ABSTRACT
Objective: Generation 5 poly [amidoamine] dendrimers are promising multipotent gene delivery vectors that provide favorable DNA condensation properties; however, their high toxicity limits their applications. Toxicity of PAMAM dendrimers depends on their type, generation and applied dosage in a way that lower generations [lower than G5 dendrimers] and anionic dendrimers have lower toxicity than higher generations and cationic dendrimers. The aim of this study is to evaluate the effect of PEGylation on toxicity of G5 PAMAM dendrimers
Methods: In this study, to improve their characteristics as gene delivery carriers, G5 PAMAM dendrimers were conjugated to polyethylene glycol molecules [PEG, molecular weight 3500] at three different molar ratios of 10, 20 and 30. Also the number of conjugated PEG chains was quantified using TNBSA and Ellman assays. The effect of different degrees of PEGylation on cytotoxicity and transfection efficiency of modified PAMAM dendrimers toward BT-474 and MCF-10A cell lines were assessed
Results: Compared to unconjugated, PEG conjugated PAMAM dendrimers had lower in vitro cytotoxicity, particularly at higher PEG to PAMAM molar ratios. Among all prepared PEG-PAMAM dendrimers, G5 PAMAM dendrimers that conjugated to PEG at a molar ratio of 10/1 had the highest in vitro transfection rate in both cell lines
Conclusion: Our results showed that these PEG-conjugated PAMAM dendrimers possess a great potential for in vitro gene delivery
ABSTRACT
Probiotics are live cultures of microbes; often lactic acid bacteria, but also some other species, which when fed to animals, improve their health and growth through altering the intestinal microbial balance. In the present research, healthy chickens' gastrointestinal [GI] tracts were screened for the presence of lactic acid bacteria with probiotic properties. The probiotic properties of the isolates taken from different parts of the GI tract were evaluated. They were examined for resistance to 2% [w/v] bile salts and acidic pH, capability to adhere to the intestinal epithelium and inhibitory effects on the growth of Salmonella enteritidis and Escherichia coli. Fermentation profile analyses and sequencing data of the conserved 16S rRNA genes showed that from a total of five selected clones, four clones isolated from the duodenum and caeca were Lactobacillus salivarius and the fifth clone, isolated from the duodenum, was Lactobacillus crispatus. All the selected clones were able to adhere to the chicken's epithelial cells. The lactobacilli isolated from different parts of the GI tract had probiotic properties suitable for use in animal feed. Due to the inhibitory effects of the isolated lactic acid bacteria on the growth of pathogenic microbiota, it can be concluded that these bacteria are good candidates for treatment of chicken GI infectious diseases
Subject(s)
Animals , Salmonella enteritidis , Escherichia coli , Chickens/microbiology , Gastrointestinal Tract/microbiology , ProbioticsABSTRACT
Angiogenesis a process that results in neo-vascularization is an essential stage in growth of solid tumors and the formation of metastases. Vascular endothelial growth factor [VEGF] and its receptors, VEGFR1 [Flt-1] and VEGFR2 [KDR/Flk-1], are the major regulators for tumor angiogenesis. Recent studies showed that second domain of VEGFR-1is a key factor for VEGF/VEGFR-1 interaction. In this study, after RNA purification and cDNA synthesis, the second domain of VEGFR-1 [VEGFR-1-II] was amplified by PCR and cloned in T/A cloning vector. In order to increase the expression of the protein, we sub-cloned the gene into pET22b[+] and transformed the construct in Rosseta-gami 2, an efficient host for expression. The expression was induced by IPTG and confirmed by SDS-PAGE and Western Blotting. The recombinant protein was purified by IMAC column and the growth inhibition of human umbilical vein endothelial cells [HUVEC] was analyzed by the recombinant protein. The results of SDS-PAGE and Blotting confirmed the protein purification accuracy. The recombinant protein concentration was determined by Bradford protocol. The results showed that nearly 300 micri g/L VEGFR-1-II protein was produced. The function of this protein was confirmed by inhibition of HUVEC cells growth. Since this protein inhibited the angiogenesis in vitro it may be consider as an efficient anti-angiogenesis factor