Quantitative investigation of the dynamics and mechanical properties of cytoskeleton through cytomagnetometric and optical measurement of living cells.

点击翻译按钮获取中文摘要

Cytomagnetometry is the measurement of the magnetic field from the cells which have engulfed magnetic particles. The particles can be manipulated by an external field and hencecan be used as a probe to investigate the mechanisms of the intracellular movements and the mechanical properties of the tissues surrounding the phagosomes. After magnetizing the particles within the cells, the cell field decays due to the random motion of the phagosmes. Therefore, the cell field can be related to the energy responsible for the random motion and to the rheological properties of the tissues. In this particular research, we have focused on the viscoelasticity of the tissues. When the phagosomes containing magnetized particles are given a torque by an external field, the cell field decays quickly, but when the torque is released, the cell field shows a recoil which is ascribed to some elasticity. We have modeled the situation by a simple differential eqution with two viscous and one elastic components. This equation is driven by the Wiener process. We have mode Monte Carlo simulations to calculate the cell field from this equation. We also have derived the partial differential equation describing the time course of the probabillty density of the orientation of the phagosomes. Experimentally, we have used drugs to destroy filamentous structures such as microfilaments and microtubules. The behavior of the cell field after treatment by these drugs suggest complicated effects of these drugs to the cytoskeletal structures surrounding the phagosomes but further investigation is necessary to compare the results with the numerical experiments of the model. Optical study using the confocal laser scanning microscope has been started but has not produced enough results to be compared with the magnetic study.