Search

Microvesicles (MVs) derived from human mesenchymal stem cells (MSC MVs) were demonstrated to ameliorate inflammation in lungs. We have found their content of mRNA for keratinocyte growth factor was partly involved in their therapeutic effects. As MSC MVs also contained a substantial quantity of angiopoietin‐1(Ang‐1) mRNA, which plays an essential role in vascular stabilization and resolving inflammation, we hypothesized that Ang‐1mRNA might similarly account for a part of their therapeutic effects. We downregulated Ang‐1mRNA expression in MVs, using a lentivirus vector carrying Ang‐1short hairpin RNA to transfect MSCs. A mouse model of lipopolysaccharide induced acute lung injury (ALI) was used in vivo. We also studied in vitro interactions between Ang‐1mRNA deficient MVs on macrophages and human lung microvascular endothelial cells. Compared with negative control, Ang‐1mRNA deficient MVs increased the influx of neutrophils and macrophage inflammatory protein‐2 levels in bronchoalveolar lavage fluid by 136% and 105%, respectively, suggesting a deteriorative lung inflammation and a failure to restore pulmonary capillary permeability assessed by Evan's blue dye and bronchoalveolar lavage albumin level. In vitro, the addition of Ang‐1mRNA deficient MVs failed to maintain the integrity of endotoxin‐stimulated microvascular endothelial cells and abrogated the decrease in tumor necrosis factor‐α level and the increase in interleukin‐10 level mediated by negative control in RAW 264.7 cells. In summary, the therapeutic effects of MVs in ALI, and their immunomodulatory properties on macrophages were partly mediated through their content of Ang‐1mRNA. StemCells2017;35:1849–1859 MSC MVs improved lung injury as assessed by histology at 48 hours. H&E staining of lung section demonstrated a reduction in inflammatory cell influx, blood, edema, airspace congestion, and wall thickening (scale bars = 200μm). Ang‐1 SiRNA MSC MV significantly eliminated the beneficial effects of MSC MVs.

Batch experiments were carried out to determine the capacity of Bacillus cereus biomass to adsorb Co(II) ions from aqueous solution with respect to pH, initial Co(II) concentration, contact time and biomass dose. The experimental data were modeled by Langmuir and Freundlich isotherm models. Langmuir model resulted in the best fit of the adsorption data. The maximum adsorption capacity for Co(II) was 68.10 mg/g. The best correlation was provided by the second-order kinetic model. The practical implication of this study is the development of an effective and economic technology for Co(II) removal from contaminated waters.

The study described the sorption of Cd(II) by a novel extracellular biopolymer (B-11) produced from Bacillus cereus B-11. The effect of experimental parameters such as pH, initial concentration and contact time, sorbent dosage on the sorption was studied. The langmuir isotherm better fitted the sorption data, the maximum adsorption capacity was 80.64 mg.g-1. The kinetic rates were best fitted to the pseudo-second-order model. It was concluded that the prepared B-11 can be used as an effective and environmentally friendly biosorbent for the removal of Cd(II) ions from aqueous solution.