[Experimental study of subcutaneous osteogenesis by bone marrow stromal cells with A-PCPC in Beagle dogs]

To study the osteogenic capability of the construct combined dog's bone stromal cells with active porous calcium phosphate cement (A-PCPC) in nude mice in vivo.

Isolated bone marrow stromal cells (BMSCs) were expanded and osteogenically induced in vitro. Their osteogenic phenotype was evaluated by cytochemistry. The tissue engineering complex was constructed with BMSCs/A-PCPC in vitro. After SEM scanning, the complex of BMSCs/A-PCPC was implanted into the subcutaneous tissue of the nude mice as experimental group, and A-PCPC as control group. The engineered bone was harvested 2,4,8weeks post-implantation and processed for HE staining, then evaluated by histology and histomorphometry.

Cytochemistry showed alkaline phosphate activity, Von Kossa staining proved the formation of mineralization nodules. Scanning electron microscopy showed the cells adhered to the inner surface of the A-PCPC. HE staining showed a small group of woven bone formation 2 weeks later in the experimental group, while the formation of bone less in the control group. Woven bone turned into trabecular bone gradually at 4 weeks in the experimental group, while the control group showed a large number of bone-like tissue. Histomorphometry showed more mature bone in the experimental group than the control group at 8 weeks.

The A-PCPC/BMSCs composites show good osteogenetic activity and could promote mineralization of the immature bone. It can be used as the bone tissue engineering scaffolds. Supported by Innovation Fund for Science and Technology Development of Pudong New District(Grant No. PKJ2009-Y19).