Biomechanical Modeling and Characterization of Cells

Abstract

The study of the cell mechanics and its response to the external mechanical excitation has great importance in biology and medical sciences since it can help to understand and identify the causes, progression, and cures of diseases. The study of deformation and motion of cells involves the cooperation of various disciplines like biology, chemistry, and mechanics. The application of microelectromechanical systems (MEMS) in biomedical devices has expanded vastly over the last few decades, with MEMS devices being developed to measure different characteristics of cells. The study of cell mechanics offers a valuable understanding of cell viability and functionality. Cell biomechanics approaches also facilitate the characterization of important cell and tissue behaviors. In particular, understanding the biological response of cells to their biomechanical environment would enhance the knowledge of how cellular responses correlate to tissue-level characteristics and how some diseases, such as cancer, grow in the body. This study focuses on modeling the viscoelastic mechanical properties of single suspended human mesenchymal stem cells (hMSCs). Mechanical properties of hMSC cells are particularly important in tissue engineering and research for the treatment of cardiovascular diseases. We evaluated the elastic and viscoelastic properties of hMSC cells using a miniaturized custom-made MEMS device. Our results were compared to the elastic and viscoelastic properties measured by other methods such as atomic force microscopy (AFM) and micropipette aspiration. Different approaches were applied to model the experimentally obtained force data, including elastic, Kelvin, and Standard Linear Solid (SLS) models, and the corresponding constants were derived. These values were compared to the ones in the literature that were based on micropipette aspiration and AFM methods. We then utilized a tensegrity model, which represents major parts of the internal structure of the cell and treats the cell as a network of microtubules and microfilaments, as opposed to a simple spherical blob. The results predicted from the tensegrity model were consistent with the recorded experimental data. The modal analysis of the tensegrity model allowed for analysis of the cell’s natural frequencies.