Abstract:

BACKGROUND: Autogenous seed cells combined with natural or compositive scaffold are commonly used in construction of tissue engineered cartilage, which face the problems of insufficient seed cells, poor security and biocompatibility, as well as uneven distribution of cells in scaffold.
OBJECTIVE: To investigate chondrogenic induction of mesenchymal stem cells (MSCs) derived from Wharton’s jelly of the human umbilical cord and to fabricate non-scaffold tissue engineered cartilage in vitro.
METHODS: MSCs were isolated and cultured from Wharton’s jelly of the umbilical cord, and the phenotypes were detected by flow cytometry. The Wharton’s jelly MSCs were cultured with chondrogenic media and detected with histochemistry and immunohistochemistry assay. Expressions of glycosaminoglycan (GAG), type Ⅱ collagen and Sox-9 were analyzed by reverse transcription-polymerase chain raction (RT-PCR). Non-scaffold tissue engineered cartilage was fabricated in vitro by high density cell number with chondrogenic induction medium, and then succeeded pellet was culture in bioreactor.
RESULTS AND CONCLUSION: Wharton’s jelly of human umbilical cord was abundant with stem cells. Flow cytometric analysis revealed that Wharton’s jelly stem cells expressed CD44, CD105 and CD271 rather than hemopoietic stem cell markers. The cells were positive expressed HLA-ABC, and negative expressed HLA-DPDQDR. The histochemistry and immunohistochemistry showed that Wharton’s jelly MSCs weakly expressed chondrocyte marker, which strongly expressed GAG and type Ⅱ collagen after chondgenic induction. RT-PCR results demonstrated that Wharton’s jelly MSCs and chondrogenic induction cells were both expressed Sox-9 and type Ⅱ collagen. Non-scaffold tissue engineered cartilage block was formed with high density cell number culture and bioreactor chondrogenic induction in vitro. The results revealed that Wharton’s jelly MSCs maybe a new seed cells for fabricating tissue engineered cartilage in vitro.