[Influence of transforming growth factor-beta1 inducing time on chondrogenesis of bone marrow stromal cells (BMSCs): in vitro experiment with porcine BMSCs].
OBJECTIVE
To explore the influence of transforming growth factor (TGF)-beta1 inducing time on the chondrogenesis of bone marrow stromal cells (BMSC), and on the construction of tissue engineering cartilage.


METHODS
BMSCs were obtained from the greater trochanters of 3 pigs, cultured, seeded onto the cylindrical scaffolds made of polyglycolic acid at the density of 5.0 x 10(7) cells/ml, and then cultured with chondrogenesis media containing TGF-beta(1) (10 ng/ml), insulin-like growth factor-I (50 microg/L), and dexamethasone (40 microg/L) to be induced by TGF-beta(1) for 2 weeks (Group A), 4 weeks (Group B), 6 weeks (Group C), 8 weeks (Group D), or 10 weeks (Group E) respectively. 10 weeks later the cylindrical scaffolds underwent gross observation and histological examination. Alcin blue method was used to examine the content of proteoglycan (GAG). Immunochemistry and Western blotting were used to examine the type II collagen. The cylindrical scaffolds underwent biomechanical analysis.


RESULTS
HE staining showed cartilage lacunae increasing in number from the periphery to center of the cylindrical scaffolds with the extended inducing time, and were arranged more uniformly progressively. Histochemical staining showed GAG accumulation. Immunohistochemistry and Western blotting showed that the content of type II collagen increased gradually, the amount of type II collagen stabilized after 6 weeks' culture, and there was no significant difference in the content of type II collagen between Group C and Group E. Biomechanical analysis showed that the modulus of elasticity and compression strength of the groups induced for more than 6 weeks (Groups C, D, and E) were all higher then those of Groups and B.


CONCLUSIONS
TGF-beta(1) inducing time is correlated with the cartilage engineering characteristics with BMSC as seed cells. Induction for 6 weeks helps construct tissue engineered cartilage with good tissue structure, chemical composition and biomechanical properties.
Liu
Tian-yi
TY
Department of Plastic Surgery, Shanghai 9th People's Hospital, Shanghai Jiaotong University, Shanghai, China.
Zhou
Guang-dong
GD
Wei
Xian
X
Wu
Xiao-li
XL
Chen
Fu-guo
FG
Cui
Lei
L
Liu
Wei
W
Cao
Yi-lin
YL
D000818:Animals; D015153:Blotting, Western; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D020219:Chondrogenesis / Q000187:drug effects*; D024043:Collagen Type II / Q000378:metabolism; D007150:Immunohistochemistry; D011509:Proteoglycans / Q000378:metabolism; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013552:Swine; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods; D016212:Transforming Growth Factor beta / Q000494:pharmacology*
D024043:Collagen Type II; D011509:Proteoglycans; D016212:Transforming Growth Factor beta