Project

Micro-Systems & Control Laboratory, NTHU


Cell patterning Labchip for tissue engineering applications

Liver on a chip

Objectives:

End-stage organ failure or tissue loss is one of the most disastrous and costly issues in medicine. Up to date, hundreds of millions of patients still suffer from disease¡¦s torment and over million surgical procedures are estimated to be performed each year to treat these disorders worldwide. Over the last 50 years, transplantation of a wide variety of tissues, reconstructive surgical techniques, and replacement with mechanical devices have significantly improved patient outcomes and become the most effective treatment. Unfortunately, organ and tissue transplantation are imperfect solutions because surgical reconstruction undergoes a critical problem due to lacking of abundant suitable organs and tissues form limited available human donors, which greatly restrict the therapeutic results of surgery. In the year of 1987, J. Vacanti and R. Langer coin a promising fashion named ¡§Tissue Engineering¡¨ and aim at ending up the problem owing to the limited source of donor¡¦s organs. Tissue engineering is an interdisciplinary field that applies the principles and methods of engineering and the life sciences and targets at regenerating natural tissues and regenerating artificial organs toward the development of biological substitutes that could restore, maintain, or improve tissue and organ function for human transplantation. In the tissue engineering, porous scaffolds combined with adequate target cells and culture method have been used to provide with physical and chemical cues for the cell culture, attachment, proliferation, differentiation into functional tissues. Although advanced biodegradable scaffolds, which morphologically mimic the human tissue, are developed to mainstream biomaterial used as microenvironmental matrix for the cell culture, it is still insufficient to guide, place and distribute the heterogeneous cells to reconstruct complicated architectures of complex tissue especially like kidney and liver. In particular, hepatic sinusoids, the special liver¡¦s micro-vascular systems, which are lined by liver sinusoid endothelial cells to form a radiate pattern, are essential for normal liver functions and hepatic survival (Fig 1.). Thus, how to develop an effective cell manipulating method that could achieve adequate positioning of both hepatic and endothelial cells to reconstruct the complex liver tissue according to its native architecture has become the important and challenging issue in liver tissue engineering.

          

Fig. 1. Illustration of liver organ. The enlarged and cross-sectional view shows one unit of the liver tissue, the classic hepatic lobule.

Technical Approach:

To reconstruct the appropriate heterogeneous pattern of the classic hepatic lobule consisting of hepatic and endothelial cells and to modulate interactions for further cell behavior are the challenged and important steps toward the development of successful artificial liver and highly relies on the cell patterning technique. Fine cell patterning techniques capable of precisely controlling cell position provide the basis ability for rebuilding cell blocks; play a crucial role in the field of tissue engineering, as well as cell-based biosensors, medical diagnostics, and drug delivery. In recent years, a variety of advanced progresses in tissue engineering have been dedicated to the developments of manifold cell patterning techniques for tissue engineering applications, such as photolithography, microcontact printing, microfluidic patterning, laser-guide direct writing, ink-jet printing and dielectrophoresis (DEP). Among these cell-patterning approaches, electric-field induced DEP effect offers the capability of active and in-parallel cell-manipulation to rapidly achieve precise positioning of heterogeneous cell populations with high cell viability and high patterning resolution, which is a superior candidate considering to be applied to the field of Tissue engineering. For this goal, a rapid heterogeneous-cells patterning microfluidic chip via the enhanced DEP trap is designed and demonstrated to facilitate the reconstruction of lobule-mimetic liver tissue in vitro. By taking advantage of the novel electrode design, which simulated and analyzed via CFDRC software, the enhanced inhomogeneous field-field could be generates in spatial to precisely snare plenty of individual cells to form the desired lobule-mimetic pattern via the high-precision DEP manipulation. With the novel design and materialization of this microfluidic chip (Fig. 2), the original randomly distributed liver cells in our chip could be manipulated in parallel and align into desired radiate pearl-chain array to form the lobule-mimetic radiate pattern, mimicking from the morphology of real liver tissue, with good cell viability after cell-patterning DEP manipulation. Heterogeneous integration of liver-cell patterning is demonstrated on our microfluidic chip with several thousands of hepatic cells and endothelial cells snared and patterned on the patterning area of about one millimeter scale (Fig. 3). High-resolution cell pattering methods capable of controlling the heterogeneous cells as well as the cell-cell interactions, which potentially modulate the cell behavior, would enable reproducible control over the cellular microenvironment and could benefit the maintenance of cell functions in vitro physiological systems. Based on our knowledge, this research reports the first result of lobule-mimetic liver tissue reconstruction in-vitro. This proposed cell-patterning chip demonstrates the rapid in-parallel heterogeneous patterning of live liver cells via a novel enhanced DEP trap design inside the microfluidic chip and potentially could be applied for the further studies in biological research, biomedical investigation and tissue engineering. For more detail, please see our paper published at the journal of Lab on a Chip, 2006, 6(6), pp. 724-734. Furthermore, this paper is honorably selected as the ¡§Hot article¡¨ and the ¡§inside cover¡¨ at the issue of 2006, 6 of Lab on a Chip. Also, a research highlight is received and announced by RSC Chemical Biology at June, 7, 2006, as shown in the Fig. 4 below.

