Dip-pen nanolithography(DPN) has been developed to pattern monolayer film of various molecules in submicrometer dimensions through the controlled movement of ink-coated atomic force microscopy(AFM) tip on a desired su...Dip-pen nanolithography(DPN) has been developed to pattern monolayer film of various molecules in submicrometer dimensions through the controlled movement of ink-coated atomic force microscopy(AFM) tip on a desired substrate, which makes DPN a potentially powerful tool for making the functional nanoscale devices. In this letter, using direct-write dip-pen nanolithography to generate nanoscale patterns of poly-L-lysine on mica was described. Poly-L-lysine molecules can anchor themselves to the mica surface through electrostatic interaction force, so stable poly-L-lysine patterns, such as square, line, circle and cross, could be obtained on freshly cleaved mica surface. From AFM image of the patterned poly-L-lysine nanostructures on mica, we know that poly-L-lysine was flatly bound to the mica surface. These oriented patterns of poly-L-lysine on mica can provide the prospect of building functional nanodevices and offer new options for this technique in a variety of other significant biomolecules.展开更多
AIM: To describe distribution of the phosphorothioated antisense oligodeoxynucleotides (PS-asODNs) conjugated to galactosylated poly-L-lysine (Gal-PLL) in mice, and to observe their effects on expression of HBV gene i...AIM: To describe distribution of the phosphorothioated antisense oligodeoxynucleotides (PS-asODNs) conjugated to galactosylated poly-L-lysine (Gal-PLL) in mice, and to observe their effects on expression of HBV gene in the 2.2.15 cells and transgenic mice.METHODS: According to the result of direct sequencing of PCR amplified products, a 16 mer phosphorothioate analogue of the antisense oligodeoxynucleotides (PS-asODNs) directed against the HBV U5-like region was conjugated to the hepatotropic Gal-PLL molecules. Its distribution was demonstrated using asODNs labeled with ^32p at the 5' terminus with a T4-polynucleotide Kinase. Its inhibition effect on HBV expression was observed in the transfected 2.2.15 cells and transgenic mice.RESULTS: The Gal-PLL and asODNs could form stable complex at a molar ratio of 2:1. As shown in the HBV-transfected 2.2.15 cells, the inhibition effects of asODNs alone and asODNs conjugated to Gal-PLL, at 10μmol/L for both, on HBsAg and HBeAg production were different,the former being 70 % and 58 %, respectively, and the latter being 96 % and 82 %, respectively. A more pronounced reduction was also observed in viral DNA load in the culture supernatant for the test with Gal-PLL-asODNs. Among many mouse organs, livers retained more asODNs molecules after administration. The preferential concentration in liver was found to be 52.14 % for Gal-PLL-asODNs, as high as 2.38-fold of that for asODNs (21.9 %). Both elements decreased gradually in liver, with 2.9 % of the former, 5.99 % of the latter retained 24 hours after the administration. The injection interval, therefore, was recommended to be 24 hours. In the transgenic mice, serum HBsAg decreased significantly (P<0.01) at the 12th day after administrating Gal-PLL- asODNs, the serum HBV DNA turned negative in 4 of the 6 mice.CONCLUSION: Antisense oligodeoxynucleotides conjugated to Gal-PLL can be concentrated in liver and intaked by hepatocytic cells. This may result in specific inhibition of expression and replication of HBV in vitro and in vivo.展开更多
文摘Dip-pen nanolithography(DPN) has been developed to pattern monolayer film of various molecules in submicrometer dimensions through the controlled movement of ink-coated atomic force microscopy(AFM) tip on a desired substrate, which makes DPN a potentially powerful tool for making the functional nanoscale devices. In this letter, using direct-write dip-pen nanolithography to generate nanoscale patterns of poly-L-lysine on mica was described. Poly-L-lysine molecules can anchor themselves to the mica surface through electrostatic interaction force, so stable poly-L-lysine patterns, such as square, line, circle and cross, could be obtained on freshly cleaved mica surface. From AFM image of the patterned poly-L-lysine nanostructures on mica, we know that poly-L-lysine was flatly bound to the mica surface. These oriented patterns of poly-L-lysine on mica can provide the prospect of building functional nanodevices and offer new options for this technique in a variety of other significant biomolecules.
基金the Natural Science Foundation of China,No.39370648
文摘AIM: To describe distribution of the phosphorothioated antisense oligodeoxynucleotides (PS-asODNs) conjugated to galactosylated poly-L-lysine (Gal-PLL) in mice, and to observe their effects on expression of HBV gene in the 2.2.15 cells and transgenic mice.METHODS: According to the result of direct sequencing of PCR amplified products, a 16 mer phosphorothioate analogue of the antisense oligodeoxynucleotides (PS-asODNs) directed against the HBV U5-like region was conjugated to the hepatotropic Gal-PLL molecules. Its distribution was demonstrated using asODNs labeled with ^32p at the 5' terminus with a T4-polynucleotide Kinase. Its inhibition effect on HBV expression was observed in the transfected 2.2.15 cells and transgenic mice.RESULTS: The Gal-PLL and asODNs could form stable complex at a molar ratio of 2:1. As shown in the HBV-transfected 2.2.15 cells, the inhibition effects of asODNs alone and asODNs conjugated to Gal-PLL, at 10μmol/L for both, on HBsAg and HBeAg production were different,the former being 70 % and 58 %, respectively, and the latter being 96 % and 82 %, respectively. A more pronounced reduction was also observed in viral DNA load in the culture supernatant for the test with Gal-PLL-asODNs. Among many mouse organs, livers retained more asODNs molecules after administration. The preferential concentration in liver was found to be 52.14 % for Gal-PLL-asODNs, as high as 2.38-fold of that for asODNs (21.9 %). Both elements decreased gradually in liver, with 2.9 % of the former, 5.99 % of the latter retained 24 hours after the administration. The injection interval, therefore, was recommended to be 24 hours. In the transgenic mice, serum HBsAg decreased significantly (P<0.01) at the 12th day after administrating Gal-PLL- asODNs, the serum HBV DNA turned negative in 4 of the 6 mice.CONCLUSION: Antisense oligodeoxynucleotides conjugated to Gal-PLL can be concentrated in liver and intaked by hepatocytic cells. This may result in specific inhibition of expression and replication of HBV in vitro and in vivo.
