Objective To establish a new method to measure the elastic modulus of living circulating tumor cells (CTCs) by micropipette aspiration. Methods Living CTCs were enriched by commercial microfluidic chips and identified individually using EpCAM antibody under fluorescence microscope. The elastic modulus of CTCs was measured using micropipette aspiration and compared with cancer cell lines. Results For the elastic modulus of different cancer cell lines, heterogeneity was found not only between the different types of cancer cell lines but also inside the same cell line. The CTCs in breast cancer had a smaller elasticity modulus compared with MCF-7 cancer cell line. Conclusions This method can measure the elastic modulus of living CTCs, which provides cell mechanics data for studying the relationship between physical properties of CTCs and diagnosis of cancers, as well as developing the physical biomarkers of tumor cells.

Objective By comparing the physical properties (cell area, volume and elastic modulus) of red blood cells (RBCs) between newborn infants and the elderly over 80 years old, and correlation with the physiological and biochemical parameters such as total cholesterol and glycosylated hemoglobin, the effects of different ages and biochemical parameters on RBC physical properties were analyzed. Methods The mcropipette aspiration was used to measure the surface area, volume and elastic modulus of erythrocytes in newborn infants and the elderly over 80 years old, and the data were analyzed by statistical distribution analysis, correlation analysis and regression analysis. Results The mean values of RBC volume, surface area and elastic modulus in the elderly over 80 years old were smaller than those in newborn infants, and the mean values of RBC mechanical parameters in the same age group were not significantly different. The erythrocytes geometric parameter distribution of newborn infants was more concentrated than that of the elderly, while the elastic modulus distribution of newborn infants was more dispersed than that of the elderly. The mechanical properties of RBCs in newborn infants were highly correlated with the total cholesterol and gestational week; the mechanical properties of RBCs in the elderly were highly correlated with diastolic blood pressure and glycated hemoglobin. Conclusions There are significant differences in physical properties of RBCs between newborn infants and the elderly over 80 years old, and the biochemical parameters that affect physical properties of RBCs at different ages are also different.