Potential Of Periosteum Research Articles

Дослідження остеорегенераційної активності окістя нижньощелепних кісток, уражених кістами різного ґенезу

In response to the prolonged increasing influence of the radicular cyst, there is an adaptive compensatory reaction of the adjacent bone tissue and periosteum located in the area of damage. However, in the available professional literature there is no data on the activity of the marker of osteoregeneration-alkaline phosphatase in the periosteum of the mandible, which is in the growth zone of osteoblastoclastoma. The purpose of the study: to study in a comparative aspect osteoregenerative activity of the periosteum of the mandibular bones affected by radicular cyst and cystic form of osteoblastoclastoma by using the histochemical method. Histochemical studies were performed in 10 patients with large radicular cysts (d>3.0 cm) located on the mandibles – 1st clinical group, and in 9 patients with cystic forms of osteoblastoclastomas, localized on the mandibles - 2nd clinical group. Determination of alkaline phosphatase in periosteal tissues of the mandible was performed by the method of simultaneous azo combination according to Kaplow. Prepared samples of histochemicals were studied under a light microscope, the received images were photographed. Digitized images of histochemicals were analyzed using the computer program ImageJ. The accumulation of alkaline phosphatase in the periosteum of the mandibular areas affected by osteoblastoclastomas is less intense compared to the process of synthesis of this enzyme in the periosteum of the mandible, which is affected by radicular cysts of large size. Osteoregenerative potential of periosteum of mandibular bones affected by radicular cysts is much greater than in the periosteum located in the growth zone of the cystic form of osteoblastoclastoma.

Characterization of Tissue-Engineered Human Periosteum and Allograft Bone Constructs: The Potential of Periosteum in Bone Regenerative Medicine

Delayed-union or non-union between a host bone and a graft is problematic in clinical treatment of segmental bone defects in orthopedic cases. Based on a preliminary study of human periosteum allografts from this laboratory, the present work has extensively investigated the use of human cadaveric tissue-engineered periosteum-allograft constructs as an approach to healing such serious orthopedic surgical situations. In this current report, human cadaveric periosteum-wrapped bone allografts and counterpart controls without periosteum were implanted subcutaneously in athymic mice (nu/nu) for 10, 20, and, for the first time, 40 weeks. Specimens were then harvested and assessed by histological and gene expression analyses. Compared to controls, the presence of new bone formation and resorption in periosteum-allograft constructs was indicated in both histology and gene expression results over 40 weeks of implantation. Of several genes also examined for the first time, RANKL and SOST expression levels increased in a statistically significant manner, data suggesting that bone formation and the presence of increasing numbers of osteocytes in bone matrices had increased with time. The tissue-engineering strategy described in this study provides a possible means of improving delayed-union or non-union at the healing sites of segmental bone defects or bone fractures. The potential of periosteum and its resident cells could thereby be utilized effectively in tissue-engineering methods and tissue regenerative medicine.

Cartilage Tissue Engineering; Lessons Learned From Periosteum

Cartilage, due to its unique physiology (lack of vasculature), can be potentially repaired using tissue engineered in the laboratory, by combining cells and with a supporting scaffold. This requires a marriage between material science, cell biology, and translational medicine, a concept well established as Tissue Engineering. Over the years the in vivo and in vitro chondrogenic potential of periosteum has been recognised by many researchers and as such periosteum is explored both to repair cartilage defects directly by transplanting periosteum into the cartilage defect or by using periosteum as a cell source for cartilage engineering purposes. The initial example hereof is the first generation of Autologous Chondrocyte Transplantation. Graft hypertrophy and ossification remain the primary drawbacks of cartilage repair strategies using engineered cartilage. These drawbacks may (partially) be due to the endochondral ossification process that can take over when cartilage is repaired. In this process chondrogenesis of progenitor cells is followed by hypertrophy of these cells and subsequent ossification. Periosteal progenitor cells go through this process in order to heal bone fractures. This review provides an overview of the role of periosteum in cartilage repair and cartilage tissue engineering and illustrates how periosteum can be used as a model to study the endochondral process. Such studies may provide clues to further optimize cartilage tissue engineering by identifying important factors which are capable of maintaining cells in their chondrogenic phenotype. Finally, the use of periosteum to engineer cartilage in vivo at an extra-articular site is described.

Initial Evidence for the Involvement of Bone Morphogenetic Protein-2 Early during Periosteal Chondrogenesis

The potential of periosteum to form cartilage makes periosteal transplantation a viable approach to repairing defects in articular cartilage, which has a limited potential for repair. However, cartilage repair, including that by periosteal chondrogenesis, is poorly understood. Consequently, a thorough understanding of its molecular mechanisms will help to achieve the quality of neocartilage required for its clinical application in damaged joints. An in vitro model was used to study the early molecular events of periosteal chondrogenesis. During the search for the expression of transforming growth factor-beta-related mRNAs in this model system, bone morphogenetic protein-2 mRNA expression was found to be upregulated 20-fold within the first 12 hours of culture. This stimulation was dependent on the explants being suspended in agarose and did not occur with explants cultured in liquid medium. The upregulation of bone morphogenetic protein-2 mRNA expression was also enhanced by exogenously added transforming growth factor-beta1 in the presence of fetal calf serum. The upregulation, however, was not transient; rather, it persisted over a prolonged period in both transforming growth factor-beta1-treated and untreated explants. Further data indicate that this stimulation of bone morphogenetic protein-2 mRNA expression was regulated at the transcriptional level and that no new protein synthesis was required for this. Bone morphogenetic protein-2 is known to influence developmental chondrogenesis; therefore, these observations direct our attention toward an important potential role of it as a regulator of the early events in cartilage repair. Furthermore, because periosteum produces fracture (cartilage) callus, these findings may be important in defining the molecular mechanisms of fracture healing.