Expansion of chondroprogenitor cells on macroporous microcarriers as an alternative to conventional monolayer systems

Routine tissue culture methodologies can hardly cope with the scale of cell production required for the manufacture of engineered cartilage tissue products. In vitro cell expansion has become an essential step in the process of tissue engineering of articular cartilage and the optimization of expansion protocols is a fundamental issue that needs to be addressed. The expansion suitability of chondroprogenitor cells isolated from the superficial zone of articular cartilages was evaluated in both conventional monolayer and macroporous microcarrier in spinner flask cultures. Although monolayer systems promoted rapid in vitro expansion of undifferentiated cells, they present limited scalability. Alternatively, the use of CultiSpher-G microcarriers resulted in cell densities of 5.5 x 10(5) cell/ml, representing a 17-fold expansion in batch cultures. In addition, chondroprogenitor cells were capable of undergoing bead-to-bead migration, which allowed subcultivation to be performed without a harvesting step, thus improving the scalability of the expansion process. By employing macroporous microcarrier cultures it will be possible to obtain large number of chondroprogenitor cells for tissue engineering applications. Not only its satisfactory expansion potential, but more importantly the cost and operational advantages over traditional monolayer culture make this system a feasible alternative method for the extensive expansion of chondroprogenitor cells.