrared（FTIR）,1 H NMR,13 C NMR and chemical titration.The antimicrobial activities and kinetics of the copolymer against E.coli and S.aureus were examined by viable cell counting method.The compositions of the copolymers could be easily controlled by the feed molar ratio of MDAB to AA.Furthermore,the highest antibacterial activity was achieved when the molar fraction of MDAB was in a range of 5%―20%,and the killing rate reached 100% under the test conditions.In addition,the antibacterial activity of PMDAB-co-AA was maintained and stable without any loss after 15 times of repeated usage.It was proved that the PMDAB-co-AA samples targeted at cell membrane,and caused serious damage to cell integrity and inner membrane permeation.The surrounding conditions,such as pH and inorgainc salts concentrations（CaCl2 or NaCl）,also affected their antibacterial activities.

Grafting of Acrylamide and Trimethylolpropane Triglycidyl Ether onto the Gellan Gum:Synthesis and Characterization

To improve the physiochemical properties of gellan gum（GG）, GG was modified with acrylamide and trimethylolpropane triglycidyl ether（TTE）. The structure and morphology of modified GG were characterized by Fourier transform infrared（FT-IR） spectroscopy, X-ray diffraction（XRD）, differential scanning calorimetry（DSC） and scanning electron microscopy（SEM）. The characteristic peaks at 3448, 2788, 1654, 1411, 1117 and 1044 cm-1）in the FT-IR spectrum confirm the modification. The XRD and DSC data revealed that the modification enhanced the thermal stability of GG. SEM analysis suggested the modification introduced a porous microstructure, resulting in the adsorption of crystal violet. In addition, the adsorption capacity, thermal stability and swelling property of GGTTE3 were superior to GGTTE1, GGTTE2, GGTTE4 and GGTTE5.

Synthesis and Characterization of the Terpolymer of Itaconic Acid with Acrylamide and 2-Acrylamido-2-methylpropanesulfonic Acid

The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.

Method Development and Validation for the Quantification of Acrylamide in Potato Chips and Other Locally Available Food by LC-MS/MS in Bangladesh

A sensitive, precise, accurate and simple in house validated Liquid Chromatography and Tandem mass spectrometric (LC-MS/MS) analytical method was developed for the quantification of acrylamide in potato chips, a probable carcinogenic and neurotoxic compound in fried food items. Acrylamide was extracted and cleaned up by QuEChERS method, then analyzed by triple quadrupole mass spectrophotometer using positive electrospray-ionization mode and d3-Acrylamide internal standard. The analyte and internal standard were separated on a reversed-phase C18 column (100 × 2.0 mm, 2.5 μm) by gradient elution with water and methanol containing 0.1% formic acid as mobile phase. The analytical method was fully validated by assessment of linearity, specificity, precision, accuracy, selectivity and robustness with relative standard deviation of less than 4%. The calibration curves were found linear with correlation coefficient (r2) of 0.9997 over the concentration range 5 - 500 μg/L. The recoveries of Acrylamide in the concentration of 250, 400, and 500 μg/L were 97% to 104%. Based on the signal to noise ratio, the lower limit of detection (LOD) and lower limit of quantification (LOQ) were achieved 2.0 μg/L and 4.0 μg/L respectively. The proposed method was also applied to other available most popular 24 types of food (265 number of sample) first time in Bangladesh. The highest level of acrylamide has been found in fried products with the range of 197.04 μg/L to 114.63 μg/L, protein-rich food lies between 79.76 to 89.14 μg/L whereas baked food products exhibited less content in the range of 35.23 to 51.17 μg/L.

