Controlled collagen assembly to build dense tissue-like materials for tissue engineering

Intermediate states of matter, in the form of liquid crystals, are indirectly evidenced in the body. Hence concepts developed by the soft matter community have allowed the highlighting of original morphogenetic pathways, strongly suggesting how 3D structures arise at the tissue level. The clues proposed have opened the way to reproduce biomimetic, hierarchically ordered, assemblies of biological macromolecules. The present paper will focus on collagen and describe the process allowing to attain homogeneous fibrillar matrices, both at high concentrations and over long distances. Their characterization at scales ranging from mu m to cm will demonstrate suprafibrillar arrangements similar to dense connective tissues, with aligned or helicoidal geometries depending on the protein concentrations. In addition we will show that in vitro and in vivo studies validate these tissue-like constructs as repair materials for tissue engineering applications.