Trypsin is playing an important role in the processes of cancer proliferation, invasion and metastasis which require the precise information of morphology and mechanical properties on the nano-scale for the related research. In this work, living human hepatoma (SMCC-7721) cells were treated with different concentrations of trypsin solution. The morphology and mechanical properties of the cells were measured via atomic force microscope (AFM). Statistical analyses of measurement data indicated that with the increase of trypsin concentration, the average cell height and the surface roughness were both increased, but the cell viability, the cell surface adhesion and the elasticity modulus were decreased significantly. The force required to puncture the cells was also gradually reduced. It indicates that trypsin not only hydrolyses the proteins between the cell and the substrate but also the membrane proteins. The results offer valuable clues for the cancerous process study, pathological analysis and trypsin inhibitor drug development. And this work provides an effective way for overcoming the cell membrane in drug injection for cell-targeted therapy.

中文翻译：

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原子力显微镜研究胰蛋白酶浓度对活 SMCC-7721 细胞的影响

胰蛋白酶在癌症的增殖、侵袭和转移过程中发挥着重要作用，需要在纳米尺度上获得精确的形态和力学性能信息进行相关研究。在这项工作中，活人肝癌 (SMCC-7721) 细胞用不同浓度的胰蛋白酶溶液处理。通过原子力显微镜（AFM）测量细胞的形态和机械性能。测量数据的统计分析表明，随着胰蛋白酶浓度的增加，平均细胞高度和表面粗糙度均增加，但细胞活力、细胞表面粘附和弹性模量显着降低。刺破细胞所需的力也逐渐减小。这表明胰蛋白酶不仅可以水解细胞和底物之间的蛋白质，还可以水解膜蛋白。研究结果为癌变过程研究、病理分析和胰蛋白酶抑制剂药物开发提供了有价值的线索。而这项工作为细胞靶向治疗药物注射剂中克服细胞膜问题提供了一条有效途径。