A note on the role of spatial scale in imaging collagen hydrogels

Fibrillar collagen hydrogels have been used widely as bioactive scaffolds for multiple applications in biomedical and tissue engineering. The physical functions of collagen fibrils are regulated by their underlying microstructure - represented by fibrillar density and orientation. The extent to which characterization techniques are used for imaging collagen fibrillar networks has significantly reduced the usefulness of published data for biomedical engineers. This short communication explains the level of uncertainty surrounding fibrillar orientation measurements. It is discussed how a correlation between the orientation of collagen fibrils and normal distribution function can provide a robust baseline for comparative research in imaging collagen.