Abstract: The naturally occurring collagen is modified by removal of certain terminal peptide chains, which are described as telopeptides. The modified collagen, so derived, is described as atelopeptide collagen. Native collagen is immunogenic, while atelopeptide collagen is nonimmunogenic or possessed of a negligibly low level of immunogenicity.The collagen in solution is then treated according to a specific regimen under conditions whereby the collagen slowly separates from solution while exposed to mild shear forces. This procedure results in the formation of a fibrous precipitate composed of regularly ordered fibers of collagen possessed of a ropelike structure. These resulting aggregates are referred to as native fibrous micropolymers (NFM). Once the regimen or procedure is completed, and the fiber mass has been formed, the fibrous micropolymers may be freed of salt, taken up in a different solution or modified. For example, cross-links may then be introduced to stabilize the fibers.

Abstract: A method for augmenting hard or soft connective tissue, such as skin, tendon, cartilage, bone or interstitium, in a living mammal comprising implanting a proteolytic enzyme-solubilized, purified, native, in situ polymerizable collagen solution into the mammal at the augmentation site. The solution polymerizes at the site into a stable, non-reactive fibrous mass of tissue which is rapidly colonized by host cells and vascularized.