Expansion of the Number of Human Auricular Chondrocytes: Recycling of Culture Media Containing Floating Cells

Abstract

To grow a complete human size auricle by utilizing the principles of tissue engineering, a large number of chondrocytes is required for initial implantation. The number of chondrocytes can be increased by repeated passaging or by incubation with different growth factors, both of which can promote dedifferentiation. New methods of chondrocyte expansion over a relatively brief time period for potential practical application are required. In this study auricular chondrocytes were obtained from patients and cultured in vitro. Two groups of cells were created. Group A chondrocyte number was increased by repeated passaging. Group B cells were grown from floating culture medium and their number was increased both by passaging and by repeated recycling of the culture medium. Chondrocytes from both groups were implanted in nude mice for 8 weeks to generate tissue-engineered cartilage. Flow cytometry studies performed on both groups confirmed the presence of two distinct populations of structures as the source of chondrocytes from the recycled medium. Repeated recycling of the culture medium demonstrates a promising method to increase the number of chondrocytes in vitro for clinical application.