HepaChip - the project:
At the NMI ("Naturwissenschaftliches und Medizinisches Institut" at the University of Tuebingen), a lab-on-a-chip system with liver cell cultures for medical drug testing is developed in collaboration with the University of Leipzig and the companies "BSL Bioservice", "KeyNeurotek AG" and "MicrofluidicChipShop".
So far, mostly 2D-cell cultures are used in pre-clinical drug testing. In addition, ethically controversial animal experiments are performed before the drugs are clinically tested on patients. Nevertheless many undesirable effects are only discovered during the testing on human patients. The idea of the HepaChip-system is that is should enable a high predictability for possible unwanted side effects already during the development of a medical drug. For this purpose single cells are washed into the HepaChip, where they automatically assemble into particular cell aggregates at predefined positions. This is vital since cells that are not assembled in a cell cluster de-differentiate and loose their characteristics. By copying the in vivo 3D-structure of liver tissue as closely as possible, the accompanying loss of metabolic functions should be avoided in the HepaChip.
To achieve automatic assembly of the cells in the HepaChip, positive iDEP (insulator-based dielectrophoresis) is used. The design for the chip is to be optimized by means of 3D-FVM-simulations of the field distribution with CFD-ACE (ESI Group). Prototypes of the HepaChip will be fabricated by micro milling and injection molding and sputtered with gold electrodes according to the calculations. Finally the chips will be tested with real liver cells.
 In-vivo-like micro cell cultures for substance testing by dielectrophoretic cell assembly in a microfluidic chip (model from a proposal by NMI) | 
