Computational Model of Optical Stretcher

Understanding the biophysical properties of cells is one of the highly researched areas in recent years. There are many examples of the usefulness of this knowledge, such as [1], where the deformability of cells is used as a marker for distinguishing malignant cells. Thus the motivation to model elastic cells with a nucleus is quite strong and we are currently working on a computational model of a cell with a nucleus. In order to obtain a working model, one must take several steps. Among them is the calibration process. For this step, we chose biological experiment where cells are stretched using optical traps. Using this method, the cell is stretched more linearly then in experiments with holders, such as silica beads, attached to the cell. That and the fact that this method was used on circulating tumour cells (CTC) are the reasons we chose this particular experiment. In this work, we focus on the simulation of the optical stretcher and its validation for our further work. We first explain the mechanical principles of the biological experiment. Then we discuss our approach to modelling the stretching force that is applied to the surface of the cell. Afterwards, we use this method on our calibrated RBC model and compare the results from the simulations with the analytical shape the cell should achieve with a given set of laser parameters. This is the first step in obtaining calibration simulation for a model of CTC.