[Osteogenesis role played by dermal fibroblasts cultured in vitro]

Fibroblasts were harvested by in vitro culture of split-thickness skin of New-Zealand rabbit. Some opaque bone nodules were formed in the culture flasks when the fibroblasts underwent subculture for 8 days. Some of the nodules might enlarge, extend and form trabecula-like or flake-like structures, when the fibroblasts underwent subculture for 37 days. The above mentioned structures revealed golden-yellow fluorescence under the blue-violet light fluorescence microscope when the specimens were labeled with Tetracycline intravitally, denoting that they were newly formed bone tissues. In these structures, the calcium salt staining and collagen staining also showed positive reaction, fully reflecting the calcium and collagen composition. Osteogenesis caused by dermal fibroblast cultured in vitro was thus verified. There were evenly scattered oval spots in the osteogenic areas, after the specimens were treated with Alcina Blue-Sirius Red stain. Their diameter was about 10 microns, and they stained yellow color by Picric Acid. Therefore, these spots colored yellow with Picric Acid might be the dermal epithelia (and/or endothelia), which induced the fibroblasts to form the bone tissues.