Laser-induced variations of cell membrane topography

• Main Authors: Ping-Yu Hsu, 許平諭
• Other Authors: Chaw-Huang Lee
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/6d2nwq

碩士 === 國立陽明大學 === 生醫光電工程研究所 === 97 === We utilize non-interferometric wide-field optical profiolometry (NIWOP) that has axial resolution of tens of nanometers to study the interaction between laser light and the plasma membrane of CL1-5 human lung cancer cell. Two lasers are combined with NIWOP system to provide light stimulation for the plasma membrane. After laser irradiation we immediately record cell membrane topography by NIWOP. The retraction and protrusion of the edge of the cell can be modulated by violet light and infrared light, respectively. The response of the cell is proportional to the illumination time of the light. The illumination time of infrared light has to be a hundred time longer than that of the violet light in order to make significant stimulation for the cell. We found that although light irradiation makes cell edge retract or protrude, the roughness and fluctuation of cell membrane topography show no differences after light irradiation. The perturbation caused by light irradiation on the cell membrane topography may be negligible. Besides, the actin concemtration distribution is observed by fluorescence microscopy. The retraction and protrusion of the cell edge are accompanied by the decrease and the increase of actin concentration. This phenomenon may be due to cytotoxicity of violet light that rapidly destroys actin cytoskeleton and the ability of infrared light that promotes the actin monomer polymerization. We see that light irradiation stimulates change of actin concentration despite that it makes nonsense to the cell membrane. The actual mechanism is yet not fully understood and need to be further investigated. This thesis first introduces works that are related to “interactions between laser light and the cell” and the tools often used to study cell membrane topography. The principle of NIWOP and its optical setup will be explained, followed by a brief review in its applications in studying cell membrane dynamics. We then describe our experimental procedure and how the data are analyzed. In the end we make conclusions for the results.