Fig. 2. Materialization of cell-patterning microfluidic chip.

 

Fig. 3. On-chip heterogeneous-cells patterning demonstration. (a) The first group of hepatic cells are snared and patterned in radiate pearl-chains via our specific electrode design with in-parallel DEP manipulation. (b) On-chip demonstration of the rapid heterogeneous-integration patterning of hepatic cells (green fluorescence) and endothelial cells (red fluorescence), which mimics the shape and the function of sinusoid-like vascular endothelial lining cells that are shown in the classic real hepatic lobule. (c) The fluorescent control group with the two types of cells randomly distributed over the cell-patterning chamber without DEP manipulation.

 

 

Fig. 4. The ¡§inside cover¡¨ of the journal of Lab on a chip at the issue of 2006, 6 and a research highlight is received and announced by RSC Chemical Biology at June, 7, 2006

 

References:

1.      C. T. Ho, R. Z. Lin, W. Y. Chang, H. Y. Chang and C. H. Liu, "Rapid heterogeneous liver-cell on-chip patterning via the enhanced field-induced dielectrophoresis trap" , Lab Chip, 6, pp.724 - 734, (2006) (selected as Inside Cover and Hot Article of Lab on a chip Journal (2007 SCI Impact Factor: 5.8) and highlighted by RSC Chemical Biology, June 7, 2006.)

2.      Ruei-Zeng Lin, Chen-Ta Ho, Cheng-Hsien Liu, and Hwan-You Chang, ¡§Dielectrophoresis-based cell patterning for tissue engineering,¡¨ Biotechnology Journal, 2006, 1, 949-957, (one of the three papers highlighted at "In the Issue" section)

3.      Chen-Ta Ho and, Po-Chi Lin, Hwan-You Chang, and Cheng-Hsien Liu, ¡§A Cell-Patterning Biochip Based on Dielectrophoresis for liver tissue application,¡¨ Proceedings of 9th International Conference on Miniaturized  Systems for Chemistry and Life Sciences, October 9, 2005, Boston, USA, pp. 1368-1370, 2005. (MicroTAS 2005)


Collaboration:

¡P         Prof. Hwan-You Chang's Group at NTHU Life Science

¡P         Prof. Hwei-Ling Peng's Group at NCTU Biological Science

¡P         Prof. Long Hsu's Group at NCTU ElectroPhysics

¡P         Prof. Tri-Rung Yew's Group at NTHU Material Science

¡P         Prof. Hsuan-Shu Lee's Group at NTU Hospital

¡P         Prof. Yio-Wha Shau's Group at NTU Applied Mechanics

¡P         Dr. Shau-Feng Chang's Group at ITRI


Contact Information:

¡P         Chen-Ta Ho  d917725@oz.nthu.edu.tw

¡P         Chien-Yu Chen  g9533541@oz.nthu.edu.tw

¡P         Song-En Gong  g9535501@oz.nthu.edu.tw

¡P         Cheng-Hsien Liu  liuch@pme.nthu.edu.tw


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