細胞遷移模型與適性參數設計

Abstract

人工角膜被用於填補角膜捐贈的短缺，但人工角膜以聚合物作為材料仍有疑慮，故藉由組織工程，以自體細胞作為材料能解決移植排斥問題，是人工角膜移植的最佳解。然而，欲解決細胞於人工材料培養的不確定性，需先深入了解角膜細胞的基本力學行為。因此，我們研究角膜細胞，並設計細胞遷移模型。現今的細胞模型理論多著重於探討基底剛度對單顆細胞行為的影響，模型僅模擬單個細胞的參數及運動機制。針對解決多顆細胞於環境中生長及排列的情形，我們改良Odde學者之細胞遷移理論模型，加入Gillespie隨機演算法和Keren學者提出的膜力理論，建構新細胞模型以分析細胞外基質和機械力對細胞刺激與影響。模擬結果指出不只基底剛度，來自細胞外界的力、肌動蛋白單體等參數都對細胞爬行動態有重要影響。此外，我們為比對人類角膜細胞和上述細胞模型之異同，設計兩種實驗裝置，以提供合適細胞生長的環境。我們藉由Bradley開發的細胞影像分析軟體ADAPT量化觀測的遷移與形態改變過程。我們紀錄細胞遷移的軌跡模式、傷口癒合、細胞接觸抑制運動、細胞分裂、細胞貼附、以及絲狀偽足的生長等等的細胞行為。我們在實驗中發現細胞培養的過程，仍有許多影響細胞遷移的重要因素，譬如：細胞增生、細胞貼附。這些因素會影響模型中力學以及聚合速度的計算。本論文之研究貢獻在於提出一個模擬可模擬多個細胞的的遷移模型，以及分析其交互作用，從而將能夠以此細胞模型進一步研究合適的角膜細胞培養環境。未來，擬收集更多實驗數據與分析結果，以優化提出的模型參數。

Artificial corneas have been widely adopted to alleviate the lack of donor tissues, and using tissue engineering with autologous cells can overcome issue rejection in clinics. To solve the uncertainty of cell culture on the development artificial materials, we developed and designed a cell migration model after we investigated recently cell model developments. Most theories developed for cell model focused on the influence of substrate stiffness related to cell behaviors, and thus they simulated a single cell at a time and studied its details. Our model was modified from Odde’s cell migration model and applied Gillespie’s stochastic algorithm and Keren’s membrane forces theory, so cellular interactions and environmental cues could be considered and analyzed in many cells. Simulation results point out that substrate stiffness, cell mechanics and actin monomers all show important influences on the migration process. Two experiment setups were designed to conduct experiments on corneal cells and compare the results with simulation. ADAPT, a cell analysis software developed by Bradley, was employed to quantify the migration process and obtain morphodynamics of the experiment. The outcomes demonstrated cell behaviors of cell migration patterns, wound healing, cell inhibition locomotion, cell division, cell attachment, and the growth of filopodia. We found that cell behaviors such as cell division and attachment also affect migration, so it might be essential to add them to modify our model. The main achievement of this thesis is that we propose a novel cell migration model capable of simulating multiple cells and their interactions, and hence enable further investigation of suitable corneal cells culturing environments. In the future, more experimental data and analysis results could be collected to fine-tune model parameters.