| The periosteum is a heterogeneous multi-layered membrane consisting of an outer fibrous layer and an inner cambium layer. The periosteum has been reported to contain mesenchymal progenitors, or stem cells, capable of differentiating into either osteoblasts or chondrocytes depending on the culture environment. Hence, for tissue engineering fields, isolated periosteal cells and the periosteum tissue itself have many possible potentials for stimulating osteogenesis or chondrogenesis.; This study will investigate such osteogenic properties of the periosteum from three different angles: (1) the periosteum as a natural graft tissue which can be used to enhance the tendon-bone tunnel healing, (2) the specific biological characteristics of periosteal progenitor cells, and (3) the development of an organ culture model of the periosteum which can be used to investigate the mechanism of mechanical stimulation for osteogenesis characteristics of periosteum.; We demonstrated that periosteal augmentation of a tendon graft can enhance the structural integrity of the tendon-bone interface. Clinically, the use of an autogenous periosteum patch would be an optimal choice for a biological augmentation of the tendon graft in the bone tunnel. Also, we have shown that the periosteum has phenotypically distinct heterogeneous cell populations. Therefore, precautious should be taken to identify and maintain the intrinsic phenotypes of the heterogeneous cell types in the periosteum. Although harvested periosteal cells lose their phenotypic characteristics in a primary monolayer culture system, the periosteum tissue may maintain its high osteogenic potential in in vitro organ culture system. It was found that mechanical stimulation is critical factor for the periosteal osteogenesis.; The present study demonstrates possible clinical applications of the periosteum for a soft tissue-to-bone fixation and establishes the basic understanding of the biological characteristics of the periosteum. In this study, an in vitro organ culture model of post-neonatal periosteum was successfully developed using a dynamic mechanical loading, which can be effectively used to further investigate the periosteal osteogenesis. |
