以3.5 G PAMAM(3.5代聚酰胺-胺型)树状大分子为保护剂,利用微波法还原HAuCl4溶液制备金纳米粒子.考察了当3.5 G PAMAM与HAuCl4物质的量的比一定时,微波照射不同时间对金纳米粒子大小及形状的影响;以及同一照射条件下,3.5 G PAMAM与HAuCl...以3.5 G PAMAM(3.5代聚酰胺-胺型)树状大分子为保护剂,利用微波法还原HAuCl4溶液制备金纳米粒子.考察了当3.5 G PAMAM与HAuCl4物质的量的比一定时,微波照射不同时间对金纳米粒子大小及形状的影响;以及同一照射条件下,3.5 G PAMAM与HAuCl4不同的物质的量比值对金纳米粒子大小及形状的影响.利用紫外可见分光光度计、透射电子显微镜对其进行了表征.结果表明,当3.5 G PAMAM与HAuCl4物质的量的比值一定时,金纳米粒子的形状和大小受微波照射时间长短的影响不大;适当延长照射时间,制得的金纳米粒子的分散性较好.在相同照射条件下,随着3.5 G PAMAM与HAu-Cl4物质的量比值的减小,得到的金纳米粒子粒径逐渐变大,且分散性变差.展开更多
以4.5 G PAMAM(4.5代聚酰胺-胺型)树状大分子为保护剂,利用微波法还原HAuCl4溶液制备金纳米粒子。考察了在同一照射条件下,4.5 G PAMAM与HAuCl4不同物质的量比对金纳米粒子大小及形状的影响。利用紫外可见分光光度计、透射电子显微镜以...以4.5 G PAMAM(4.5代聚酰胺-胺型)树状大分子为保护剂,利用微波法还原HAuCl4溶液制备金纳米粒子。考察了在同一照射条件下,4.5 G PAMAM与HAuCl4不同物质的量比对金纳米粒子大小及形状的影响。利用紫外可见分光光度计、透射电子显微镜以及X射线衍射分析对其进行了表征。结果表明,照射时间相同时,以30 s为例,当4.5 G PAMAM与HAuCl4物质的量比为5时,得到的金纳米粒子最小;随着4.5 G PAMAM与HAuCl4物质的量比值的减小,金纳米粒子变大,且发生了不同程度的聚集。展开更多
Objective:To study the effects of the generation 4 polyamidoamine/vascular endothelial growth factor antisense oligodeoxynucleotide(G4PAMAM/VEGFASODN) compound on the expressions of vascular endothelial growth factor(...Objective:To study the effects of the generation 4 polyamidoamine/vascular endothelial growth factor antisense oligodeoxynucleotide(G4PAMAM/VEGFASODN) compound on the expressions of vascular endothelial growth factor(VEGF) and its mRNA of breast cancer cells and on the inhibition of vascular endothelial cells. Methods:We examined the morphology of G4PAMAM/VEGFASODN compound and its pH stability,in vitro transfection efficiency and toxicity,and the expressions of VEGF and its mRNA. Methyl thiazolyl tetrazolium assay was used to detect the inhibitory function of the compound on vascular endothelial cells. Results:The compound was about 10 nm in diameter and was homogeneously netlike. From pH 5 to 10,it showed quite a buffered ability. The 48-h transfection rate in the charge ratio of 1:40 was 98.76%,significantly higher than that of the liposome group(P<0.05). None of the transfection products showed obvious toxicity on the cells. The expressions of both VEGF protein and its mRNA after G4PAMAM/VEGFASODN transfection decreased markedly. Conclusion:With a low toxicity,high safety,and high transfection rate,G4PAMAM/VEGFASODN could be a promising gene vector. Specifically,it inhibits VEGF gene expression efficiently,laying a basis for further in vivo animal studies.展开更多
