Tissue engineered cartilage

Cartilage possesses limited capacity for repair and self-regeneration. Consequently, il?injury to cartilaginous tissues results in scar formation leading to permanent loss of structure and function. Increased understanding of chondrocyte physiology has enabled investigators to overcome many of these limitations experimentally. For example, isolated chondrocytes will multiply in culture, but they loose their phenotypic expression in monolayer culture. Using three-dimensional culture techniques. investigators have been able to retain the spherical shape of the chondrocytes, preserve their phenotype as measured by the production of matrix components, and generate cartilage-like; tissue in vitro. The field of tissue engineering has expanded upon this technology using biodegradable polymer templates as temporary support matrices for chondrocyte transplantation leading to neocartilage formation ii? vivo. This paper reviews the advancements in understanding of chondrocyte function and biodegradable polymers leading to the development of tissue engineered cartilage. Summarized here will be our experience with various biodegradable polymers. initially, we investigated the use of polyglycolic acid (PGA) and polylactic acid coated PGA as transplant matrices. Subsequent studies have investigated biodegradable hydrogels such as calcium alginate, polyethylene oxide. polyethylene oxide/polypropylene oxide cn-polymers (Pluronics). All of these materials allow the formation of cartilage matrix in vivo, and each has unique properties that are discussed. Also included is a discussion of potential clinical applications and progress in some of these areas.