Konjac glucomannan-based hydrogel with hyaluronic acid as a candidate for a novel scaffold for chondrocyte culture

Chondrocytes were cultured using konjac glucomannan (KGM) and hyaluronic acid (HA) as a scaffold for cartilage regeneration. They were subsequently compared with scaffolds produced using agarose hydrogels. Chondrocytes derived from Japanese white rabbits were cultured: 2.0 x 10(5) cells were seeded on KGM containing hyaluronic acid (KGM/HA) and agarose and cultured for 5 days. Their viability was assayed using WST-8 procedures; the ultimate stress and modulus of elasticity of each construct was calculated. After 3 days of cultivation, mRNA in chondrocytes, such as collagen types I and II and aggrecan, were measured using RT-PCR. Both chondrocyte-seeded constructs were stained with safranin O/fast green and were evaluated histologically. Chondrocyte viability decreased concomitantly with increasing KGM/HA or agarose concentration and with culture time. Cell viability in 2% agarose was significantly lower than that in 2% KGM/HA on the third and fifth days (p < 0.05). The primary elastic modulus increased concomitantly with increasing polysaccharide concentration. Elastic moduli of 2% KGM/HA with chondrocytes (0.389 +/- 0.119 N/mm(2)) showed little difference from those without chondrocytes (0.283 +/- 0.243 N/mm(2)), although those of 2% agarose with chondrocytes (0.403 +/- 0.094 N/mm(2)) were significantly lower than those without chondrocytes (0.736 +/- 0.227 N/mm(2); p < 0.05). Collagen type II mRNA expression was higher in KGM/HA and agarose than in monolayer cultures, although KGM/HA had lower aggrecan mRNA expression levels than did agarose. Histological tests of KGM/HA-chondrocyte constructs revealed chondrocyte aggregation and proteoglycan production in the pericellular region. The results show that KGM/HA might be useful for chondrocyte culture.