BACKGROUND: The establishment of coculture system combined with physical factors and
scaffold materials and the induction of cytokines have become the focus of
chondrogenic differentiation of bone marrow mesenchymal stem cells.
OBJECTIVE: To observe the effect of bone morphogenetic protein 7 combined with porous
tantalum on chondrogenic differentiation of bone marrow mesenchymal stem cells.
METHODS: Bone marrow mesenchymal stem cells of
Sprague-Dawley rats (provided by Beijing Huafukang Biology) were isolated and
cultured. Group intervention: (1) in the experimental group, porous tantalum
tablet was added, while in the control group, porous tantalum tablet was not
added. At 5 days after culture, cell growth on the surface of porous tantalum
tablet was observed by phalloidin staining. At 1, 3, 5, and 7 days after
culture, CCK-8 method was used to detect cell proliferation. (2) Group A was
added with chondrocyte inducer; group B with chondrocyte inducer and bone
morphogenetic protein 7; group C with domestic porous tantalum material and
chondrocyte inducer; group D with domestic porous tantalum material and
chondrocyte inducer and bone morphogenetic protein 7. At 7, 14 and 21 days
after culture, the levels of type II collagen, SRY type high mobility group
protein and matrix metalloproteinase-13 secreted by cells in each group was
detected by ELISA. Western blot assay was used to detect the expression of type
II collagen, SRY type high mobility group protein and matrix
metalloproteinase-13. This study was approved by the Animal Experimental Ethics
Committee of North China University of Science and Technology.
RESULTS AND CONCLUSION: (1) The phalloidin staining results showed that bone marrow mesenchymal stem cells grew well on
and around the porous tantalum surface. (2) At 3 and 5 days after culture, the
proliferation of bone marrow mesenchymal stem cells was slower in the
experimental group than in the control group (P < 0.05). There was no statistical difference in cell
proliferation between the two groups at 1 and 7 days (P > 0.05). (3) At 7, 14 and 21 days, the expression of type II
collagen and SRY high mobility group protein increased gradually among groups
A, B, C and D (P < 0.05). At 7
days, the expression of matrix metalloproteinase-13 decreased gradually among
groups A, B, C and D (P < 0.05).
At 14 days, matrix metalloproteinase-13 secretion of matrix in group A was
highest compared with that in group B, group C and group D (P < 0.05), but there was no significant
difference between groups B, C and D (P > 0.05). At 21 days, there was no significant difference among groups A, B,
C and D (P > 0.05). (4) Western
blot assay showed that at 7, 14 and 21 days after culture, the expression level
of type II collagen and SRY high mobility group protein increased gradually in
groups A, B, C and D (P < 0.05).
At 7 days, the expression of matrix metalloproteinase-13 decreased gradually in
groups A, B, C and D (P < 0.05).
At 14 days, the expression of matrix metalloproteinase-13 was higher in group A
than in groups C and D (P < 0.05),
and higher in groups B and C than in group D (P < 0.05). At 21 days, the expression of matrix
metalloproteinase-13 was higher in group A than in groups B, C and D (P < 0.05). No significant difference
was found among groups B, C and D (P > 0.05). (5) The results showed that bone morphogenetic protein-7 combined
with domestic porous tantalum could induce cartilage differentiation of bone
marrow mesenchymal stem cells, facilitate the expression of type II collagen
and SRY high mobility group protein, and inhibit the expression of matrix
metalloproteinase-13.