Osteogenesis of Recombinant BMP-7 Adenovirus-transduced Human Dermal Fibroblasts in Collagen Sponge / 대한해부학회지

ABSTRACT

As a preceding study to apply recombinant BMP-7 gene to the human, we investigated bone formation in immunodeficient mice by using tissue engineering and gene transplatation. Human dermal fibroblasts were transduced with AdBMP-7 and cultured with type I collagen solution to form collagen sponge. The collagen sponge containing AdBMP-7 transduced fibroblasts was transplanted into hypodermis of the mice and osteogenesis in the spongy was investigated by histochemical, electronmicroscopic, and radiologic methods at 1, 2, 4, 6, and 8 weeks. At one week after transplantation, there were fluent cells infiltration around the collagen sponge and capsular structure was formed with fibers arranged in concentric circles. New vessel formation was observed in the capsule and subcapsular area of the sponge, but there were nucleus condensation and obscure cell boundary in the cells of the central region. Lacuna containing eosinophilic structures were observed in the capsular structure at two weeks. This structures were enlarged with time and were confirmed to be bone tissue by showing positive reaction for Von Kossa stain. Cartilaginous structure was not observed in light microscopic level, but a few chondroblasts were observed in pericapsular area in electron microscopic observation. After 6 weeks, radiopaque shadows were observed at the region of transplantation. Cortical bone was formed in periphery of the sponge while marrow like structure was observed in central region; some trabecula bone, adipocytes, and well developed vessels. The percentage of bone formation in transplanted sponge at 1, 2, 4, 6, and 8 weeks were 0, 63, 88, 100, and 100% (n = 8), respectively. From these results, bone formation by BMP-7 transduced human dermal fibroblasts using collagen sponge scaffolds in immunodeficient mouse shows another potential way of human gene transplantation using recombinant BMP-7 adenovirus.