Bone and Cartilage
George W. Casarett in Radiation Histopathology: Volume II, 2019
Cartilage is a specialized type of dense fibrous connective tissue consisting of cells and matrix (fibers and ground substance) that forms most of the temporary skeleton of the fetus, provides a base or template for the development of most bones, and persists in adults as parts of joints (Figure 2A), respiratory passages (Figure 2B), and the ears. Like bone, the volume of intercellular matrix of cartilage is much greater than the total volume of the cartilage cells (chrondrocytes). Unlike bone, cartilage contains no intrinsic blood vessels, lymphatics, or nerves, although blood vessels sometimes pass through cartilage on their way to other tissues. As there are no canaliculi in the matrix, nutrients, oxygen, and cell wastes must diffuse through the matrix between perichondria! blood vessels and chondrocytes.
Cartilage Collagens
Marcel E. Nimni in Collagen, 1988
Cartilage is a specialized dense connective tissue which supports various skeletal junctions.1 It deforms under pressure, but recovers its original shape on removal of deforming pressure. The viscoelasticity and flexibility of cartilage are due to the special structure of extracellular matrix which consists of branching network of collagen fibers embedded in amorphous proteoglycan aggregates. Large quantities of water are held among these collagen-proteoglycan complexes, and most of the water is freely diffusible and exchangeable.2,3 Cartilage has no nerves and blood vessels of its own.4 The cells, called chondrocytes, are therefore nourished by diffusion through the matrix5,6 and are involved with the physiological turnover of the surrounding matrix.7
Skeletal System
David Sturgeon in Introduction to Anatomy and Physiology for Healthcare Students, 2018
There are three different types of cartilage: hyaline, elastic and fibrocartilage. The term hyaline is derived from the Greek for ‘glass-like’ and describes its translucent blue-white appearance. It is the most abundant cartilage in the body and is found in a wide variety of locations. It protects the epiphyses at moveable joints (articular cartilage), it connects the ribs to the sternum (costal cartilage), it supports the end of the nose (nasal cartilage) and is present in the larynx and trachea (respiratory cartilage). Elastic cartilage is similar to hyaline cartilage but it has a larger number of elastin fibres which provide its yellowish appearance and greater flexibility. Elastic cartilage helps to define and maintain the shape of an area where it is located and provides support for surrounding tissue. For example, it is found in the outer ear (auricle), the auditory (Eustachian) tubes at the back of the nose, and the epiglottis of the voice box (larynx). However, it is possible to transplant cartilage from one area to another and costal cartilage from the ribcage can be used to reconstruct the ear (elastic cartilage).
Preparation, thermal response mechanisms and biomedical applications of thermosensitive hydrogels for drug delivery
Published in Expert Opinion on Drug Delivery, 2023
Jinlong Luo, Xin Zhao, Baolin Guo, Yong Han
Cartilage is a connective tissue with a supporting role. There are no blood vessels and lymphatic vessels in the cartilage, and the nutrients penetrate into the intercellular matrix from the blood vessels in the perichondrium to nourish the bone cells. Cartilage tissue is poorly regenerative because it is nonvascular and its progenitor cells have limited ability to migrate, proliferate, and produce matrix [212,219]. Tissue engineering is an effective method to promote cartilage regeneration. Dorsa Dehghan-Baniani et al. prepared a thermosensitive hydrogel with enhanced mechanical properties by mixing N-(β-maleimidepropoxy)succinimide ester (BMPS) modified chitosan with β-glycerophosphate (β-GP) as tissue engineering scaffold to stimulate selective differentiation of mesenchymal stem cells into chondrocytes through in situ release of KGN. The researchers demonstrated the promise of this thermosensitive hydrogel for cartilage tissue engineering by characterizing the enhanced hydrogel shear modulus, injectability, gel behavior, long-term drug release, and in vitro results (Figure 14) [60]. Furthermore, cartilage tissue engineering provides a prospective strategy for articular cartilage regeneration by combining seeded cells with thermosensitive hydrogel scaffolds [219].
Sustained Remission with Tocilizumab in Refractory Relapsing Polychondritis with Ocular Involvement: A Case Series
Published in Ocular Immunology and Inflammation, 2021
Rebecca Farhat, Gaël Clavel, Delphine Villeneuve, Youssef Abdelmassih, Marwan Sahyoun, Eric Gabison, Thomas Sené, Isabelle Cochereau, Cherif Titah
Relapsing polychondritis (RP) is a rare autoimmune disorder characterized by recurrent, widespread, and potentially destructive inflammation of the cartilaginous tissue.1 Its incidence is estimated to be around 3.5/1,000,000/year. All types of cartilage may be involved: the elastic cartilage of the nose and ear, the hyaline cartilage of tracheobronchial tree, and proteoglycan-rich structure like the eye are some examples. The diagnosis is mainly based on clinical criteria, McAdam’s criteria. It includes six clinical features: auricular chondritis, non-erosive, seronegative inflammatory polyarthritis, nasal chondritis, ocular inflammation, respiratory tract chondritis, and cochlear and/or vestibular dysfunction. To confirm RP diagnosis, one must have any of the following one McAdam’s criterion plus histopathological confirmation or two McAdam criteria and positive response to corticosteroids or dapsone or at least three McAdam’s criteria.1,2 Ocular involvement is frequent and found in up to 51% of cases with episcleritis and scleritis being the most common.3,4 RP is usually treated with steroids and conventional immunosuppressant, or antitumor necrosis factor-alpha (TNF-alpha) agents.5 However, it is not clear what should be the next therapeutic option in refractory cases.
Injectable-platelet rich fibrin using the low speed centrifugation concept improves cartilage regeneration when compared to platelet-rich plasma
Published in Platelets, 2019
Mustafa Abd El Raouf, Xuzhu Wang, Si Miusi, Jihua Chai, Abdel Basit Mohamed AbdEl-Aal, Mekkawy M. Nefissa Helmy, Shahram Ghanaati, Joseph Choukroun, Elisa Choukroun, Yufeng Zhang, Richard J Miron
Over the last 20 years, several treatment strategies have been proposed for knee regeneration including autologous chondrocyte implantation (ACI) [5]. Other examples of treatments for cartilage lesions include bone marrow stimulation techniques, such as microfracture procedures that aim to recruit bone marrow elements to repair cartilage defects [6]. The results obtained for these treatment modalities however remain controversial with no ideal treatment modality for long-term success [1]. Often, these treatment strategies result in the formation of fibrocartilaginous tissue rather than normal articular cartilage. The repaired tissue therefore lacks the desired mechanical properties or zonal organization of the extracellular matrix (ECM) similar to those of the native articular cartilage and the biological and functional outcome of these treatments requires further improvements [7–9]. The ideal treatment modality should provide excellent repair fill with hyaline cartilage and maintain the quality of subchondral bone [10].