Selective Induction of Cell Death and the Dead Cell Detachment from a Microfabricated Cell Culture Substrate Using Femtosecond Laser Pulses

• Main Authors: Wang, Chung-Han, 王崇翰
• Other Authors: Masuhara, Hiroshi
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/16326588422921529673

碩士 === 國立交通大學 === 應用化學系碩博士班 === 103 === Construction of bio-functional devices has become one of the most important technologies for studying cellular behaviour. We aim at providing a new methodology to construct living-cell network on a culture substrate toward cell-based devices. Such devices may play an important role in controlling cellular functions such as development, proliferation, migration, differentiation and death. In order to realize the cell-based devices, induction of cell death without affecting the neighbours should be controlled. Because cell maturation is a sophisticated process involving many cell functions, the condition of individual cells is varying during this period. Furthermore, when the cells finishing their roles, they kill themselves to make places to other kinds of cells for maturing tissues. The types of cell death frequently occurs naturally in normal tissue maturation cycle. The purpose of this thesis is to find out a condition for inducing death of individual cells to remove them by utilising femtosecond laser ablation. The relation among laser parameters, cell death and the detachment of dead cell was investigated with HepG2 cell iii (human liver hepatocellular carcinoma cell line). The micro-fabricated cell culture substrate was applied to monitoring individual cells. The cells can be arranged linearly as a monolayer on a micro-pattern. When intense femtosecond laser pulses are tightly focused into a single living cell, ablation is induced as a result of multi-photon absorption. If the laser power is enough high to generate cavitation bubbles, bursting of a single cell is induced to release intracellular toxins to extracellular environment. In this case, surrounding cells receive fatal damages. In contrast, a relatively low power was set just to kill a target single cell in short period without affecting adjacent cells. We found that the target HepG2 cells were detached from the micro-fabricated pattern with 96% reproducibility. Our methodology for control of specific cell death and their detachment by utilising femtosecond laser will contribute to the development of cell-based devices. It will play a significant role in study of selectively controlling cell functions, for example, cell renewal and cell death in near future. In addition, this ability for temporally and spatially controlling cellular and tissue damages and removing an individual specific cells will receive much attention from the view point of regeneration studies.