A Porous Perfusion Bioreactor That Possess Microchannels: Its Fabrication by Selective Laser Sintering and Preliminary Evaluation of Culture of Human Hepatoma Hep G2 Cells
Hongyun Huang1, Hiromichi Naruke1, Shunsuke Oizumi1, Nobuhiko Kojima1, Toshiki Niino1, and Yasuyuki Sakai2. (1) Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, Japan, (2) Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan
Objective: Towards the final goal to engineering an implantable liver tissue equivalent, we designed and fabricated a porous scaffold that possesses a branching and joining flow channel network using a selective laser sintering (SLS) 3D fabrication technique, and evaluated its efficiency in perfusion culture of human hepatoma Hep G2 cells. Materials and Methods: We designed 3D flow channel network (inner diameter is 1 mm) by accumulating unit tetrahedrons (edge length is 4 mm) for perfusion culture. The total volume of the scaffold was 10 cm3. Bioresorbable polycaprolactone (PCL) and 80% (w/w) of NaCl salt particles as a porogen were completely mixed and applied to the SLS process. The inner structure was evaluated by X ray CT. Hep G2 cells were seeded and cultured in the scaffolds with or without such flow channel network (as a control), and their growth and functions were compared. Results and discussions: After optimization of fabrication parameters, we successfully obtained a scaffold that had a high porosity of 89% with a mean pore size of 100-200 Ám and a 3D network flow channels whose inner diameter is 800 Ám. Results of X ray CT confirmed completely interconnected flow channels as designed. A preliminary perfusion culture over 9 days demonstrated that such microchannels was necessary to guide the cells to grow and function. The basic design concept herein shows great promise for engineering implantable liver tissue equivalents.