ABS Global, Deforest, WI, USA.
J Gene Med. 2012 Sep-Oct;14(9-10):580-9. doi: 10.1002/jgm.2669.
Nonviral gene delivery has a limited efficacy partly as a result of poor nuclear delivery, yet an understanding of the mechanisms of nuclear entry is limited. The present study aimed to test the common hypothesis that most nonviral vehicles enter the nucleus during cell division.
Polystyrene particles with diameters of 24-200 nm and carboxylate or amine surface groups, were either used as is or, alternatively, were functionalized with carboxyl-, hydroxyl- or amine- terminated poly(ethylene glycol) (PEG) and subsequently microinjected into the cytoplasm of NIH/3T3 mouse fibroblast cells. The post-mitotic locations of the particles were analyzed and compared with the locations of cytoplasmically microinjected plasmid DNA (pDNA), pDNA polyplexes or nuclear localization signal (NLS)-functionalized pDNA polyplexes.
We observed that all polystyrene particles as well as the NLS-free polyplexes were excluded from the nucleus post-mitosis. By contrast, free pDNA and pDNA polyplexes containing an NLS accumulated in the nucleus after division.
These data suggest that biochemically specific modes of association with chromatin-associated proteins or other nuclear components are necessary for the nuclear inclusion of polyplexes and nanoparticles during mitosis.
非病毒基因传递的疗效有限，部分原因是核传递效果不佳，但对核进入机制的理解有限。本研究旨在检验一个常见假设，即大多数非病毒载体在细胞分裂过程中进入细胞核。
直径为 24-200nm 的带有羧基或氨基表面基团的聚苯乙烯颗粒，要么原样使用，要么用羧基、羟基或氨基封端的聚乙二醇（PEG）功能化，然后微注射到 NIH/3T3 小鼠成纤维细胞的细胞质中。分析颗粒的有丝分裂后位置，并与细胞质内微注射的质粒 DNA（pDNA）、pDNA 多聚物或核定位信号（NLS）功能化的 pDNA 多聚物的位置进行比较。
我们观察到所有聚苯乙烯颗粒以及无 NLS 的多聚物都在有丝分裂后被排除在核外。相比之下，分裂后自由的 pDNA 和包含 NLS 的 pDNA 多聚物会在核内积累。
这些数据表明，与染色质相关蛋白或其他核成分的生化特异性结合模式对于多聚物和纳米颗粒在有丝分裂期间进入核内是必要的。
