Bridging the hierarchical structures of collagen by atomic force microscopy: From nanoscale to mesoscale.

摘要

The most abundant structural protein in mammalian tissues, Type I Collagen monomer, a long rope of 300 nm in length and 1.5 nm in diameter, can self assemble into different three-dimensional structures with multiple functions as diverse as transparent cornea, tough tendon, and strong bone. Although the microscopic structure of the monomer and the macroscopic structures of some higher hierarchical assembled fibrils have been characterized during the past years, the formation of these higher hierarchical structures, and the emergence of their bioactivities on the nano-to-mesoscale, are still not so clear. In our work, AFM (atomic force microscopy) was applied in vitro, primarily as a imaging tool to investigate the self assembled protofibril patterns (bottom-up method), and also as a 'molecular broom' to create monomer bundle patterns under appropriate force (top-down method). We believe those unique discoveries in our lab will definitely cast light on the understanding of the in vivo self-assembly and related structure-property relationships of collagen, and provide a functional surface coating method for tissue engineering and cell study.