研究細胞的貼附能夠幫助我們了解細胞的生長行為，對於利用活體細胞測試毒物或是藥品對細胞活性的影響，細胞貼附與否是判斷細胞生長情形的重要指標之一。近來量測細胞的電阻抗特性逐漸取代了細胞染色法，藉由分析細胞的阻抗特性，能夠幫助我們迅速且有效觀察細胞特徵行為。本研究提供一研究細胞貼附對阻抗影響的新方法，根據L929細胞貼附過程中細胞形態的變化，分別建構6個模型，模擬討論細胞貼附過程中，量測阻抗因電極上受細胞與細胞外基質蛋白(ECM)覆蓋的面積不同、細胞-電極距離的不同，所造成的阻抗變化特性。研究結果顯示，隨著電極表面受細胞覆蓋的面積愈大、細胞-電極距離愈小，會使得中頻的歸一阻抗變化量(NIC)愈大；隨著電極表面受細胞外基質(ECM)覆蓋的面積愈大，會使得低頻的歸一阻抗變化量(NIC)愈小，當電極表面受細胞與ECM覆蓋面積達92.16 %時，中頻(100 kHz)阻抗變化值達1260 %，低頻(1 Hz)阻抗變化達-81.9 %。模擬結果說明了當量測電極尺寸與表面所覆蓋的細胞面積愈相近時，細胞貼附所造成的阻抗變化會愈明顯，也說明了細胞貼附時所分泌產生的ECM物質，會造成低頻阻抗量測值下降的現象。; Analysis of cell adhesion property can help us to understand cell growth situation and test cytotoxicity effect of different toxicants to cells. Recently, electrical cell substrate impedance sensing (ECIS) replaced cell staining; analyzing the impedance characteristics of cells will help us to study the situation and property of cell growth behavior rapidly and effectively. In this study, we proposed a new approach to analyse the L929 cell growth on electrode surface using finite element method (FEM) simulation. According to L929 cell morphology change on cell covered electrode surface during growth, six electrical models were designed respectively. FEM simulation was carried out to measure impedance response due to the change of coverage cell, extracellular matrix (ECM) area on electrode, and the change of resistive gap region of cell-electrode. The results showed that the larger cell covered area on electrode and shorter cell-electrode gap caused maximμm change in normalized impedance change (NIC) at intermediate frequency (100 kHz), and at lower frequencies (1 Hz) minor change in normalized impedance change (NIC) was observed due to ECM covered on electrode surface. When the coverage of cell and ECM reached 92% of total electrode area, the impedance at intermediate frequency changed by 8 folds and at lower frequency impedance changed by -0.8 folds from that of measured impedance in bare electrodes. FEM simulation results showed that when cell covered area is similar to electrode size, the significant change in impedance will be observed. The result also indicated the ECM protein produced by cell attachment will contribute to decrease the impedance at lower frequency.
