Cite this: Lab Chip, 2013, 13, 3578 Liver-cell patterning Lab Chip: mimicking the morphology of liver lobule tissue3 Received 2nd April 2013, Accepted 1st May 2013 DOI: 10.1039/c3lc50402f www.rsc.org/loc Chen-Ta Ho, a Ruei-Zeng Lin, b Rong-Jhe Chen, a Chung-Kuang Chin, a Song-En Gong, a Hwan-You Chang, b Hwei-Ling Peng, c Long Hsu, d Tri-Rung Yew, e Shau-Feng Chang f and Cheng-Hsien Liu* a A lobule-mimetic cell-patterning technique for on-chip reconstruction of centimetre-scale liver tissue of heterogeneous hepatic and endothelial cells via an enhanced field-induced dielectrophoresis (DEP) trap is demonstrated and reported. By mimicking the basic morphology of liver tissue, the classic hepatic lobule, the lobule-mimetic-stellate-electrodes array was designed for cell patterning. Through DEP manipulation, well-defined and enhanced spatial electric field gradients were created for in-parallel manipulation of massive individual cells. With this liver-cell patterning labchip design, the original randomly distributed hepatic and endothelial cells inside the microfluidic chamber can be manipulated separately and aligned into the desired pattern that mimicks the morphology of liver lobule tissue. Experimental results showed that both hepatic and endothelial cells were orderly guided, snared, and aligned along the field-induced orientation to form the lobule-mimetic pattern. About 95% cell viability of hepatic and endothelial cells was also observed after cell-patterning demonstration via a fluorescent assay technique. The liver function of CYP450-1A1 enzyme activity showed an 80% enhancement for our engineered liver tissue (HepG2+HUVECs) compared to the non-patterned pure HepG2 for two-day culturing. Introduction Regenerative medicine has an urgent demand for engineered tissues and organs to solve the shortage of tissue source. 1 Over the past two decades, tissue engineering has been of high interest in tissue regeneration but lacks the capability to reconstruct complicated architectures of tissue especially like the liver. A variety of recent progress in tissue engineering has been dedicated to the development of cell-based artificial tissue. 2,3 Cellular patterning techniques, which provide the basis of development for rebuilding cell blocks, play a crucial role in a series of applications such as tissue genetic morphologies, 4,5 medical diagnostics, 6 and drug delivery. 7,8 A functional organ is normally constructed from multiple cell types organized in unique structures to perform its specific and complex functions. 3 Thus, efficient reconstruction of complex tissue structures according to their native morphol- ogies is significant to the in vitro development of functional tissue. 9 The efficient reconstruction of complex artificial tissues according to their genetic morphologies, such as liver, highly relies on the fine cellular patterning method. Traditional tissue engineering methods use scaffolds for tissue reconstruction. Although advanced biodegradable scaf- folds, 10,11 which morphologically mimic human tissue, have been developed as the cultured matrix for the cell attachment, it is still insufficient to guide, place and distribute the heterogeneous cells to reconstruct complicated architectures of tissue especially like kidney and liver. In particular, hepatic sinusoids, the special micro-vascular systems of the liver which are lined by liver sinusoid endothelial cells to form a radiating pattern, are essential for normal liver function and hepatocyte survival. 12 Thus, fine cell-patterning techniques are important in tissue engineering because the adequate posi- tioning of both hepatic and endothelial cells to reconstruct the complex liver tissue according to its native architecture is the major challenge in liver tissue engineering. 4,5 However, most tissue engineering capabilities deal with relatively simple tissues and fail to arrange heterogeneous cell types to reconstruct the complicated tissues with adequate precision. Recent advances in passive cell patterning techniques, which focus on chemically modifying cell-adhesive substrate a Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan 300, R.O.C.. E-mail: liuch@pme.nthu.edu.tw; Tel: +886-3-5742496 b Institute of molecular medicine, National Tsing Hua University, Hsinchu, Taiwan 300, R.O.C. c Department of Biological Science and Technology, National Chiao-Tung University, Hsinchu, Taiwan 300, R.O.C. d Department of Electrophysics, National Chiao-Tung University, Hsinchu, Taiwan 300, R.O.C. e Department of Materials Science and Engineering Department, National Tsing Hua University, Hsinchu, Taiwan 300, R.O.C. f ITRI, Hsinchu, Taiwan 300, R.O.C. 3 Electronic supplementary information (ESI) available: Videos showing the demonstration of on-chip liver-lobule-mimetic cell patterning. See DOI: 10.1039/ c3lc50402f Lab on a Chip PAPER 3578 | Lab Chip, 2013, 13, 3578–3587 This journal is ß The Royal Society of Chemistry 2013 Published on 01 May 2013. Downloaded by National Chiao Tung University on 28/04/2014 01:52:47. View Article Online View Journal | View Issue