Self-Assembled Collagen—Apatite Matrix with Bone-like Hierarchy

摘要

Bone tissue strength depends, aside from its cellular components, on its density (ratio mineral vs organic phase), its matrix composition (mainly hydroxyapatite (HA) and collagen), its overall structure (microarchitecture of compact and trabecular compartments), and its rate of remodeling. Microarchitecture is the most important criterion used by surgeons to assess bone quality as well as normal mechanical functionality and is, thus, extensively studied in tissue engineering. A three-dimensional, hierarchical organization over many length-scales (nano-, micro-, millimeters and more) characterizes this particularly complex composite material. Indeed, "mineralized collagen fibrils" organize into bundles to form fibers ("fibril arrays") that further pack in regularly dense and ordered networks ("fibril array patterns"). Another essential characteristic is the coalignment between the crystallographic c-axes of the hydroxyapatite nanocrystals and the long axes of the collagen fibrils.