Size-Dependent Endocytosis of Gold Nanoparticles

• Main Authors: Sheng-Hann Wang, 王盛翰
• Other Authors: Arthur Chiou
• Format: Others
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/7g44k5

碩士 === 國立陽明大學 === 生醫光電工程研究所 === 97 === Gold nanoparticles (GNPs) have been widely applied in biomedical imaging, gene/drug delivery and photo-thermal therapy due to their unique optical properties. We have used 80nm-sized GNPs to study the morphologic changes of living cells (human lung cancer cell, CL1-0) under drugs (Cytochalasin D) interactions by using the dark field optical section microscopy (DFOSM)[1]. This study indicates that large size GNPs are immobilized on the cell’s membrane rather than eaten by cells. The prior studies used transmission electron microscopy (TEM) and fluorescent confocal microscopy have suggested that the endocytosis of GNPs is size-dependent. In this thesis, we used dark-field optical section microscopy (DFOSM) to study the endocytosis of GNPs with different sizes (13 nm, 45 nm, 70 nm and 110 nm) by various cells (human lung cancer cell, CL1-0 and HeLa cells). Compared with early research of endocytosis of GNPs which usually using TEM and mass spectrometry for quantification, the DFOSM provides a way to define whether GNPs are in up-taken into cytosol or adhesion on the cell membrane of living cell instantaneously. Using the colors of scattering light of GNPs and section-ability of DFOSM, we can obtain the 3-D distribution of GNPs and quantify GNPs on different focal plane of living cells. Furthermore, we used the scattering signals of GNPs as the contrast. Because of the simple conjugation bio-chemistry between DNA/proteins and GNPs, the GNP can act the biomolecular carrier and contrast agent simultaneously. No extra modification is necessary. The combination of DFOSM and GNPs provides a three dimensional observation of living cells. It is better than the fluorescence confocal microscopy because the fluorescence dyes and quantum dots have higher cytotoxicity and lower bio-compatibility.