Seasonal variations play an essential role in the metabolism, behavior and activity of the laboratory animals. This study was aimed to examine whether mitochondrial function can be influenced by the seasonal changes a...Seasonal variations play an essential role in the metabolism, behavior and activity of the laboratory animals. This study was aimed to examine whether mitochondrial function can be influenced by the seasonal changes and how large is the impact of these fluctuations on experiments with using animal models and further results interpretation. Liver mitochondria were isolated from male Wistar rats and exposed to calcium ions, PAMAM dendrimers G2.5 or their combination: (Ca2+) and dendrimer. The scientific hypothesis assumed that dendrimer G2.5 is able to limit the detrimental effect of Ca2+ ions on mitochondria function, possibly through affecting the following parameters: calcium transport, mitochondrial potential and membrane fluidity. The activity of mitochondria was monitored using fluorescent labels. The changes in calcium transport were detected using Calcium Green 5-N, the mitochondrial membrane potential and membrane fluidity were elucidated using JC-1 and DPH, respectively. The experiments were carried out during the autumn (October/November) or during the spring (May/June). The obtained data emphasize the effect of seasonal differences on liver mitochondria originating from laboratory animals and outline the importance of planning the experiments during the same seasonal period in order to receive objective and reliable results in the future. Finally, it was revealed the neutral effect of G2.5 dendrimer on mitochondria and its inability to protect mitochondria against overload of calcium ions regardless of seasonality. It was also evidenced that liver mitochondria isolated from autumn-derived animals were more sensitive to calcium and/or dendrimer exposure in comparison with mitochondria isolated from animals investigated during the spring.展开更多
目前,实现半导体纳米粒子的大小、形状可控是调控半导体纳米粒子光电等性能的重要手段。利用有机物,特别是有机高分子聚合物可以对纳米粒子进行控制。聚合物可以提供稳定的空间,限制纳米粒子的继续生长,防止粒子的聚集、沉淀。此外,聚...目前,实现半导体纳米粒子的大小、形状可控是调控半导体纳米粒子光电等性能的重要手段。利用有机物,特别是有机高分子聚合物可以对纳米粒子进行控制。聚合物可以提供稳定的空间,限制纳米粒子的继续生长,防止粒子的聚集、沉淀。此外,聚合物还可以钝化材料,为粒子提供良好的表面状态。其中树状大分子因为具有独特的结构,特别适合做金属纳米粒子的主体。通过树状大分子的封装或包裹,纳米级的金属原子簇或胶体粒子保持稳定。用于树枝状大分子保护的金属簇(化合物)纳米粒子的制备研究主要采用PAMAM多代树状大分子。按照文献的方法,合成3.5 G PAMAM树状大分子做保护剂,从而制备了CdS纳米粒子,得到的粒子大小均匀。本文同时考察了3.5 G PAMAM与CdS不同物质的量比时对制得的纳米粒子的大小、尺寸的影响情况。展开更多
文摘以3.5 G PAMAM(3.5代聚酰胺-胺型)树状大分子为保护剂,利用微波法还原HAuCl4溶液制备金纳米粒子.考察了当3.5 G PAMAM与HAuCl4物质的量的比一定时,微波照射不同时间对金纳米粒子大小及形状的影响;以及同一照射条件下,3.5 G PAMAM与HAuCl4不同的物质的量比值对金纳米粒子大小及形状的影响.利用紫外可见分光光度计、透射电子显微镜对其进行了表征.结果表明,当3.5 G PAMAM与HAuCl4物质的量的比值一定时,金纳米粒子的形状和大小受微波照射时间长短的影响不大;适当延长照射时间,制得的金纳米粒子的分散性较好.在相同照射条件下,随着3.5 G PAMAM与HAu-Cl4物质的量比值的减小,得到的金纳米粒子粒径逐渐变大,且分散性变差.
