177 MRI monitoring of osteogenesis of human bone marrow stromal cell-based tissue engineering constructs

Bone marrow stromal cells (MSCs) are a promising cell resource of osteoprogenitor cells for bone tissue engineering. However, the diverse characteristics of osteoprogenitor cells within the bone marrow of individual subjects require varying treatments to stimulate osteogenic differentiation. Thus, an effective monitoring system is needed to identify the progression of osteogenesis. Magnetic resonance (MR) microscopy was used in the present study to monitor osteogenesis of tissue engineering (TE) constructs prepared by human bone MSCs seeded on scaffolds of gelatin sponges. The characteristics of MR images and parameters corresponded to osteogenic progression of TE constructs exposed to differentiation medium, significantly differing from control groups exposed to basic medium. Upon quantification, MR image and parameters correlated well to cell seeding densities and alkaline phosphatase activities of various TE constructs. In conclusion, MR can effectively detect the biochemical cascades of osteogenic differentiation of TE constructs and may be a promising, noninvasive monitoring system to provide three-dimensional information for bone tissue engineering.