Figure 1.

Cartilage Composition, Disease Progression, Tissue Engineering, and Treatment Modalities. [A] Cartilage is composed of a type II collagen network (blue), interwoven with long hyaluronan chains (green) and their associated proteoglycan complexes. [B] Cartilage injuries often increase in size and can result in joint-wide degenerative changes. [C] Cartilage tissue engineering combines cells, materials, and factors in order to treat damaged cartilage. [D] Two distinct modes of biofactor delivery for cartilage applications. (Left) Joint preservation via bioactive factor incorporation into biomaterial carriers to target cells within the joint. (Right) Tissue replacement via cell-based scaffolds that are supplemented with growth factors.