1. Multiscale structure and biological role of collagen

In biological tissues, cells are surrounded by a complex, bioactive matrix - the extracellular matrix. It provides mechanical support to cells, while regulating their behavior. It is involved in cell survival, proliferation, migration and differentiation. The composition of this matrix varies from one tissue to another, but overall it consists of an interstitial fluid held together by a three-dimensional network of hydrated proteoglycans (polysaccharides attached to a central protein) and fibrous proteins, of which collagen is the most abundant.

Strictly speaking, collagen does not refer to a single protein, but to a family...