Characterization and phenotypic stability of human disc cells in vitro.

Successful in vitro studies of disc cells require interaction of the cell with a compatible microenvironment which favors expression of the disc cell phenotype. The objective of this study was to characterize cells grown by standardized methods of isolation and passage, and culture cells from the human annulus in three-dimensional culture. Cells from the annulus of 11 individuals were cultured in alginate or agarose for ten days, and extracellular matrix components were evaluated with immunohistochemistry and quantitative analysis of the percent of colonies producing Type I or II collagen, 4-sulfated chondroitin sulfate or keratan sulfate. Results show production of these four extracellular matrix products through multiple passages and support the phenotypic stability of disc cells in three-dimensional culture.