Fixed Bed Reactor Systems for the Expansion and Differentiation of STEM CELLS for CELL Therapy

Human mesenchymal stem cells (hMSC) are qualified for cell therapy. hMSC-TERT are modified by transfection with a telomerase activity. The alginate-encapsulated stem cell line is an implantable therapeutic cell system which possess the potential to counteract endocrine deficiencies in vivo. In the special case of cell therapy the cells have to be differentiated prior to use.

An automated GMP conform process includes three steps: (1) the expansion of the hMSC-TERT (2) the encapsulation of the harvested cells and (3) the differentiation of the encapsulated cells. For the first step the suitability of various nonporous microcarriers for cultivation of hMSC with a harvesting procedure using trypsin, accutase and collagenase was investigated. The yield and the vitality of the cells after harvesting are of particular interest.

For the cultivation of the human mesenchymal stem cells (hMSC) we used fixed bed reactor systems at different scales. The cultivation of the encapsulated cells was carried out in fixed bed bioreactors based on commercial syrings.

The expansion of human mesenchymal stem cells on nonporous microcarriers are preferable when the cells need to be kept in viable condition. The qualification of disposable plastic syringes as small scale single-use fixed bed reactors for the cultivation and differentiation of the encapsulated cells showed compared to the reference cultures no disadvantage concerning the viability and differentiation potential. The use of fixed bed reactor systems was successfully introduced as disposable small-scale fixed bed bioreactors for the cultivation and differentiation of implantable therapeutic cell systems.