Effect of culture medium osmolality on the expansion of human articular chondrocytes in serum-free medium

Abstract

Due to its poor ability for self-repair, cell therapy procedures for the restoration of human articular cartilage have been developed. Articular chondrocyte implantion (ACI) is one such therapy wherein human articular chondrocytes (HACs) are isolated from a cartilage biopsy obtained from a patient, expanded in monolayer cultures and later injected back into the patient. The limited number of cells obtained from biopsy must be expanded into at least 10 million cells in order to be clinically applicable. For this purpose, serum, which stimulates high proliferation of the cells, is generally supplemented into the culture medium. Serum has several disadvantages, however, such as the limited availability of autologous serum and non-physiological responses from the cells due to its use. Therefore, the development and use of serum-free media (SFM) is a potential improvement for cell therapy procedures like ACI. We performed a literature search regarding potential components for the development of a SFM that would result in expansion of HACs comparable to, or better than, serum-containing media (SCM). A composition for SFM was made and growth of HACs using this composition was examined. Expansion was observed and compared in a commercial medium designed specifically for chondrocyte cultures, serum-containing media (media supplemented with 10% fetal bovine serum; FBS) and the newly developed SFM using two different types of basal media. Results revealed that the SFM composition attained the best expansion in SFM based in Iscove’s modified Eagle’s medium (IMDM), which showed a 3.35-fold higher maximum cell density than HACs grown in SCM during long-term cultures. It was concluded that this SFM composition obtained from literature search would be acceptable for the expansion of HACs in subsequent studies. Different basal media have differing medium osmolalities. Medium osmolality is a culture parameter which can have devastating effects on cell growth if not controlle...