gms | German Medical Science

Auricular chondrocytes are easy accessible, not only for applications in reconstructive surgery, also for a potential a use in autologous chondrocyte transplantation and various more tissue engineering procedures. The present study investigated the suitability of high density cultures for the redifferentiation of dedifferentiated auricular chondrocytes and revealed basic data concerning cellular morphology and metabolic state of in monolyer amplified and in high density transfered auricular chondrocytes, respresenting the entity of elastic cartilage. Primary isolated auricular chondrocytes were cultured in alginate beads and the emigrated chondrocytes were cultured up to 8 passages in monolayer culture. Monolayer chondrocytes were removed from each passage and transfered to high density cultures. Each culture was subsequently investigated with morphological, immunolocalization and biochemical methods for the expression of cartilage specific markers like collagen type II and proteoglycanes as well as intracellular, transmembranous and extracellular proteins like cadherins and integrins. Further proteins like MMP signaling apoptotic cell death were analysed. Furthermore, cellular morphology was investigated by transmission electron microscopy. When dedifferentiated chondrocytes from passages P1-P4 were transfered to high density culture, they recovered a chondrocyte phenotype. Western blot analysis revealed expression of several cartilage specific proteins and electronmicroscopy demonstrated regular chondrocyte morphology with extracellular matrix accumulation. Cells harvested from passages P5 – P8 did not express chondrocyte specific proteins, instead they expressed apoptotic signaling proteins. The study reveals, that during in monolyer culture dedifferentiated auricular chondrocytes would regain a chondrocyte phenotype within high density cultures until passage 4. High density cultures ensure efficient conditions for auricular chondrocyte redifferentiation after monolayer amplification and guarantee save conditions for chondrocyte transplant manufacting in reconstructive surgery.