文摘以4.5 G PAMAM(4.5代聚酰胺-胺型)树状大分子为保护剂,利用微波法还原HAuCl4溶液制备金纳米粒子。考察了在同一照射条件下,4.5 G PAMAM与HAuCl4不同物质的量比对金纳米粒子大小及形状的影响。利用紫外可见分光光度计、透射电子显微镜以及X射线衍射分析对其进行了表征。结果表明,照射时间相同时,以30 s为例,当4.5 G PAMAM与HAuCl4物质的量比为5时,得到的金纳米粒子最小;随着4.5 G PAMAM与HAuCl4物质的量比值的减小,金纳米粒子变大,且发生了不同程度的聚集。
基金Project (No. 30572140) supported by the National Natural Science Foundation of China
文摘Objective:To study the effects of the generation 4 polyamidoamine/vascular endothelial growth factor antisense oligodeoxynucleotide(G4PAMAM/VEGFASODN) compound on the expressions of vascular endothelial growth factor(VEGF) and its mRNA of breast cancer cells and on the inhibition of vascular endothelial cells. Methods:We examined the morphology of G4PAMAM/VEGFASODN compound and its pH stability,in vitro transfection efficiency and toxicity,and the expressions of VEGF and its mRNA. Methyl thiazolyl tetrazolium assay was used to detect the inhibitory function of the compound on vascular endothelial cells. Results:The compound was about 10 nm in diameter and was homogeneously netlike. From pH 5 to 10,it showed quite a buffered ability. The 48-h transfection rate in the charge ratio of 1:40 was 98.76%,significantly higher than that of the liposome group(P<0.05). None of the transfection products showed obvious toxicity on the cells. The expressions of both VEGF protein and its mRNA after G4PAMAM/VEGFASODN transfection decreased markedly. Conclusion:With a low toxicity,high safety,and high transfection rate,G4PAMAM/VEGFASODN could be a promising gene vector. Specifically,it inhibits VEGF gene expression efficiently,laying a basis for further in vivo animal studies.
文摘Seasonal variations play an essential role in the metabolism, behavior and activity of the laboratory animals. This study was aimed to examine whether mitochondrial function can be influenced by the seasonal changes and how large is the impact of these fluctuations on experiments with using animal models and further results interpretation. Liver mitochondria were isolated from male Wistar rats and exposed to calcium ions, PAMAM dendrimers G2.5 or their combination: (Ca2+) and dendrimer. The scientific hypothesis assumed that dendrimer G2.5 is able to limit the detrimental effect of Ca2+ ions on mitochondria function, possibly through affecting the following parameters: calcium transport, mitochondrial potential and membrane fluidity. The activity of mitochondria was monitored using fluorescent labels. The changes in calcium transport were detected using Calcium Green 5-N, the mitochondrial membrane potential and membrane fluidity were elucidated using JC-1 and DPH, respectively. The experiments were carried out during the autumn (October/November) or during the spring (May/June). The obtained data emphasize the effect of seasonal differences on liver mitochondria originating from laboratory animals and outline the importance of planning the experiments during the same seasonal period in order to receive objective and reliable results in the future. Finally, it was revealed the neutral effect of G2.5 dendrimer on mitochondria and its inability to protect mitochondria against overload of calcium ions regardless of seasonality. It was also evidenced that liver mitochondria isolated from autumn-derived animals were more sensitive to calcium and/or dendrimer exposure in comparison with mitochondria isolated from animals investigated during the spring.
文摘目前,实现半导体纳米粒子的大小、形状可控是调控半导体纳米粒子光电等性能的重要手段。利用有机物,特别是有机高分子聚合物可以对纳米粒子进行控制。聚合物可以提供稳定的空间,限制纳米粒子的继续生长,防止粒子的聚集、沉淀。此外,聚合物还可以钝化材料,为粒子提供良好的表面状态。其中树状大分子因为具有独特的结构,特别适合做金属纳米粒子的主体。通过树状大分子的封装或包裹,纳米级的金属原子簇或胶体粒子保持稳定。用于树枝状大分子保护的金属簇(化合物)纳米粒子的制备研究主要采用PAMAM多代树状大分子。按照文献的方法,合成3.5 G PAMAM树状大分子做保护剂,从而制备了CdS纳米粒子,得到的粒子大小均匀。本文同时考察了3.5 G PAMAM与CdS不同物质的量比时对制得的纳米粒子的大小、尺寸的影响情况。
