Abstract:

Objective　To observe the heterotopic osteogenesis of autogenousmarrowstromal cells loading on porous calci- um phosphate ceramic scaffoldswith rhBMP2gene transfection in a Sprague-Dawley ratmodel.Methods　Autogenous marrowstro- mal cells were obtained from left femurs and tibias of 20 male adult SD rats under general anesthesia and sterile condition and cul- tured inα-Minimal Essential Medium supplemented with 15% fetal bovine serum. RhBMP2gene was transfected into stromal cells by means of LipofectAMINETM2000 reagent five days after primary culture. The stably gene expressive cells were selected with G- 418 for 14 days and mixed with stromal cells without transfection. The mixture cells were seeded and subcultured for another 10 days in porous calcium phosphate bioceramic that had been subjected to surface-modification via soaking in human plasma fibronec- tin. The cell-ceramic compoundwas implanted subcutaneously and intramuscularly in the corresponding rat. Lab animalswere sac- rificed at two-week intervals till twenty weeks postoperatively and the involved samples were removed.Results　Morphologic and histological study demonstrated that cell-ceramic compound had an ability of heterotopic osteogenesis, which was similar to that of autogenous osteoblasts in previous study.Conclusion　It seems that autogenous stromal cells with rhBMP2transfection acts as a bioreactor promoting proliferation and differentiation of stem cells when they are replanted into the corresponding animals.

Key words: heterotopic osteogenesis, autogenousmarrowstromal cells, calcium phosphate, human bone morphoge- netic protein 2, gene transfection