Nonphospholipid Fluid Liposomes with Switchable Photocontrolled Release

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• 作者：Zhong-Kai Cui ; Thida Phoeung ; Pierre-Antoine Rousseau ; Gaulthier Rydzek ; Qian Zhang ; C. Geraldine Bazuin ; Michel Lafleur
• 刊名：Langmuir
• 出版年：2014
• 出版时间：September 16, 2014
• 年：2014
• 卷：30
• 期：36
• 页码：10818-10825
• 全文大小：402K
• ISSN：1520-5827

文摘

We created novel nonphospholipid photosensitive liposomes from a mixture of a monoacylated azobenzene amphiphile (AzoC₁₀N⁺) and cholesterol sulfate (Schol). This system belongs to the family of sterol-enriched nonphospholipid liposomes that were shown to form stable large unilamellar vesicles (LUVs) with enhanced impermeability. Fluid bilayers were successfully prepared from AzoC₁₀N⁺/Schol (25/75 molar ratio) mixtures, and LUVs could be derived at room temperature using standard extrusion methods. The isomerization process of the bilayer-inserted AzoC₁₀N⁺ was characterized. Leakage from these liposomes could be induced by the photoconversion of AzoC₁₀N⁺ from its trans form to its cis form. This photocontrolled release from fluid liposomes contrasts with the case of phospholipid-based azo-containing liposomes, which are generally required to be in the gel phase to be photosensitive. It is proposed that the very high degree of conformational order of the monoalkylated amphiphile and the tight packing of the hydrophobic core of the AzoC₁₀N⁺/Schol liposomes make them responsive to the presence of the bulky cis azo isomer. Interestingly, the liposome impermeability could be fully restored by the photoisomerization of the cis form back to the trans form, providing a sharp on-and-off control of payload release. In addition, these nonphospholipid liposomes display a very limited passive release. Therefore, it is shown that AzoC₁₀N⁺/Schol LUVs can be used as nanocontainers, whose content can be released by light in a controlled and switchable manner.