Biofabrication and Characterization of Collagens with Different Hierarchical Architectures

Herein, three categories of collagens with different hierarchical architectures, including collagen molecules (Col), collagen microfibrils (F-col), and collagen fiber bundles (Ag-col), were systematically biofabricated based on the biosynthesis pathway of natural collagen. Their macroscopic properties, that is, physicochemical and biological properties, and hierarchical structures were evaluated synthetically. The results showed that Col had a rigid rod-like fibrous triple helix structure, whereas F-col and Ag-col had the typical D-periodic cross-striated patterns with lengths of about 54 and 60 nm in the longitudinal direction, respectively. We further found that collagens with higher hierarchical structures had more superior thermal stability, mechanical properties, and biodegradability. Among all three collagens, Ag-col was the best: it had the highest bioactivity and hemostatic properties and could better promote cell adhesion, growth, and proliferation and better improve the secretion of growth factors. Overall, we have a reason to believe that collagens with a higher hierarchical structure can serve as a better alternative source of collagenous materials for further applications in biological industries.