Swelling Performance Studies of Acrylamide/Potassium 3-Sulfopropyl Methacrylate/Sodium Alginate/Bentonite Biohybrid Sorbent Hydrogels in Binary Mixtures of Water-Solvent

In this study, it was to investigate the swelling performance of novel biohybrid composite hydrogel sorbents containing acrylamide/potassium 3-sulfopropyl methacrylate/sodium alginate/bentonite in water and binary mixtures of water-solvent. Novel hydrogels were synthesized with free radical solution polymerization by using ammonium persulfate/N,N,N’,N’-tetramethylethylenediamine as redox initiating pair in presence of poly(ethylene glycol) diacrylate as crosslinker. Swelling experiments were performed in water and binary mixtures of water-solvent (acetone, methanol and tetrahydrofuran) at 25°C, gravimetrically. Some swelling and diffusion properties of the hydrogels were calculated and they were discussed for the biohybrid/hybrid hydrogel systems prepared under various formulations. It has been seen the lower equilibrium percentage swelling ratio values (62% - 124%) in all solvent compositions in comparison with the equilibrium percentage swelling ratio values in water (718% - 2055%). Consequently, the hydrogel systems developed in this study could serve as a potential device for water and water-solvent binary mixtures.

Melatonin alleviates oxidative stress,inflammation,apoptosis,and DNA damage in acrylamide-induced nephrotoxicity in rats

Objective:To investigate the effects of melatonin on renal inflammation,oxidative stress,apoptosis,as well as DNA and tissue damage in acrylamide-induced nephrotoxicity in rats.Methods:Fifty male rats were randomly divided into five groups.The control group received distilled water by gastric lavage for 11days and the acrylamide group was administered acrylamide(50 mg/kg,i.g.)for 11 days.The MEL10+ACR and MEL20+ACR groups received intraperitoneal melatonin 10 and 20 mg/kg,respectively,for 11 days,and acrylamide(50 mg/kg,i.g.)was administered 1h after melatonin injection.The MEL20 group was injected with melatonin(20 mg/kg)for 11 days.Kidney function tests were performed and biochemical and inflammatory parameters were determined.In addition,histopathological,immunohistochemical,and immunofluorescence examinations were carried out.Results:Melatonin significantly abated acrylamide-induced rise in serum urea and creatinine levels.Acrylamide caused oxidative stress,inflammation,apoptosis,as well as DNA and tissue damage in the kidneys.Melatonin treatment alleviated acrylamide-induced renal damage by exhibiting antioxidant,anti-inflammatory,and antiapoptotic effects.Moreover,melatonin significantly ameliorated acrylamide-caused histopathological changes in kidney tissue.Conclusions:Melatonin attenuates acrylamide-induced renal oxidative stress,inflammation,apoptosis,and DNA damage in rats.

Blood Compatibility of Amphiphilic Poly(N-α-acrylamide-L-lysine-<i>b</i>-dimethylsiloxane) Block Copolymers

Amphiphilic block copolymers poly(LysAA-b-DMS) consisting of a hydrophilic poly(N-α-acrylamide-L-lysine) [poly(LysAA)] segment with different molecular weights and a hydrophobic polydimethylsiloxane (PDMS) segment were prepared as follows. The precursor copolymer poly(Boc-LysAA-OtBu-b-PDMS) was obtained from radical polymerization of N-α-acrylamide-N-ε-tert-butoxycarbonyl-L-lysine-tert-butylester (Boc-LysAA-OtBu) initiated with 4,4’-azobis(polydimethylsiloxane 4-cyanopentanoate) (azo-PDMS) with the molecular weight of PDMS Mw = 4.3 × 103 in the presence of 2-mercaptoethanol (2-ME) as a chain-transfer agent. Removal of the protecting groups of the precursor copolymer was carried out in 80% trifluoroacetic acid aqueous solution to give poly(LysAA-b-DMS)-1-3. The weight average molecular weight of poly(LysAA-b-DMS)-1-3 was Mw = 1.02 × 104 – 2.52 × 104. From the 1H-NMR and fluorescence spectra measurements, poly(LysAA-b-DMS)-1-3 was determined to self-organize and form core-shell micelles in water. The critical micelle concentration (CMC) increased to 1000 - 4000 mg·L–1 with increasing molar ratio of the poly(LysAA) segment from 0.42 to 0.65. From morphological analysis with a scanning probe microscope (SPM), poly(LysAA-b-DMS) has microphase-separated structures made up of hydrophilic and hydrophobic regions with the domain size ranging from several tens to several hundreds of nanometers. Inhibition of thrombin activity of poly(LysAA-b-DMS) was evaluated from the Michaelis constant (KM) and catalytic activity (kcat) for the enzymatic reaction of thrombin and synthetic substrate S-2238 in the presence of poly(LysAA-b-DMS). The KM and kcat were 0.10 - 0.11 mM and 4.04 × 105 – 4.26 × 105 min–1, respectively. Fibrinolytic activity was also verified from the transformation of plasminogen to plasmin by tissue plasminogen activator (t-PA) using synthetic substrate S-2251 in the presence of poly(LysAA-b-DMS). The KM and kcat were 0.07 mM and 5.73 × 106 –5.95 × 106 min–1, respectively.

