Strategy for the selection of scaffolds for tissue engineering

A strategy for developing scaffolding materials for prostheses capable of inducing tissue regeneration is presented. It is based on knowledge of the stimuli cells need to carry out their programs of division, morphogenesis, and differentiation, that is, of tissue building. The source of the stimulation is shown to be the extracellular matrix (ECM), in or on which cells in tissues live. A capsule view of the molecular diversity and the supramolecular architecture of the ECM is given with the idea that it can be imitated. The desired properties of scaffolding materials assembled from biological and engineering considerations allow the reader to evaluate biomaterials available for creating prostheses. Keeping in mind the ideal properties sought, a series of case histories is presented as a vehicle for examining prosthetic devices, and the materials used for them. Engineered or processed, naturally occurring, tissue replacements for articular cartilage, small caliber artery, periodontal tissues, cruciate ligament, and skin are reviewed from the point of view of how cells react to the scaffolds and how effectively a functional tissue replacement is restored in vivo. An approach to creating scaffolds by deducing their structure mathematically from their function in vivo is discussed as a first step in imitating the design of a body part. Finally touched on is the task of creating information-rich scaffolds like the ECM.