The Growth of Cartilage Cells in Vitro and the Effect of Intermittent Compressive Force. A Histological Evaluation

Abstract

Chick epiphyseal chondrocytes are isolated from 15 day old embryos and subsequently grown as small high density cultures (aggregates consisting of 2 × 10⁵ cells), which can be handled individually.

Histological evaluation showed a considerable increase in the dimensions of the nucleus and the cells 2-6 hours after initiating the growth of the chondrocytes by adding 10% serum to the culture medium. After 24 hours of culture the proportion of the matrix in the aggregate was increased from 0% to about 45%. In a series of experiments these aggregates were exposed to intermittent compressive force (ICF) with a peak value of 130 mbar above ambient and a frequency of 0.3 Hz. The nuclear and cell-dimensions of ICF-exposed chondrocytes were significantly larger than under control conditions when measured after 24 and 48 hours. Concomittantly, chondrocytes in ICF-exposed aggregates synthesized and deposited significantly more matrix in the aggregates as compared to controls. This model can be used to further study the direct effect of mechanical force on the synthesis and deposition of matrix components by cartilage cells in vitro.