丙烯酰胺/丙烯酸钠/2-丙烯酰胺基-2-甲基丙磺酸钠共聚物耐盐机理

分别采用常规实验评价和分子动力学模拟方法,研究了丙烯酰胺/丙烯酸钠/2-丙烯酰胺基-2-甲基-丙磺酸钠共聚物(P(AM/AANa/AMPSNa))和部分水解聚丙烯酰胺(HPAM)在不同类型阳离子存在下的溶液性质,并从原子分子水平探讨了P(AM/AANa/AMPSNa)的耐盐机理。实验结果表明,在相同浓度下,不同阳离子对P(AM/AANa/AMPSNa)黏度影响能力的大小顺序为:Ca2+>Mg2+>Na+。与HPAM分子相比,在P(AM/AANa/AMPSNa)分子链上一定量的磺酸基增强了分子链内带负电基团的静电排斥作用,且对阳离子吸引弱,有效增加了分子链流体力学体积;强极性的磺酸基使水化层更致密,溶液中阳离子在穿透水化层时需克服更大的能量势垒,导致阳离子对带负电基团的静电屏蔽作用较弱,使P(AM/AANa/AMPSNa)更耐盐。

2023年湖南省市售婴幼儿配方乳粉中丙烯酰胺污染状况及暴露风险初步评估

目的:调查2023年湖南省市售婴幼儿配方乳粉中丙烯酰胺污染状况,并对0~36月龄婴幼儿经乳粉摄入丙烯酰胺的暴露风险进行评估。方法:随机采集湖南省市售婴幼儿配方乳粉23份,采用稳定同位素稀释-超高效液相色谱-串联质谱法测定样品中丙烯酰胺含量,结合婴幼儿配方乳粉推荐消费量,估算0~36月龄婴幼儿丙烯酰胺暴露量。结果:23份样品中丙烯酰胺的检出率为60.9%(检出限为0.3μg·kg^(-1)),均值2.4±2.4μg·kg^(-1),各月龄婴幼儿每日经婴幼儿配方乳粉摄入的丙烯酰胺为0.021~0.025μg·kg^(-1)bw,其暴露限值均高于10000。结论:2023年湖南省市售婴幼儿配方乳粉中丙烯酰胺污染较轻,对婴幼儿健康影响有限。

丙烯酰胺/甲基丙烯酰氧乙基三甲基氯化铵的水分散聚合物制备

以丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为共聚单体,过硫酸铵为引发剂,自制聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)为分散剂,在硫酸铵水溶液中采用水分散聚合法,制备了丙烯酰胺/甲基丙烯酰氧乙基三甲基氯化铵共聚水分散体.考察了分散聚合过程中体系黏度变化,引发剂用量、硫酸铵的用量、分散剂的用量对共聚物黏度、分子量、颗粒尺寸的影响,并对其结构进行了鉴定.实验发现,在30℃,AM、DMC总单体质量分数为15%,DMC与AM物质的量比为1∶9,过硫酸铵浓度范围为0.70×10^(-4)~2.8×10^(-4)mol/L,硫酸铵质量分数范围为26.51%~28.1%,分散剂PDMC质量分数范围为1.1%~1.3%条件下,可以制备出黏度低、稳定性好的丙烯酰胺/甲基丙烯酰氧乙基三甲基氯化铵共聚水分散体.

