In the present study, galactosylated chitosan(Gal-CS) was conjugated with methoxy poly(ethylene glycol)(m PEG) as a hydrophilic group. The structure of Gal-CS-m PEG polymer was characterized and the nanoparticles(NPs)...In the present study, galactosylated chitosan(Gal-CS) was conjugated with methoxy poly(ethylene glycol)(m PEG) as a hydrophilic group. The structure of Gal-CS-m PEG polymer was characterized and the nanoparticles(NPs) were prepared using ironic gelation method. The study was designed to investigate the characteristics and functions of Gal-CS-m PEG NPs. The morphology of Gal-CS-m PEG NPs was observed by SEM and it was a compact and spherical shape. The size of the NPs was approximately 200 nm in diameter under the ideal process parameters. The interaction between Gal-CS-m PEG NPs and p DNA, and the protection of p DNA against DNase I and serum degradation by Gal-CS-m PEG NPs were evaluated. Agarose gel electrophoresis results showed that Gal-CS-m PEG NPs had strong interaction with p DNA at the weight ratio of 12:1, 4:1 and 2:1 and could protect p DNA from DNase I and serum degradation. Gal-CS-m PEG NPs exhibited high loading efficiency and sustainable in vitro release. The blood compatibility studies demonstrated that Gal-CS-m PEG NPs had superior compatibility with erythrocytes in terms of aggregation degree and hemolysis level. Gal-CS-m PEG NPs showed no cytotoxicity on L929 cells, which is a normal mouse connective tissue fibroblast, but showed inhibitory effects on the proliferation of Bel-7402 cells, which is a liver cancer cell line. In conclusion, Gal-CS-m PEG NP is a bio-safe and efficient gene carrier with potential application in gene delivery.展开更多
A bioflocculant producing potential bacteria was isolated from the circulating seawater of bio-filter using streak plate methods.The bacteria was identified through biochemical characteristics,partial 16S ribosomal ri...A bioflocculant producing potential bacteria was isolated from the circulating seawater of bio-filter using streak plate methods.The bacteria was identified through biochemical characteristics,partial 16S ribosomal ribonucleic acids(rRNA),nucleo-tide sequencing,and BLAST analysis of the gene sequence that showed the bacteria have 99%similarity to Pseudoalteromonas sp.and deposited in GenBank as Pseudoalteromonas sp.NUM8 with accession number JX435820.Influences of time course assay,carbon sources,nitrogen sources,inoculum size,as well as initial pH on the bacteria producing extracellular bioflocculant activity were investigated.The results showed that the strain optimal production period of microbial bioflocculant was at 72 h(flocculating activity of 94.5%),then dropped slowly.The bacteria optimally produced the bioflocculant when 1.0%sucrose and 0.5%sodium nitrate were used as sole sources of carbon and nitrogen with flocculating activities of 92.8%and 93.8%respectively.Also,the bacteria produced the bioflocculant optimally when initial pH of the medium was 5.0(flocculating activity 93.2%),and when Ca^(2+)was used as cation(flocculating activity 93.4%).The culture condition of inoculum size of 3%(v/v)was optimal flocculant pro-duction(flocculating activity 94.4%).Composition analyses indicated the bioflocculant to be principally a glycoprotein made up of about 34.3%protein and 63.4%total carbohydrate.展开更多
基金the National ‘12th Five-year’ High technology Research and Development Program of China (No. 2014AA093605)the Zhejiang Science and Technology Project (No. 2013C 33192)
文摘In the present study, galactosylated chitosan(Gal-CS) was conjugated with methoxy poly(ethylene glycol)(m PEG) as a hydrophilic group. The structure of Gal-CS-m PEG polymer was characterized and the nanoparticles(NPs) were prepared using ironic gelation method. The study was designed to investigate the characteristics and functions of Gal-CS-m PEG NPs. The morphology of Gal-CS-m PEG NPs was observed by SEM and it was a compact and spherical shape. The size of the NPs was approximately 200 nm in diameter under the ideal process parameters. The interaction between Gal-CS-m PEG NPs and p DNA, and the protection of p DNA against DNase I and serum degradation by Gal-CS-m PEG NPs were evaluated. Agarose gel electrophoresis results showed that Gal-CS-m PEG NPs had strong interaction with p DNA at the weight ratio of 12:1, 4:1 and 2:1 and could protect p DNA from DNase I and serum degradation. Gal-CS-m PEG NPs exhibited high loading efficiency and sustainable in vitro release. The blood compatibility studies demonstrated that Gal-CS-m PEG NPs had superior compatibility with erythrocytes in terms of aggregation degree and hemolysis level. Gal-CS-m PEG NPs showed no cytotoxicity on L929 cells, which is a normal mouse connective tissue fibroblast, but showed inhibitory effects on the proliferation of Bel-7402 cells, which is a liver cancer cell line. In conclusion, Gal-CS-m PEG NP is a bio-safe and efficient gene carrier with potential application in gene delivery.
基金This work was supported by the Public Welfare Pro-jects in Zhejiang Province(No.LGN21C200001)the Public Welfare Projects in Zhoushan city(Nos.2021C 41005 and 2021C41007)the Natural Science Foun-dation of Marine Fishery Institute of Zhejiang Province(No.2020KF 010).
文摘A bioflocculant producing potential bacteria was isolated from the circulating seawater of bio-filter using streak plate methods.The bacteria was identified through biochemical characteristics,partial 16S ribosomal ribonucleic acids(rRNA),nucleo-tide sequencing,and BLAST analysis of the gene sequence that showed the bacteria have 99%similarity to Pseudoalteromonas sp.and deposited in GenBank as Pseudoalteromonas sp.NUM8 with accession number JX435820.Influences of time course assay,carbon sources,nitrogen sources,inoculum size,as well as initial pH on the bacteria producing extracellular bioflocculant activity were investigated.The results showed that the strain optimal production period of microbial bioflocculant was at 72 h(flocculating activity of 94.5%),then dropped slowly.The bacteria optimally produced the bioflocculant when 1.0%sucrose and 0.5%sodium nitrate were used as sole sources of carbon and nitrogen with flocculating activities of 92.8%and 93.8%respectively.Also,the bacteria produced the bioflocculant optimally when initial pH of the medium was 5.0(flocculating activity 93.2%),and when Ca^(2+)was used as cation(flocculating activity 93.4%).The culture condition of inoculum size of 3%(v/v)was optimal flocculant pro-duction(flocculating activity 94.4%).Composition analyses indicated the bioflocculant to be principally a glycoprotein made up of about 34.3%protein and 63.4%total carbohydrate.
