Development of cartilage tissue engineering techniques based on biomedical research

The extracellular matrix (ECM), present between cells, is the authentic substrate for most cells in living organisms. Interplay between the ECM and cells plays a critical role in regulating cell differentiation, proliferation, apoptosis, and matrix synthesis. A substantial characteristic of hyaline cartilage is that a few chondrocytes, which are the sole cells in this tissue, are surrounded by the abundant ECM. Therefore, the ECM is considered to be a key regulator of cartilage development and regeneration. The limited potential of articular cartilage to self-repair leads to the demand for surgical procedures to treat symptomatic cartilaginous lesions. However, no previous procedures have successfully provided long-lasting hyaline cartilage repair for such lesions. On the other hand, cartilage tissue engineering or autologous chondrocyte implantation (ACI) is expected to be an ideal procedure for cartilaginous lesions [1, 2]. Tissue engineering techniques basically comprises three key factors including scaffolds, cells, and signals. Among these factors, a number of studies have emphasized the importance of selecting suitable biomaterials as scaffolds for cell adhesion, proliferation, and ECM production [2–9]. For the reason mentioned in the first paragraph, scaffolds for cartilage regeneration are especially required to provide the functional role of tissuespecific ECM.