Building competitive (bio)materials by collagen self-assembly
| When |
May 24, 2022
from 11:00 to 12:00 |
|---|---|
| Where | Salle des thèses |
| Attendees |
Nadine Nassif |
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In biological tissues, a common feature is the presence of dense arrays of biopolymers with ordered geometries at the ultrastructural level. A relationship was established between such 3D arrangements formed by biological polymers and molecules at liquid crystal state (see publications of Y. Bouligand). This structural analogy between living tissues and liquid crystals suggests that similar mechanisms of formation occur in both systems although it has not been demonstrated yet. For type I collagen (the major structural protein of connective tissue), different liquid-crystal phases were evidenced through an increase of concentration in vitro namely nematic, precholesteric, and cholesteric (see publications of M.M. Giraud-Guille). Relying on these observations, we have set innovative approaches to build three-dimensional highly concentrated collagen matrices with features and properties similar to that of living tissues. In particular, I will show how it is possible with the same process to reproduce three different tissues namely cornea (1), dentin (2), and mature bone (3); the former being transparent, stiff, and flexible, and the others mineralized and particularly tough. The resulting materials provide original models to study fundamental questions on tissue morphogenesis, thus highlighting the importance of physico-chemical processes occurring in tissue formation that are more generally discussed from a biological and/or biochemical control point of view. The in vivo investigations will be shown to evaluate their potential as competitive biomaterials for tissue repair since strong complications are related to auto- and allografts although they are still considered the gold standard for bone and cornea, respectively.