基于AFM的药物刺激前后淋巴瘤活细胞的形貌及弹性的变化

摘要

原子力显微镜(AFM)的发明为研究单个活细胞的形貌结构及物理特性提供了新的技术手段.然而,由于缺少合适的固定方法,利用AFM对动物悬浮活细胞的形貌进行高分辨率成像还面临着巨大的挑战.本文提出一种基于微柱阵列和静电吸附相结合的动物悬浮细胞固定方法.通过微柱阵列的机械钳制和多聚赖氨酸的静电吸附实现了对单个淋巴瘤B细胞的固定,并在此基础上利用AFM动态观测了不同浓度Rituximab刺激下淋巴瘤B细胞的表面形貌及弹性的变化.经过0.2 mg· mL-1的Rituximab刺激2h后,细胞表面的褶皱增加,细胞的杨氏模量从196 kPa减小到183 kPa.经过0.5 mg·mL-1的Rituximab刺激2h后,细胞形貌发生显著变化并出现突起结构,细胞的杨氏模量从234kPa减小到175 kPa.实验结果表明淋巴瘤细胞形貌和弹性变化的幅度随着Rituximab刺激浓度的增加而增加,加深了对Rituximab作用效果的认识.%Atomic force microscopy (AFM) provides a means for characterizing the surface topography and biophysical properties of individual living cells under near-physiological conditions.However,owing to the lack of adequate cellular immobilization methods,AFM imaging of living,suspended mammalian cells is still a big challenge.In this paper,a method is presented for immobilizing individual living B lymphoma ceils that combines mechanical trapping with pillar arrays and electrostatic adsorption with poly-L-lysine.In this way,the topography and elasticity changes of individual B lymphoma cells that were stimulated with different concentrations of Rituximab were observed and measured dynamically.When the cell is stimulated by 0.2 mg · mL-1 Rituximab for 2 h,the cell topography becomes more corrugated and Young's modulus decreases from 196 to 183 kPa.When the cell is stimulated by 0.5 mg· mL-1 Rituximab for 2 h,the cell topography changes more significantly and some tubercles appear,and Young's modulus decreases from 234 to 175 kPa.These results thus provide a unique insight into the effects of Rituximab on individual cells.