细胞三维受控组装为组织工程和再生医学等研究领域拓展了新的理论和技术。由于器官是由不同细胞组成并具有复杂微观结构的三维结构体,多细胞组装是细胞组装技术发展的关键。针对多细胞组装问题,本研究基于气动控制的多细胞组装平台,利...细胞三维受控组装为组织工程和再生医学等研究领域拓展了新的理论和技术。由于器官是由不同细胞组成并具有复杂微观结构的三维结构体,多细胞组装是细胞组装技术发展的关键。针对多细胞组装问题,本研究基于气动控制的多细胞组装平台,利用压缩空气作为动力,采用非水平排列方法设计多喷头模块,设计并构建了实现多细胞三维受控组装的硬件系统和控制系统,并基于该系统进行了3种颜色基质材料的组装和2种活细胞的组装实验。结果表明:本系统可实现3个喷头的准确切换和组装,组装过程中喷头喷射的启停响应迅速,启停响应延迟小于5 ms;成型精度小于30μm,喷头间不易发生干扰;系统易于实现多喷头扩展和控制。该系统在三维空间内可完成3种材料的阶梯结构、圆环形腔结构、多边形结构等多种有重要生物应用价值结构的成型组装,并完成2种活细胞组装。CD34和Oil red O染色实验结果显示,组装的细胞在结构内生长良好,细胞定位准确并保持细胞性状。本研究为制造复杂的人体组织和器官提供了新的技术。展开更多
Cationic polyethylenimine （PEI） with dextran fluorescein anionic （DFA） or oligodeoxynucleotide （ODN） could form polyelectrolyte complex by self-assembly as a gene delivery vector. This study was designed to inve...Cationic polyethylenimine （PEI） with dextran fluorescein anionic （DFA） or oligodeoxynucleotide （ODN） could form polyelectrolyte complex by self-assembly as a gene delivery vector. This study was designed to investigate the effects on pharmaceutical characteristics and cell uptake PEI after a long-circulation modification with poly（ethylene glycol） （PEG）. DFA or ODN reacted with PEI or PEI-PEG to form polyelectrolyte complexes. Surface characters of these complexes and the retardation of ODN by PEI and PEI-PEG were evaluated. The uptake rates of DFA/PEI and DFA/PEI-PEG complexes by MCF-7 cells were evaluated by flow cytometry. Confocal laser scanning microscopy was utilized to visualize the internalization of these complexes. ODN/PEI complex showed the dependence of their size and ξ potential on the N/P ratio. ODN/PEI-PEG complex were much less affected by N/P ratio and their size was around 30 100 nm. PEI and PEI-PEG retarded ODN even at N/P ratio as low as 4, and complete retardation was found at N/P ratio of 8. The uptake rate by MCF-7 cells was direct correlated to the DFA concentration and incubation time, and the uptake rate could exceed 99% under the selected condition. The results in this study showed that PEI self-assembly polyelectrolyte complex after stealth or long circulation modification may increase the ability as a gene vector to delivery genes into cells.展开更多
By means of indirect double immunofluorescent staining, the coordination of PI antigen and perichromonucleolin (PCN), the constituent of nuclear periphery and nucleolus respectively, in the assembly and disassembly of...By means of indirect double immunofluorescent staining, the coordination of PI antigen and perichromonucleolin (PCN), the constituent of nuclear periphery and nucleolus respectively, in the assembly and disassembly of chromosome pellicle during mitosis was studied. It was found that in 3T3 cells, during mitosis PI antigen began to coat the condensing chromosome .surface earlier.than PCN did. However, both of them completed their coating on chromosome at approximately the same stage of mitosis, prometaphase metaphase. The dissociation of PI antigen from chromosome pellicle to participate the formation of nuclear periphery took, place also ahead of that of PCN. At early telophase PI antigen had been extensively involved in the formation of nuclear periphery, while PCN remained in association with the surface of decondensing chromosomes. At late telophase, when PI antigen was localized in an fairly well formed nuclear periphery, PCN was in a stage of forming prenucleolar bodies.展开更多
文摘细胞三维受控组装为组织工程和再生医学等研究领域拓展了新的理论和技术。由于器官是由不同细胞组成并具有复杂微观结构的三维结构体,多细胞组装是细胞组装技术发展的关键。针对多细胞组装问题,本研究基于气动控制的多细胞组装平台,利用压缩空气作为动力,采用非水平排列方法设计多喷头模块,设计并构建了实现多细胞三维受控组装的硬件系统和控制系统,并基于该系统进行了3种颜色基质材料的组装和2种活细胞的组装实验。结果表明:本系统可实现3个喷头的准确切换和组装,组装过程中喷头喷射的启停响应迅速,启停响应延迟小于5 ms;成型精度小于30μm,喷头间不易发生干扰;系统易于实现多喷头扩展和控制。该系统在三维空间内可完成3种材料的阶梯结构、圆环形腔结构、多边形结构等多种有重要生物应用价值结构的成型组装,并完成2种活细胞组装。CD34和Oil red O染色实验结果显示,组装的细胞在结构内生长良好,细胞定位准确并保持细胞性状。本研究为制造复杂的人体组织和器官提供了新的技术。
基金National Nature Science Foundation of China (Grant No.30772665)Beijing Nature Science Foundation (Grant No.7083111).
文摘Cationic polyethylenimine （PEI） with dextran fluorescein anionic （DFA） or oligodeoxynucleotide （ODN） could form polyelectrolyte complex by self-assembly as a gene delivery vector. This study was designed to investigate the effects on pharmaceutical characteristics and cell uptake PEI after a long-circulation modification with poly（ethylene glycol） （PEG）. DFA or ODN reacted with PEI or PEI-PEG to form polyelectrolyte complexes. Surface characters of these complexes and the retardation of ODN by PEI and PEI-PEG were evaluated. The uptake rates of DFA/PEI and DFA/PEI-PEG complexes by MCF-7 cells were evaluated by flow cytometry. Confocal laser scanning microscopy was utilized to visualize the internalization of these complexes. ODN/PEI complex showed the dependence of their size and ξ potential on the N/P ratio. ODN/PEI-PEG complex were much less affected by N/P ratio and their size was around 30 100 nm. PEI and PEI-PEG retarded ODN even at N/P ratio as low as 4, and complete retardation was found at N/P ratio of 8. The uptake rate by MCF-7 cells was direct correlated to the DFA concentration and incubation time, and the uptake rate could exceed 99% under the selected condition. The results in this study showed that PEI self-assembly polyelectrolyte complex after stealth or long circulation modification may increase the ability as a gene vector to delivery genes into cells.
文摘By means of indirect double immunofluorescent staining, the coordination of PI antigen and perichromonucleolin (PCN), the constituent of nuclear periphery and nucleolus respectively, in the assembly and disassembly of chromosome pellicle during mitosis was studied. It was found that in 3T3 cells, during mitosis PI antigen began to coat the condensing chromosome .surface earlier.than PCN did. However, both of them completed their coating on chromosome at approximately the same stage of mitosis, prometaphase metaphase. The dissociation of PI antigen from chromosome pellicle to participate the formation of nuclear periphery took, place also ahead of that of PCN. At early telophase PI antigen had been extensively involved in the formation of nuclear periphery, while PCN remained in association with the surface of decondensing chromosomes. At late telophase, when PI antigen was localized in an fairly well formed nuclear periphery, PCN was in a stage of forming prenucleolar bodies.
