以光學同調斷層掃描觀察癌細胞滅活過程

Abstract

在本論文中，我們在不同雷射照射條件下利用800奈米波長的高解析度光學同調斷層掃描系統來觀察SCC4口腔癌細胞死亡的過程。癌細胞培養在有金奈米環鍵結光敏劑磺化鋁酞菁(AlPcS)及沒有鍵結光敏劑的金奈米環溶液內，讓細胞吞噬金奈米環。運用侷域表面電漿子共振在1300奈米和1064奈米附近的兩種不同幾何大小金奈米環樣品，在光學同調斷層掃描的同時，利用四種不同雷射來照射癌細胞，包括1310奈米連續波雷射、1064奈米連續波雷射、1064奈米飛秒雷射和660奈米連續波雷射。1310奈米和1064奈米連續波雷射主要是透過金奈米環侷域表面電漿子共振產生光熱效應來損害癌細胞。除了光熱效應，藉由產生加強的雙光子吸收，1064奈米飛秒雷射可以激發AlPcS有效地生成單態氧對觀察的細胞造成傷害。660奈米連續波雷射可以透過單光子吸收激發AlPcS而生成單態氧損害觀察的癌細胞。以光熱效應滅活觀察的癌細胞會造成細胞壞死。透過生成單態氧滅活，細胞膜保持完整並且細胞內部物質聚集成團後產生強散射。在此情況下細胞經由凋亡的過程死亡。照射660奈米連續波雷射時，可以透過高速同調斷層掃描觀察到細胞內部物質流失的過程。

The use of a high-resolution optical coherence tomography (OCT) system with the operation wavelength around 800 nm to scan SCC4 cancer cells under different laser illumination conditions is demonstrated. The cancer cells are incubated with Au nanorings (NRIs), which are either linked with the photosensitizer, AlPcS, or not, for them to be up-taken by the cells. Two Au NRI samples of different geometries for inducing localized surface plasmon (LSP) resonance around 1310 and 1064 nm are used. Four different lasers are utilized for illuminating the cells under OCT scanning, including 1310-nm continuous (cw) laser, 1064-nm cw laser, 1064-nm femtosecond (fs) laser, and 660-nm cw laser. The 1310- and 1064-nm cw lasers mainly produce the photothermal effect through the LSP resonance of Au NRIs for damaging the observed cells. Besides the photothermal effect, the 1064-nm fs laser can produce strong two-photon absorption through the assistance of the LSP resonance of Au NRI for exciting AlPcS to effectively generate singlet oxygen and damage the observed cells. The 660-nm laser can excite AlPcS through single-photon absorption for generating singlet oxygen and damaging the observed cells. With the strong photothermal effect, the observed cells can be killed through the process of necrosis. Through the generation of singlet oxygen, the cell membrane can be preserved and the interior substances are solidified to become a hard body of strong scattering. In this situation, the cells are killed through the apoptosis process. Illuminated by the 660-nm cw laser, a process of interior substance escape is observed through high-speed OCT scanning.