Abstract:

Objective　Seed cell study is an essential area in the research of tissue engineering·To evaluate the potential- ity of marrow stromal cell(MSCs) as seed cell in the regeneration of tissue engineered cartilage, formation of cartilage nodules by culture expanded MSCs pellets under the induction of TGF-βwas investigated.Methods　MSCs were cultured and expandedin vitro. Cell pellets containing 1×106MSCswere obtained by centrifugingMSCs solution at 1 000 r/min in 5 ml centrifugation tube· Pellets were exposed to cell culture media containing 20 ng/mlTGF-βfor 7 days and then cultured for another 7 and 21 days·The nodules were moved out of the tube and cartilage formationwas observed by stereomicroscope, light microscope and electronic mi- croscope·Results　10 days after exposure to TGF-β, pellets contracted and formed small and round nodules on the bottom of the tubes·The nodules grewbigger slowly and reached maximal diameter of 1·8mm in 28 days·The surface of the noduleswas smooth and bright white·Histological examination showed that extra cellular matrix formed in 14 days and in some areas cells situated in lacuna·In 28 days′specimens, a lot of cells situated in lacuna could be observed and the histological appearance looked much similar to cartilage·Electronic microscope observation demonstrated that in 28 days′specimens a large amount of collagen fiber ex- isted·Conclusion　Under the induction of TGF-β, MSCs could differentiate into chondrogenesis cell and form cartilaginous nod- ulesin vitro. This indicated thatMSCs could be the potential seed cells in the regeneration of cartilage employing method of tissue engineering.

Key words: tissue engineering, cartilage, marrow stromal cell, transforming growth factor-β