Effects of the PEG molecular weight of a PEG-lipid and cholesterol on PEG chain flexibility on liposome surfaces
Effects of the PEG molecular weight of a PEG-lipid and cholesterol on PEG chain flexibility on liposome surfaces
复制标题
DOI：
10.1016/j.colsurfa.2015.03.006
复制
发表时间：
2015-06-05
影响因子：
5.2
通讯作者：
Moribe, Kunikazu
中科院分区：
文献类型：
--
作者：
Abe, Kozue;Higashi, Kenjirou;Moribe, Kunikazu
进行变温H-1 NMR研究以研究PEG-脂质中的聚（乙二醇）（PEG）的分子量和胆固醇添加到脂质双层中对脂质体表面PEG链柔性的影响。PEG-脂质，即，将PEG分子量为750、2000和5000的L-α-二硬脂酰磷脂酰乙醇胺（DSPE）-PEG修饰为约100 μ g/ml的脂质体。100 nm。DSPE-PEG中PEG的1H NMR峰被宽峰和尖峰重叠，分别对应于刚性和柔性PEG组分。当PEG分子量增加时，PEG峰变得尖锐，表明长链PEG在脂质体表面更灵活。随着PEG链长的增加，伸入水相的柔性组分比例增加。当胆固醇含量从0增加到30 mol %时，也发生峰锐化，表明胆固醇掺入到脂质双层中增强了PEG链的灵活性。此外，PEG链的灵活性显着增加时，胆固醇离域的脂质双层浓度高于20摩尔%。在脂质双层中胆固醇的存在下，脂质的侧向扩散显著影响PEG链的灵活性。(C)2015 Elsevier B.V.版权所有。
A variable-temperature H-1 NMR study was performed to investigate the effects of the molecular weight of poly(ethylene glycol) (PEG) in PEG-lipids and cholesterol addition to the lipid bilayer on PEG chain flexibility at the liposomal surface. PEG-lipids, i.e.,L-alpha-distearoylphosphatidylethanolamine (DSPE)-PEG, with PEG molecular weights of 750, 2000, and 5000 were modified to liposomes of ca. 100 nm. The 1H NMR peak of PEG in DSPE-PEG was overlapped by broad and sharp peaks, corresponding to rigid and flexible PEG components, respectively. When the PEG molecular weight was increased, the PEG peak became sharp, indicating that long-chain PEGs were more flexible on the liposome surface. The proportion of flexible components projecting into the water phase increased as the PEG chain length increased. Peak sharpening also occurred when the cholesterol content was increased from 0 to 30 mol%, demonstrating that cholesterol incorporation into the lipid bilayer enhanced the PEG chain flexibility. In addition, the PEG chain flexibility significantly increased when cholesterol was delocalized in the lipid bilayer at concentrations above 20 mol%. Lateral diffusion of the lipid with the presence of cholesterol in the lipid bilayer significantly affected the PEG chain flexibility. (C) 2015 Elsevier B.V. All rights reserved.