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Effects of Mechanical Vibration on Bone Tissue
Published in Redha Taiar, Christiano Bittencourt Machado, Xavier Chiementin, Mario Bernardo-Filho, Whole Body Vibrations, 2019
Christiano Bittencourt Machado, Borja Sañudo, Christina Stark, Eckhard Schoenau
Cartilage tissue is of utmost importance for bone tissue biology and development. It is present in human body joints, nose, bronchial tubes, ears and intervertebral disks, being also essential for endochondral ossification and fracture regeneration. The flexible articular cartilage contains no blood vessels or nerves, composed by so-called chondroblasts (cells that produce the extracellular matrix) and the chondrocytes (chodroblasts caught in the matrix) laying in spaces called lacunae. Water fills approximately 70% of all cartilage matrices. The extracellular matrix is mainly composed of proteoglycans (15% to 40% of the dry weight) and type II collagen (40% to 70% of the dry weight), however there are other types of collagen in articular cartilage. The hyaline cartilage is the most prevalent type of cartilage found in human body. It can be identified in articular surfaces, anterior end of the ribs, tracheal rings and growth plates (nonmineralized region of growth near the end of developing bones). The elastic cartilage forms the external ear, epiglottis and Eustachian tubes, presenting great elasticity; and the fibrocartilage, forming the pubic symphysis, intervertebral disks and tendon-bone attachments.
Chemomechanical couplings in articular cartilages
Published in Benjamin Loret, Fernando M. F. Simões, Biomechanical Aspects of Soft Tissues, 2017
Benjamin Loret, Fernando M. F. Simões
Articular cartilage is a soft hyaline tissue that minimizes friction between diarthroidal joints covering long bones. The thickness of a diarthroidal joint varies typically from 2 to 4 mm, Fig. 14.2.2. Cartilage from adult animals and humans is avascular, aneural and alymphatic. Nutrients are transported from the synovial fluid towards the cells by convection, water diffusing through the articular surface and extracellular matrix. The cells in foetus and young subjects, called chondroblasts, are very active and they produce the extracellular matrix (ECM) composed essentially of fibrillar proteins (elastin, fibronectin and mainly collagen) and highly negatively charged proteoglycans. In adults, the chondroblasts become almost inactive; they are then called chondrocytes and their volume decreases, Stevens and Lowe [1993], p. 52. Mature chondrocytes occupy only 2% of the volume, Fig. 14.2.3. In that respect, cartilage is the opposite extreme of a syncitium, like the heart muscle or onion tissue, where the intercellular space and extracellular matrix are absent, cells occupy most of the volume and are linked together by gap junctions.
Principles and Biological Pathways to Tissue Regeneration: The Tissue Regenerative Niche
Published in Claudio Migliaresi, Antonella Motta, Scaffolds for Tissue Engineering, 2014
Ranieri Cancedda, Claudia Lo Sicco
MSC differentiate into chondroblasts forming a soft callus. First, chondroblasts synthesize cartilage specific matrix such as type II collagen and proteoglycans; then the cartilage undergoes into hypertrophy and mineralization in a spatial organized manner. During this phase, new vessels begin to invade calcified hypertrophic chondrocyte and woven bone formation occurs with a recruitment of new MSCs. Recruited MSCs play a key role in the mobilization of macrophages and in the induction of their functional switch from a pro-inflammatory to a pro-resolving phenotype, as well as the subsequent formation of a bone regenerative niche through recruitment of specific bone marrow-derived circulating endothelial and pluripotent mesenchymal progenitors with vasculogenic and osteogenic properties, respectively.
Alternative Plasma-Facing-Material Concepts for Extreme Plasma-Burning Nuclear Fusion Environments
Published in Fusion Science and Technology, 2019
One can learn from nature and the plethora of examples of how natural materials have evolved exhibiting robust intrinsic self-healing and adaptive properties, in some cases under extreme environmental conditions. For example, self-healing properties of bone tissue upon fracture undergo a set of interactions and reactions from the biomolecular to the cellular to the macroscale tissue level supported by a porous network interface structure so-called spongious bone whereby healinglike agents attempt to reconstruct bone tissue at crack sites. The mobility of chondroblasts (i.e., cells that make cartilage and aid in bone healing) and osteoblasts (i.e., cells that break down bone material to reshape it) and their synergistic function to reconstruct bone rely on the combination of multiscale ductile and resilient properties that dynamically enable the fractured bone to reconstitute itself over time.13–15
Collagen of porcine auricle has unique biochemical and biophysical characteristics
Published in Soft Materials, 2019
Kenji Ishi, Hiroko Hoshi, Mina Takahashi, Koji Kitagawa, Masataka Hoshi, Norihiro Kawaguchi
It has been reported that auricular cartilage has unique potential in stem cell research (6,7). Human auricular perichondrium harbors a unique cell population that consists of cartilage stem and progenitor cells (7–9). The perichondrium, which surrounds the cartilage, contains progenitor cells capable of differentiating into chondroblasts. The progenitor cells within the perichindrium proliferate faster than mature chondrocytes and are able to differentiate into other mesenchymal tissues under defined conditions. Additionally, the connective tissue growth factor (CTGF) is a well-known fibroblast mitogen and angiogenic factor. Strong and persistent CTGF gene expression was particularly prominent in the mesenchyme of the cardiovascular system (aorta, auricular tissue, renal glomeruli). In the adult mouse, CTGF is involved in wound healing, as well as fibrotic and vascular disease (39). The reason why PAC-A promotes cell proliferation is not clear, but the fibrillogenesis and viscoelasticity of PAC-A may be related to functions such as those of perichondrocyte matrix.