Ultrastructure of periosteal cells induced by bone morphogenetic protein 7 in vitro / 中国组织工程研究

ABSTRACT

BACKGROUND:Study confirms that bone morphogenetic protein can induce osteogenesis;however the ultrastructure of periosteal cells induced by bone morphogenetic protein-7 remains poorly reported. OBJECTIVE:To study the bioactivity and ultrastructure of periosteal cells induced by bone morphogenetic protein-7 in vitro. METHODS:The primary periosteal cells isolated from adult tibial bone were in vitro cultured, and then divided into experimental group and control group. In the experimental group, cells were cultured with bone morphogenetic protein-7 and culture adjuvant;while cells in the control group were only cultured with the adjuvant. Three samples in each group were tested at 5, 10, 15 days, respectively. The general structure of cultured cells was observed using von Kossa staining, and the ultrastructure was observed under transmission electron microscopy. RESULTS AND CONCLUSION:The periosteal cells in the two groups grew wel in vitro, showing uniform morphology. Early cells were spindle-shaped, with strong three-dimensional sense and ful transparency;mitotic cells were short columnar or cubic shaped, there were a lot of rough endoplasmic reticulum and Golgi complex in osteoblasts under electron microscope. Later stage of cells developed from long fusiform into wide shuttle and irregular shape, there were a large number of matrix vesicles within the cells under the electron microscope. The membrane coating, alkaline phosphatase and calcium-binding protein in the cytoplasm, as wel as calcium crystals were found. The osteogenesis basement and lateral sides appeared projections, which were connected with adjacent bone cells. Induction of bone morphogenetic protein-7 in vitro promotes the osteoblasts proliferation, division and bone formation speed. The results suggest that bone morphogenetic protein-7 can significantly enhance the proliferation ability of osteoblasts in vitro.