Abstract
In the field of bone tissue engineering, supply of nutrition and oxygen to the cells on and in scaffold is a significant issue. Many studies about the effect of large pores in scaffold on bone formation have been reported. However, there is no scaffold that keeps cells alive and has large suitable size for practical use. In this study, we built multilayer structure graft composed of bead-cell sheets to make a large space for entry of blood vessels. Bead-cell sheets consisted of beta-tricalcium phosphate (beta-TCP) porous beads, human bone marrow stromal cells (HMSCs) and matrices produced by the cells, and the space for vessels was kept with collagen gel. The grafts were implanted subcutaneously in nude mice. After 3 weeks, blood vessels reaching to the central area of graft were observed. In addition, osteogenesis was recognized near the surface. These results should suggest the necessity of preparation of large space or pores for blood vessels, and indicate the good osteoconductivity of bead-cell sheet.
