The chondrocyte: biology and clinical application.

Chondrocyte is a unique cell type in articular cartilage tissue and is essential for cartilage formation and functionality. It arises from mesenchymal stem cells (MSCs) and is regulated by a series of cytokine and transcription factor interactions, including the transforming growth factor-beta super family, fibroblast growth factors, and insulin-like growth factor-1. To understand the biomechanisms of the chondrocyte differentiation process, various cellular model systems have been employed, such as primary chondrocyte culture, clonal normal cell lines (HCS-2/8, Ch-1, ATDC5, CFK-2, and RCJ3.1C5.18), and transformed clonal cell lines (T/C-28a2, T/C-28a4, C-28/I2, tsT/AC62, and HPV-16 E6/E7). Additionally, cell culture methods, including conventional monolayer culture, three-dimensional scaffold culture, bioreactor culture, pellet culture, and organ culture, have been established to create stable environments for the expansion, phenotypic maintenance, and subsequent biological study of chondrocytes for clinical application. Knowledge gained through these study systems has allowed for the use of chondrocytes in orthopedics for the treatment of cartilage injury and epiphyseal growth plate defects using tissue-engineering approaches. Furthermore, the potential of chondrocyte implantation for facial reconstruction, the treatment of long segmental tracheal defects, and urinary incontinence and vesicoureteral reflux are being investigated. This review summarizes the present study of chondrocyte biology and the potential uses of this cell in orthopedics and other disciplines.