Intestine model (human/porcine)

Fraunhofer Institute for Interfacial Engineering and Biotechnology

The standardized in vitro model for the investigation of absorption mechanisms at the intestinal barrier is based on a 2-D test system with CaCo-2 cells (colon carcinoma cell line), which is cultivated on an artificial PET insert membrane. This test system was considerably improved in the Department of Cell and Tissue Engineering by modifying the cell cultivating conditions. With a dynamic 3-D cell culture on acellularized small intestine segments in a bioreactor system an improved development of cell-typical characteristics was obtained. Cells cultivated under dynamic conditions in the bioreactor system show a morphology typical of enterocytes (Fig. 1). Cells cultivated under static conditions are flattened (Fig. 2) and possibly their characteristic physiological properties have been changed. A further modification represents the extension of the system with primary endothelial cells as a natural barrier on the blood vessel side for intestinal transport
(Fig. 3).

We now also want to use and optimize this method for the cultivation of primary intestine epithelial cells. The absorbing epithelial cells of the small intestine have in vivo a life span of 3-7 days; a long-term culture in vitro is so far not realizable.

The 3D intestine test system will in the future enable the investigation of resorption, toxicity and bioavailability of orally applied active substances and targeted improvement of formulations.