Analysis of the contractile work of a single cardiomyocyte by atomic force microscopy.

Atomic force microscopy (AFM) is widely used for the imaging and characterization of biological cells because of its nanoscale spatial resolution and force resolution. However, in the previous studies, the inability to effectively detect the contractile work of cardiomyocytes and the 3D dynamic expressions of their contraction and relaxation behaviors posed significant challenges. Therefore, this work presents a method for the analysis of the contractile work of a single cardiomyocyte by AFM. Two different contractile work measurement modes of cardiomyocytes are proposed, which are the constant height contact mode and the constant force contact mode. The differences in the contractile work were analyzed in two measurement modes. The changes in the contractile work of a single cardiomyocyte in the two measurement modes were studied, and the accuracies of the two measuring models were verified using ginseng extract. After the action of drugs, the contraction force of cardiomyocytes and the work done by contraction force increased. The experimental results indicated that the detection results of the ginseng water extract acting on the same cardiomyocyte by nanomanipulation technology were consistent with its pharmacological effects. Thus, it is reliable to detect the mechanical properties of cardiomyocytes using the nanomanipulation system. This study provides a new method for measuring the contraction force and contractile work of a single cardiomyocyte.