The hexosamine biosynthetic pathway (HBP) plays essential roles in growth and development in plants. However, insight into the biological function of glutamine:fructose-6-phosphate amidotransferase 1 (GFAT1), mediating the first regulatory step of the HBP, remains unclear in plants. Here, we report the molecular characterization of Arabidopsis AtGFAT1 gene. AtGFAT1 was highly expressed in mature pollen grains, but its expression was not detectable in the rest of the organs. Pollen grains bearing the gfat1-2 knockout allele displayed defects in a polar deposition of pectin and callose in the pollen cell wall, leading to no genetic transmission of the gfat1-2 allele through the male gametophyte. AtGFAT1 overexpression increased glucosamine (GlcN) content and enhanced resistance to tunicamycin (Tm) treatment, while RNAi-mediated suppression reduced GlcN content and resistance to Tm treatment. However, the decrease in Tm resistance by RNAi suppression of AtGFAT1 was recovered by a GlcN supplement. The exogenous GlcN supplement also rescued gfat1-2/gaft1-2 mutant plants, which were otherwise not viable. The gfat1-2/gfat1-2 plants stopped growing at the germination stage on GlcN-free medium, but GlcN supplement allowed wild-type growth of gfat1-2/gfat1-2 plants. In addition, reactive oxygen species production, cell death and a decrease in protein N-glycosylation were observed in gfat1-2/gaft1-2 mutant plants grown on GlcN-free medium, whereas these aberrant defects were not detectable on GlcN-sufficient medium. Taken together, these results show that the reduction of protein N-glycosylation was at least partially responsible for many aberrant phenotypes in growth and development as well as the response to Tm treatment caused by AtGFAT1 deficiency in Arabidopsis.

The aim of this study was to fabricate and characterize acellular porcine pericardium that can be used to patch cardiovascular repair. Porcine pericardial tissues were treated with 10 mM Tris-HCl and sodium dodecyl sulfate (SDS) at different concentrations and time intervals. The optimal decellularization protocol was determined according to elimination of cellular components and DNA via histology and DNA quantification, respectively. There were no significant changes in stress and fracture strain after decellularization. Liquid extracts from the decellularized pericardium caused no cytotoxicity towards human fibroblasts, were capable of supporting an appropriate attachment of human endothelial progenitor cells, and did not cause a local inflammatory effect after 30 days of transplantation in mice.

In study, insulin loaded chitosan nanoparticles were prepared via ionic gelation method using cross-linking agent sodium tripolyphosphate (STPP). To have best result for the preparation of nanoparticles, a commercial chitosan with a degree of deacetylation DD of 75 % was adjusted to 85 % - 90 % which was determined by FTIR method. The obtained deacetylated chitosan was studied for the effect of pH, concentration, ratio of chitosan and STPP. Then the insulin loaded chitosan TPP nanoparticles were prepared by ionic gelation method. These nanoparticles could deliver 91.6 % insulin at pH = 3.5, with the chitosan concentration of 1 mg/mL and the chitosan:STPP ratio of 4:1. The TEMs indicate that chitosan nanoparticles were spherical in shape and the particles size was smaller than 100 nm. Investigation of FTIR and entrapment efficiency assert that insulin loaded chitosan nanopartiles have been prepared and can become a drug delivery system via oral in the future.