Smart biomaterials for tissue engineering of cartilage.

Biological regeneration using cartilage tissue engineering in which cells are grown on biomaterial scaffolds and then implanted into the cartilage defects could provide new treatment options for articular cartilage defects. This review aims to give an overview of the wide variety of biomaterials that are currently developed as scaffolds for cartilage tissue engineering. Emphasis will be placed on the current development of the materials that are able to direct cell differentiation and metabolism. These so-called "smart" biomaterials are produced by modifying the physical properties of the scaffolds using peptide sequences and most importantly by developing materials that can deliver proteins to enhance tissue regeneration. Besides providing drug delivery systems, the materials respond to environmental stimuli or release their cargo on cellular demand. However, critical issues remain, such as the transferability of basic science insights to clinical products and the applicability of certain data sets to human patients.