上皮細胞之彈性逆散射光譜的量測與分析

Abstract

目前許多研究指出光散射光譜對於結構與折射率的變化非常敏感；藉由分析初期癌化細胞的逆散射光譜，可以得到細胞在病變過程中，細胞核大小變化的資訊以及折射率的改變。因此光散射光譜在生醫工程的運用上，可提供細胞初期癌化時，結構變化的資訊。因此是一種有潛力實現非侵入式上皮細胞初期癌化檢測之技術。 本研究之目的希望能建立一套實驗系統及方法，來準確測量並分析上皮細胞之逆散射光譜，因為許多癌症均發源於上皮細胞。本論文主要提出了一光學量測架構，來測量上皮細胞細胞核的逆散射光譜。除了設計實驗來驗證系統的可行性外，也測量了人類胚胎上顎間質細胞及癌化上皮鱗狀細胞的逆散射光譜，並與Mie theory (米氏定律)之理論值作比對，以求得細胞核的大小，進而判斷細胞是否產生癌化，並建立光譜分析的資料庫。 同時本架構也加上了頻率域光學同調斷層掃描(FD-OCT)技術，更進一步蒐集逆散射光，並利用光譜式光學同調斷層掃描術(SOCT)的時頻分析方式，來提高空間以及頻譜解析度，目前已經能藉由此架構分析蓋玻片的厚度，未來希望能藉由FD-OCT來準確定量出聚苯乙烯球的大小，接著更進一步來計算細胞核的厚度。

Recently, many researches indicate that light scattering spectroscopy (LSS) is greatly influenced by the change of structure and refractive index. By analyzing the backscattering light spectroscopy of early stage cancer cells, the changes of their nuclear size and refractive index during the development of precancerous lesions can be revealed. Therefore, LSS is a promising technique for noninvasively detecting precancerous lesions in vivo. This thesis builds up an optical system and research methods for measuring and analyzing the backscattering light of individual epithelial cells. Our optical system contains two part, one part can directly measure the LSS form living cell. The other part combines the LSS technique with low coherence interferometry (LCI) which is called Fourier domain optical coherence tomography (FD-OCT) to detect the depth resolved backscattering signal form an object. The spectroscopic optical coherence tomography (SOCT) method is adapted to find out more scattering information. In this thesis, I use our optical system to examine the relationship between the backscattered light of cell nucleus and enlargement of cancer cell nucleus. First, I validate our optical system with polystyrene beads and then measure the backscattering spectroscopy of living cells including human embryonic palatal mesenchymal (HEPM) cells and oral squamous carcinoma cells (CA9-22). I find out the nuclear size by fitting the result with Mie theory. Also, I characterize the axial resolution of the FD-OCT part of the system and use the system to measure the thickness of a coverslip. In the future, I will use the FD-OCT and SOCT to find out the size of polystyrene beads and then investigate the structural information of cell nucleus.