Micromechanical tests of single collagen fibrils using AFM

Lanti Yang (BPE and PBM group)

Background

Collagen is the principal, tensile stress-bearing component of connective tissue. Over the past decade, several studies have been directed towards the elucidation of the hierarchical structure of collagen and to relate the structure to its function and mechanical properties. In summary, the hierarchical structure can be described as follows: 5 tropocollagen molecules (collagen triple helices from which the propeptides are enzymatically removed) assemble into microfibrils. These microfibrils aggregate in the lateral and longitudinal direction to form fibrils and the fibrils further assemble into fibers. It must be noted that microfibrils never have been isolated but researchers nowadays agree on this microfibrillar structure based mainly on X-ray data and AFM imaging.

Objective

In this project, in order to provide more insight in the relationship between the hierarchical structure of collagen and its biomechanical properties, the isolation of single collagen fibrils from commercially available collagenous materials and the micromanipulation techniques like atomic force microscopy (AFM) have been combined to study the micro-mechanical properties of single collagen fibrils.

This project is a collaboration between the Biophysical Engineering Group and the Polymer Science and Biomaterials Group.