Regeneration of Articular Cartilage: Opportunities, Challenges, and Perspectives

Histology of articular cartilage. a) This figure illustrates a sample of human cartilage from a tissue microarray developed by the cooperative human tissue network (CHTN) of the National Cancer Institute (http://www.chtn.nci.nih.gov/). Cartilage is predominantly an avascular, aneural and alymphatic load-bearing connective tissue consisting of a single cell type known as the chondrocyte. Chondrocytes are cytoplasmically isolated and their energy requirements are derived through glycolysis (Archer & Francis-West, 2003). They possess a high matrix/cell volume ratio. They do not divide after skeletal maturity unless the cartilage becomes diseased. Blood vessels are only present in subchondral bone. The unicellular nature of cartilage and the absence of blood vessels, nerves, and lymph vessels highlight its architecturally simple design, making it particularly attractive for tissue engineering and regenerative medicine. b) Superficial zone of equine articular cartilage. c) Middle zone of equine articular cartilage. The sections are 7 μm thick and were stained with hematoxylin and eosin.