Assessment of fluidity of different invasomes by electron spin resonance and differential scanning calorimetry
Assessment of fluidity of different invasomes by electron spin resonance and differential scanning calorimetry
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DOI：
10.1016/j.ijpharm.2011.04.020
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发表时间：
2011-06-30
影响因子：
5.8
通讯作者：
Fahr, Alfred
中科院分区：
文献类型：
--
作者：
Dragicevic-Curic, Nina;Friedrich, Manfred;Fahr, Alfred
本研究的目的是调查膜软化成分（萜烯/萜烯混合物，乙醇）对侵袭体中磷脂膜流动性的影响，其中除了磷脂酰胆碱和水，还含有乙醇和萜烯。此外，将mTHPC掺入侵袭体中，以研究其与囊泡膜中磷脂的分子相互作用。通过电子自旋共振（ESR），使用自旋标记物5-和16-doxyl硬脂酸和差示扫描量热法（DSC）的双层膜的流动性进行了研究。添加1%的单一萜烯/萜烯混合物导致包含囊泡的磷脂酰基链的C16原子周围的流动性显著增加。然而，这是不可能区分的影响，单一的萜烯或萜烯混合物。将mTHPC掺入囊泡的双层中降低了酰基链的C16原子附近的流动性，表明其定位在双层的内部疏水区中。这些结果与DSC测量结果一致，表明萜烯增加了双层的流动性，而mTHPC降低了流动性。因此。侵袭体代表具有非常高的膜流动性的囊泡。然而，没有发现侵袭体的流动性和它们的渗透增强能力之间的直接相关性，表明除了流动性之外，其他现象也可能是mTHPC的皮肤递送改善的原因。(C)2011爱思唯尔有限公司版权所有。
The aim of this study was to investigate the influence of membrane-softening components (terpenes/terpene mixtures, ethanol) on fluidity of phospholipid membranes in invasomes, which contain besides phosphatidylcholine and water, also ethanol and terpenes. Also mTHPC was incorporated into invasomes in order to study its molecular interaction with phospholipids in vesicular membranes. Fluidity of bilayers was investigated by electron spin resonance (ESR) using spin labels 5- and 16-doxyl stearic acid and by differential scanning calorimetry (DSC). Addition of 1% of a single terpene/terpene mixture led to significant fluidity increase around the C16 atom of phospholipid acyl chains comprising the vesicles. However, it was not possible to differentiate between the influences of single terpenes or terpene mixtures. Incorporation of mTHPC into the bilayer of vesicles decreased fluidity near the C16 atom of acyl chains, indicating its localization in the inner hydrophobic zone of bilayers. These results are in agreement with DSC measurements, which showed that terpenes increased fluidity of bilayers, while mTHPC decreased fluidity. Thus. invasomes represent vesicles with very high membrane fluidity. However, no direct correlation between fluidity of invasomes and their penetration enhancing ability was found, indicating that besides fluidity also other phenomena might be responsible for improved skin delivery of mTHPC. (C) 2011 Elsevier B.V. All rights reserved.