2.16 Collagen-GAG materials

Tissue engineering scaffolds are used extensively as three-dimensional analogs of the extracellular matrix (ECM). As a native component of the ECM, collagen-based biomaterials have a history of use in the field of tissue engineering. Collagen-glycosaminoglycan (CG) scaffolds in particular have long been utilized in vivo as ECM analogs for the regeneration of skin and peripheral nerves, and are currently being considered for the regeneration of a range of mineralized and soft tissues. Experimental characterization and theoretical modeling techniques have been used to describe a number of properties of CG scaffolds, notably pore microstructure, specific surface area, tensile and compressive mechanical properties, cell attachment, and permeability. Here we describe the fabrication, and characterization, and modeling of a series of CG and mineralized CG scaffolds. We will discuss their use in vitro as standardized 3D materials to study the influence of material parameters on cell phenotype and behaviors such as motility, contraction, differentiation, and matrix synthesis. We will conclude with a discussion of their use in vivo to induce tissue regeneration following injury for a range of soft and hard tissues, notably skin, peripheral nerves, brain, lung, cartilage, bone, fibrocartilage disks, and the conjunctiva.