Lipid chain length effect on the phase behaviour of PCs/PEG:2000-PEs mixtures.: A spin label electron spin resonance and spectrophotometric study
Lipid chain length effect on the phase behaviour of PCs/PEG:2000-PEs mixtures.: A spin label electron spin resonance and spectrophotometric study
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DOI：
10.1016/s0301-4622(01)00201-0
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发表时间：
2001-10-18
影响因子：
3.8
通讯作者：
Sportelli, L
中科院分区：
文献类型：
--
作者：
Belsito, S;Bartucci, R;Sportelli, L
用自旋标记电子自旋共振(ESR)光谱和固定波长分光光度法研究了磷脂酰胆碱(PC)与聚乙二醇磷脂酰乙醇胺(PEG2000-PES)的完全水合水分散体。聚乙二醇酯：2000-PE是一种胶束形成的聚合物脂质，广泛用于通过空间稳定效应延长PC脂质体在血液循环中的寿命。PC脂和聚乙二醇2000-PE聚合物脂具有相同的双甘酯(DM)或双硬脂酰基(DS)的酰化链长。研究了DMPC/PEG：2000-DMPE和DMPC/PEG：2000-DSPE混合物在整个相对组成范围内(0-100摩尔%)的变化。在这两种分散体系中，常规的低温自旋标记ESR谱和400 nm处的吸光度与温度的关系表明，随着PEG2000-PES含量的增加，从片层到胶束的转变。脂质组装体的物理状态，无论是片状还是胶束状，不仅取决于PEG2000-PES的含量，而且还取决于脂质基质的碳氢链的长度。在具有较长碳氢链的分散体中(即，在DSPC/PEG：2000-DSPE混合物中)比在具有较短酰链的分散体(即，在DMPC/PEG：2000-DMPE混合物中)更容易实现胶束化。饱和转移电子自旋共振(ST-ESR)和吸光度测量反映了聚乙二醇2000-PES在低含量时双层膜的解聚和脂质聚集体的尺寸减小。(C)2001 Elsevier Science B.V.保留所有权利。
Spin-label electron spin resonance (ESR) spectroscopy and spectrophotometry at fixed wavelength are used to study fully hydrated aqueous dispersions of phosphatidylcholines (PCs) with poly(ethylene glycol: 2000)-phosphatidy-lethanolamines (PEG:2000-PEs). PEG:2000-PE is a micelle-forming polymer-lipid that is extensively used for increasing the lifetime of PC liposomes in the blood circulation through a steric stabilisation effect. The PC lipids and the PEG:2000-PE polymer-lipids have the same acyl chain length of either dimiristoyl (DM) or distearoyl (DS) chains. DMPC/PEG:2000-DMPE and DSPC/PEG:2000-DSPE mixtures were investigated over the entire range of relative compositions (0-100 mol%). In both dispersions, the low-temperature conventional spin label ESR spectra and the temperature dependence of the absorbance at 400 nm give an indication of the conversion from lamellae to micelles with increasing PEG:2000-PEs content. The physical state of the lipid assemblies, lamellar or micellar, is dependent not only on PEG:2000-PEs content, but also on the length of hydrocarbon chain of the lipid matrix. Micellisation is attained more readily in dispersions with longer hydrocarbon chains (i.e. in DSPC/PEG:2000-DSPE mixtures) than in those with shorter acyl chains (i.e. in DMPC/PEG:2000-DMPE mixtures). Saturation transfer ESR (ST-ESR) and absorbance measurements reflect the disaggregation of the bilayers and a reduction in the size of the lipid aggregates by PEG:2000-PEs at low content. (C) 2001 Elsevier Science B.V. All rights reserved.