@article{Lehmann_Martin_Mannigel_Kaltschmidt_Sack_Anderer_2013, title={Three-dimensional scaffold-free fusion culture: the way to enhance chondrogenesis of in vitro propagated human articular chondrocytes}, volume={57}, url={https://www.ejh.it/ejh/article/view/ejh.2013.e31}, DOI={10.4081/ejh.2013.e31}, abstractNote={Cartilage regeneration based on isolated and culture-expanded chondrocytes has been studied in various <em>in vitro</em> models, but the quality varies with respect to the morphology and the physiology of the synthesized tissues. The aim of our study was to promote <em>in vitro</em> chondrogenesis of human articular chondrocytes using a novel three-dimensional (3-D) cultivation system in combination with the chondrogenic differentiation factors transforming growth factor beta 2 (TGF-b2) and L-ascorbic acid. Articular chondrocytes isolated from six elderly patients were expanded in monolayer culture. A single-cell suspension of the dedifferentiated chondrocytes was then added to agar-coated dishes without using any scaffold material, in the presence, or absence of TGF-b2 and/or L-ascorbic acid. Three-dimensional cartilage-like constructs, called single spheroids, and microtissues consisting of several spheroids fused together, named as fusions, were formed. Generated tissues were mainly characterized using histological and immunohistochemical techniques. The morphology of the <em>in vitro</em> tissues shared some similarities to native hyaline cartilage in regard to differentiated S100-positive chondrocytes within a cartilaginous matrix, with strong collagen type II expression and increased synthesis of proteoglycans. Finally, our innovative scaffold-free fusion culture technique supported enhanced chondrogenesis of human articular chondrocytes <em>in vitro</em>. These 3-D hyaline cartilage-like microtissues will be useful for <em>in vitro</em> studies of cartilage differentiation and regeneration, enabling optimization of functional tissue engineering and possibly contributing to the development of new approaches to treat traumatic cartilage defects or osteoarthritis.}, number={4}, journal={European Journal of Histochemistry}, author={Lehmann, M. and Martin, F. and Mannigel, K. and Kaltschmidt, K. and Sack, U. and Anderer, U.}, year={2013}, month={Nov.}, pages={e31} }