Insulin and Ascorbate Have a Much Greater Influence Than Transferrin and Selenous Acid on the Growth of Engineered Cartilage in Chondrogenic Media

Tissue engineering of cartilage, which is a much sought-after approach for treatment of osteoarthritis and cartilage defects, requires appreciable culture time. Chemically defined chondrogenic media (CM) are commonly employed as they offer a promising alternative to serum-based media, and often include insulin, transferrin, and selenous acid (ITS) as well as ascorbate [1]. Concentrations of ITS constituents have been optimized based upon their ability to stimulate proliferation of a variety of cell types [2]. However, little is reflected in the literature as to the influences of various ITS constituent concentrations upon cartilage matrix deposition by chondrocytes. In engineered cartilage constructs that seek to match compositional and mechanical properties of native cartilage, knowledge of such influences would be highly desirable, especially when optimizing nutrient, hormone and vitamin supply for large constructs wherein rates of transport and consumption become more critical. Furthermore, this information would prove useful in modeling growth and remodeling of engineered tissues. Therefore, this study seeks to elucidate mechanical and biochemical properties as a direct result of modulating ITS and ascorbate concentrations within chondrocyte-agarose constructs.