Partial nitrification in free nitrous acid-treated sediment planting Myriophyllum aquaticum constructed wetland strengthens the treatment of black-odor water.

Black-odor water pollution in rural areas, especially swine wastewater, can lead to the deterioration of water quality and thus seriously affect the daily life of people in the area. However, there is a lack of effective treatment measures with simultaneous attention to carbon, nitrogen and sulfur pollution in rural black-odor water bodies. This study evaluated the feasibility of an in-situ pilot-scale constructed wetland (CW) for the synchronous removal of COD, ammonium, and sulfur compounds in the swine wastewater. In this study, the operation strategy of CW sediment pretreated with free nitrous acid (FNA) and Myriophyllum aquaticum plantation was established. Throughout the 114-day operation, the total removal efficiencies of COD and ammonium nitrogen in experimental groups were 81.2 ± 4.2 % and 72.8 ± 1.8 %, respectively, which were significantly higher than CW without any treatment. Removal efficiencies of Sulfur compounds, i.e. sulfide, sulfate, thiosulfate, and sulfite, were 92.3 ± 1.9 % (61.2 % higher than the no-treatment group), 42.1 ± 3.8 %, 97.9 ± 1.7 %, and 42.7 ± 4.5 % respectively. High-throughput sequencing and qPCR revealed that experimental group significantly increased denitrification genes (nirK, nosZ) and sulfur oxidation genes (soxB, fccAB) and enriched the corresponding microbial taxa (Bacillus, Conexibacter and Clostridium sensu stricto). Moreover, metabolic pathways related to nitrogen and sulfur and the degradation of organic matter were up-regulated. These results indicated that partial nitrification in CW planted with M. aquaticum promoted sulfur oxidation denitrification and heterotrophic denitrification. Overall, the in-situ pilot-scale study revealed that the cultivation of M. aquaticum in FNA-treated CW can be a sustainable approach to treat black-odor water bodies.

Cartilage regeneration using adipose-derived stem cells and the controlled-released hybrid microspheres.

OBJECTIVE: This study was to evaluate the effect of hybrid microspheres (MS) composed of gelatin transforming growth factor-beta (TGF-beta1)-loaded MS and chitosan MS on the enhancement of differentiation of adipose-derived stem cells (ASCs) into chondrocytes in pellet culture in vitro and the reparative capacity of pellet from ASCs and the hybrid MS-TGF used to repair cartilage defects in vivo. METHODS: The morphology of the controlled-released MS was observed with scanning electron microscopy (SEM) and mechanical property was also tested in this study. In vitro TGF-beta1 release was evaluated by an enzyme-linked immunosorbent assay. The protein expression of Collagen II was tested by Western blot. In addition, a preliminary study on cartilage regeneration was also performed in vivo. RESULTS: When chondrogenic differentiation of ASCs in both MS was evaluated, the protein expression of Collagen II became significantly increased for the hybrid MS-TGF, as compared with the gelatin MS-TGF. Mechanical result showed that the hybrid MS was superior to the gelatin MS. Observation of histology in vivo demonstrated that the pellet from ASCs and the hybrid MS-TGF promoted cartilage regeneration in the defects of articular cartilage much better than other groups. CONCLUSION: Our study demonstrated that the pellet from ASCs and the hybrid MS-TGF can provide an easy and effective way to construct the tissue engineered cartilage in vitro and in vivo.

Enhanced chondrogenesis of adipose-derived stem cells by the controlled release of transforming growth factor-beta1 from hybrid microspheres.

BACKGROUND: Articular cartilage has a limited self-regenerative capacity, and tissue engineering is a promising solution to the problem of cartilage damage. OBJECTIVE: The aim of this study was to evaluate the effect of hybrid microspheres (MS) composed of transforming growth factor (TGF)-beta1-loaded gelatin MS and chitosan MS on enhancement of the differentiation of adipose-derived stem cells (ASCs) into chondrocytes in pellet culture. METHODS: In vitro TGF-beta1 release was evaluated by an enzyme-linked immunosorbent assay. The content of DNA and glycosaminoglycans (GAGs) was tested by biochemical methods. In addition, quantitative PCR was used to analyze the expression of collagen II and aggrecan. RESULTS: Increased proliferation of ASCs was observed in the hybrid TGF-beta1-loaded MS in comparison to the TGF-beta1-loaded gelatin MS. The chondrogenic differentiation of ASCs in both constructs was evaluated, and GAG content and the gene expression of collagen II and aggrecan were significantly higher in the hybrid TGF-beta1-loaded MS than in the TGF-beta1-loaded gelatin MS. CONCLUSIONS: Enhanced differentiation of ASCs by hybrid TGF-beta1-loaded MS may provide an easy and effective way to construct tissue-engineered cartilage.