Advanced glycation end products induce neural tube defects through elevating oxidative stress in mice

Our previous study showed an association between advanced glycation end products （AGEs） and neural tube defects （NTDs）. To understand the molecular mechanisms underlying the effect of AGEs on neural tube development, C57BL/6 female mice were fed for 4 weeks with com- mercial food containing 3% advanced glycation end product bovine serum albumin （AGE-BSA） or 3% bovine serum albumin （BSA） as a control. After mating mice, oxidative stress markers including malondialdehyde and H202 were measured at embryonic day 7.5 （E7.5） of ges- tation, and the level of intracellular reactive oxygen species （ROS） in embryonic cells was determined at E8.5. In addition to evaluating NTDs, an enzyme-linked immunosorbent assay was used to determine the effect of embryonic protein administration on the N-（carboxymethyl） lysine reactivity of acid and carboxyethyl lysine antibodies at E10.5. The results showed a remarkable increase in the incidence of NTDs at El0.5 in embryos of mice fed with AGE-BSA （no hyperglycemia） compared with control mice. Moreover, embryonic protein administration resulted in a noticeable increase in the reactivity of N-（carboxymethyl） lysine and N（ε）-（carboxyethyl） lysine antibodies. Malondialdehyde and H2O2 levels in embryonic cells were increased at E7.5, followed by increased intracellular ROS levels at E8.5. Vitamin E supplementation could partially recover these phenomena. Collectively, these results suggest that AGE-BSA could induce NTDs in the absence of hyperglycemia by an underlying mechanism that is at least partially associated with its capacity to increase embryonic oxidative stress levels.

Pore Structure Regulation of Carboxyethylated Microfibrillated Cellulose Films

Carboxyethylation is a recent chemical pretreatment for preparation of microfibrillated cellulose(MFC).The carboxyethylated MFC film prepared by coating method has compact structure and high mechanical properties.In order to expand its application,three approaches including using organic solvents,different drying methods and cationic additives,have been adopted in this paper to enrich and regulate the pore structure of MFC film.The results show that all the approaches can improve the pore structure but decrease the mechanical properties of MFC film.When organic solvents such as ethanol,isopropanol and n-butanol were used to replace the water in MFC suspension or pre-dried MFC film,the pore structure of films were increased.Additionally,the film obtained by freeze-drying or air-drying after freezing in liquid nitrogen or freezer has high porosity but poor strength.The best drying process is to rewet dry MFC film,freeze in liquid nitrogen and then freeze-dry.Moreover,the addition of cationic polyelectrolytes or alkene ketone dimer(AKD)in MFC suspension can also significantly increase the film's porosity.Through the above approaches,the porosity of carboxyethylated MFC film can be regulated between 20% and 90%.

Carboxyethylated Microfibrillated Cellulose Fibers Prepared from Different Raw Materials

Carboxyethylation pretreatment was used to prepare microfibrillated cellulose(MFC)in this study.In order to evaluate the adaptability of this pretreatment method,carboxyethylated MFC was prepared from six different cellulosic materials.The carboxyl content,degree of polymerization,water retention value,charge density,chemical structure,size distribution,and micromorphology of the materials before and after pretreatment and grinding were studied and compared.The viscosity,ultraviolet(UV)transmittance,and thermal stability of the MFC samples at a certain concentration were determined.The results showed that the carboxyl content,water retention value,charge density,degree of polymerization,size distribution,and micromorphology of the pretreated and ground samples varied with those of the raw materials.The initial viscosity varied based on the type of raw material used.The MFC suspension prepared from cotton linter pulp had the highest UV transmittance,while the MFC prepared from bleached softwood kraft pulp had the highest viscosity at a low shear rate.After thermal degradation,the amount of residual char from the MFC prepared with the thermo-mechanical pulp was slightly higher than that of the other MFCs.This study demonstrates that carboxyethylation is an effective pretreatment method for different cellulosic materials.