Osteoarthritis (OA) is a slowly developing articular disease, characterized mainly by cartilage degeneration, which is reflected clinically by a gradual development of joint pain, stiffness, and loss of full range of movement.
Several cytokines, matrix metalloproteinases, and growth factors [ 10, 12- 15] take part in the regulation of articular cartilage homeostasis, and in developing articular cartilage, IGF-I is an inducer of collagen and aggrecan synthesis, representing an important factor in the maintenance of the chondrocyte phenotype as well as cartilage integrity and metabolism.
Since fully developed articular cartilage is an avascular tissue, glucose reaches chondrocytes through diffusion from the synovial fluid [ 11], where its concentration is identical to and reflects that in the plasma, both under normal conditions and in noninflammatory and inflammatory types of arthritis, excluding those associated with infections [ 12].
The mechanism of posttraumatic elbow contracture is intra-articular effusion, which induces the elbow joint to develop intra-articular adhesion and capsular thickening, limiting flexion, extension, and pronosupination, thus resulting in posttraumatic elbow stiffness, loss of motion, and considerable impairment in daily life.
Seropositive patients are also more likely to develop extra-articular features such as nodules, lung disease and vasculitis [ 37- 39].
Rheumatoid arthritis (RA) is a chronic inflammatory disorder that involves synovial joints and may develop extra-articular manifestations [ 1].
Consequently, a major portion of the research effort has focused on applications in orthopaedics with emphasis on the development of techniques for developing bone, articular cartilage, ligaments, tendons and nerve.
Indeed, Dowthwaite and colleagues [ 51] showed that Notch receptor was expressed on the surface of articular cartilage of a 7-day-old calf by a progenitor cell population; this matches previous results in developing mouse articular cartilage [ 8].
In this work, novel porous silk fibroin (SF) scaffolds derived from horseradish peroxidase (HRP -mediated crosslinking of HRP -mediatedtrated aqueous SF solution (16 wt%) in crosslinkingwith salt-leaching and freeze-drying methofologies were developed for articular cartilage tissue engineering (TE) applications.
