基于光镊技术的血红细胞膜剪切模量测量

Shear modulus measurement of RBCs based on optical tweezers technique

为了测量细胞外钙离子浓度对人血红细胞力学特性的影响,提出了一种基于光镊技术的细胞膜剪切模量测量方法。在倒置显微镜上集成光镊系统,可利用双光阱对粘贴微球的人血红细胞进行横向拉伸操控并分析细胞形变与光阱力的关系,从而测量得到细胞膜的剪切模量。通过测量不同浓度氯化钙溶液中血红细胞膜剪切模量,分析了血红细胞力学特性受细胞外钙离子浓度的影响。测量结果显示对比PBS中的正常血红细胞,经浓度为100、200、300、400和500μM的氯化钙溶液处理过的血红细胞膜的平均剪切模量分别减少了7. 8%,20. 3%,34. 4%,48. 4%及59. 3%。为了验证测量结果,建立了血红细胞力学模型并对其施加单向拉伸力进行仿真,得到的仿真结果与测量结果一致。此测量方法为其他细胞力学特性的测量提供了参考。

In order to measure the influence of extracellular Ca2+concentration on the mechanical properties of human red blood cells,a measurement method of cell membrane shear modulus based on optical tweezers is proposed.An optical tweezers system is integrated on the inverted microscope,the optical tweezers system can utilize the dual traps to transversely stretch and manipulate the human red blood cell attached with microspheres,and analyze the relationship between the cell deformation and the optical trap force,and then the shear modulus of the cell membrane is measured.Through measuring the shear modulus of the red blood cell membrane in the CaCl2 solution with different concentrations,the influence of extracellular Ca2+concentration on the mechanical properties of red blood cells is analyzed.The results show that compared with normal red blood cells in PBS,the mean shear modulus of red blood cell membrane treated with CaCl2 solutions with concentrations of 100,200,300,400 and 500μM decreases by 7.8%,20.3%,34.4%,48.4%and 59.3%,respectively.In order to verify the measurement results,a mechanical model of red blood cell is established and a uniaxial stretching force is applied to simulate the uniaxial stretching force applied to the cell.The simulation results are consistent with the measured results.This method provides a reference for the measurement of other cellular mechanical properties.