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Anatomy, physiology and disease
Published in C M Langton, C F Njeh, The Physical Measurement of Bone, 2016
Macroscopically, bone is organized in a complex but efficient manner. Haversian bone is the principal structure. Vascular channels are arranged circumferentially around lamellae of bone to form an osteon, an irregular braching cylinder composed of a neurovascular canal surrounded by layers of cells within the bony matrix. Osteons are connected to each other by Volkmann’s canals which are oriented perpendicularly to the osteon. The vascular canals resemble capillaries which allow or limit transport of ionic material to bone. Unlike trabecular bone, which is intimately associated with the surrounding bone marrow, cortical bone has two surfaces: one on the inner side which faces the marrow and is called the endosteal surface, and one on the outer side facing soft tissue and muscle, known as the periosteal surface. The endosteal cells interact with a number of factors (see below) which are involved in bone formation and resorption. The periosteum has an outer fibrous layer, and an inner layer composed of chrondrocyte and osteoblast precursor cells. Appositional bone growth occurs in this layer.
Techniques and Applications of Adaptive Bone Remodeling Concepts
Published in Cornelius Leondes, Musculoskeletal Models and Techniques, 2001
Nicole M. Grosland, Vijay K. Goel, Roderic S. Lakes
Although it constitutes only 20% of the skeleton, trabecular bone has a greater overall surface area than does cortical bone and is considered to possess greater metabolic activity. Relative density (i.e., the ratio of specimen density to that of fully dense cortical bone — usually 1.8 g/cc) provides the criterion upon which the classification of bone tissue as cortical or cancellous is based. The relative density of trabecular bone varies from 0.05 to about 0.7 while that of cortical bone is approximately 0.7 to about 0.95.20 The external surface of bone is covered by a periosteum consisting of a fibrous connective tissue outer layer and a cellular inner layer. The periosteum not only serves for the attachment of muscles, but aids in protection and provides additional strength to the bone. Moreover, the periosteum provides a route for circulatory and nervous supply, while actively participating in bone growth and repair.16
Bionanocomposites
Published in Satya Eswari Jujjavarapu, Krishna Mohan Poluri, Green Polymeric Nanocomposites, 2020
Archita Gupta, Padmini Padmanabhan, Sneha Singh
The non-collagenous proteins, such as bone inductive proteins (osteopontin, osteonectin, and osteocalcin), growth factors and cytokines (insulin, such as growth factor and osteogenic proteins), and proteins of extracellular matrix (bone sialoprotein and proteoglycans), provide a major contribution to the biological function of the bone (Liu et al. 2007). While the collagen makes fibers and minerals deposit in between them, simultaneously the ground substances (proteins, polysaccharide, and mucopolysaccharide) fill the space between fibers and minerals. Since the release of ions from the bone regulates the cell function, the presence of doping elements such as magnesium, strontium, potassium, and sodium can affect the bone cell-mediated functions. These organic and inorganic components play an essential role in bone metabolism, but the major function is actually regulated by the bone cells. Mainly four different cell types are found in the osseous tissue as represented in Figure 8.2, which play a major role in remodeling, namely osteoprogenitor cells, osteocytes, osteoblasts, and osteoclasts (Kargozar et al. 2019). The osteoprogenitor cells are the undifferentiated ones present at the deep layers of bone marrow, periosteum, and endosteum that develop into osteoblasts. Osteocytes are the mature cells involved in maintaining the mineral concentration of the bone matrix. Osteoblasts, the differentiated bone cells, are present in the growing areas of the bone (periosteum and endosteum) and secrete collagen fibers during osteogenesis. Finally, the osteoclasts are the multinucleated cells formed by the fusion of precursor cells. They are present at the bone surface and injury site, thereby assisting the bone remodeling process by breaking down the matrix and releasing calcium.
