Dissolution behavior of lipid monolayer-coated, air-filled microbubbles: Effect of lipid hydrophobic chain length
Dissolution behavior of lipid monolayer-coated, air-filled microbubbles: Effect of lipid hydrophobic chain length
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DOI：
10.1021/la026082h
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发表时间：
2002-11-26
期刊：
影响因子：
3.9
通讯作者：
Longo, ML
中科院分区：
文献类型：
--
作者：
Borden, MA;Longo, ML
包覆微米级气泡(微泡)的脂质单层壳层的气体传输特性和溶解行为对于开发稳定的超声造影剂、药物输送载体和有效的氧气载体具有特别重要的意义。在目前的研究中，Epstein和Plesset关于将气泡溶解到静止的脱气介质中的模型被修改为包括一个术语，用于描述脂膜的气体渗透阻力。通过将该模型与脂膜、充气微泡在脱气水介质中溶解的实验数据进行比较，确定了一系列同源磷脂的壳阻。气体渗透阻力是控制脂膜微泡溶解速度的一个重要因素，并且随着脂类疏水链长的增加而单调增加。在溶解过程中，脂类以一种连续的方式从壳层中脱落，以使短链脂类适应气核的收缩体积。观察到了长链脂类的屈曲和脱脂的循环过程，并提出了一种涉及相对单层粘合拉链的机制来描述这一现象。
The gas transport properties and dissolution behavior of the lipid monolayer shell coating a micron-scale bubble (microbubble) are of particular interest for developing stable ultrasound contrast agents, drug delivery vehicles, and efficient oxygen carriers. In the current study, Epstein and Plesset's model for the dissolution of a bubble into a quiescent, degassed medium was modified to include a term for the gas permeation resistance of the lipid shell. The shell resistances for a homologous series of phospholipids were determined by comparing this model to experimental data of lipid-coated, air-filled microbubbles dissolving in a degassed aqueous medium. The gas permeation resistance is a significant factor in controlling the dissolution rate of lipid-coated microbubbles and was found to increase monotonically with lipid hydrophobic chain length. During the dissolution process, lipid was shed from the shell in a continuous manner for short-chain lipids to accommodate the shrinking volume of the gas core. A cyclic process of buckling and lipid shedding was observed for long-chain lipids and a mechanism involving adhesive zippering of apposing monolayers is proposed to describe this phenomenon.