重金属离子对肺表面活性物质单层膜的影响

为了探究重金属对肺表面活性物质（PS）膜的影响，利用Langmuir–Wilhelmy膜天平，研究了不同种类和浓度的重金属离子与PS单层膜的相互作用.发现Cr³⁺、Cu²⁺、Hg²⁺、Pb²⁺、Cd²⁺、Ni²⁺6种重金属离子均使PS单层的π-A等温线G-LE相变阶段外扩，而Fe³⁺可诱导单层缩合.随后，选取Cd²⁺，Cu²⁺，Hg²⁺，Fe³⁺4种离子进一步探究了重金属浓度对PS单层膜表面活性的影响规律，进行了可压缩模量分析，并结合红外光谱（FTIR）和原子力显微镜（AFM）探究其作用机理，发现Cu²⁺，Fe³⁺和Hg²⁺均会以浓度依赖的方式与PS单层的极性头部发生络合作用，形成复合物，改变膜的稳定性；而Cd²⁺的影响明显弱于其他3种金属离子，但也能使得PS单层有序性增强.

Effect of heavy metal ions on the surface activity of pulmonary surfactant monolayer membrane

In order to investigate the effect of heavy metals on pulmonary surfactant (PS) membranes, the interaction between different types and concentrations of heavy metal ions and PS monolayer membranes were studied using Langmuir-Wilhelmy membrane balances. The six heavy metal ions of Cr³⁺, Cu²⁺, Hg²⁺, Pb²⁺, Cd²⁺ and Ni²⁺ all expanded the π-A isotherm G-LE phase transition phase of PS monolayer, while Fe³⁺ induced monolayer condensation. Subsequently, Cd²⁺, Cu²⁺, Hg²⁺and Fe³⁺ were selected to further investigate the effect of heavy metal concentration on the surface activity of PS monolayer films,the compressible modulus analysis was carried out, and the mechanism of action was explored by combining infrared spectroscopy (FTIR) and atomic force microscope (AFM). Cu²⁺, Fe³⁺ and Hg²⁺ all cooperated with the polar head of PS monolayer in a concentration-dependent manner to form a complex and change the stability of the membrane, while the effect of Cd²⁺ was obviously weaker than the other three metal ions, but it could also enhance the PS monolayer order.