In silico modelling of long bone healing involving osteoconduction and mechanical stimulation
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2023
Jean-Louis Milan, Ian Manifacier, Nicolas Rousseau, Martine Pithioux
In many instances natural bone healing and consolidation leads to the complete reconstruction of the injured tissue. The periosteum, a highly vascularized bone envelop, is a major contributor to the healing process. The periosteum acts as a clear boundary between the area where bone tissue must regrow and surrounding tissues. In addition, the periosteum favors the supply of mesenchymal cells that can differentiate into osteoblasts and synthesize bone matrix. Unfortunately, in the case of large bone lesions of either pathological (tumorous or infectious) or traumatic origin, the periosteum may be completely damaged. As a result, the risk of inadequate bone reconstruction remains significant and unpredictable. Such lesions may result in a pseudo arthrosis preventing any future consolidation (Rolland and Saillant 1995).
Spectral analysis and biological activity assessment of silver doped hydroxyapatite
Published in Journal of Asian Ceramic Societies, 2021
Umit Erdem, Busra Moran Bozer, Mustafa B. Turkoz, Aysegul U. Metin, Gurcan Yıldırım, Mustafa Turk, Saffet Nezir
The periosteum is a thick layer that surrounds the bone from its outer part and is rich in collagen fibrils and fibroblasts. The inner layer contains osteoprogenitor cells [69]. This structure of bone tissue is found to increase the vitality of materials 30% more in addition to the normal proliferation in the test results. This means that the synthesized material can be fast to heal in the outer part in repairing the bone tissue, due to fast adaptation and support to the bone. Osteoblasts are found in bone tissue at a rate of 4–6% [70]. The results of the cytotoxicity indiacate that the material in the osteoblast is not toxic, does not prevent its viability, and causes excessive proliferation. Thus, the osteoblasts will continue their normal biological function in case the material is applied and will not disrupt the natural structure by not increasing excessively.
Decellularized inner body membranes for tissue engineering: A review
Published in Journal of Biomaterials Science, Polymer Edition, 2020
Ilyas Inci, Araz Norouz Dizaji, Ceren Ozel, Ugur Morali, Fatma Dogan Guzel, Huseyin Avci
Periosteum covers the outer surface of bones and it is comprised of two layers which are cambium layer (inner) and fibrous layer (outer). The cambium layer mainly contains skeletal progenitor cells and the fibrous layer is composed of fibroblasts, collagen and elastin [188,189]. It is well known that periosteum possess significant regenerative potential for the induction of bone healing and remodeling [190]. In a study [191], rabbit periosteum collected from proximal tibias were treated with 3 slightly different decellularization methods. In all the 3 groups, samples were freeze-thawed and then treated with Triton X-100, SDS, DNase and RNase except in the third group in which samples were treated with NaCl instead of SDS. After decellularization of periosteum, histological staining revealed that cells were completely removed and DNA quantification studies showed that the ratio of DNA content was less than 5% in all of the groups in comparison with native tissue. It was demonstrated also the contents of collagen and GAGs were protected better in the third group compared to the first two groups. Moreover, in vivo allogeneic subcutaneous embedding studies showed that in the third group, immunological response was lower than the other groups and it showed higher biocompatibility. In another study [192], periosteum isolated from rabbits were decellularized by using chemical, physical and enzymatic techniques. During decellularization, at first samples were exposed to freeze-thaw cycles at temperatures -80 °C and 37 °C and then samples were treated with Triton X-100, SDS and DNase. H&E and DAPI staining showed the complete removal of the cells. In addition, DNA quantification results revealed that almost more than 95% nuclear material was degraded during decellularization (Figure 13). In characterization studies, GAGs and collagen structures of the samples were analyzed by using Safranin O and Masson’s trichrome staining, respectively. It was found that collagen content was not significantly different than the native periosteum however contents of GAGs in decellularized samples were significantly lower than the native periosteum. In vitro studies demonstrated that periosteum-derived cells (PDCs) could attach and proliferate on the decellularized samples which proved the cytocompatibility of decellularized membranes. Furthermore, in order to study in vivo biocompatibility, allogeneic subcutaneous implantations into the backs of rabbits were performed and histological results showed no severe immunogenic host response. The significance of this study is that, an ECM-based periosteum scaffold with a high potential for bone tissue engineering applications was successfully prepared and characterized.