Mechanical properties of reconstituted collagen fibrils. A study on reconstitution methodology and influence of in vitro maturation.

Acid extracted collagen from rat skin was reconstituted into fibrils at physiological pH and ion concentration. The fibrils were indistinguishable from native collagen in ultrastructural appearance. This report describes a procedure for reconstituting collagen fibrils into thin membranes which allows the preparation of a set of collagen membranes with identical mechanical properties. Reconstituted collagen fibrils showed a gain in mechanical strength upon maturation in vitro similar to the increase in mechanical strength known to occur during maturation of collagenous tissues in vivo. It is suggested that the changes in the mechanical properties of reconstituted collagen fibrils during in vitro maturation may reflect the changes observed during in vivo maturation of collagenous tissues. The possible influence of the amounts of reducible intermolecular cross-links on the gain in strength during maturation is discussed.