Three-dimensional culture of human disc cells within agarose or a collagen sponge: assessment of proteoglycan production.

The objective of the present study was to assess proteoglycan production by human intervertebral disc cells cultured in vitro in selected cell carriers. Based on previous studies which evaluated disc cells seeded into collagen sponge, collagen gel, agarose, alginate or fibrin gel three-dimensional (3D) cell carriers, collagen sponge and agarose were found to provide superior microenvironments for formation of extracellular matrix (ECM). A standardized test design was used to evaluate ECM formed after 14 days of culture using the 1,9-dimethylmethylene blue (DMB) assay to assess sulfated glycosaminoglycan (S-GAG) production. Although agarose culture showed higher S-GAG levels compared to collagen sponge (2.94+/-2.20 (19) microg/ml S-GAG (mean+/-S.D. (n)) vs. 0.94+/-0.77 (22), respectively, p=0.0003), this is off-set by the significantly lower proliferation rate associated with culture of disc cells in agarose.