Application of mesenchymal stem cells as a vehicle to deliver replication-competent adenovirus for treating malignant glioma

Although gene therapy was regarded as a promising approach for glioma treatment,its therapeutic efficacy was often disappointing because of the lack of efficient drug delivery systems.Mesenchymal stem cells(MSCs) have been reported to have a tropism for brain tumors and thus could be used as delivery vehicles for glioma therapy.Therefore,in this study,we attempted to treat glioma by using MSCs as a vehicle for delivering replication-competent adenovirus.We firstly compared the infectivity of type 3,type 5,and type 35 fiber-modified adenoviruses in MSCs.We also determined suitable adenovirus titer in vitro and then used this titer to analyze the ability of MSCs to deliver replication-competent adenovirus into glioma in vivo.Our results indicated that type 35 fiber-modified adenovirus showed higher infectivity than did naked type 3 or type 5 fiber-modified adenovirus.MSCs carrying replication-competent adenovirus significantly inhibited tumor growth in vivo compared with other control groups.In conclusion,MSCs are an effective vehicle that can successfully transport replication-competent adenovirus into glioma,making it a potential therapeutic strategy for treating malignant glioma.

Performance of biological phosphorus removal and characteristics of microbial community in the oxic-settling-anaerobic process by FISH analysis

Performance of biological phosphorus removal in the oxic-settling-anaerobic(OSA) process was investigated. Cell staining and fluorescent in situ hybridization(FISH) were used to analyze characteristics and microbial community of sludge. Experimental results showed that phosphorus removal efficiency was near 60% and the amount of biological phosphorus accumulation in aerobic sludge of the OSA system was up to 26.9 mg/g. Biological phosphorus removal efficiency was partially inhibited by carbon sources in the continuous OSA system. Contrasted to the OSA system,biological phosphorus removal efficiency was enhanced by 14% and the average total phosphorus(TP) contents of aerobic sludge were increased by 0.36 mg/g when sufficient carbon sources were supplied in batch experiments. Staining methods indicated that about 35% of microorganisms had typical characteristics of phosphorus accumulating organisms(PAOs) . FISH analysis demonstrated that PAOMIX-binding bacteria were predominant microbial communities in the OSA system,which accounted for around 28% of total bacteria.