Anorganic bone mineral coated with tetra-cell adhesion molecule enhances the activation of osteoblast-like cells

The construction of a biomimetic environment for tissue engineering, and for implants and grafts should take into account the channels through which chemical and biomechanical signals that contribute to differentiation and morphogenesis are conducted. The most commonly used peptide for surface modification is arginine-glycine-aspartic acid(RGD), the signaling domain derived from fibronectin(FN). The proline-histidine-serine-arginine- asparagine(PHSRN) sequence serves as a synergistic site that enhances the binding affinity of the RGD sequence. Also ßig-h3 is a cell adhesive protein whose expression is highly induced by TGF-ß in several cell types. And ßig-h3 has been considered to promote cell adhesion and spreading through EPDIM of the 4th fas-1 domain sand YH present in each of the fas-1 repeat domains. Herein, we synthesized Tetra-Cell Adhesion Molecule(T-CAM), which is the recombinant protein containing an RGD sequence in tenth type III domain and a PHSRN sequence in the ninth type III domain of fibronectin, and YH sequence and EPDIM sequence in fourth fas-1domain of ßig-h[1] Therefore, the purpose of this study was to evaluate the cellular activity of osteoblast-like cell to anorganic bone mineral coated with T-CAM, while comparing the results with those to anorganic bone mineral. The number of viable cells significantly increased for ABM/T-CAM group at 4 and 7 days after culturing, as compared to control and ABM. The of ALP mRNA was also similar in all groups on the 10 and 20 days after culturing. The expression of osteopontin mRNA was highest on ABM/T-CAM on the 10 and 20 days. A greater expression was observed on the 30^th day of culturing for ABM and ABM/T-CAM, as compared to control. Although the ABM group also had the staining of intercellular bridges among the particles, significant staining on intercellular bridges, in the osteoblast-like cell culture of the ABM/T-CAM group, was much more intense and frequent. Compared to the ABM-grafted group, the defects of ABM/T-CAM-grafted groups revealed active new bone formation in the middle area of the defects. we suggest that the presence of T-CAM remarkably effects the differentiation of osteoblast-like cell grown on HA. Then ABM/T-CAM templates may be effective as endosseous grafts, and may serve as tissue engineered substitutes for autologous bone grafts.