Variation of thermal conductivity of DPPC lipid bilayer membranes around the phase transition temperature.
Variation of thermal conductivity of DPPC lipid bilayer membranes around the phase transition temperature.
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DOI：
10.1098/rsif.2017.0127
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发表时间：
2017-05
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影响因子：
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通讯作者：
Van Dessel S
中科院分区：
文献类型：
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作者：
Youssefian S;Rahbar N;Lambert CR;Van Dessel S
鉴于其两亲性和化学结构，磷脂在水性环境中表现出强烈的热致性和溶致性相行为。在相变温度附近，磷脂从凝胶状状态转变为流体晶体结构。在这种转变中，脂质双层的许多关键特性，如结构和热性质发生变化。在这项研究中，我们采用原子模拟技术研究的结构和潜在的机制，在二棕榈酰磷脂酰胆碱（DPPC）脂双层周围的流体-凝胶相变的传热。为了研究这种现象，我们对一系列不同的温度梯度进行了非平衡分子动力学模拟。结果表明，DPPC双层膜的热性能与温度梯度密切相关。较高的温度梯度导致DPPC脂质双层的热导率增加。我们还发现，DPPC的热导率是最低的转变温度，其中一个脂质小叶是在凝胶相，另一个是在液晶相。这基本上与在转变温度下脂质的两个小叶之间的热阻的增长有关。这些结果为开发工程应用的新型隔热材料提供了重要的新见解。
Given their amphiphilic nature and chemical structure, phospholipids exhibit a strong thermotropic and lyotropic phase behaviour in an aqueous environment. Around the phase transition temperature, phospholipids transform from a gel-like state to a fluid crystalline structure. In this transition, many key characteristics of the lipid bilayers such as structure and thermal properties alter. In this study, we employed atomistic simulation techniques to study the structure and underlying mechanisms of heat transfer in dipalmitoylphosphatidylcholine (DPPC) lipid bilayers around the fluid–gel phase transformation. To investigate this phenomenon, we performed non-equilibrium molecular dynamics simulations for a range of different temperature gradients. The results show that the thermal properties of the DPPC bilayer are highly dependent on the temperature gradient. Higher temperature gradients cause an increase in the thermal conductivity of the DPPC lipid bilayer. We also found that the thermal conductivity of DPPC is lowest at the transition temperature whereby one lipid leaflet is in the gel phase and the other is in the liquid crystalline phase. This is essentially related to a growth in thermal resistance between the two leaflets of lipid at the transition temperature. These results provide significant new insights into developing new thermal insulation for engineering applications.