电推进粒子网格法模拟中计算加速方法的研究综述

粒子网格法(PIC)模拟电推进装置等离子体时具有很强的第一性,但是模拟过程中计算负载很大,故PIC模拟的计算加速方法不可或缺。本文从电推进装置基本性质、低温等离子体物理特性和PIC算法特点作为切入点,明确了PIC方法在电推进装置模拟过程中计算负载高的原因;结合国内外的研究现状,从建模、时空尺度、算法与并行三个层面介绍了对应计算加速方法的原理和效果;对各类计算加速方法进行了总结和展望。

丙烯酰胺/丙烯酰氧乙基二甲基苄基氯化铵共聚水分散体的制备

以丙烯酰胺(AM)、丙烯酰氧乙基二甲基苄基氯化铵(DMBC)为共聚单体,过硫酸铵为引发剂,自制聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)为分散剂,在硫酸铵水溶液中采用水分散聚合法,制备了丙烯酰胺/丙烯酰氧乙基二甲基苄基氯化铵共聚水分散体。考察了反应温度、硫酸铵浓度、单体配比、链转移剂浓度、分散剂用量、引发剂用量对共聚物黏度、相对分子质量、颗粒尺寸的影响。实验发现,制备丙烯酰胺/丙烯酰氧乙基二甲基苄基氯化铵共聚水分散体较优配方为:温度65℃,硫酸铵质量分数为27.6%,AM、DMBC总单体质量分数为15%,DMBC∶AM(质量比)=(0.297~0.363)∶1,链转移剂用量为0.078 g/L,分散剂质量分数2.7%~3.6%,过硫酸铵质量分数范围为4.38×10^(-4)~5.84×10^(-4)mol/L。

聚丙烯酰胺树脂的反相悬浮聚合制备及吸水性能研究

以丙烯酰胺为单体、过硫酸铵为引发剂、单硬脂酸甘油酯为分散剂、N,N-亚甲基双丙烯酰胺为交联剂,采用反相悬浮聚合法制备了聚丙烯酰胺吸水树脂。考察了分散剂、交联剂、引发剂、单体浓度、油水比、反应温度、反应时间等因素对吸水倍率和产率的影响。结果表明,单硬脂酸甘油酯用量为3%、N,N-亚甲基双丙烯酰胺为0.12%、过硫酸铵为0.5%、单体浓度为30%、油水比范围为4:1~6:1、反应温度在70~75℃、反应时间为4 h时,聚丙烯酰胺树脂的吸水倍率和产率较高。利用傅里叶变换红外光谱仪、热重分析仪和凝胶渗透色谱仪对产物进行了测试表征。

AM-AMPS共聚吸水树脂的制备与性能研究

用丙烯酰胺(AM)和2-丙烯酰胺基-2-甲基丙磺酸(AMPS)两种单体采用溶液共聚方法,用过硫酸铵和亚硫酸氢钠作引发剂,N,N-亚甲基双丙烯酰胺作交联剂,制备了AM-AMPS共聚物吸水树脂。考察了AM/AMPS比例、引发剂用量、交联剂、pH、反应温度、反应时间等工艺条件对吸水倍率的影响。结果表明,AM/AMPS质量比为1/2~1/1,引发剂用量为0.3%,交联剂为0.06%~0.1%,pH值为7,反应温度在35~40℃,反应时间在2~4h时,制备的树脂有良好的吸水性。采用傅里叶变换红外光谱仪、热重分析仪和凝胶渗透色谱仪对产物进行了测试表征。