Objective: To explore the possibility of xenogenic calf cortical bone with partial trabecular bone as cell carriers in tissue engineering, and to provide direct evidence for clinical application of matrix scaffold.
Methods: Rabbit bone mesenchymal stem cells (BMSCs) were seperated and cultured on the surface of xenogenic calf cortical bone with partial trabecular bone. Relative growth rate was measured and cytotoxicity was graded. The growth, proliferation and matrix secretion of BMSCs in calf cortical strut were observed by scanning electron microscope. Sixty 3-month-old New Zealand rabbits were divided into 3 groups (20 in each group): a BMSCs/bone xenograft group, a simple bone xenograft group and an autogenous iliac bone group. Each group was implanted with the BMSCs induced osteogenic composite calf bone, simple bone xenograft and autogenous iliac bone into the ala of ilium. The expressions of bone morphogenetic protein-2 (BMP-2) mRNA were detected by reverse transcription polymerase chain reaction in 4, 8, 12, 24 weeks after the operation.
Results: The toxicity gradation was 0 to 1. BMSCs adhered the surface of calf cortical strut and extended in the cancellous bone, and extracellular matrices were found. The BMP-2 mRNA expression in the simple bone xenograft group was lower than that in the BMSCs/bone xenograft group and the autogenous iliac bone group at all time points (P<0.05),which was lower in the BMSCs/bone xenograft group than that in the autogenous iliac bone group (P<0.05).
Conclusion: Rabbit BMSCs combined with calf cortical bonescaffold with partial cancellous bone have good osteogenic capacity in the New Zealand rabbits.