Cartilage regeneration using principles of tissue engineering

It is well known that articular cartilage in adults has a limited ability f or self-repair. Numerous methods have been devised to augment its natural h eating response, but these methods generally lead to filling of the defect with fibrous tissue or fibrocartilage, which lacks the mechanical character istics of articular cartilage and fails with time. Recently, tissue enginee ring has emerged as a new discipline that amalgamates aspects from biology, engineering, materials science, and surgery and that has as a goal the fab rication of functional new tissues to replace damaged tissues. The emergenc e of tissue engineering has facilitated the generation of new concepts and the revival of old ideas all of which has allowed a fresh approach to the r epair or regeneration of tissues such as cartilage. The collaborations betw een scientists with different backgrounds and expertise has allowed the ide ntification of some key principles that serve as the basis for the developm ent of therapeutic approaches that now are less empiric and more hypothesis -driven than ever before. The current authors review some of the considerat ions regarding the various models used to test and validate the above repai r methods and to address different aspects of the cartilage repair paradigm . Also, some key principles identified from past and current research, the need for the development of new biomaterials, and considerations in scale-u p of cell-biomaterial constructs are summarized.