聚赖氨酸-聚乙二醇-聚赖氨酸与DNA聚离子复合物胶束的研究

Studies on polyion complex micelle consisting of poly(L-lysine)-poly(ethylene glycol)-poly(L-lysine)and DNA

将聚(Nε-苄氧羰基赖氨酸)-聚乙二醇-聚(Nε-苄氧羰基赖氨酸)(PLL(Z)-PEG-PLL(Z))中的氨基去保护得到两端为聚阳离子的嵌段共聚物聚赖氨酸-聚乙二醇-聚赖氨酸(PLL-PEG-PLL),并对其与DNA结合形成的聚集体的性质进行了研究.结果表明:PLL-PEG-PLL与DNA形成了聚离子复合物胶束;DNA与PLL通过静电作用形成核,PEG包裹在其外面,得到的聚离子复合物胶束为均相体系,即使在化学计量点也不会沉淀,保持着很好的流动性和稳定性,这一点对基因治疗是很重要的;而且随着PLL段的增加,包覆效果更好;聚离子复合物胶束使得DNA具有较强的核酶抗性;大小在10～35nm之间,呈球形;聚离子复合物胶束能够用于基因的传递,使基因在昆虫细胞系SF9中能够表达出蛋白质.

PLL-PEG-PLL were obtained by deprotection of amino of PLL(z)-PEG-PLL(z). The properties of polyion complex micelle (PIC) which consists of PLL-PEG-PLL and DNA were investigated. It showed:PLL-PEG-PLL could condense DNA, larger PLL were generally more effective at condensation; the system is homogenous and can not precipitate even under charge-neurtralized condition. Remarkable increase in the nuclease resistance of DNA through the incorporation into the core of PIC;PIC were spherical, the size were 10～35?nm. PIC can apply to gene delivery and the DNA can express in the cell line SF9.