ObjectiveTo explore environmental conditions under which bone marrow stromal cells could be induced into osteogenic phenotype.MethodsRat bone marrow stromal cells were isolated and proliferated in vitro, and the 3rd passage was divided into the group A (control group), group B (cells cultured in the medium containing dexamethasone, β-glycerol disodium phosphate salt hydrate, vitamin C and active form of vitamin D3), and group C (on the bases of group B, the cells were cultured additionally with fracture hematoma extract). On the post-induction day 5, 8, and 11, the morphological changes were observed and the osteogenic markers such as alkaline phosphotase (ALP), collagen type Ⅰ (Col Ⅰ) and osteocalcin (OCN) were assayed with immunohistochemical staining, the calcification was manifested with von Kossa staining.ResultsIn the group A, no evident osteogenic effects had been observed. In the group B, on 5th day post-induction, some bone marrow stromal cells underwent a morphological change, and mild expression of ALP and Col Ⅰ was observed but with no calcification effect. On 8th day post-induction, the ratio of morphologically changed cells increased, and the expression of ALP and Col Ⅰ increased still with no evident calcification. On 11th day post-induction, anti-OCN staining was positive and the calcium nodes were showed by von Kossa staining. The phenotype changes in the group C were similar to group B, but were more evident.ConclusionBone marrow stromal cells can be induced into osteogenic phenotype in vitro with small molecular inducers. Fracture hematoma extract can enhance this effect thus might be used as an addictive in osteogeneration.

Objective To explore the possibility of repairing injured facial nerve with tissue engineering technology and neural stem cells(NSCs).The complex consisted of NSCs,scaffold and NT-3.NSCs were immature cells with the potential of self-renewal and multiple differentiation to neurons and glial cells.The scaffold with porous surface was made of hyaluronic acid and collagen(HA-Col gel) which degenerate in vivo after transplantation.NT-3 is the signal to promote neurons survival in vitro.Methods NSCs of S-D rat were co-cultured with scaffold and NT-3 in vitro.The two stumps of disconnected facial nerve of rabbit were re-connected with the complex.Electrophysiology and morphology tests were used to examine functional and morphological changes.Results Result] NSCs adhered to the HA-Col gel and survived.Injured facial nerve fixed by NSCs-HA-Col gel-NT-3 complex showed significant improvement in function and anatomical structure.Conclusion Combinative implant of NSCs,HA-Col gel and NT-3 may promote the regeneration of injured facial nerve.